Mr. Peabody

My beautiful 95 A4 is just that, thought with 37K on it, it only averages 17 in the comute and perhaps 19 on brisk cruse with my 3.07. I don't want to lose much more mileage but I would like an additional 50 ft/lb of torque from 1500 to 5000 for the street. What direction is cost effective (relatively speaking) on the basis that is strictly going to be a year round DD that will see an additional 15 a year for perhaps the next 10 yeas. thus reliability is important. I take good care of my cars and usually get 150 to 200K on them over the years but now looking for some toy to go along

I used the search engine to try and find the pros & cons of a cross tube installed after the cat. But didn't find much, perhaps I'm not expressing H-pipe properly. May consider Corsa exhaust if ever decide to change from stock. Would appreciate your advice.

Where does the cost effectiveness vs longevity meet on a roots type of blower setup taking into consideration I wouldn't be able to do something at that level myself.

Thanks
Mark

bogus

To start with, you will NOT get 50 ft lbs of torque without effecting mileage. HP and torque are tied together... increase one, the other goes up.

My suggestions:

LT4 Hot Cam kit
Dana 44 from a manual car, 3.45 rear gears
High-flow cats
long tube headers (this is not legal in CA, we can't relocate our cats, damnit)
Quality cat back (corsa is my fave)
2800 stall Torque Converter

That'll perk things up.

REDC4CORVETTE

Just install a set of 3.54 gears,that should do it.

reed62783

If its a dd i would leave your 3.07 in. You can gain close (not 50) to that just by doing exhaust and long tube headers. W/o that the best thing would be larger cam (hot cam kit is popular). You wont need a d44 in it for a dd, unless you want to go over 400hp and will use drag radials on it at the track.

redcorvettedave

I don't know about the torque increase .......but the butt increase can
be improve the next time you drive....the A4 in a 95vette is very response if you drive in "D" .. It pulls much harder in the lower gear with your electronic trannsmision.

The best thing to do is:
1. Shift kit
2. 2800 TC for launching
3. tranny cooler

with leaving the 3.07s in......lower gears are great but
the trade off would be traction and rev limit! PEACE

cv67

DD...50 ft lbs...Yep, stroker kit

tjwong

This would be the cheapest route and the best SOTP reward! Or you can spend big bux doing other performance mods. In the end you may want to anyways but gears are the best bang for the dollar. Also it depends on how "radical" you want to make your car. A LT4 Hot Cam or a 219 cam would be a good addition for Hp and Torq, provided you have a decent exhaust system to go with it. Going with much larger cams degrades street manners. A convertor would definitely help in this case with your 60 foot times which would translate to even great gains at the end of the track. All this matters only if you plan on occasionally racing the car.

Mr. Peabody

Thank you all for you advice & opinions.

To me it sounds like long tube headers & Corsa exhaust seem the most practicle road to start down.

I don't see myself changing the rear gear ratio from 3.07 as that will not really accomplish what I want. ie I'm not looking to get into the torque range quicker, I want more torque over the entire range without limiting my rpm at the top end.


Once again Thank you for your advice.

Mr. Peabody

Is this really true that the shift points are different from 1st to 2nd and then from 2nd to 3rd if you drive in "D" rather than in the overdrive position?

Even if the shift point was higher in the rpm range, how could it "pull harder"? Is the air/fuel mixture curve different thus producing a different torque curve?

Thanks,

Peabody

vader86

If you increase Tq then youre going to increase HP, and its easier for us to enumerate the latter.

Best thing is to add a higher stall TC, it'll feel like youve got more torque. Then install a cooler, to make it last a good long while (heat kills the 4L60/700r4).

Then if you want more, add gears.

Gar

If you want the car as a DD and want good gas mi. I would not make major changes. A motor is nothing but a pump. Make it breath better. I would go with a quality cat back exhaust system and if that doesn't satisfy you add headers. Put in a K&N air filter if you haven't done that yet. A good set of plug wires like MSD or Spira's will help a little with the mpg. I would bet your mpg would stay the same or get a little better BUT you won't get fifty more lb. of torque. Twenty five or so is more like it. Later if that's not enough for ya you can add heads and a cam. I would stick with the rear gears and stall speed ( these will both hurt you mpg) you have until you decide to do the head/cam work and then you will also have to get involved with computer tuning/editing. $$$$

Mr. Peabody

Understood sir, but I was always taught that it is torque that both moves and improves the rate of acceleration in a car not HP.

So rather than ask how to obtain more hp (which might be interpreted as how to add more HP at the top of the RPM curve) I was asking for ways to improve lower and mid-range torque which for the street is what I really want to accomplish

vader86

Its too difficult to do with the stock camshaft, and the design of the intake manifold on the LT1 to increase low/midrange.

You can certainly pick a cam that makes its best power at lower rpms, or add a supercharger to increase port velocity at low rpm, but with the LT1's intake your best bet is to just add gears and TC to get you into its powerband quicker, so it'll feel like you've got the power.

aboatguy

Most common engine performance modifications (i.e. heads, cam) move the torque curve up the rpm range (nitrous, and stroking are two exceptions). If what you want is, low-end grunt gears are a good option. However, if you change your gears you will have to reprogram the shift points in the computer (your tranny is controlled by the computer and the tables have the upshift/downshifts delineated by mph!). The good news is on your 95 you can calibrate the speedo and the transmition shift points easily via Tuner Cat or one of the other tuning programs. I installed a Dana 44 with 3.45s and it brought the low end to life on my 95. I would put them in again in a heartbeat however; I had the stock 2.59 rear.
Mike

Corvette Kid

Here's what I would do with your goals in mind. If you can use long tubes, go with Stainless Works 1 5/8" pipes. You will need to call them though and find out if they've FINALLY gotten the A4 fitment problems worked out. The Hotcam is hard to beat for a performance upgrade while still retainining good mileage and driveability. Might as well add 1.6 RRs and better springs while you're at it. Port match the intake and heads and do just a mild clean up port job on the heads but DON'T get carried away. Keep your 3.07 gears, you'll never regret it for a DD such as you intend to use it. Finally, a good dyno tune in the hands of a good tuner will optimize all of this. Eventually you may want to add a mild converter matched to your low end torque, probably 2200-2400 would be plenty for your purposes. I guarantee this will meet your goals and your mileage will not suffer if tuned properly. My engine is beyond what I've suggested here and it gets 1 more MPG on the highway than it did stock and is about the same around town. If I ever get around to replacing my 105K O2 sensors, I'm sure it'll improve more. Good luck and keep us posted.

Oh, I almost forgot, you asked about an H pipe. The LT4 system has this, it's the only difference between it and the LT1 system. Take temp readings of your system every couple of inches beyond the resonator. You'll find one area that will be significantly hotter than anywhere else. Put your crossover there.

redcorvettedave

Cost effective ..don't want to loose much MPG!..longevity etc.
you can't always have it both ways.....Modding the vette
cost $$$$$$$ and 90% of the time some reduce in mileage....

50 extra pounds of tq......is a reasonable goal but it will cost something
but for now get the most of what you have....the 95vette is a solid performer!!! Get good rear tires.....shift kit....TC.....tranny cooler
tune up .....learn to drive it launching and such...you will be satisfied
until you have the funds for LT headers and RR and whatever you want! Oh yea you dont' need exhaust unless you like the musclecar sound because the 95 vette stock exhaust flows good and a cat back
would not be cost effective!!!! PEACE!!!