3.8redbird

iTrader: (3)

8.0 Airfuel ratio? what fuel were you using?

deion82

E85 fuel

jalper

iTrader: (9)

anymore pictures of the motor, also what intake was used, very nice job

wrp

At the end of the day those may not be the numbers you were looking for but they are very impressive and there are two significant things I can see. First the Roots blower looks to be very reliable and second the options you have for the bug catcher and so forth are very good. I have a 4 liter Whipple on a 408 and got 800/800 at 16 lbs of boost. Everything was a custom one off machined solution and the serpentine belts wouldn't hold so we had to build an entire cog drive for the unit. Not sure what you my be used to but I would venture that 600+ torque is going to be a hoot to drive. Great build. One thing I am working on is the AIT. We've relocated the heat exchanger reservoir to the trunk and we are using one that we can use dry ice in if necessary. Maybe there is something to be had there. Also, have you considered a 100 shot?

deion82

You make good points. It did make over 600 tq from 3,000 rpm on. I'm going to try a pull in the morning with the 15 lbs boost to see what it makes with the ait lower. Either way it will be fun to drive.

3.8redbird

iTrader: (3)

What was the ambient temp outside during the pulls?
How long were the pulls taking?

Still a sick looking setup and worst case I would throw it in a rat rod and be a badass

deion82

Ambient air temp was 90 degrees out side.

Pulls were about 15 seconds long.

deion82

Ok so what should i set the A/F ratio at and timing for a 15.5 psi pull?

I also have a 19psi setup i can put on. What recommendations for timing and A/F for that?

The 9lb pull produced the most hp and ait were not to bad and changes to the timing or A/F on that setup?

IKnowtheFuture

iTrader: (5)

e85 stoich is about 9.8, around 33% more fuel than gasohol. so try 7.5:1 and see if it gets any better. could always hook up egt probes if you have the cash flow.. or 14-71's are also cool, get one from a top fuel dragster. with the magnesium housing and all. only takes 900hp to turn them at there power level. prob less at yours lol

deion82

I actually have all injectors on top of the blower. An update i set the A/F ratio to 7.5. Went to make a pull and as soon as we put a load on the engine it started chug and went dead rich like 6.2A/F. So we stopped and let it idle and went up and down to let the ecu learn. Went to try another pull and the exact sae thing dead rich and started to surge, lug as soon as he pulled back on the throttle A/F came right back to where it should be. I'm guessing the stock coils just don't have enough to keep it lit under a rich, 15.5lbs pull. what's your thoughts on the coils? I'll be wiring up my holley DIS coils that came withthe kit and trying that in the next couple days.

wrp

I'm gonna guess if you study your logs you will see some knock at the higher AIT levels. We did a pull at 775/845 on pump[ gas with AFR 11.8 12 degrees of timing and 190+ IATs. We were at a consistent 21 lbs of boost though.

Fbodyjunkie06

iTrader: (10)

It's probably not the coils. Coils have been proven to 1500hp tons of times. I'd check simpler things like in the tune first before you go mechanical.

Check to see if it was pulling timing first. How much timing are you running under wot? or what are you commanding?

IKnowtheFuture

iTrader: (5)

try a different wideband o2 maybe? that one could be shot.. what do your STFT say?

rons 00z

iTrader: (10)

is the wideband being used calibrated for gas or ethanol? if it's gas that AFR should be in the 11's or they can just change the reading to stoich and get it around .75 instead of worrying about doing the conversions. does it not build anymore power at 15lbs with more timing? you should be making a **** load more power. for example on my stock ls1 with a 224/224 tsp cam at 15lbs and 12 deg. i made 600rwhp in my camaro. something isnt right

wrp

+1 I am betting knock is pulling timing due to the heat.

rons 00z

iTrader: (10)

he's using e-85, i havnt seen any cases of heat or knock ever being an issue. however i could be wrong.......if it is pulling timing from "knock" i wonder if it's the blower causing it from the harmonics.

Ws6kid.

holy cowwwwww

twinturbo496

iTrader: (2)

How did you determine the timing requirements? How do the spark plugs look?

deion82

Well I'd like thank everyone for all the advice. We had a successful night on the dyno. Dropping the boost to 9 psi and putting the Holley coils on. I tried to gap the plugs at .020 but kept blowing out cylinders. Talked with Holley and they said to gap at .030. First pull I made like 820hp @ 6,500 and 709ftlbs tq @ 5,100 rpm. So about 100 hp gain by plug gap and coils. I guess someone was correct that stock ls coils don't work with Holley system. At the end of the day with richening the engine and raising the timing I made a peak of 843hp @ 6,500 and still climbing but we stopped there and 749tq @5,200 rpm on 9 lbs of boost. The engine was still making tq with each timing change but just ran out of time. Overall I'm happy now. Thanks again for the help and advice.

3.8redbird

iTrader: (3)

Damn big gains and still only 9lbs. Let er eat