Circle Track 3.1L (Modded)

[communityracingchallenge]

Ok, i re read this and I still don't know what you ended up using or what tuning you have done for the mods.

Ben, true "performance mods" we didn't really do anything to the motor. We did put in a new intake manifold gasket. Mostly, we lighten the car.. got it down to 2790 lbs.. with driver its at 2950.. we have to add 50 lbs lead to get to minimum 3000 lbs for racing. We moved the RF strut in and back a little more, giving us a hair more caster and camber. We also replaced the struts all the way around.. that probably helped more then anything.

Whats interesting.. and perhaps it is just the difference between the years.. but we did nearly the exact same job on the 91 Grand Prix that we did on the 94 Grand Prix.. but the 91 is no where near as fast as the 94. Its about a 1.25 sec off the pace..

The Winter Time Project will be to actually install some of the performance mods, though I have to admit, I'm still confused as to what can and can not be done. There seems to be a lot of differing opinions as to what plentums, what heads, what valves can go where. Your first post in this thread had a ton of great information in it, but then later posts said don't do this, don't do that.. and we decided not to try something mid season which would set us back a race weekend or two.

Ben, your just down the road in Warsaw.. perhaps we should touch base and decide what we really want to do to this thing.

[SappySE107]

Ok, i re read this and I still don't know what you ended up using or what tuning you have done for the mods.

[ForcedFirebird]

Got the car back on the track with the mods described above and SHE'S A RUNNER !!! In a 4 car FWD-Only Dash with the SHO, an Intrepid (with a 3.3) and a LHS (with a 3.5 HO) the Grand Prix took the lead on the first lap and held off the SHO while having a 1/4 track on the two Dodges !!

Can't wait to finish my new motor!

[communityracingchallenge]

Got the car back on the track with the mods described above and SHE'S A RUNNER !!! In a 4 car FWD-Only Dash with the SHO, an Intrepid (with a 3.3) and a LHS (with a 3.5 HO) the Grand Prix took the lead on the first lap and held off the SHO while having a 1/4 track on the two Dodges !!

[communityracingchallenge]

some taurus SHO's are v8's, as well-keep that im mind.

Front Wheel Drive V8's are not allowed.. so no newer SHO's or Caddy's

[no_doz]

some taurus SHO's are v8's, as well-keep that im mind.

[FastZ34Lumina5]

Yes it did run rich. It did not run very good at an idel. but at 6000 RPMS it ran great. Wear can I send this video to??? I have it on DVD.

3.4 DOHC injectors in a 3.1 ECM without reprogramming will idle like shit and run pig rich. I want the video

[communityracingchallenge]

I got the motor pulled out today.. took a bit long then I expected.. that bottom motor mount was a bitch. Hidden behind that bracket, I would have never found it, thanks to a friend who knew it was back there.

Tomorrow we start pulling it apart.

Total shop time was 6 hours.

[SappySE107]

3.4 DOHC injectors in a 3.1 ECM without reprogramming will idle like shit and run pig rich. I want the video.

You aren't running 3500 heads on a stock 3.1 block so I guess that is ruled out.

Run 3.4 camaro head gaskets, 3400 cylinder heads and fuel rail and manifolds and TB.

[communityracingchallenge]

Good information guys.. though I think there is still some conflicting opinions on the 3500 and/or 3400 heads on the stock 3.1 block.

Dave - in Re to : First question, does it have to sound stock? Like if you pull up for Tech and it's idling like a 9 sec dragster would they let it pass? lol the answer is no, it doesn't have to sound stock. The rules say "stock appearing" which is plenty wiggle room for a pirate like myself. Some of the cars have their spark advance at 36* and they can barely idle.

The Mods I like the best are the ones that are mostly plug & play and don't require boring out the block, replacing the block, mounts, tranny.. things that aren't easily reversible if a tech inspector finally says enough. Chaning heads, intake manifolds, exhaust manifolds, porting out throttle bottles, intake/exhaust manifolds, valve jobs.. those are easier fixed and more tolerable.

And anything which increases compression is a big plus.. not a street car, doesn't have to idle well.. doesn't have to get good mileage, doesn't have to pass smog. My experience is racing fuel, high compression = cheap source of increased horse power.

[FastZ34Lumina5]

We used to have a 1991 Z24 cav with a 3.1 in it. And we raced on a 1/4 mile Dirt track. We ran a Under drive pully. Also we ran the 3.4 DOHC fule Injectors. In the 3.1 and at a higher RPM it ran better.We also by passed the AC IDK if it did much but it was less weight and one less pully to turn We ran the car right in first gear. It was a auto and we welded the gears to make it a posse and that helped alot. We ran for 10 lap heat race and 20 lap main event. it ran about 6000 RPMS.In first gear. It held together all year and we Dominated. I also have videos to prove this. That this 3.1 V6 ran at that rpm for that long and never had a problum.

[Superdave]

The valves will clear without doing anything. The combustion chamber is bigger than the bore thoug which was the issue.

A 1990 is OBD1 still. Don't just put bigger injectors in there.

i would use a crank scraper on your next motor setup.

Didn't you say on V6Z24 that a .040 bore on a 3.1 would clear the larger chamber?

[ForcedFirebird]

Hey circletrack, forced firebird waz up! Glad to see you two!

I've been here longer that *other site*, lol.

[Driver_10]

Hey circletrack, forced firebird waz up! Glad to see you two!

[SappySE107]

The valves will clear without doing anything. The combustion chamber is bigger than the bore thoug which was the issue.

A 1990 is OBD1 still. Don't just put bigger injectors in there.

i would use a crank scraper on your next motor setup.