first outing with the 3500!

[1QUICKHATCH]

Well I now have a 3500 in the car due to a head gasket going on the 3400 only a month after I did the LIM gaskets.

The 3500 is the one out of my old Alero, it has ported heads, 3400 head gaskets, ported rear exhaust manifold from the 3400, LIM gasket matched at the heads, stock 2000+ plenum, 56mm TB, 97 3100 injectors on a 2000+ fuel rail/regulator and yes still on a stock 3.1mpfi tune!

The track sucked, little to no prep, 100% humidity, 12-13*c, 30km/h head wind! the 3500 pulls harder down low compared to the 3400 resulting in worse 60 ft's than last time. barely ran a new best of 15.609 @89.80mph. Ran lots of 15.7 and 15.6's.


slip:
rt ... .295
60' ... 2.375
330... 6.557
1/8... 10.080
mph...70.40
1000...13.082
1/4...15.609
mph...89.80

Going to go back next friday as long as the weather is good, with the 65mm TB installed and possibly 2.5" cat back. The 56mm TB, 2" exhaust and tune are really holding this thing back!

here is an in car vid from the track of one of the slower runs! You can see how bad the car floats in the top end! (needs sturts bad!)

http://www.youtube.com/watch?v=JUn8rcdEft4

[RobertISaar]

The 56mm TB, 2" exhaust and tune are really holding this thing back!

IIRC, your trans is also a contributing factor.

[19Cutlass94]

Those are the times I was running with my 3400 running on the stock 3100PCM.

[BXX]

Thats actually aboot spot on to the best time on my old 96 CS (largeport 3100 LIM/UIM 56mm TB, CAI, Tune, 2.5 full exhaust)

Unfortunately I averaged 16.5 due to my RR caliper deciding it wanted to seize up

[1QUICKHATCH]

Those are the times I was running with my 3400 running on the stock 3100PCM.

what all did you have done on your 3400?

Yes Robert the trans is a problem too! right now with the shorter tire i am hitting the rev limiter in 2nd going through the traps depending on when I shift in to 2nd. I did a quick port job on a 00+ plenum yesterday and opened it up for the 65mm TB, so it will be installed before i go back on friday night. Didn't get a chance to do the exhaust because I had to work this weekend, but I may just wait untill I get the headers on then do the full exhaust.

don't know how far I am going to go with the car, I have too many other projects on the go right now, but its providing some fun untill I get my Cutlass on the road again!

what is every one else running for transmissions? I am thinking of going with a 4t65e and OBD II swap now that I have HP Tuners!

[xtremerevolution]

Wow, I expected a little better than that. I'm guessing with better conditions and some track prep, you'd do better.

Hell, even the Regal on the stock Series 1 3800 L27 pulled a 16.1 with much smaller tires than factory (215/45/17) and nothing but intake and exhaust with 80% humidity. Something definitely sounds a bit wrong there.

[RobertISaar]

3.1 tune on a 3500 is horrible.... goes WAY lean up top, especially when combined with the ~19.8lb/hr injectors he's running.

[xtremerevolution]

3.1 tune on a 3500 is horrible.... goes WAY lean up top, especially when combined with the ~19.8lb/hr injectors he's running.

That would do it! Get that car running properly and go back out there!

Thank God you don't have a turbo...

[RobertISaar]

i believe the TH125 is still in? with the crappy FDR as well?

the fact that the 3500 heads are ported makes it even worse.... even more airflow than the ECM is expecting.... the only thing saving this from a spectacular detonation related death is because the 3.1/3 speed tunes don't run as much advance at WOT as a 3500 likes for max power.

[xtremerevolution]

i believe the TH125 is still in? with the crappy FDR as well?

the fact that the 3500 heads are ported makes it even worse.... even more airflow than the ECM is expecting.... the only thing saving this from a spectacular detonation related death is because the 3.1/3 speed tunes don't run as much advance at WOT as a 3500 likes for max power.

