• sac02
  • Paddock Rat
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  • Registered: 2009-11-04
  • Posts: 68

Topic: Aftermarket tach with shift light?

Give me some opinions about aftermarket tachs and shift lights. 

We've got a quarter million mile engine, with a water pump impeller design that is known (according to enthusiast boards) to cavitate and not flow well over 6000rpm (redline ~7K).  We want to short-shift to keep the revs low and improve our chance of finishing from "candy bar in Kirste Alley's hand" to "snowball's chance in hell"

5" tachs with BIG ASS shift lights are $50 on craigslist.

One team member thinks it's a waste of money; use the stock tach.
One team member thinks a BIG ASS tach and shift light will encourage/remind the driver not to let the revs get too high.
One team member doesn't care.

Thoughts?

  • From: Toronto, Ontario
  • Registered: 2009-05-03
  • Posts: 1,114

Re: Aftermarket tach with shift light?

Depending on the stock tach's setup, you could tap the feed an make your own shift light....but if you're spending on Craigslist, why not an old MSD box with rev limiter? Then you can avoid crankshaft/block cavitation when you miss a downshift...you soon get the feel of the limiter and know how hard to rev...I bought an ebay box cheap last year...it was a GM performance blue box...I think it was cheap because it wasn't an "official" MSD 6AL...it can be done!

Jim "Endo" Anderton
30 years of racing and still not Brambilla.....
  • From: San Diego, CA
  • Registered: 2010-02-11
  • Posts: 156

Re: Aftermarket tach with shift light?

What car?  You might want to try underdriving the water pump.  Works for SE-Rs.

4 Reply by sac02 (edited by sac02 2010-03-19 01:21 PM)

  • sac02
  • Paddock Rat
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  • Registered: 2009-11-04
  • Posts: 68

Re: Aftermarket tach with shift light?

jimeditorial wrote:

Depending on the stock tach's setup, you could tap the feed an make your own shift light....but if you're spending on Craigslist, why not an old MSD box with rev limiter? Then you can avoid crankshaft/block cavitation when you miss a downshift...you soon get the feel of the limiter and know how hard to rev...I bought an ebay box cheap last year...it was a GM performance blue box...I think it was cheap because it wasn't an "official" MSD 6AL...it can be done!

Just for reference, how much is "cheap"?  I don't think we'll do that, but maybe.  The current idea is that we'll keep our shiftpoints low to try to preserve the engine, but if we really need those extra revs once in a while, we'll have them when we need them, say to pass a car we've been dicing it up with or something.

rockwood wrote:

What car?  You might want to try underdriving the water pump.  Works for SE-Rs.

lol, it is an SE-R.  We just don't have access to the tools to fabricate a larger WP pulley. 

I guess we could get a pair of calipers, take a measurement, and head to the junkyard...

Or do you happen to know any direct swaps (since you appear to know SE-R's)?

  • Registered: 2009-09-22
  • Posts: 367

Re: Aftermarket tach with shift light?

sac02 wrote:
jimeditorial wrote:

Depending on the stock tach's setup, you could tap the feed an make your own shift light....but if you're spending on Craigslist, why not an old MSD box with rev limiter? Then you can avoid crankshaft/block cavitation when you miss a downshift...you soon get the feel of the limiter and know how hard to rev...I bought an ebay box cheap last year...it was a GM performance blue box...I think it was cheap because it wasn't an "official" MSD 6AL...it can be done!

Just for reference, how much is "cheap"?  I don't think we'll do that, but maybe.  The current idea is that we'll keep our shiftpoints low to try to preserve the engine, but if we really need those extra revs once in a while, we'll have them when we need them, say to pass a car we've been dicing it up with or something.

rockwood wrote:

What car?  You might want to try underdriving the water pump.  Works for SE-Rs.

lol, it is an SE-R.  We just don't have access to the tools to fabricate a larger WP pulley. 

I guess we could get a pair of calipers, take a measurement, and head to the junkyard...

Or do you happen to know any direct swaps (since you appear to know SE-R's)?

Only problem - your once in a awhile will turn into once or twice a lap with all the traffic out there. I shift our car when I can hear the valves float, of course I need all the revs I can get.

I'd try and address the water pump issue if it was me - or actually lower the rev limit. Not sure that the gauge is the answer.

