VTC_WS6

iTrader: (9)

First of all, the information here is a god-sent, I can't thank you guys enough for putting together such a well rounded tech-based site for LS1/F-bodies! I'm a realative new owner to F-bodys myself having just purchased a 2000 T/A WS6 M6 about a month ago.

Now to F-bodys I'm new, but to the world of cars I'm not. I'm certainly no mechanical engineer by trade, but I've got a very solid fundamental knowledge of cars and how things work. That being said, ever since I bought my car and I shared it with friends on a local S. Fla board, there's been this one particualr LS1 owner who'se been ragging on me at every chance. I guess it hurts his pride that he's not the only LS1 owner on this particular board or what, whatever the case is this kid's been nothing but a tool for no reason, but he brought up this interesting argument with regards to gears.

I noted a recent race I lost to a turbocharged Civic. The particulars of the race were that it was a 40mph/2nd gear roll, at the 3rd honk when we hit it, the Civic would instantaneously pull a good 1/2 car or so and hold it there. At the top of 3rd and 4th (race ended for me at around 5k in 4th with me creeping up) I'd crawl back up on him, so I noted that perhaps if I had a nice set of 4:10's outback, that might have helped my cause some since the rate of acceleration would naturally have been a little steeper with a shorter FD. We all know that a rear is nothing more than a gear-driven mechanical torque multiplier, so all things equal, the shorter the gear the more rapid the rate of acceleration provided you maintain traction (I know there's a little more involved in it with tire size, gear ratios and redline/powerband, trying to keep this as simple as possible). Bottom line, he's telling me "gears are worthless from a roll". I just can't see how that is so. Whether your in first at 10mph, or 6th at 140mph, the steeper gear out back is functioning the same way, providing a larger multiplication factor to the rear wheels.

So, is there any valid point to his argument, or am I reading this the wrong way? Your imput as always is greatly appriciated, thanks guys!

SSCamaro99_3

iTrader: (1)

It depends on how fast you want to go. 4.10's will give you a gearing advantage until 117 (stock F-body) higher geared cars. The gearing avantage is lost when you have to shift to 5th, while other cars remain in 4th. You regain a gearing advantage when they shift to 5th or OD.

As an example, I ran a auto/stalled car from a roll. Power is very similar. I have 4.10's and he as 3.42's. Both are on stock rev limiters. I had a gearing advantage, and pulled on him up to 117 or so. I shifted to 5th (0.74) while he was in D (1.00), and we held steady. He had a gearing advantage overall of 3.42 to 3.03 (4.10x0.74) up until his car would have hifted to OD (0.7) at about 135. 3.42x0.7=2.39 to my 3.03, as I can hold 5th until 156. I added this because the cars are very similar. He runs a larger cam, and I have less drivetrain loss.

VTC_WS6

iTrader: (9)

Yea see that I understand completley. In this case, I guess the comparison would be for a pair of relativley stock ones like mine (lid & catback). The way I see it, unless you're making a groutesque amount of power (i.e. 7-8-900whp+), the shorter FD will net an advantage in the rate of acceleration. Of course the 4:10 car will also run out of gear quicker, but the advantage is had each time the 3:42 car throws the next gear.

We've been dealing with this in the Honda world forever. Guys have jumped on the "use the LS transmission, taller gears are better" for ages but it's been proven time and time again, the shorter the gears, the quicker you will accel. (1/4 based, for highway racing i.e. 60-80mph rolls, the LS trans might actually be at a slight advantage), the biggest factor there is traction.

Ragtop 99

iTrader: (7)

Traction is the key. If you have 4.10s and you spin in 2nd then the advantage is lost. SS makes a very good point. If you can limit the top speed of your race to rev limited 4th gear, then 4.10s help. If you race to 130 mph, going to 4.10s may not not help.

SSCamaro99_3

iTrader: (1)

He was a 3.42 auto car. His gearing advantage was 0.39 overall. Between my shift to 5th at 117, and 130 he didn't really pull up on me, but things were even. I started at his rear tire at 50 mph. Through third (I thought about grabbing second) and fourth I pulled from his rear tire to him being at the back edge of my door. He held steady there from 117-130. He woud have shifted to OD at 136 or so, and I should have pulled away again. I ran the scenario with me having a 3.90 gear set, and the difference wasn't huge. I would gain some room in 4th, but have less mechanical advantage in 5th. Tradeoffs. I like the 4.10's. I am not over 117 mph as mush as I am below it. They are a fun gear set.

VTC_WS6

iTrader: (9)

Yea I'm definatley looking to step up to some 4:10's in a bit after I get the car where I want it (minus the cam), seems like alot of fun!

GT Griller

iTrader: (8)

When i used to race from a roll i was still in 1st at 40 i didn't hit 2nd till about 50 thats with 3.23's, i know that crusing 40 in second i was only revving like 2500 rpms. I think u were in the wrong gear.

Tranzor

gearing would definitely help from a roll... car felt so much quicker once I added 4.10 gears, which was one of my first mods I ever did.

If running out of RPM is a concern for you, all you have to do is add a nice cam with a higher power band and some bolt-ons to help it breathe.

With my wheel/tire combo on the street (OEM Z06 wheels, 295/35/18 out back), I don't run out of RPM in 4th gear until about 130 mph. This is because my rev limiter is set at 6900 with my setup... needless to say I'm not worried about losing many races from a roll.

SSCamaro99_3

iTrader: (1)

If you are talking to me, my car is an M6. My buddy had the A4.

GT Griller

iTrader: (8)

Na i was talking about the vtc_ws6 guy. I didn't see him specify M6 or A4.

SSCamaro99_3

iTrader: (1)

VTC_WS6

iTrader: (9)

M6 / 3:42's