26 Reply by aventari (edited by aventari 2016-12-01 06:07 PM)

  • From: San Diego
  • Registered: 2015-05-03
  • Posts: 147

Re: Tires poking past fender

On my 93 Accord which is very similar suspension-wise to your Prelude I'm sure, I run 15x8 +20mm wheels with a 225/45-15 in a square set up.

It handles really good, a bit of understeer, but you can get the rear out if you want on higher speed corners. It's just about perfect for safe Lemons/Chump racing. You don't want a twitchy oversteery mess in a race with cars 12 inches away from you.
The key for us was getting -3.0 degrees of camber in the front and leaving the rear stock with  0 degrees. That also evened out front tire wear.

At the last race at Laguna Seca a few weeks ago, I ran a 1:51 which is pretty respectable for a 125hp F22A motor in a 4 door family car. 


I *really* like the trailer fender flares posted above-- I'm going to do that before my next race.

Takata R&D :: 1993 Accord - team captain - rear drum brakes lol
GoPro 360 Heros :: BMW E28  - co-captain
  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 786

Re: Tires poking past fender

Thanks for your feedback-
I have 15x7 wheels with +10 off set and mounted 225s BFG non Rival-s.  But at the NH race in Oct., I had the 195s on the rear.
I stripped as much weight as possible from the Prelude, so it is light, especially in the rear.
But I will try to dial in more camber in the front, but on 1987 Prelude, I don't think you can adjust the rear camber anyways.
In general, I do want a "safe", predictable car, not twitchy, that feels stable, since I probably drive a bit beyond my actual skill and capability level, so the car can make up for my lack in talent...

Z

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022
  • gunn
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  • From: SF, CA
  • Registered: 2010-12-18
  • Posts: 1,011

Re: Tires poking past fender

MZAVARIN wrote:

Thanks for your feedback-
I have 15x7 wheels with +10 off set and mounted 225s BFG non Rival-s.  But at the NH race in Oct., I had the 195s on the rear.
I stripped as much weight as possible from the Prelude, so it is light, especially in the rear.
But I will try to dial in more camber in the front, but on 1987 Prelude, I don't think you can adjust the rear camber anyways.
In general, I do want a "safe", predictable car, not twitchy, that feels stable, since I probably drive a bit beyond my actual skill and capability level, so the car can make up for my lack in talent...

Z

Speaking of twitchy, have you checked your bushings? My car is of a slightly newer vintage (95 tbird) but some of my car's rubber bits were original.
After noticing the car acted a little more twitchy (in japanese Best Motoring lingo: "undaaa... undaaa.... undaaa... dorriiifftoo!"), I took a look a few months ago and found my rear swaybar endlinks had a big metal ring with a rod bolt through it where there should have been a bushing. Basically, there was a noticable amount of slop before the bolt would touch the side of the ring and start applying force to the sway bar (as desired). Made for a little more interesting non-linear handling.

I'm not sure what the equivalent may be on your Prelude but it's probably worth investigating while you are mucking about before the next race.

Myopic Motorsport's #888 Ceci n'est pas une Citron Thunderbird ("This is not a lemon" but a 1995 tbird w/ 93 V8 swap + shopping cart rear wing + engine mounted frito maker)
2017 Sears Pointless Organizer’s Choice
Frito Making Tbird from 2018 Sears Pointless Engine Heat BBQ - http://goo.gl/csaet4
  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 786

Re: Tires poking past fender

Thanks for the advice...I'll definitely check it out....I need to lift the car up to secure the muffler which was rattling seriously during the end of the NH race...and I'll look over the bushings...hopefully before the miserable New England winter sets in....I kinda miss The City....although it is not the same as it was when I left it over 20 years ago...and not by choice...but by wife

Z

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022

30 Reply by SwarlesInCharge (edited by SwarlesInCharge 2016-12-03 06:19 AM)

  • Registered: 2013-07-24
  • Posts: 112

Re: Tires poking past fender

Brett85p wrote:
Judge Phil wrote:

And not to rain on your Big Fat Tires and Everything parade, but every single E30 I have seen in Lemons with huge wide tires ended up being substantially slower around the track than it had been with ordinary stock-size pizza-cutters.

