V8EATR

^ huh? I don't see why people get all crazy about gears. Gears will do nothing from a roll on most lsx powered cars, hell on most cars period. Especially with the mn12 gearing in the gto's. They have a broad torque curve and make lots of it. With the cam in my sig I make 400whp from 5k on up and the car is never below that in a race. The mustang in this case was just making more power.

evangto87

iTrader: (6)

the mn12 has a very bad 3-4 shift extension. The 4-5 is MUCH better then the fbody trans. Gears will do a lot in any car in any situation as long as its geared properly. In a full weight GTO, gears are huge... yes on the roll as well.

My buddy in his cammed ls1 gto raced another friends 335i. He had about a car length on the bmw until the 3-4 shift... the bmw came from a car length back to over a car length ahead. The GTO then stopped his pull at the top of 4th gear. And held it there through fifth. This happened every race. This was a 228/232 duration cam on a 112.

redbird555

iTrader: (14)

Gears can make quite the difference, the shorter gears as evan said will help keep you in your powerband during shifts, and also get you there more quickly. Its pretty clear in the vid the gto lost steam after he shifted. Shorter gears would have put him right back in higher rpms.

Case and point here. But I agree the 5.0 was making a little more power with less weight. I think it would be a dead heat with some gears and an intake though

Cwarta

iTrader: (12)

I must say I am noticing this, even with all my new found power. the 3-4 shift is a bastard, and drops me down just a little to much :/

When I have my trans doen Im thinking of C6Z gearing......

HioSSilver

iTrader: (8)

x2...

Guy probably was'nt turning the gto tight enough.

T.Man

My LS2 GTO fell on its face on the 3-4 shift. 1-3 it ran hard and stayed in the meat of the band.

Your car is definitely falling below 5K RPM on the 3-4 shift.

3.90's and an MN12 tranny is awesome. Look at how hard PSM's Z28 ran with that combo. It could only help an obese GTO, not hurt it.

Case in point - Recently there was a video posted of a mild H/C LS1 GTO with 3.90's racing a pretty gnarly H/C LS2 that made 460+ WHP and it was a damn good race. The LS2 barely crept back up at the top of 4th. Gears help.

HioSSilver

iTrader: (8)

No doubt they are geared a little long with 3.45's.

evangto87

iTrader: (6)

3.46s*** . Just being picky.

And gears will ALWAYS help heavy vehicles.. regardless of what speed you start at. The mn12 was geared to correct the 4th gen issue with the 4-5 shift. In my opinion, the over corrected. But either trans gear issue can be solved with more rear end gear.

Sticks n Stones

Either can be solved with more torque. Seriously, why the hell are all you guys talking like we have a no torque ford modular?!?! Just cam and rev the damned engine to 6800rpm and you will be fine.

Steep gears are like big stall converters: great down low but hurt you the higher the speeds get.

evangto87

iTrader: (6)

has nothing to do with Ford modular.. has to do with keeping power to the ground at all times. And gears dont hurt your car on the top end.. theres always another gear to grab. 3.90s-4.10s make 5th a power gear. And i reved my GTO 7100... still fell on its face with a 3500 converter on the 2-3 shift. But what do i know... i drive a ford..

V8EATR

I put 4.10's in my 05' Mustang GT from the original 3.55's and it did nothing from a roll. Zip, zero, zilch. Not even 1 inch better from a rolling start. It was the most worthless mod I have ever done. My GTO only weighs about 150lbs more and makes 120wtq more than the mustang did, it doesn't need gears. It multiplies torque but for a shorter period of time.

clonedws6

iTrader: (6)

3.90s woke my car up a lot. Even from a roll

V8EATR

I think most of you with gears are just going off the "butt dyno" and not actual hard data. I say this because when I had my GT I have a buddy with an 01 cobra at the time that was a dead even race every time. It was literally dead even everytime we raced, looked like we were just parked next to eachother. I did gears and it was the exact same race but the car "felt faster."

Cwarta

iTrader: (12)

Im gunna have to disagree here. I lovd my 3:91`s and could I get my hands on a reasonably priced set ill be getting some 4:10`s. Gears made a HUGE difference. My car doesnt like high rolls (60+) anyways, and neither do I. Low rolls with gears and I slaughtered cars I shouldnt have.

Its scientifically proven that there isa trade off from going with steeper gears, but no matter what gears will get you point a to point b quicker than taller gears. Fact, and I have DATA to back it up lol. As long as you can stick it gears will help every time. Unless you go full retard with 7.40`s or something then you may be a ra tard

Sticks n Stones

This is my dyno when I was heads/cam (mid range torque cam) and stock cubes. Every pro or veteran road course or drag strip racer will tell you that you want to shift from peak hp down to peak torque for optimum accelleration. Gears aren't gonna help that car unless I got the traction to use all that extra leverage off the start. from a roll, it would not benefit at all. btw, the breakup at 6500rpms was valve float due to craptastic TSP springs that came on the heads.

same thing here: I lost a car 60-130 against a friend who was tied with me the week before the gear change. just like the old hands told me might happen. higher ratios eat up more friction. just like high stall converters do.

