Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Marc wrote:

now we need batteries, let's say 45seconds of full capacity power. some quick math tells you that the bigger reason for many batteries will be the voltage requirement, not the ultimate capacity. the highlander motors take 288V so 300V is probably a reasonable target.  so we need 25 of the smallest cheap batteries. the smallest cheap battery is about 30lbs, it can be brought down to 1/2 that weight with a bit more spending. so 400lbs by the time you add the brackets & such.

the controller will be at least 50lbs. and the turbine is 100lbs so that puts the whole drivetrain at 824lbs.

there's also the issue of having about $6k wrapped up in that drivetrain.

Don't use batteries. You won't need to store the power for long periods of time, just during decelerations. Which are quickly followed up by accelerations which is where you need more power then the turbine provides. Find, or make, large capacity capacitors to use instead of heavy batteries. Caps can also source more amps then can batteries.

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Yes, you just need a generator big enough to handle the average horsepower used. can you point me to a reasonably priced & lightweight generator head?

Reasonably priced, yes. Don't know about lightweight. http://www.govliquidation.com/list/c7210/lna/1.html A little hunting might find you something right-sized. Under "Item Manifest", click on NSN and it'll usually give you more specifics. Condition A1 is brand new, Condition H7 is scrap, but there's a lot of stuff that goes to DRMO coded H7 that's easily repairable.

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

The first Porsche "hybrid", Ferdinand, had an electromechanical transmission like that... Heavy, expensive, got some of the worst gas mileage of the war, and was unreliable as hell.  Just sayin' wink

Batteries are too heavy or too expensive, capacitors will barely store a few seconds' worth of charge for the same money, and direct electrical transmission is inefficient, heavy, and also expensive.

A CVT of some sort, as prosaic as it might sound, would be a better bet, IMO. You COULD use a Prius-like transmision - a planetary gearbox where your main feed is your turbine, your side feed is a small electric motor, and your output has another electric motor attached to it that compensates for the power draw/output of the side feed motor. You can add a small battery pack for some regen capacity, but you don't have to. But then again, a snowmobile or similar tranny is much easier, and given the "not get kilt by wife" requirement, might be a better idea in the grand scheme of things.

K Car Stalker

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

the ideal situation would be that allison 250 turbine. the output won't mind being reved up & down . and a TH425 transaxle.

linking the two with a short driveshaft and a scatter shield (or go with more of a torque tube design with integrated scatter shield), remove the torque converter and implement a driveline brake to not shatter the trans and overspeed the turbine in park/neutral.

the whole thing will require an interesting electronics package, but that's not hard. the hard parts would all be being used within their operating parameters. some extra care would be needed to not overheat the turbine when stalled. it's not designed for being stalled other than initial startup.

the only thing that could throw this would be if the output spins the wrong way. i have no way of knowing that right now, but if it does, there are potential fixes.

supercaps would be interesting. but that makes the kill switch requirements very difficult to meet. you're talking about massive energy that can be released in milliseconds.

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Rather than using the Audi CVT or tuning the weights/springs on a snowmobile CVT, I wonder if you could make the snowmobile CVT computer controlled so that the engine runs at a constant rpm.  First, put heavy weights and a light spring in the CVT so that it wants to spin out to high gear.  Then fabricate a pincher-type claw thing with skateboard wheels on the fingers that will squeeze down into the "V" of the engine-side pulley and prevent the pulley from changing diameter.  Sort of like how a "launch lever" works on modified French mopeds.  Add some kind of hydraulic or electric actuator to the pincher and you can control the CVT's gear ratio on the fly.  A pretty simple feedback loop controller will keep the engine at a constant RPM while varying the speed at the wheels.  I hope that makes sense.

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

discontinuuity wrote:

Rather than using the Audi CVT or tuning the weights/springs on a snowmobile CVT, I wonder if you could make the snowmobile CVT computer controlled so that the engine runs at a constant rpm.  First, put heavy weights and a light spring in the CVT so that it wants to spin out to high gear.  Then fabricate a pincher-type claw thing with skateboard wheels on the fingers that will squeeze down into the "V" of the engine-side pulley and prevent the pulley from changing diameter.  Sort of like how a "launch lever" works on modified French mopeds.  Add some kind of hydraulic or electric actuator to the pincher and you can control the CVT's gear ratio on the fly.  A pretty simple feedback loop controller will keep the engine at a constant RPM while varying the speed at the wheels.  I hope that makes sense.

that's not a completely terrible idea. but that's essentially what the audi CVT is. it's a snowmobile CVT with a diff built in and a direction reverser clutch and you get to control the size of the two pulleys hydraulically.

your idea has more je ne sait quoi to it, but it's effectively the same minus the appropriate lubrication and with more skate wheels.