Lemonaid dominate on 205/50/15s in their E30

We were curious if wider tires helped Lemonaid but guess not. We were considering upping to 225s but are cheap and slow no matter what we do so we'll stay with 205s.

-Robert, Party Sheep Racing
The Jerry Lundegaard GMAC Financing Award, Joliet 2013 [Cutlass Ciera w/ Iron Duke]
Eta E30: IL Fall '15, MI Spring '16, IL Summer '16, MI Spring '17, KY '17, MI Summer '21, KY '21, MI Summer '21, MI Fall '22

31 Reply by DRVOLKS (edited by DRVOLKS 2016-12-03 07:06 AM)

  • From: Pembroke MA 02359
  • Registered: 2016-06-27
  • Posts: 151

Re: Tires poking past fender

Mike we saw your handy work great job. I wish to Thank you and your team for making us feel so welcome please say hi to every one.
On fenders we are in the beginning of a new build 1999 VW Golf 2 DR with a 2L TDI CR engine and a DSG automatic. i will be doing a build post some where so people can follow.

On the fenders I thing the VW Beetle fenders will work for any one plastic and cheap junk yard stuff.  We are going big on this car with rubber too.
Have been talking with  rollcagecomponents@gmail.com the car is gutted and ready going with 1 3/4 120 wall DOM nascar driver doors.
I still have the Beetle looking for someone to run it next year all set to go what do you think Mike team up??

Bob Mann
DRVOLKS

32 Reply by TeamLemon-aid (edited by TeamLemon-aid 2016-12-03 08:58 AM)

  • From: Iowa
  • Registered: 2010-04-20
  • Posts: 2,660

Re: Tires poking past fender

We have instead worked at getting camber and using the 205's better.  Part of the reason we haven't gone up in size is we ran the exact same wheels and tires on the Metro, so it was just easier having the same wheels and tires for both cars.  I don't know if 225's would be faster for our E30 or not.  I'm also too cheap to buy new rims and find out.  Remember that more grip puts more stress on your car, so using the max grip of what you have at all times may be better than increasing The potential of grip but still not always using it.

The development on our E30 has been 5 years and a lot of races.  Several of those races were not a good result.

People remember our recent success but forget all the races we broke for a little bit or had driver malfunctions. smile


SwarlesInCharge wrote:
Brett85p wrote:
Judge Phil wrote:

And not to rain on your Big Fat Tires and Everything parade, but every single E30 I have seen in Lemons with huge wide tires ended up being substantially slower around the track than it had been with ordinary stock-size pizza-cutters.

Lemonaid dominate on 205/50/15s in their E30

We were curious if wider tires helped Lemonaid but guess not. We were considering upping to 225s but are cheap and slow no matter what we do so we'll stay with 205s.

LemonAid - Changing kids lives one lap at a time.

33 Reply by SwarlesInCharge (edited by SwarlesInCharge 2016-12-03 05:19 PM)

  • Registered: 2013-07-24
  • Posts: 112

Re: Tires poking past fender

TeamLemon-aid wrote:

We have instead worked at getting camber and using the 205's better.  Part of the reason we haven't gone up in size is we ran the exact same wheels and tires on the Metro, so it was just easier having the same wheels and tires for both cars.  I don't know if 225's would be faster for our E30 or not.  I'm also too cheap to buy new rims and find out.  Remember that more grip puts more stress on your car, so using the max grip of what you have at all times may be better than increasing The potential of grip but still not always using it.

The development on our E30 has been 5 years and a lot of races.  Several of those races were not a good result.

People remember our recent success but forget all the races we broke for a little bit or had driver malfunctions. smile

Yeah, we benefited from getting more negative camber, which helped with handling but mostly was important not to roast the outer edges of the front tires in a few hours.