Raoul-Duke

iTrader: (6)

Not to hijack this thread about gear talk but I'm about to throw some 3.73s in my Z/28 because I'm rebuilding my busted 10 bolt within the end of this month. I'm wondering if I should even do it now. I'm not trying to shift more for no benefit.

V8EATR

^ if you go to the track alot and have a sticky enough tire to take advantage of it, by all means, gear it up. But if your expecting it to do anything from a rolling start, don't.

T.Man

3v cars arent exactly known for their high RPM power output.

Answer me this - Why do 4V modulars swear by gear? Their motto is "The more gear, the better". Answer? They make most of their power in the upper RPMs. A cammed LSx motor generally shifts the powerband to the right a bit and is usually spun up around 7K RPM. Would make sense to want to keep her singing up there wouldn't it?

My anecdotal proof is my race with a member ORANGEPEEL (Scott). Both of us cammed LS1 Camaro SS's with his being a bit heavier with leather, full option SLP etc.

Both had full exhaust with TDs, lid, clutch, tune etc. Only difference was slight cam difference (both 23x/24x) and my stock 3.42s to his 4.10s. I made 411 WHP and 370ish WTQ. He made 403whp and 370ish WTQ.

At the track, I went 12.3 at 116.55 and he went 12.0x at 117.xx

From a 50 roll, me in 1st gear and him in 2nd. I jumped out on him by a half car and kept my half car all through 2nd, he was creeping up in 3rd. At the top of 3rd, getting ready to throw 4th, he came around me and pulled out a car. He threw 5th and I wasn't coming back in 4th.

I "made more power", was lighter, shifted faster and he still came around me at the track and on the street.

Cwarta

iTrader: (12)

This is extracted from LS1gto

You pretty much hit the nail on the head, but I feel there is a very important point to note.

THERE IS NO FREE LUNCH. When you gear a car down, you will accelerate harder in each gear, but you will shift out of each gear quicker. Here is a scenario assuming 6800 RPM shifts.

3.91's: You start at 35 mph in 2nd gear. You have the advantage until you need to shift. You shift out of 2nd at 63 mph. The guy with 3.46's shifts out of 2nd at 71 mph. You will get destroyed in this time period.

So, only at 71 mph do you have the advantage again. You maintain this advantage to 91 mph where you shift to 4th. The guy with 3.46's can stay in 3rd until 104 mph. Only then do you get the advantage back. Until you shift out of 4th at 131 mph. The guy with 3.46's can stay in 4th till 148 mph.

3.91's have the advantage, 35-63, 71-93, 104-131
3.46's have the advantage, 63-71, 93-104, 131-148

Now it appears the 3.91's have a greater advantage due to it dominating more of the mph range. However, 3.91's will only offer a 13% gain when it is in the lead. 3.46's will offer a 28% gain while still in 2nd gear (and the 3.91's are in 3rd), and a 26% advantage when in 3rd gear (and 3.91's are in 4th), and a 5% advantage in 4th gear (when 3.91's are in 5th)

For the most part, the cars will average the same distance traveled per time. NO FREE LUNCH. But they will trade leads over the race and whoever is in the lead at the specified 'end' will win. This explains why 3.91's can increase your performance at the track even though you gain no extra power. You get to use more of 4th gear than the guy with 3.46's.

Racing to 155 mph, the 3.91's will be the perfect gear because 5th gear will end right at 155 mph. The guy with 3.46's will have just gotten to 5th.

Mathmatically proven FACT here, not 2 buddys racing on different days:

The 3:91 geared car will gain exactly 3.123456789 lengths by 155 MPH
vs the 3:46 geared car, if both cars are identicle with the exception of gears.

And more knowledge:

Okay, I also have to say, would everyone just stop talking about how 3.91's will hurt your top end. Top end in 6th with 3.46's is ~259 mph. Unless you have ~1225 hp (rwhp required to attain 259 mph @6800 RPM), you are not going to notice a loss of top speed with going with 3.91's. Actually, the 3.91's WILL INCREASE TOP SPEED.

They do this by applying more wheel torque in 6th gear than 3.46's would.

HioSSilver

iTrader: (8)

3.73's are awesome for a full bolt-on car. A buddy has those in his m6 bolt-on car. His car went 11.9@116 w/o headers. 3.90's would be maximum gear you could use.....unless your car is really heavy.