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

for grins, here's the ratio calculations if i use a TH425 from a toronado (other apps may have different ratios, but i could not find them)


1st:2.48:1, 2nd:1.48:1, 3rd:1.00:1 final:3.07

redline = 6000
tire rev/mile = 900

1st goes to 52mph
2nd goes to 88mph
3rd goes to 130mph

that should be pretty good. shorter gears would give better acceleration for the speeds we use in Lemons (i usually use a target max of 110mph)

odds are the trans valve body won't be able to inteligently shift for power coming from a turbine so i'll probably need to use a manual valve body and shift between gears myself. as long as i configure the gate to be able to slam back and forth between 2nd and 3rd everything should be great.

no matter which transmission i use, the wait for the better turbine is the task at hand right now.

83

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Anything using parts from a Toronado I approve.  If I remember right people would use the gear select lever to go from 2nd to 3rd in the Toronado anyway as a way to improve performance.

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Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

BoB wrote:

Anything using parts from a Toronado I approve.  If I remember right people would use the gear select lever to go from 2nd to 3rd in the Toronado anyway as a way to improve performance.

That’s a good point, the old automatic transmissions did not have “save the engine” as part of their strategy. I may not need a manual valve body at all. Certainly not worth messing with till it’s in the car and it works first.

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

If its anything like the C4 tranny in our Fairmont, or the Powerglide in old Parkwood, you can shift between 2nd and drive any time you want too, and it will be in the highest gear. As long as the input RPMs are such that high is an option at that RPM. They just use a mechanical rod or cable to judge throttle possition, and of course can "see" the RPM coming in.

Constructor/Owner/Driver - Billy Beer Ford Futura

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Is there a need for a TH425 with a turbine? It's a tad heavy, to say the least, and it's not like you're making a thousand lb/ft at the shaft, and your power output is smooth as silk. THM325-4L would be over 100lb lighter and has an extra gear.

Don't forget to overhaul the thing - since you don't have a torque converter or a clutch, you're going to put a lot of extra wear on clutches and band if you're gonna shift without letting off the throttle (turbine still has significant inertia). Overhaul kit, new band, plus a few random odds and ends and a Transgo shift kit oughtta set you back no more than $300. It should take you about 2-3 days to complete an overhaul; don't forget to get an ATSG book, it's only 25 bucks or so.

I got most of my parts here when I overhauled my Buick's 4L60E: http://www.transmissionpartsusa.com/ They're pretty decent at shipping stuff out promptly, and have a good selection.

K Car Stalker

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

firegremlin wrote:

Is there a need for a TH425 with a turbine? It's a tad heavy, to say the least, and it's not like you're making a thousand lb/ft at the shaft, and your power output is smooth as silk. THM325-4L would be over 100lb lighter and has an extra gear.

Don't forget to overhaul the thing - since you don't have a torque converter or a clutch, you're going to put a lot of extra wear on clutches and band if you're gonna shift without letting off the throttle (turbine still has significant inertia). Overhaul kit, new band, plus a few random odds and ends and a Transgo shift kit oughtta set you back no more than $300. It should take you about 2-3 days to complete an overhaul; don't forget to get an ATSG book, it's only 25 bucks or so.

I got most of my parts here when I overhauled my Buick's 4L60E: http://www.transmissionpartsusa.com/ They're pretty decent at shipping stuff out promptly, and have a good selection.

mostly because i never heard of the THM325-4L. i was ready to rant about the transmission layout and whatnot, but you're right, that trans may be perfect.

Thanks!

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

A suprisingly high number of you guys know about and work with turbines so let me ask for everyone's help here.

I'm looking around for a different turbine that meets the following requirements:

-250SHP+ (with the "or more" being kept in reason, i don't want a 1200hp T58, that will never spool coming out fo a corner)

-output RPM under 8000RPM (can be with seperate gearbox, but must be officially rated for the application)

-seperate power turbine (not a signle shaft design)

-under 400lbs

-60" or less in length

-32" or less in diamater (preferably much smaller like 20" in diameter)

-electric starter, i don't want to carry a huffer trailer with me.

-under $10,000 (most of which gets offset by the sale of my radial engine)


the pricing is the hard thing to find information. right now i'm looking into the PT6A turboprop engine. it seems to tick all the boxes but i don't know the price yet. i found one at 7000hours and not rebuilt which may be cheap (rebuild interval is 3500hours so it;s been rebuilt once and is now at the 2nd interval) I can get help doing a full inspection on it and likely it'll just be down on power a bit and have a bit higher oil consumption. not that big of a deal.

so how about it guys, what other engines meet the above specs?

89 (edited by Scotty 2012-07-05 11:13 AM)

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Marc, here you go again with an epic build.

I must inject this from the start...