One of my buddies A&D'd in July and completely blew the doors off our times, in a car and on a track he'd never driven before. First full lap! So yeah, fatter meats might not do any good since weren't using all we had to start with. And may make body roll even more cartoonish.

Yeah, true. You impressively broke a wheel and bracket in April. We're finding the weakest links in the car but also ourselves, and slowing improving. As long as we spend most our time on the track instead of patching in the pits, still winning at life IMHO.

-Robert, Party Sheep Racing
The Jerry Lundegaard GMAC Financing Award, Joliet 2013 [Cutlass Ciera w/ Iron Duke]
Eta E30: IL Fall '15, MI Spring '16, IL Summer '16, MI Spring '17, KY '17, MI Summer '21, KY '21, MI Summer '21, MI Fall '22
  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 786

Re: Tires poking past fender

DRVOLKS wrote:

Mike we saw your handy work great job. I wish to Thank you and your team for making us feel so welcome please say hi to every one.
On fenders we are in the beginning of a new build 1999 VW Golf 2 DR with a 2L TDI CR engine and a DSG automatic. i will be doing a build post some where so people can follow.

On the fenders I thing the VW Beetle fenders will work for any one plastic and cheap junk yard stuff.  We are going big on this car with rubber too.
Have been talking with  rollcagecomponents@gmail.com the car is gutted and ready going with 1 3/4 120 wall DOM nascar driver doors.
I still have the Beetle looking for someone to run it next year all set to go what do you think Mike team up??

Bob Mann
DRVOLKS

Bob!
We'll definitely need to plan on having garages next to each other in NJ.  Shoot me an email anytime about your team ideas.

Sounds like the VW build is going forward!  Keep me posted!

There was a black VW Golf at the NH race, as I recall, that had the fastest lap time...they did not rank too highly in the standings though....I think they got some penalties...they were driving like ..."aggressives"...cut me off and whacked me in the front bumper hard, right before the straight, for which I got a black flag and they did not get called in....oh well....judges said I was not the only one that had problems with their driving....can't blame the car though....! 

You guys in the E30s with the fat tires were relatively curteous!

Let me know if you need a local cage builder....Chris Howard...does a great job, did many Lemons cars,....charges around $2000

Mike Z

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022

35 Reply by DRVOLKS (edited by DRVOLKS 2016-12-04 07:27 AM)

  • From: Pembroke MA 02359
  • Registered: 2016-06-27
  • Posts: 151

Re: Tires poking past fender

Mike we plan to do the  chump WATKINS GLEN May 26-28 Its a high cost track but is one of the top super speedway tracks around.
I did it this year and was hooked super fast  speeds. The new Golf will be a site and a supper fast ride.
We have found the key to MPG with the diesel platform .
Bob Mann
DRVOLKS

  • From: Hayward, CA
  • Registered: 2010-03-23
  • Posts: 1,762

Re: Tires poking past fender

Late to this party, but I love this topic, it comes up sooooo much.

1. Bigger tires are more expensive.

2. Bigger tires are heavier, and that weight affects the car in several ways.
a. The cars acceleration is slower because the big wheels and tires have more interia. Interia = mass x radius^2 (radus squared). Get the tire weights from tire rack and run that calculation for both assuming all the listed tire weight is at the edge of the tire (the tire radius = 1/2 diameter listed).
b. deceleration is slower, because of the same reason. Big wheels and tires have lots of interia, which you have to slow down and you'll over heat your brakes.

3. Big tires give you more grip, so you'll corner faster, assuming you can slow down enough from your slower straight line speed

The Eyesore Miata, which just WON the December Sonoma race last weekend runs 13" or 14" wheels to keep the intertia low, and to be able to accelerate faster. Because that is more important for getting through traffic of 180 cars, than being the fastest guy through the corner.

Put those big wheels on the shelf for a while, get the car out and race it a few races adn see what breaks. Then do a testing day at a fast track and a many turn track and see which is faster (Like Willow Springs and Buttonwillow).

