What rear gears are you turbo street people running? Highway race
01-05-2009, 12:54 PM
#62
Moderator
iTrader: (2)
Join Date: Jan 2002
Location: THE CHI
Posts: 977
Likes: 0
Received 0 Likes
on
0 Posts
gearing is VERY important...
01-05-2009, 03:37 PM
#63
Launching!
iTrader: (1)
Join Date: Mar 2008
Location: All Over
Posts: 293
Likes: 0
Received 0 Likes
on
0 Posts
I would disagree for the low street ratios..
My choices would be around 3.42 as perfect in stick or auto. 3.73 in m6 is still fine.
3.73 in track car auto is still fine.
This low numerical gear stuff seems to be urban legend .Go search the old boosted lists.There are tons of m6 cars that are running great times with 3.73 and even 4.10 gears. There are lots of auto guys with 3.73 gears.,Heck JM our resident TT aps 402 car did high 9s at near 140 with 4.10s and his 4l80e.
So your theory is he would have done low 9s with maybe 2.73 or 3.08s???
If the car can't make boost because of gearing then add lingenfelter two step/antilag box.This would help even on autos..or possibly small shots of nitrous.
And you don't always want the turbos to come out too strong off the line anyway.
Around town anything under three seems terribly doggy to me. Even with a bigger engine. Maybe on a 427 or bigger and you are not going to get much better traction with those 2.73s or 3.08s. You want to gear so you can go thru the traps in third on auto and fourth on stick to save that extra shift mostly. On a street car not very important at all.
That said am going with 3.54 gears and Dana 60. 9 inch would be my second choice.
That new m9 looks really cool.
And would welcome some real proof on this lower gear legend but the boosted lists pretty much tell the tale. And as said off boost anything under 3.0 is just horrible to me around town.
Now if you are building the car for bonneville salt flats welll maybe these under 3.0 ratios.
And who really needs to push their car past 200mph..??
And whats the update on your car there Kwikkar. Might send my turbos to same place in january or so to make sure have them back in summer but your car seems to be taking forever..??
My choices would be around 3.42 as perfect in stick or auto. 3.73 in m6 is still fine.
3.73 in track car auto is still fine.
This low numerical gear stuff seems to be urban legend .Go search the old boosted lists.There are tons of m6 cars that are running great times with 3.73 and even 4.10 gears. There are lots of auto guys with 3.73 gears.,Heck JM our resident TT aps 402 car did high 9s at near 140 with 4.10s and his 4l80e.
So your theory is he would have done low 9s with maybe 2.73 or 3.08s???
If the car can't make boost because of gearing then add lingenfelter two step/antilag box.This would help even on autos..or possibly small shots of nitrous.
And you don't always want the turbos to come out too strong off the line anyway.
Around town anything under three seems terribly doggy to me. Even with a bigger engine. Maybe on a 427 or bigger and you are not going to get much better traction with those 2.73s or 3.08s. You want to gear so you can go thru the traps in third on auto and fourth on stick to save that extra shift mostly. On a street car not very important at all.
That said am going with 3.54 gears and Dana 60. 9 inch would be my second choice.
That new m9 looks really cool.
And would welcome some real proof on this lower gear legend but the boosted lists pretty much tell the tale. And as said off boost anything under 3.0 is just horrible to me around town.
Now if you are building the car for bonneville salt flats welll maybe these under 3.0 ratios.
And who really needs to push their car past 200mph..??
And whats the update on your car there Kwikkar. Might send my turbos to same place in january or so to make sure have them back in summer but your car seems to be taking forever..??
01-05-2009, 03:44 PM
#64
I have been setting up race cars, perf cars, 4X4s, etc for over 30 years. There has always been a formula to get the most efficiency out of any combo. This is just another learning curve and usually at someone's expense. Mighty Mouse has probably the best combo and example right now on a matched setup, (8.70's@160mph! 1.3 60', with a 3.00 gear and I believe a 25.5"-26" tire, and 3850lbs). In the next few years we may all rethink our positions on this subject. A few of you mentioned LOAD. This is the key on a turbo setup. EVERY SETUP IS DIFFERENT!! Unless you copy one. Today I was just talking to Chris C. (Veeee8), and he is about to order his M-9 with a 3.00 gear, (has 400 trans). His car spools extremely quick! (There is a video in the boosted section). He should be around 1000-1100rwhp when all is said and done. Everything is a mathmatical solution in this field. It is the combo of driveability, spool time, load, tire size, gear ratio, trans ratios and converter stall, weight, and distance, (1/8th or 1/4 mile), etc. Get out your calculators!
Basically, most street cars are medium weight, (3400-3800lbs) averaging 600-1100HP. Many of you probably haven't tested swapping gears as it is very expensive. What you have now is usually based on past experience. Turbo cars, with todays technology, may be a little unorthodox as 800-1100HP street cars are becoming more prevalent and can sustain a 3.00-3.25 gears as the engine load requires it to cross the traps between the 6500-7000rpm ranges. It is all in the combo you chose. Due diligence is required as there is not room for big money mistakes. I believe the guys running the steeper gears, (3.42-4.10) may be working at their power range and type of turbo and how fast it spools. But, if you really have a massive amount of power, don't rule out the higher ratios, (3.00-3.25). It may be different with a manual trans. Time will tell. Good Luck!