Head Hoopy Frood
www.mostlyharmlessracing.com
  • From: Frisco, Texas
  • Registered: 2009-05-02
  • Posts: 1,430

Re: Aftermarket tach with shift light?

Waste of money. Heck, even in my "real" race car, I never look at the tach.  If you have a proven known issue, under drive the water pump or put in a bigger radiator. Do you know it doesn't cool at high rpm? In this whole Lemons thing, I see LOTS of people designing solutions to perceived problems... Most of them end up or stay in the pits. My goal is to do as little to the stock components as possible except cutting weight from it.

"Don't mess with Lexas!" LS400. We survived another one! See website link for build details.
Maker of the "unofficial Lemons fish!" - If you ask nice, I'll likely give you one at the track.

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  • Mulry
  • Mulry
  • Ayatollah of Rock-n-Rollah
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  • From: Dallas, TX
  • Registered: 2009-05-01
  • Posts: 4,607

Re: Aftermarket tach with shift light?

You could always just skip getting the new tach and just add an adjustable shift light. You can get them new from Jegs for like $45 and probably cheaper on eBay.

http://www.jegs.com/i/Proform/778/67005C/10002/-1

We used one like this in the car at Infineon and it was a good reminder team-wide to not frag the engine. By agreement, we set it kind of low and nobody really followed it 100% of the time, but it was good as a reminder. And we did (finally) complete the full race. Was the implementation of a shift light causal or merely coincidental? I dunno. But it's cheap and can't hurt, right?

If you're creative, you can easily put in a bigger radiator. Or a second one. Lemons loves serial radiators, especially when they get mounted entirely outside the body shell. Cheers.

Pat Mulry, TARP Racing #67

Mandatory disclaimer: all opinions expressed are mine alone & not those of 24HOL, its mgmt, sponsors, etc.

8 Reply by rockwood (edited by rockwood 2010-03-19 02:04 PM)

  • From: San Diego, CA
  • Registered: 2010-02-11
  • Posts: 156

Re: Aftermarket tach with shift light?

sac02 wrote:
rockwood wrote:

What car?  You might want to try underdriving the water pump.  Works for SE-Rs.

lol, it is an SE-R.  We just don't have access to the tools to fabricate a larger WP pulley. 

I guess we could get a pair of calipers, take a measurement, and head to the junkyard...

Or do you happen to know any direct swaps (since you appear to know SE-R's)?

Figured it was.  That RPM range was too familiar.  I'm an SE-R guy that's going to field a car built by my arch-nemisis: Honda.

And yes, there is a direct swap, what's it worth? big_smile

Seriously, a Nissan Stanza water pump pulley will work.  Need to clearance the oil pump relief spring area a little (around the freeze plug) to get it to fit.  If you can't find it at the yard, Courtesy Nissan will probably have it for pretty cheap.

Not sure on the belt needed, but just take the stock one and cut it (assuming it doesn't fit), put it on with the tensioner 3/4 of the way to fully right (P/S pump closer to the block) and measure the air gap between the ends, then add that to the part of the part number that indicates length and head to your local autoparts store.

  • From: Toronto, Ontario
  • Registered: 2009-05-03
  • Posts: 1,114

Re: Aftermarket tach with shift light?

sac02, I think it was 70 bucks, but they can be had for less...the circle track guys often use two and change them regularly just to be safe...they work, you can choose the limit with rpm "pills" and you sure know it when you hit the redline! Not subtle...

Jim "Endo" Anderton
30 years of racing and still not Brambilla.....
  • VKZ24
  • VKZ24
  • Lemons Staff Stalker
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  • From: Wilson, NC
  • Registered: 2009-05-20
  • Posts: 1,840

Re: Aftermarket tach with shift light?

Mulry wrote:

You could always just skip getting the new tach and just add an adjustable shift light. You can get them new from Jegs for like $45 and probably cheaper on eBay.

http://www.jegs.com/i/Proform/778/67005C/10002/-1

We used one similar from Summit.  I'm too busy to look at a tach but that light is hard to miss.

Our engine doesn't like to be over revved so the light reminds us to shift before we go too far.  Of course we have a rev limiter, but we'd rather not use that as a shift reminder.

Captain
Team Super Westerfield Bros.
'93 Acura Integra - No VTEC Yo!

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