Dudes Ex Machina: https://www.facebook.com/dudesexmachina

?Everyone who has ever built anywhere a 'new heaven' first found the power thereto in his own hell- Frederick Nietzsche
  • From: Kalamazoo MI
  • Registered: 2013-06-10
  • Posts: 117

Re: Tires poking past fender

Yeah but those steam rollers are going to look tough. Anyone can win a race using a proper car with proper tires.  The challenge is winning something while looking like it doesn't belong in the winners circle.  Right?

Should really retheme it like this to piss off BMW enthusiasts.  The big aero, big flares, etc will look perfect with those huge tires.

http://en.autowp.ru/image/format/picture/picture-gallery-full/a/amg/mercedes-benz/c_dtm/mercedes-benz_c_amg_dtm_31.jpeg


I mean, a Geo Metro doesn't NEED 9" wide low offset wheels with 255 width tires.  Its totally counterproductive.  But you can't possibly look like a credible Porsche on 14x6's right?

http://i130.photobucket.com/albums/p280/Mike_Gruizinga/2016-10-10%20awful%20computer%206_zpsqgiwvaom.jpg

Mike @ Charnal House Inc.
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  • Registered: 2009-05-26
  • Posts: 36

Re: Tires poking past fender

mackwagon wrote:

The Eyesore Miata, which just WON the December Sonoma race last weekend runs 13" or 14" wheels to keep the intertia low, and to be able to accelerate faster. Because that is more important for getting through traffic of 180 cars, than being the fastest guy through the corner.

Put those big wheels on the shelf for a while, get the car out and race it a few races adn see what breaks. Then do a testing day at a fast track and a many turn track and see which is faster (Like Willow Springs and Buttonwillow).

Correction, we run stock 14-inch wheels (and stock size 185 section tires!) because we are cheap as hell. Full stop. For sure, they are light, but that doesn't enter the equation in a performance context. The lightness is nice mostly in the pits - tossing spares into trucks, changing wheels at the end of the day.

I'd take a wider (stickier) tire on a wider wheel in a heartbeat... if we could do it for no money. Though we'd also have to spend the time to set the car up to make the best use of wider tire, which involves more work... and we're lazy as hell. I mean, have you seen our car?

But I agree that many cars out there aren't maximizing the tire width they already have. Either in their driving or in their setup. Spending time on the alignment and observing tire wear patterns can extract more grip and/or life, but it's sorta silly if the car isn't even being driven at the limits of its grip.

  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 786

Re: Tires poking past fender

mackwagon wrote:

Late to this party, but I love this topic, it comes up sooooo much.

1. Bigger tires are more expensive.

2. Bigger tires are heavier, and that weight affects the car in several ways.
a. The cars acceleration is slower because the big wheels and tires have more interia. Interia = mass x radius^2 (radus squared). Get the tire weights from tire rack and run that calculation for both assuming all the listed tire weight is at the edge of the tire (the tire radius = 1/2 diameter listed).
b. deceleration is slower, because of the same reason. Big wheels and tires have lots of interia, which you have to slow down and you'll over heat your brakes.

3. Big tires give you more grip, so you'll corner faster, assuming you can slow down enough from your slower straight line speed

The Eyesore Miata, which just WON the December Sonoma race last weekend runs 13" or 14" wheels to keep the intertia low, and to be able to accelerate faster. Because that is more important for getting through traffic of 180 cars, than being the fastest guy through the corner.

Put those big wheels on the shelf for a while, get the car out and race it a few races adn see what breaks. Then do a testing day at a fast track and a many turn track and see which is faster (Like Willow Springs and Buttonwillow).

Ya.....but?:
1) Bigger tires and wheels are not that much more expensive...Tires are maybe a $12-13 per tire difference?...so $50 for a set....that should last for ?3 races....compare to other expenses...does not seem that much...

