B_ROCKS_IT

Ran at the track on the 14th, my best was 12.2 @ 125.6, obviously traction problems and also my first time ever on a drag track. Once I was getting the launch dialed in the clutch started slipping... Time for the 8.8, slicks and a twin plate clutch/katech flywheel. I still cant believe the stock diff is holding up after repeated 2 step launches on my power levels, but no way it would stick it out with slicks.


Anyways, the gear ratios available are: 3.08 3.27 3.31 3.55 3.73 4.11 4.30 4.56 4.88 5.13 5.71.

With the stock being 3.73, I am trying to decide whether to go shorter or taller, I have never changed ratios on a car before so I dont know what to expect.

I feel like a turbo car should have taller gears to stretch its legs and spool better. At the track I was crossing the line almost bouncing off the rev limiter at 125, so leaning towards the 3.55, but all of your thoughts are welcome.

Also feel free to chime in about the clutch setup, my builder says the one he has planned is good to 1400whp, but cost for everything including the flywheel will be around $1800...

FuzzyLog1c

iTrader: (4)

I say 3.27 or 3.31 and a McLeod RXT. In the meantime, start in second. If you ever get a TR6060 (Magnum T56), I recommend going with the 2.66 close gear ratio. Since you're drag racing the car, you probably don't want an aluminum flywheel.

Dmax/04V

With twin screws I would drop down to a 3.55 or higher( not too high). Those turbos should build boost faster with more load on the motor higher egts, pressure etc.... you know the drill. Steel flywheel for drag strips as fuzz said, aluminum lightweight is the way to go if you are running auto x and such which is my case, but they are not the most friendly thing for launches as the inertia carried dissipates much quicker with lower mass.

Sweetwilliebrownjr

I did 3.55s in mine (Maggie), and kinda wish I'd went 3.31. Mines a daily driver though, and never sees a track.

DougNuts

iTrader: (1)

If we change our rear gear ratio, is there a quick and easy way to correct the speedometer?

B_ROCKS_IT

yes, good point I forgot about that???

FuzzyLog1c

iTrader: (4)

It can be corrected in the tune.

punishmentcycle

iTrader: (6)

ur tuner can calibrate the speedo in 2 secs

Skidmarcx

3.31s

runsfromdacops

id go 373 (i have 373in mine now)or 3.88s
any one that tells you that a 3.55 or lower has never owned a fast turbo car.
gear the as high as you can for what u think youll run at the track in 4th gear. any thing more or less is just a waste.

itsslow98

iTrader: (18)

Major facepalm on this one.

OP, what is your goal down the road for mph at the track? With 3.55s and a 26.6" tire I can run 4th out to 145mph at 6500rpms. I think the 3.55s are a good all around gear for street strip setups.

With your 3.73s, 26" tire you should be able to run 4th out to 135@6500rpms.

Bottom line for turbo cars with manuals is you wanna stay in boost and let the engine do the work. With 3.73s+ thats more time shifting and less time in boost.

You can use this to test out different gear ratios, tire heights etc.
http://www.csgnetwork.com/multirpmcalc.html

runsfromdacops

for a drag/roll race car you want to use gears 1-4. and you want 4th to top out just a little higher then your planing on going.


you could put some 2.43s in their and just use 1-2 as most of the guys here with out a turbo car or cars will tell you. i mean your skiping 2 whole shifts right? it must be faster that way.... NOT!!


my #s are based on a 28" DR as thats what i have.if your on a 26" tire idd look at 3.73s or 3.55s

itsslow98

iTrader: (18)

Ill just skip your first few sentences. And your 3.73s with a 28" tire are virtually a 3.42 rear gear. So you made my point for me.

Very few V1 guys run that tall of a tire unless they are running just at the track. 3.55s are the best setup for most turbo cars IMO because with a 26" tire its still low enough to load the turbo and with a 28" tire its acts like a 3.27 rear gear which is still great for a turbo car.

runsfromdacops

maybe i missed the tire size hes on. but never the less im moving up to 4.11s with a 28" tire as i think the 3.73 are kinda lazy and leave some on the table as it were


and when it comes down to it with the 8.8 swap gearing changes are super cheap. so its not a life changing choice

itsslow98

iTrader: (18)

If hes hitting the rev limiter in 4th at around 125 he must be running around a 25.5" tire. Like you said though, 8.8 gears are dirt cheap so having to swap down the road wont break the bank.

Im shocked your going up in gearing with an 800rwhp turbo car. Totally opposite of what everyone does. For you power you should be running out of gear by the 1320 with that setup. You should be well over 130mph.

runsfromdacops

i have been around high hp manual turbo cars for a long time and i can assure you that the big boys gear their cars for max mph that they can run the 1/4 in and not 1 mph more.

sure puting some lower gears and letting that turbo pull feels fast and cool but if you take it to the track youll be disaponted as you have gone slower then before the gearing change

just my .02

ColeGraham

iTrader: (8)

Because


So much win...at least for reformed V1 owners like me...