blu98ta

iTrader: (4)

I just went down to the local 1/8 mile strip and ran my ta. With headers(and cats) and a programmer (and thats all for now) I ran a best of 8.865. I have 3.42's that I want to put in. What will the difference be in the 1/8 mile and what would be a good guess for the 1/4? I also noticed that my 1st gear (I have an automatic) was what was beating everyone(yea, I NEVER lost). I raced a pretty modded rx-7, a couple new stangs, and a couple souped up old stangs, and they could not find anything that could beat me. Good ole' GM proved itself again tonight. Anyways, If anyone can help with my questions that would be great. Also, does 2.099 sound like a good 60 ft. time?

mikemodano9c

going from 2.73's to 3.42's is a huge difference...trust me...do it

Colonel

With a stock converter, I agree. It will make a VERY nice difference. But with a 3500 stall or better and a high STR, I disagree. It won't matter much.

Colonel

"Also, does 2.099 sound like a good 60 ft. time?"

For a stock converter and 2.73s? Yeah, that's pretty good.

BuffJoeyD

iTrader: (2)

I did 8.9 1/8th with the 2.73s. I will hit the track soon with the 3.42s- and all I can say is I was hitting 9.0 in my bolt on v6 with 3.42s. Id bet the gear change will make a bigg diff for the v8 =)

nuzee

iTrader: (2)

Going from 2.73 to 3.42 I improved a solid .25 sec 1/4 mi ET (hi-13.2s to lo-13.0s). 60 ft times improved approx .1 better (hi-2.0s to hi-1.9s). This is all with stock converter. Around town driving is MUCH better w/snappy light-throttle response. My city mpg improved slightly too!

I did a computer simulation of the gear change with a hi-stall converter and the ET improvements diminish significantly. As said above, maybe 0 to .1 improvement depending on stall speed/str. Hope this helps your decision!

King James

iTrader: (13)

So are you saying to just stick with 2.73's and go with a big stall???

I did some "testing" on a back country road last night and my completely stock Z is shifting into 3rd right between 95-100 mph, probably completing the shift right around 100 mph. Now I'm only trapping 104 in the 1/4 so wouldn't 3.42's or 3.73's help me to actually be crossing the line closer to shifting to 4th vs. just shifting to 3rd.

Oh, and I'm thinking 3.73's or 3.42's and a TCI 3800 are in my future but I want to make sure I'm heading in the right direction.

nuzee

iTrader: (2)

King James
If you are on a budget and only concern is 1/4 times, then a big stall/STR w/2.73s seems to work well (computer simulation). I beleive this holds true in the real world too. I've read about some guys going 11s w/2.73s.

To me, a big stall w/2.73 would be too loose to drive around town. To make it more driveable, a high STR would be needed. I've read on Yank's site that lower STRs extend the torque multiplication over a wider rpm range vs. high STRs. So, using a very high STR will have some performance tradeoff.

So, IMHO it is best to do both gear change and TC if you want best street & strip performance. I guess it would be ok to just go with a big TC w/2.73s if all you were concerned about is strip performance on a budget. For solely street performance (no street racing) my vote goes to gears.

86 IROC

iTrader: (14)

Thank you for posting your results. I asked this question a few times and couldn't get a straight answer. What about trap speed? How much did it increase? I'd love to see a side by side comparison of your best slip w/ 2.73's vs. your best slip w/ 3.42's

Wicked_Hugger99

iTrader: (1)

On my 99 z A4 i ran 13.37@104.5mph w/ 2.05 60ft(hopefully line lok will help me heat em up better) on 275/40 BFG DRs 2.73s,2200 stall( local guy modified stock converter), shift kit, lid, ory, dynomouth, free mods. I switched to 3.42s,and added ported Tb, Slp maf, 160stat, and Speed Inc mail order tune and now it feels much quicker but Im goin to track 2morrow nite to see if it really is. Ill post times after. I hope its got a 12.9 in it.

Kent1

I would get the 3:73 gears best all around gear for town, country, and drag strip. Get a mid or radical convertor your choice. cheers......

nuzee

iTrader: (2)

86 IROC,
I dug out my log book & here are some times for each gear:

w/2.73s
1/11/03; 2.089; 8.652@83.51; 13.270@106.37
1/11/03; 2.129; 8.656@83.63; 13.275@106.19
5/24/03; 2.075; 8.656@84.40; 13.290@106.13

w/3.42s
8/30/03; 2.032; 8.395@84.73; 13.018@106.91
11/8/03; 1.961; 8.350@84.69; 12.984@106.64
11/8/03; 1.963; 8.349@84.57; 12.987@106.58

86 IROC

iTrader: (14)

Once again - you da man! Much appreciated. I've had the posi & gears for months, just now getting around to doing the swap in a week or two.