2a and b) Weight difference is not that different...?extra 5 lbs per tire/wheel....and depending on what you get...you could probably make it even less of a difference if you shopped around? So maybe 20 pound difference total?  That weight difference might be the difference whether the race is before of after Thanksgiving dinner.....and I am certainly more than 20 pounds heavier that anyone else on my team...maybe I should join a Weight Watchers Racing Team....instead of taking out the heater core, dash board, glass, etc. to make the car lighter....

3) But more grip?!...yea....in the corners....tires screeching...3 wide....bumper to bumper...doors a rubbin"....rubber a flyin"....pedal to the metal...with visions of me being a F1 Professional Race Car hero....flyin' through the corners...(all those F1 cars have wide tires....so why shouldn't I....)
And I only have 225s on 7.5 inch rims....imagine a Prelude with 9 inchers and 255s!!!!  Tire envy.....maybe some day the Prelude will be as cool looking as a Geo Metro....

mz

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022
  • From: San Diego
  • Registered: 2015-05-03
  • Posts: 147

Re: Tires poking past fender

Obviously you can go overboard with size (like huge heavy 17's on a Miata or Prelude), but I feel like 225/45-15 is a sweet spot. On 8" wheels the large amounts of grip gained  over a 195/50 or 205/50 is totally worth the minor downsides.

Takata R&D :: 1993 Accord - team captain - rear drum brakes lol
GoPro 360 Heros :: BMW E28  - co-captain
  • From: Seacoast NH
  • Registered: 2013-01-01
  • Posts: 472

Re: Tires poking past fender

MZAVARIN wrote:
mackwagon wrote:

Late to this party, but I love this topic, it comes up sooooo much.

1. Bigger tires are more expensive.

2. Bigger tires are heavier, and that weight affects the car in several ways.
a. The cars acceleration is slower because the big wheels and tires have more interia. Interia = mass x radius^2 (radus squared). Get the tire weights from tire rack and run that calculation for both assuming all the listed tire weight is at the edge of the tire (the tire radius = 1/2 diameter listed).
b. deceleration is slower, because of the same reason. Big wheels and tires have lots of interia, which you have to slow down and you'll over heat your brakes.

3. Big tires give you more grip, so you'll corner faster, assuming you can slow down enough from your slower straight line speed

The Eyesore Miata, which just WON the December Sonoma race last weekend runs 13" or 14" wheels to keep the intertia low, and to be able to accelerate faster. Because that is more important for getting through traffic of 180 cars, than being the fastest guy through the corner.

Put those big wheels on the shelf for a while, get the car out and race it a few races adn see what breaks. Then do a testing day at a fast track and a many turn track and see which is faster (Like Willow Springs and Buttonwillow).

Ya.....but?:
1) Bigger tires and wheels are not that much more expensive...Tires are maybe a $12-13 per tire difference?...so $50 for a set....that should last for ?3 races....compare to other expenses...does not seem that much...

2a and b) Weight difference is not that different...?extra 5 lbs per tire/wheel....and depending on what you get...you could probably make it even less of a difference if you shopped around? So maybe 20 pound difference total?  That weight difference might be the difference whether the race is before of after Thanksgiving dinner.....and I am certainly more than 20 pounds heavier that anyone else on my team...maybe I should join a Weight Watchers Racing Team....instead of taking out the heater core, dash board, glass, etc. to make the car lighter....

3) But more grip?!...yea....in the corners....tires screeching...3 wide....bumper to bumper...doors a rubbin"....rubber a flyin"....pedal to the metal...with visions of me being a F1 Professional Race Car hero....flyin' through the corners...(all those F1 cars have wide tires....so why shouldn't I....)
And I only have 225s on 7.5 inch rims....imagine a Prelude with 9 inchers and 255s!!!!  Tire envy.....maybe some day the Prelude will be as cool looking as a Geo Metro....

mz


  It's not the same as adding 20lbs. to your torso.  The wheels and tires are rotating weight. Rotating weight has much more effect on acceleration/ decal. than static weight.  Lighter wheels and tires are easier on the suspension too

"We Got Screwed" NHMS 2017, 4th NHMS 2020,  4th NJMP 2021,
"Judges Choice" NHMS 2021,10th NJMP 2022, 3rd Thompson 2022
#847 Batmobile  aka-"Beulah"  search Squidrope Racing on Facebook
  • Registered: 2016-08-16
  • Posts: 41

Re: Tires poking past fender

Someone said something about big rubber being harder on parts of the car that were never designed to handle that much grip.