Basically, most street cars are medium weight, (3400-3800lbs) averaging 600-1100HP. Many of you probably haven't tested swapping gears as it is very expensive. What you have now is usually based on past experience. Turbo cars, with todays technology, may be a little unorthodox as 800-1100HP street cars are becoming more prevalent and can sustain a 3.00-3.25 gears as the engine load requires it to cross the traps between the 6500-7000rpm ranges. It is all in the combo you chose. Due diligence is required as there is not room for big money mistakes. I believe the guys running the steeper gears, (3.42-4.10) may be working at their power range and type of turbo and how fast it spools. But, if you really have a massive amount of power, don't rule out the higher ratios, (3.00-3.25). It may be different with a manual trans. Time will tell. Good Luck!
01-05-2009, 04:00 PM
#65
Due to circumstance, I just removed my K walked 3.43 gear/diff. Bearing let go @ 120,000 miles.
So,..I had a 2.73 gear'd diff laying around,...I didn't have much of a choice. So, the 2.73 gear is in the car with C6 Z06 clutch packs, and hardned left output shaft.
I don't know how it's going to react. If it is **** poor slow out of the gates,...I don't see why it would be a big deal to just clutch it one time(dump the clucth)(from a dig or roll)...and get the car moving. I'm waiting on wastegate flanges at the moment so, I can't drive the car but, I should have the parts in two days. So,...i'll give some feedback then. The car(c5) makes 787 and 696 and it is setup for the highway, and some drag strip action.
So,..I had a 2.73 gear'd diff laying around,...I didn't have much of a choice. So, the 2.73 gear is in the car with C6 Z06 clutch packs, and hardned left output shaft.
I don't know how it's going to react. If it is **** poor slow out of the gates,...I don't see why it would be a big deal to just clutch it one time(dump the clucth)(from a dig or roll)...and get the car moving. I'm waiting on wastegate flanges at the moment so, I can't drive the car but, I should have the parts in two days. So,...i'll give some feedback then. The car(c5) makes 787 and 696 and it is setup for the highway, and some drag strip action.
Very happy with the result of my big cam'd twin turbo 2.73 gear'd setup. From a 35mph roll, I think I may be able to rule the world.
Stay tuned.
(sub 1000 to the wheels...787rwhp)
01-05-2009, 08:11 PM
#66
2. What about if I did some front susp work (i'm stock 83k mile shocks and springs now)
3. What about if I ran on a track prepped with VHT and didn't have FWD cars dragging water all the way down the track?
4. What about if I ran at a sea level track?
I bet if I made all these changes I could go 9.7 @ 138
Gearing has affected my car drastically so yes, I do believe in what I'm saying. I went from 3.50's which would 60' 2.0's due to not being able to leave under any boost because of wheel spin to 1.6's with 2.75's.
I guess I'm not doing that good though, on 16psi I'm only trapping 37+ mph faster than a stock F-body.
Last edited by Zombie; 01-05-2009 at 08:49 PM.
01-05-2009, 09:56 PM
#69
Moderator
iTrader: (2)
Join Date: Jan 2002
Location: THE CHI
Posts: 977
Likes: 0
Received 0 Likes
on
0 Posts
1. How much do you think i'd pick up swapping to a power glide with 4.10's and 28" tall tires?
2. What about if I did some front susp work (i'm stock 83k mile shocks and springs now)
3. What about if I ran on a track prepped with VHT and didn't have FWD cars dragging water all the way down the track?
4. What about if I ran at a sea level track?
I bet if I made all these changes I could go 9.7 @ 138
Gearing has affected my car drastically so yes, I do believe in what I'm saying. I went from 3.50's which would 60' 2.0's due to not being able to leave under any boost because of wheel spin to 1.6's with 2.75's.
I guess I'm not doing that good though, on 16psi I'm only trapping 37+ mph faster than a stock F-body.
2. What about if I did some front susp work (i'm stock 83k mile shocks and springs now)
3. What about if I ran on a track prepped with VHT and didn't have FWD cars dragging water all the way down the track?
4. What about if I ran at a sea level track?
I bet if I made all these changes I could go 9.7 @ 138
Gearing has affected my car drastically so yes, I do believe in what I'm saying. I went from 3.50's which would 60' 2.0's due to not being able to leave under any boost because of wheel spin to 1.6's with 2.75's.
I guess I'm not doing that good though, on 16psi I'm only trapping 37+ mph faster than a stock F-body.
i would expect low 1.3 60 foots with a car like yours assuming you have a transbrake... and im sure track can be poor on certin nights but to say that there is NO prep what so ever at a nice track like the one in vegas? ive never been there but i find that hard to believe.
just to let you know we grudge raced an entire event at night in 40 degree weather! after it has rained the two previous nights with NO track prep besides for the first 50 feet that we did our self with a sprayer.
01-06-2009, 07:19 PM
#72
Moderator
iTrader: (2)
Join Date: Jan 2002
Location: THE CHI
Posts: 977
Likes: 0
Received 0 Likes
on
0 Posts
best grudge racing around.. tons of big money action.
and my car dead hooked! but then again it hooks coming out of a carwash