A tune is definitely in order. Hell, I wouldn't even give that car WOT till I tuned it.

[1QUICKHATCH]

3.1 tune on a 3500 is horrible.... goes WAY lean up top, especially when combined with the ~19.8lb/hr injectors he's running.

do you think it would work any better/safer with 3.4 dohc injectors on a pre 99 rail/reg. w/the 65mm TB, still on the 3.1 tune?

[RobertISaar]

at least with the LQ1 injectors(at 43.5PSI), you'll be at 21 lb/hr, which is still significantly lower than stock 3500 injectors(24lb/hr).

if you threw the 55PSI regulator on with the LQ1 injectors, you'll bump up to ~23.6.

still doesn't correct for the fact that the ECM is expecting a much smaller airflow than in reality, but at least you wouldn't run into 100% injector duty cycle as quickly. i don't suppose you're watching any of this with a wideband?

[jman093]

LQ1 injectors are dual pattern injectors anyways. You wouldn't even be shooting the fuel at the intake valve in an OHV engine. You'd be shooting it around it, letting it pool up in drops and then getting sucked in the chamber. Kind of like my LQ1 is doing right now with the single pattern L32 injectors.

Rob, If he is still running the MPFI PCM, would he really need bigger injectors since they are pulsed twice per every power stroke instead of just once? I imagine you could get quite a bit more capacity out of them with a tune increasing the pulse width for each pulse.

Honestly I don't understand the reason for running the inferior 3100 manifolds on ported 3500 heads and the old-school batch fire injection meant for a completely different engine. It has to be making less horsepower than a stock 3500. 211hp in a 92 Lumina is going to go faster than 15.6

[RobertISaar]

it probably IS making less HP than stock due to leaning WAY out at higher RPM(and 3500s LOVE them some extra rich AFRs).

with MPFI, it basically does all of the calcs a SFI PCM does, then cuts the BPW in half and instead of shooting all of the fuel for 1 4-cycle event at once, it shoots half every 3 reference pulses(1 revolution). if the duty gets high enough(100%), the injectors will never actually close and will be delivering their full rating of fuel. that's "double-fire" mode, there is a single-fire mode as well that acts like SFI in that it delivers all of the fuel at once(just not sequentially), but it is not enabled in stock tunes until you get the BPW under ~.9mSec.

17.4 lb/hr injectors are 17.4 lb/hr injectors no matter what the firing scheme.

[1QUICKHATCH]

LQ1 injectors are dual pattern injectors anyways. You wouldn't even be shooting the fuel at the intake valve in an OHV engine. You'd be shooting it around it, letting it pool up in drops and then getting sucked in the chamber. Kind of like my LQ1 is doing right now with the single pattern L32 injectors.

Rob, If he is still running the MPFI PCM, would he really need bigger injectors since they are pulsed twice per every power stroke instead of just once? I imagine you could get quite a bit more capacity out of them with a tune increasing the pulse width for each pulse.

Honestly I don't understand the reason for running the inferior 3100 manifolds on ported 3500 heads and the old-school batch fire injection meant for a completely different engine. It has to be making less horsepower than a stock 3500. 211hp in a 92 Lumina is going to go faster than 15.6

I am running a 3500 van front manifold and a ported 3400 rear manifold (header style) from a Grand am with a 2.5" down pipe off the manifold to the cat then 2" from the cat back to the 2.5" flowmaster. the 3400 TB on it is also smaller than a stock 3500 TB (stock is 65mm IIRC).

not going to be able to make it back to the track this friday night, I had some other stuff come up that I have to take care of first, and I would like some more bugs out of it first.

it will go faster but not this week, might not be untill september. depends on how much I work on it.

Robert, no wide band yet its on the shopping list! any that you recomend? I was looking at the one from 14point7.com...? just want to have something that works with hptuners so that I can use it on more than one car.