What mod would best help the 3.1 in improving performace. I was thinking headers ? My brother has a LG4 and he does nothing but tell me how my 3.1 will never have any ***** like the LG4. So i promised myself that one day my itty bitty 3.1 will stomp his car into the ground. I know its possible. I have around 400, what mod will give me the greatest gain

 

1)Take off the smog pump (less drag on the motor- free mod if you can do away with it without having the need for smog inspections).
2) ASP crank pulley only. (Again, less drag on the motor turning the accesories. Do NOT use the alt reduction pulley, you'll have charging problems at idle) aprox $50
3)Change the original catalytic convertor to a modern unit. Any modern unit is a "high flow" unit conpared to that 20 year old original dinosaur. aprox $75
4) A decent cat-back exhuast system like a Dynomax sells for under $200

You will notice a difference in aceleration with these. Not a lot, but it is the most bang for the buck you are going to get out of a 3.1 60* V6- trust me.

After that if you are feeling mechanically inclined and have a few more dollars to spend in the near future, the very next thing I will strongly recommend is some CompCams 1.52 roller tip rockers. They WILL work with your stock valve springs. The factory stamped steel rockers claim to be 1.5's but actually range from 1.42-1.49 range and are not roller. The extra lift AND the roller aspect will help the motor rev slightly quicker AND will give slightly more power, cooler valve train temps, and better gas milage. You will be able to rev the motor into a slightly higher powerband thus resulting in more usable power.

 

if you could do your own work there is a slew you can do for 400.


cam and rockers, drop the smog and a/c and p/s, open the air box, tb bypass, drop the muffler for a glasspack. and if cash is still permiting build a cold-air and boost the coil


oh and almost forgot to say port the heads and intake

 

first thing to do is, TomP's tune up. do a search and read through the whole thing. thats where you will be the best off. that way, anything else you do after that, you will get the most gains out of it.

 

If your looking for some good ways to improve performance and dont wanna spend over $180 then all the mods in my signature were under that much.

 

If it were me....

Headers + Catback
5 Speed swap

Nothing will make a difference like those 2 things.

Matter of fact, in good tune, a stock 3.1/T5 will outrun a L03 auto

 

Also, find a 86-89 TPI intake style air induction system - it's the best you'll find. Might even modify it, so that you use smooth tubing in place of the flex tube stuff.

 

Ive already done that and used 3" PVC pipe to connect the intake and the engine

 

How hard is a auto to T5 swap ?

 

the t-5 swap is gonna take you more then a weekend thats forsure, but if you know how to work on cars it can be done

 

Ok I'm totally stupid....
where is the smog pump?
I have a 1990 Firebird.. v6 3.1

 

Lower passanger side corner of the motor.

T5 swap = a weekender, if you have all the parts. It is well worth it, IMHO.

 

So when you delete the smog pump, do you just take the belt off it? Do I need to disconnect anything more? If so does the short belt you'd use for instance bypassign your AC, would that belt work? Cause I haven't touched my smog pump and every lil mod and service job I've done on my car I learned from here.


Any assitance is greatly apprciated

 

oh and I didn't mean to jack your thread brother.
Sorry

 

Take if off, Buy a smog pump delete pulley and bolt it on there. Use the same belt and route it.

 

yeah but then you still have a pulley.........take it off and play with belt size.

 

or take it off, and get a 90.5" belt (I believe is what I got, lol!)

 

ok then that works too...lol.

Iwant to change mine to a serp belt......but the question is routeing on a change over like that.

 

Ok I bought a 915 belt size, It went on rather smooth. I did notice a slight increase in hp and performace. However what I'm really happy about is the sound of my exhaust is a lil different. Sounds a lil more deep and mellow. So could anyone explain to me by taking out the smog pump what excatly I've done? lol


Oh and camarors8992, the guy who started this thread, delete your smog pump, you'll be happy with the results.

 

my car will be a daily driver, we have friends here that can just hand us our inspection stickers so inspections wouldn't be a problem. How long did it take you to do it ? How much was the belt ? How difficult was it ? Where did you get the delete pully?

 

basically the bnest way to explain how a smog pump works is like blowing air on a fire. You increase the heat intensity. The smog pump blows raw air into the exhaust gasses flowing into the catalytic convertor and heat them up more, thus burning up more emissions. In '87, the 2.8's burned clewan enough for that years requirements that GM never installed a smog pump on the '87 2.8l mpfi automatics.

The pump is turned by the crankshaft via the serpetine belt. This robs HP and makes you have to lay on the throttle harder to go the same amount as you would without the extra strain of turning the pump- federal gimmicks- just like the oxygenated gasoline crap we deal with here in Calif. It burns cleaner per gallon, but you need more gallons to go the same distance so ultimately you are using more fuel and creating more polution- political BS and a money game.

 

Save another $150, call summit, order NOS-05131NOS for $549.95. Spend a day installing it per the instructions. Jet for 100hp if you want it to last forever, 125hp if you want to go fast and you don't mind potentially fragging the engine. I'm confident 150hp would hold, but I haven't tried it yet.

On a completely stock 3.1 it'll go from 17.1 1/4 mile times to 14.0, 13.9, etc.

Then forget about picking on LG4's, go straight for the LS1's, 5.0 Mustangs, Corvettes, etc. The 3.1 with nitrous still doesn't spin off the line like a V8. It's fun to take a sub-thousand dollar junk V6 Fbody and walk on a far superior car.

Of course this assumes that the tires are fair, suspension is all there and not falling apart, and the engine isn't already knocking.

 

Can a 100 shot really shave 3 seconds off of stock time slip. I'm not doubing you but that seems a little far fetched. If it can, than all the better, and I'll be ahead of the game with the headers and exhuast combo.

 

Stock the car Gteched consistent 16.8's-17.0's, on the same stretch of road with two adult passengers, and a huge air bubble in the nitrous line (I play the 3.1L on the cheap side, no purge setup) it gteched 14.6. When hauling *** like no other the air bubble is about like hitting a brick wall, it seemed like something had let go, I'm sure it added at least a second to the time.

In addition to the numbers (in case you dont' have any faith in the Gtech) the car also eviscerated a 93 Mustang GT 5spd. I felt kinda bad since we stalked the poor thing for 5 miles in the multi-color bird till we got side by side at a stoplight.

At any rate, its a huge difference. My 3.1L was/is my winter beater and daily driver. I've got 2 L98's, and a TPI 355 that should be pushing 400hp, guarenteed the 3.1L on the spray is faster, and with less tire spin too.