SonofaBish

iTrader: (5)

We found the problem with my fuel system to be that one of the fuel pumps was dead! So, just as a temporary crutch, to make sure that indeed, that was the only issue at this point, my buddy but a 190lb Subaru pump in place of the dead 255lb Walboro and went to work...

On 15lbs of boost, we made one pull to 4500 rpms, and the car made 712rwhp/769rwtq.... however, we had to cut the run off at that rpm b/c we were running out of fuel... when the other 255 gets in there, it will easily be able to support this boost level... We're guessing that, if let run to redline, the HP number would have been in the area of 780rwhp... So, we pulled back the boost and tuned went for my goal..

On 13lbs of boost, and ONLY 13* of WOT timing, the car made 692rwhp and 702rwtq... The jump in the graph is where the dyno lost the tach signal...



However, as awesome as this is, the victory is quite BITTERSWEET... on the way home, i spent most of the 1.5hr ride on the phone, excited about finally having my baby back, and about how rediculous and insane the car was to drive around the street... got to the parkway, gave it one hit, and bam... bad news.... i'm not 100% sure yet, but i believe its the head gaskets... my buddy asked me if the ARP head studs were retorqued after a couple heat cycles and i know they werent... he said he's guessing that's the issue. I used GM MLS head gaskets... what we're thinking, is that b/c the studs werent retorqued, it eventually lifted the heads under boost, and the coolant going into the exhaust is what made the wideband read lean when i felt the hitch... definitely white smoke pouring outta the damn car tho, and the overflow resevior is about full... The 1 thing that i do feel good about is that when taking the oil fill cap off, there's really no blowby, so i feel pretty confident that the engine is fine....
Once we have good head gaskets and the second walboro fuel pump in there, she'll easily make 800/800 to the wheels... then again, i may opt for bigger injectors, and then THE SKY'S THE LIMIT!!! However, its probably done for the year now, with winter quickly approaching...

SonofaBish

iTrader: (5)

Any suggestions on the situation are welcomed... Just FYI, The heads are a set of ported and polished 5.3 heads... but i went with Mahle -16cc dish pistons to pull the CR down to 9:1

Also, A/F was consistently b/w 11.8 and 12 ... when we go the car on the street, she was making about 1/2lb more boost than on the dyno, so we immediately turned the boost controller down to get it back to where it was on the dyno

MIGHTYMOUSE

iTrader: (59)

did you bother putting good fuel in it or methanol spray at least?

its going to be leaner on the street than on the dyno

I don't think its the retorque that got you

SonofaBish

iTrader: (5)

No, the point of this build was to be a street machine... run only 93 pump gas....

not spraying meth....that's in my future plans for it...

when we were on teh street, taking some logs and making sure that the A/F was fine, he told me that the A/F was staying fine... i was driving, not paying attention to the guage... but the tuner told me that it was fine... .

SonofaBish

iTrader: (5)

what do you think was the cause for it lifting the heads?

like i said earlier, i'd like to feel pretty confident that nothing happened to the motor, and that its just a head gasket issue... there doesnt seem to be any blowby coming out of the oil filler cap, and the car still runs/idles fine and dandy - i would expect it to not run so great if i blew the rings out of it or something... maybe i'm wrong tho

hellbents10

iTrader: (10)

Detonation on pump is what caused the heads to lift.

Inspector12

iTrader: (29)

I agree with MM in that I don't think a car with 13* of timming and only 13lbs of boost would be a cause of you blowing a head gasket, but not going to say what it is cause there is no telling without looking at it etc.. Good luck very nice results I'll keep my fingers crossed for you on hoping nothing is hurt on your motor.

SonofaBish

iTrader: (5)

I don't know for sure, obviously, but we logged, and there was no knock whatsoever on the dyno or on the street... wouldnt the knock sensors pick up detonation?

Quik

iTrader: (7)

wow bish isnt what stated what i said...

Quik

iTrader: (7)

damm bish i guess i knew what i was talking about..thts exactly what i was saying



dont forget ppl that where he dynoed it was inside a warm building. last night the outside temps were in the 40s. that would be a good 20* or so cooler then on the dyno. and we all knwo cooler air leans a motor out. so with a 12.0 A/F in a 70* building then go to a 4X* temp and running even leaner at same boost levels youll pop gaskets like a 15yr old with zits

LASTLS1

iTrader: (7)

Detonation got you. Trust me I'm the "blown head gasket king"! remember one thing about 93 octane, YOU NEVER KNOW WHAT YOUR GOING TO GET! Your octane can range from 85-93 octane and alcohol contnet from 10%-30%. I fI were ever going to build a "pump gas" car I would buy the most crappy fuel I could find (87 octane from citco) and tune it on that. This way when you get a bad batch of fuel from a good station you won't hurt your head gaskets or worse. Btw, I've never heard of retorqueing mls gaskets?

LASTLS1

iTrader: (7)

The computer should read and compensate for that.

Quik

iTrader: (7)

it can only detech and pull a certain amount of timing out if the tuner set them up that way. but in how fast a spike happens there is no way a knock sensor is going to save the motor from shitting on itself. chalk this up to the tuner making the car to lean

Quik

iTrader: (7)

neither have I on hte head gaskets. his tuner is a big import guy, not sure on his experience with other types of boosted appicaitons

SonofaBish

iTrader: (5)

I'm not pointing the finger anywhere... just praying that its just the head gasket and that the motor is fine....

even if it were the tune, that can be adjusted and new head gaskets can go in... as long as the motor is fine, then i will feel much better

Quik

iTrader: (7)

well get a compression checker and see what cylinder popped. if #7 is low then its just a good chance that the motor is fine. If alot of them are low then you might possibly have motor issues.

bish its great making big numbers and allows for small *****'s to grow larger but on street back it down some to be safe. the traction difference at 7xx and 5xx is about the same on cool roads. get it fixed, turn it down then turn it up on the track. let car live long

SonofaBish

iTrader: (5)

well, my tuner posted up on the local forum that he took a look at the dyno pulls and i was apparently mistaken. The A/F's were in the 11.4-11.7 range....

I guess we'll just have to tear into and see what the problem was... i'm beginning to fear its more issues with the fuel pumps... but those are replaceable... as long as the longblock is fine, i'll be relieved

But then again, it could be what Quik accused me of on the local board - maybe i turned the boost way up after i left the tuner's with hopes that i would blow up the engine, then having something else to bitch about to the builder of the engine.... lol... what a joke

Zombie

iTrader: (2)

Negative, you are out of maf and runing open loop. Computer can't compensate, it just goes off of the PE table.

*edit* I meant PE table, not VE table

LASTLS1

iTrader: (7)

It doesn't compensate off of the intake air temp senor? If not why is it there? Or once the maf is maxed out it doesn't do anything beyond that point? I don't use a maf, that's why I'm asking.

Wonderbread

iTrader: (51)

Not to be a ***** but getting on it at all knowing the fuel system was inadequate probally was not the best idea, should have waited to make sure that everything was right. I doubt it is a head gasket like everyone else said, I am sure you lifted the head, but because you detonated the hell out of it. I hope you can get lucky and that is all it is. Change and check your oil and see if it sparkles, that is one place to start.