Reduce your engine speed before the transmission with x:1 gear or belt drive... Does the turbine turn CW or CCW?

Use a regular ass transmission. TH700

I have probally the most high tech TH700 ever constructed (for road racing). And have a few of them.

PM me if you want to talk about going this route.

This time maybe the KISS rule will help you achieve your first two goals in post #1.

I would hate to see your passion for packaging cause you 90% of your problems again.

Another unique configuration would be a VETTE rear mounted trans/axle with tunnel to the front.

_______________
#3 IROC MAIDEN

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

A buddy of mine picked up two gas turbine generator sets at the navy base for less than 1000.00 each.  maybe gas/turbine-Electric hybrid would be simpler?

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#3 IROC MAIDEN

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Scotty wrote:

A buddy of mine picked up two gas turbine generator sets at the navy base for less than 1000.00 each.  maybe gas/turbine-Electric hybrid would be simpler?


[BoKu plugs ears...]

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Scotty wrote:

Another unique configuration would be a VETTE rear mounted trans/axle with tunnel to the front.

Wow. All the Vette guys have been dying for a mid-engine version for the C7. But a jet turbine FWD mid-engine version? This would make heads explode. Therefore, I agree. smile

Pat Mulry, TARP Racing #67
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Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Marc wrote:

...the pricing is the hard thing to find information. right now i'm looking into the PT6A turboprop engine. it seems to tick all the boxes but i don't know the price yet...

You've probably already figured this out, but even thrashed PT6s have pretty high core value, usually well up the five digits. I think your only hope there is get one so bent or burned that nobody in aviation will touch it any more.

The three sites I follow for junk like that are:

http://www.aigaviation.com/aviationsalv … eList.aspx

http://www.phoenixaviationmgrs.com/CurrentSalvage.aspx

https://www.usau.com/caf_claims_salvage.php

What you'll be looking for is a crop duster crash with either fire or catastrophic damage to the output section. Some candidates might be:

http://www.aigaviation.com/aviationsalv … ageId=1350

http://www.aigaviation.com/aviationsalv … ageId=1340

Or maybe some Eurocoptertrash:

https://www.usau.com/caf_claims_salvage … p?SA_Id=39

Good luck, and may the odds and ends be in your favor!

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

BoKu wrote:

You've probably already figured this out, but even thrashed PT6s have pretty high core value, usually well up the five digits. I think your only hope there is get one so bent or burned that nobody in aviation will touch it any more.

Perfect for Lemons!   smile

"I don't suffer from insanity, I enjoy every minute of it!"
IOE winner in the Super Snipe -- Buttonwillow 2012
IOE winner in Super Snipe v2.0 -- Buttonwillow 2016
"Every Super Snipe in Lemons has won an IOE!"

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

I just spoke to my buddy with the two gen sets. He said they were 40HP each and ultra light due to Helo transport. he scraped them both last year as for he they were 400hz gen sets and would only work for radio equipment. he said the cool thing about using a gen set turbine is that they already have the reduction box built in and reduced the normal opperating RPM to 3800 from 28,000.  Now here is the kicker; he said because those gensets are 400HZ they can be found all over the place at military salvage places but they DO NOT advertize them because they are worthless. So you would have to call around.

Now here is the super kicker, They have 120HP and 180HP versions out there.  Hope this info can help.

Now here is the super dupper kicker; he got the gen sets for 50.00 each. that seems like it's in budget. LOL

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#3 IROC MAIDEN

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Oh and the gensets are already electric start...

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#3 IROC MAIDEN

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

The size of the turbines including reduction boxes was " less than half a 55 gallon drum"

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#3 IROC MAIDEN

98

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

Scotty I think post 74  kind of sums up why Marc is not going with electric.  I know there are a couple other posts in the thread to discussing him not going that way.  Not saying it wouldn't work but he has an idea in his head with the way he wants to go, so no reason to keep trying to get him to change directions.  Heck leaves it open for you and then we can get 2 turbine cars racing each other which sounds even better than just one.

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Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

I remember in an old interview with Art Arfons he said he would pick up surplus jet engines with bad fins and just remove the bad fan blade and the oposite blade so it was balanced. LOL

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#3 IROC MAIDEN

Re: version 3.0: The MR2 gets a gas turbine engine (Project Outline)

BoB wrote:

Scotty I think post 74  kind of sums up why Marc is not going with electric.  I know there are a couple other posts in the thread to discussing him not going that way.  Not saying it wouldn't work but he has an idea in his head with the way he wants to go, so no reason to keep trying to get him to change directions.  Heck leaves it open for you and then we can get 2 turbine cars racing each other which sounds even better than just one.


yeah I knew the electric hybrid was a stretch... but the turbines from a genset would be perfect. Already RPM reduced, and electric start.

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#3 IROC MAIDEN