This is what 255's will do to a geo metro tie rod once you add ABS to the car.

https://scontent-atl3-1.xx.fbcdn.net/v/t1.0-9/14054898_1119779154779787_2187065873942978634_n.jpg?oh=5c10e763f5da975a9b9e4601e32e8362&oe=58EB19F8

That was done at an autocross event, and we bent another at the next race, Although a curb may have been involved.

  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 786

Re: Tires poking past fender

squidrope wrote:
MZAVARIN wrote:
mackwagon wrote:

Late to this party, but I love this topic, it comes up sooooo much.

1. Bigger tires are more expensive.

2. Bigger tires are heavier, and that weight affects the car in several ways.
a. The cars acceleration is slower because the big wheels and tires have more interia. Interia = mass x radius^2 (radus squared). Get the tire weights from tire rack and run that calculation for both assuming all the listed tire weight is at the edge of the tire (the tire radius = 1/2 diameter listed).
b. deceleration is slower, because of the same reason. Big wheels and tires have lots of interia, which you have to slow down and you'll over heat your brakes.

3. Big tires give you more grip, so you'll corner faster, assuming you can slow down enough from your slower straight line speed

The Eyesore Miata, which just WON the December Sonoma race last weekend runs 13" or 14" wheels to keep the intertia low, and to be able to accelerate faster. Because that is more important for getting through traffic of 180 cars, than being the fastest guy through the corner.

Put those big wheels on the shelf for a while, get the car out and race it a few races adn see what breaks. Then do a testing day at a fast track and a many turn track and see which is faster (Like Willow Springs and Buttonwillow).

Ya.....but?:
1) Bigger tires and wheels are not that much more expensive...Tires are maybe a $12-13 per tire difference?...so $50 for a set....that should last for ?3 races....compare to other expenses...does not seem that much...

2a and b) Weight difference is not that different...?extra 5 lbs per tire/wheel....and depending on what you get...you could probably make it even less of a difference if you shopped around? So maybe 20 pound difference total?  That weight difference might be the difference whether the race is before of after Thanksgiving dinner.....and I am certainly more than 20 pounds heavier that anyone else on my team...maybe I should join a Weight Watchers Racing Team....instead of taking out the heater core, dash board, glass, etc. to make the car lighter....

3) But more grip?!...yea....in the corners....tires screeching...3 wide....bumper to bumper...doors a rubbin"....rubber a flyin"....pedal to the metal...with visions of me being a F1 Professional Race Car hero....flyin' through the corners...(all those F1 cars have wide tires....so why shouldn't I....)
And I only have 225s on 7.5 inch rims....imagine a Prelude with 9 inchers and 255s!!!!  Tire envy.....maybe some day the Prelude will be as cool looking as a Geo Metro....

mz


  It's not the same as adding 20lbs. to your torso.  The wheels and tires are rotating weight. Rotating weight has much more effect on acceleration/ decal. than static weight.  Lighter wheels and tires are easier on the suspension too


Hmmm...I guess you are probably correct.....probably has something to do with cetrifugal and centipetal forces and such?....I was never great at Physics and I probably forgot most of the stuff I learned in my "Physics for Bone Heads" in college...there is probably an obvious explanation to some automotive engineer or race car tuner/engineer...

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022
  • From: Pembroke MA 02359
  • Registered: 2016-06-27
  • Posts: 151

Re: Tires poking past fender

mgbgt89 wrote:

Someone said something about big rubber being harder on parts of the car that were never designed to handle that much grip.

