Apologies from Hardhead (me) re: 4.08 gears in my Q

[HeavyDuty]

After a 240 mile round trip to Jacksonville, turning 2500 rpm @ 80 mph, I think I'll keep my 3.5x rear gearing. My tech said he liked what it came with, Q45Tech posted about not being able to run through the traps at the top of 3rd (although not all encounters are exactly 1320 feet) but I was hell bent for more streetlight>streetlight acceleration.

I'm rethinking that now trying to decide if 3.8x would be worth the trade off either. At this time I think I'll wait until my JWT ECU & TCU arrives (hopefully by this time next year, I sent them the boxes in like..........October....... :rolleyes ......) to see what it will do for me before upping the gear.

[elwesso]

Im not sure I would do it..... In the 1/4 mile, it makes your 60' speed better, but with the stock gears you can make it through in 2nd.... With the 4.08, you have to shift into 3rd.... So in essence it makes your 1/4 mile slightly slower.....

[sultan]

it adds a shift to the quarter but the car should accelerate faster.

assuming this excel gear speed calculator i have is accurate, the 4.083 with stock height tires would put you almost up to 3000 rpm at 80mph. what really stinks is 5th gear on the Z32 manual transmission is .752 compared to 4th gear on the stock auto with is .694. if a manual transmission swap was feasible, you would be running about 250rpm higher at 80mph than with the stock transmission. coupled with the 4.083 rear end it would accelerate great, but on the highway it would really suck for cruising and gas mileage.

[HeavyDuty]

Sorry, I meant top of *second*, not third, but like I said, not all confrontations are 1/4 mile long. Hell, I haven't been able to get to the track in *for-e-ver*, that sucks.

If I were to install a GearVendors.com under/overdrive, then "bring it on". Then that same 80mph 3000 rpm would be 2160.

Gas mileage is one thing, beating the heck out of the engine is what I'd like to avoid.

Even the 3.8 would raise cruise rpm to 2,700 & change.

[maxnix]

I am in the same camp. I don't do 1/4 mile drag races, and I seldom accelerate at WOT from 0-60 mph and then cruise.

What I do often is pass daydreamers and left lane bandits on the highway in the 60-90 mph range, and I wouldn't alter a thing about the gearing for that performance. To me, a 4.08 only makes sense if a five speed were available, and all the attendant ECU and TCU and shiftgate changes. Probably not going to happen.

[PalmerWMD]

I prefer my 4.08 and dont mind the extra revving on teh hiway one bit.On uphills I would always stress about downshifting or not, to prevent lugging and keep the ATF flow up, and now I just dont worry about it.

theoretically I could get some extra ring wear but since this all occurs at fully lubroicated warmed -up situation I am pretty sure that extra ring wear is aloe to nil.I suspect bearing wear will actually be less due to less lugging and teh extra ATF flow wont hurt either.

On hiway I can still get 22 mpg at moderate (75mph) speeds and 18 to 19 mpg at high speeds ( 85-100mph most of the way).

In town I now dont worry about keeping it in "3" but just set it to "D" all day and leave it.

I feel drivability has actually improved.

Fred..

[nuQ]

can only hope the new KS's will improve my mileage!!! over 20mpg seems impossible, now!!! just did around 120 highway miles (mostly on cruise at 70 mph). and 30 "spirited" miles (a few WOT takeoffs). just under 16 mpg. my throttle body is so clean you could eat off it, and with a flashlight could see that the plenum wasn't all that bad. i'll be doing a plenum job with new KS's and O2 sensors, hope this improves things!!!!

[PalmerWMD]

Actually I have been seeijng my in town winter milage drop to 11 mpg.

but thats due to my car neervr getting warm anyone and alwasy running in warmup mode.

Once a weeek I make sure the engine gets <warm> so I can get rid of the water and fuel, that accumulate in my oil during the week.

Fred...

[elwesso]

can only hope the new KS's will improve my mileage!!! over 20mpg seems impossible, now!!! just did around 120 highway miles (mostly on cruise at 70 mph). and 30 "spirited" miles (a few WOT takeoffs). just under 16 mpg. my throttle body is so clean you could eat off it, and with a flashlight could see that the plenum wasn't all that bad. i'll be doing a plenum job with new KS's and O2 sensors, hope this improves things!!!!

No doubt... I hope it even gets me up to 3mpg better.... My goal is to get to 16mpg in the Q and not change my driving habits.....

With bad KS, ive found the car runs much better with midgrade, 89 octane..... Something to try.....

[nuQ]

wes, still on schedule for the plenum job, this week, right????jeff

[elwesso]

Yes... I will keep everyone updated with my day to day progress (mainly to help my writeup while its fresh on my mind)..... As of now it starts the 26th.... I have both memory cards for my camera empty.....