Gears... who has 1/4 mile times vs stock?

Mike_W

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I want to know if getting 3.55 gears will actually MAKE your car faster, or only make it feel faster. Anyone run the 1/4 with 3.07 and then run it with 3.55 - all else being the same?

Thanks,
Mike
 

Paul Hawker

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In my 96 GTS (Headers, K&N, Borla) my best time with stock rear was 12.1 at Pomona. With 3.54 I hit a best of 11.9. Other factors may apply, but that was my experience. Most drag racers will say it should not make a big difference, and some may disagree. The jury is still out. I would not buy the gear for drag racing, as it is not as strong as stock, and puts additional load on drive train, however for driving on the street, it transforms the car into a much better, and more exciting ride.
If you are ever in San Diego, give me a call, and I'll give you a ride in my SRT. You can decide for yourself.
 
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Mike_W

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Man, I am ALWAYS in S.D. Casa De Pica at Old Town. Best margaritas, and best food.

Mike
 

FE 065

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Selecting the right gear ratio is part of every serious racer's list of things to do.

I put a 3.73 in my '94 Viper and the difference on the street was tremendous.


I've got a 3.45 waiting to go into my FE. It's good for about 132mph @ 6000rpm with stock tires for example.

The 3.55s will allow about 128mph.
 

Chuck 98 RT/10

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Been following this debate for years. Like Paul said, the jury is still out. I recall only one case where somebody claimed actual before/after 1/4 times and the difference was .2. A reasonable gain but there just aren't many cases to substantiate it. Not talking SOTP feel here, I mean REAL numbers.
 

genXgts

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I've raced roll ons with the motor city madman in his near identical GTS to mine, several times, as well as dozens of 1/4 mile runs and we are within 5 hundredths of a second at the track and dead even on gear roll ons. I on 3.07 he on 3.45 I think it was. He went back to stock 3.07 and we just ran again on roll ons, no 1/4 miles yet this year and after 3 runs, from 2nd gear up to 4th we are dead even again.

Net result in our case gears did nothing, nadda, zilch.
Your mileage my vary!
 

SnakeEye

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I've found that on my SRT-10 the change to 3.55's was a great move. The car is much more responsive and potent on the street not to mention allowing for ~138mph 4th gear run at the strip. Obviously a stock SRT-10 won’t run that fast but it does provide for some headroom should a power adder be used later on. An addition benefit is 5th and 6th now have become usable gears on more than just the Autobahn. The stock 3.07 gears just felt lazy and put a killing on the clutch during any type of aggressive launch - I'm glad to be rid of them. One would think earlier Vipers might have similar findings.
 

joe117

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genxgts,
If you and your buddy have identical cars except he had 3.45 and you had 3.07,
and you both are in second gear for a roll on,

I don't see how the car with the 3.45 isn't going to pull away from the one with the 3.07.

Now, after you shift a few, and get well into 4th, the difference will be less obvious.

But like I said, from a roll, both cars in second gear, the car with the 3.45 will for sure pull away from the 3.07 while both cars are in second.
 

Saleen-Explorer

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I would think a 3.45 geared Viper would easily pull away from a stock 3.07? Especially with all the talk about how dramatic a gear change is on the Viper, how much more responsive and quick it is etc. I know with the older n/a dohc Cobras, going from the stock 3.27 to say a 4.10 or 4.30 gear was like a night and day difference.

In the 1/4 it would probably be close b/c of the extra gear shift.
 

genXgts

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I speakum no lies. :)

We run each other just about every time we go cruising, and can confidently say that the gear in his car did not affect acceleration at all, I'll shoot this thread to him and hopefully he'll chime in.

1/4 mile times did not change but as noted the extra bang into 4th would eat all of that up if the 3.07 car stayed in third.

After literally dozens of rollons in every gear, from a dig, every possible scenario, from 0 to over 130mph, the pre with 3.45 and post 3.07 (back to OEM) the difference in our cars was nil. And remains that way today, although we have not hit the 1/4 yet this year.

Just my experience but has sold me on leaving in OEM if your looking for measurable gains as opposed to seat of the pants.
 

FE 065

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Well, I hear ya, but the SOTP difference is so great, how could it not show up in roll ons or the strip is the question? I know passing other cars (for example) in my '94 Viper went from Clark Kent to Superman after switching to a 3.73. Did you guys ever switch cars when MCMM had his stiff gear? If so, I'm wondering if the SOTP felt stronger in his car for you when you drove it. ..Though I do remember some dirt bike experiences where a 500cc-600cc single 4 stroker didn't really side by side drag any faster after stiffening up the gear ratio a bit. :(
 

joe117

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The 3.45 has a mechanical advantage over the 3.07 that's a fact.
If you are both in second gear and you stay in second gear through the entire roll on, then the car with the 3.45 is giving more power to the wheels. That is a fact.

If you and your buddy do a roll on and stay in the same gear, there is no way the cars can accelerate the same unless one car has more power than the other. That is a fact.

If both cars had the same rear ratio and you did a roll on with one car in second and the other in third, the car in second would pull away up to the redline in second. That is a fact.

The only reason a stock Viper might not do better in a 1/4 mile with a 3.45 is because of the extra shift and perhaps traction limitations.
The 3.45 will give more power to the wheels from a standing start and all through the 1/4 mile.
That's not just SOTP, that is a fact.
 

Tom F&L GoR

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I think this graph illustrates the result. It calculates torque at each RPM from engine, through each gear of the transmission, through the two example rear end gears, and then the amount of thrust (where the tire meets the road and pushes the vehicle forward. At a dead start, the greater mechanical advantage helps acceleration (assuming there is sufficient traction.) Once rolling, it depends on where each car is in their powerband. A roll on from 45 mph to 100 mph should theoretically be a tie.

36thrust2.gif


Courtesy Western Washington / Pacific Northwest Chapter of VCA.
 

genXgts

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Once rolling, it depends on where each car is in their powerband. A roll on from 45 mph to 100 mph should theoretically be a tie.

But is that fact Tom?:)

I'll toss in it's a tie as well from 30-120, 50-120 and 70-120, I've done them all my OEM 3.07 gear to MCMM's 3.45, and then again my OEM 3.07 gear to MCMM's 3.07 gear. He went back to OEM from 3.45.

Neat chart, remember that the common gear swap is to a 3.45 which would be a mid point between those 2 plots plus or minus.
 

Black SRT

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Just bought a new 6-speed, 400 HP Cadillac CTS-V with 3.73 gears. This car is an absolute ball to drive on the street. However, took it the drags last Friday and couldn’t hook up in anything but 4th gear. Power-shifted to 2nd and never went below 5,000 rpm; same with a power-shift to 3rd and tires finally hooked up in 4th. Now imagine these gears in a torque monster like the Viper. If I only speed-shift the SRT-10 I still get lots of wheel spin and this was also true with my Gen II. If you go to lower gears on a Viper better plan on a good set of drag radials for track use. Street driving might be a bit more fun but tougher to keep the wheels on the pavement.
 

AG98RT10

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All I know is I drove a new SRT-10 and it felt sluggish compared to my RT with headers and breathing mods and 3.54s. No doubt the SRT would take over above 150, and probably on any road coarse (it handles much better), but for straight line acceleration in any given gear, there is no doubt the 3.54 gears put down more torque earlier.
I had to put Kumhos on the rear to even begin to use the available torque. Michelins just spin, which is scary in third.
If I bought a new SRT, I'd probably get 3.54s in it.
 
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