This is what 255's will do to a geo metro tie rod once you add ABS to the car.

https://scontent-atl3-1.xx.fbcdn.net/v/t1.0-9/14054898_1119779154779787_2187065873942978634_n.jpg?oh=5c10e763f5da975a9b9e4601e32e8362&oe=58EB19F8

That was done at an autocross event, and we bent another at the next race, Although a curb may have been involved.

I do not see a tire size doing that . I tire has some thing called slip angle once you hit it you slide or spin it!!
There are three basic thing for a car to go fast

  • weight

  • power

  • tire size

Yes there a few other things to but these are your basic!!

45 Reply by the shaolin (edited by the shaolin 2016-12-10 02:44 PM)

  • From: Menomonee Falls, WI
  • Registered: 2013-02-12
  • Posts: 300

Re: Tires poking past fender

MZAVARIN wrote:
squidrope wrote:
MZAVARIN wrote:

Ya.....but?:
1) Bigger tires and wheels are not that much more expensive...Tires are maybe a $12-13 per tire difference?...so $50 for a set....that should last for ?3 races....compare to other expenses...does not seem that much...

2a and b) Weight difference is not that different...?extra 5 lbs per tire/wheel....and depending on what you get...you could probably make it even less of a difference if you shopped around? So maybe 20 pound difference total?  That weight difference might be the difference whether the race is before of after Thanksgiving dinner.....and I am certainly more than 20 pounds heavier that anyone else on my team...maybe I should join a Weight Watchers Racing Team....instead of taking out the heater core, dash board, glass, etc. to make the car lighter....

3) But more grip?!...yea....in the corners....tires screeching...3 wide....bumper to bumper...doors a rubbin"....rubber a flyin"....pedal to the metal...with visions of me being a F1 Professional Race Car hero....flyin' through the corners...(all those F1 cars have wide tires....so why shouldn't I....)
And I only have 225s on 7.5 inch rims....imagine a Prelude with 9 inchers and 255s!!!!  Tire envy.....maybe some day the Prelude will be as cool looking as a Geo Metro....

mz


  It's not the same as adding 20lbs. to your torso.  The wheels and tires are rotating weight. Rotating weight has much more effect on acceleration/ decal. than static weight.  Lighter wheels and tires are easier on the suspension too


Hmmm...I guess you are probably correct.....probably has something to do with cetrifugal and centipetal forces and such?....I was never great at Physics and I probably forgot most of the stuff I learned in my "Physics for Bone Heads" in college...there is probably an obvious explanation to some automotive engineer or race car tuner/engineer...


To clarify, each pound of unsprung weight is worth 3 pounds of sprung weight.  That 5# per wheel is the approximate equivalent of adding 60# to your gut.

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  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 786

Re: Tires poking past fender

the shaolin wrote:
MZAVARIN wrote:
squidrope wrote:

  It's not the same as adding 20lbs. to your torso.  The wheels and tires are rotating weight. Rotating weight has much more effect on acceleration/ decal. than static weight.  Lighter wheels and tires are easier on the suspension too


Hmmm...I guess you are probably correct.....probably has something to do with cetrifugal and centipetal forces and such?....I was never great at Physics and I probably forgot most of the stuff I learned in my "Physics for Bone Heads" in college...there is probably an obvious explanation to some automotive engineer or race car tuner/engineer...


To clarify, each pound of unsprung weight is worth 3 pounds of sprung weight.  That 5# per wheel is the approximate equivalent of adding 60# to your gut.

OK...I could stand to lose 10-20 lbs. off my rusty old body, but 60 lbs. ain't happening..

Anyways, very interesting...."Unsprung Weight"....interesting concept added to my auto education....
But I needed to start surfing the internet to understand...

Hmmm:

Examples:
Car 1) Car weighs 3300 pounds, 300 of which is in the wheels (75 pounds each)
Car 2) Car weighs 3300 pounds, 100 of which is in the wheels (25 pounds each)

Car 2 will accelerate faster?

Or:

In racing we try to minmize unsprung weight because it hurts handling. When the weight isn't supported by the springs, the shocks and tires control that weight. On bumpier tracks, a large amount of unsprung weight can become difficult to control, and reduce tire contact to the racing surface, which will reduce grip. Also, since the tires are controlling the unspung weight it can, in certain situations, cause heat build up, affecting tire perfomance. Also, really light race cars (mine is 2500 pounds, so it's considered light), are very sensitive to unsprung weight, so we attempt to minimize it whenever possible

Or:

Turn a bike upside down, take the back tire/tube off & put the bare rim back on.

Turn the pedals.

Now put the tire & tube back on, & do the same thing.

See how much harder it was to turn the pedals?

So:
I am not sure how, in the real Lemons world, this would really affect a beat up old Prelude, driven by some inexperienced loony maniac, who in his own mind drives like a stream lined F1 racer.  Besides, not too many tire options, and wheel options are very limited by $$.

I'm thiking: I just need more grip on the turns to make up for my lack in talent, and to avoid getting black flags for "4 offs"...although acceleration out of the turns would also help....I give up...probably just time to sign up for some driving lessons....

Let me know if you have any good YouTube video for my education!
Thanks!
Z

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  • From: Queens, NY
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Re: Tires poking past fender

The unsprung weight is not controlled. while sprung weight is controlled.
So that means, greatest effect in suspension.
It will mostly effect the car behavior with bumps. Like hitting rumbling strip. With heavier unsprung weight, it will make the whole suspension assembly move with greater momentum. So shocks will work extra duty in that case, bushings will see extra load.

math wise wont hurt acceleration in straight line, its so minimal that makes no difference.
Usually will help acceleration in corners.
Braking usually improved.
top speed is usually effected great deal with wider tires. Rolling tire is not most aerodynamic thing.

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Re: Tires poking past fender

People spend a lot of light wheels and fancy light suspension parts to remove unsprung weight. Some invert shocks or run in-board rear brakes as feasible (we did in an off-road vehicle). http://www.formula1-dictionary.net/unsprung_weight.html

MZAVARIN wrote:

Examples:
Car 1) Car weighs 3300 pounds, 300 of which is in the wheels (75 pounds each)
Car 2) Car weighs 3300 pounds, 100 of which is in the wheels (25 pounds each)

Car 2 will accelerate faster?

http://www.nsxprime.com/forum/showthrea … ir-results
I didn't see that he compensated with ballast sprung but did do back-to-back at least.

Also, http://www.caranddriver.com/features/ef … res-tested

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  • From: el aye, so cal
  • Registered: 2011-06-01
  • Posts: 330

Re: Tires poking past fender

These are 3 very interesting links.  Thanks for posting them.

SwarlesInCharge wrote:

http://www.formula1-dictionary.net/unsprung_weight.html
http://www.nsxprime.com/forum/showthrea … ir-results
http://www.caranddriver.com/features/ef … res-tested

Likely, the greatest effect the typical Lemon racer will see as a result of a substantial change in wheel size and un-sprung weight is not in acceleration/deceleration or in how quickly the suspension reacts but rather the effect of the change in tire sidewall flex on overall spring rate.  And, that's not to say the effect will be bad.  A lower profile tire will effectively increase the spring rate which is generally good, to a point.  Ideally, you would take a bunch of different sized wheels and tires to a big open paved lot and do some skid pad testing.  It's more than most Lemons teams are willing to do but it would give you the most real data.  Not all the data as you would not learn much about transitional handling characteristics but it would give you a good idea as to which setup is quickest.

Also, the law of unintended  consequences is hard at work when making these kinds of changes.  We recently went from a 15" to a 17" wheel so that we could go from a 205 wide tire to a 225.  The difference in cornering forces was significant.  To the point that we now have an oil starvation problem in longer left hand corners and we spun our first wheel bearing, ever.  Both, it would seem, the result of higher cornering forces.

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50 Reply by shamwow (edited by shamwow 2016-12-13 08:57 AM)

  • From: Kalamazoo MI
  • Registered: 2013-06-10
  • Posts: 117

Re: Tires poking past fender

Yeah but guys!!!!  Come on!!

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