[Pupsvette76]

I will have to try that... Ur saying just turn up the timing sitting at idle and see if it will go past the normal rpm without driving it... Is that correct?

[cobalt327]

Originally Posted by Pupsvette76

I will have to try that... Ur saying just turn up the timing sitting at idle and see if it will go past the normal rpm without driving it... Is that correct?

Yes, that's the idea. As long as the engine is not under a load, it will tolerate a lot more timing than you could otherwise use.

[Pupsvette76]

I will do that tomorrow if I get a chance

[cobalt327]

Originally Posted by Pupsvette76

I will do that tomorrow if I get a chance

Don't get your hopes up too much- the chances are good something else altogether will be the prob, but at least this will eliminate one thing as a possibility and it's easy enough to do...

What about the turbo? Any chance the bearings or shaft is binding, and not letting the turbo spool up like it should? Because if it's not spinning up, it becomes a big restriction in the exhaust system.

[Pupsvette76]

I don't think so it makes boost and it also spins for about 30 seconds after shut down so it's pretty free spinning I actually turned it up to 20 psi just to see

[Project89]

Originally Posted by F-BIRD'88

I bet that 9sec firebird is using a efficient air to water intercooler, cooling down the charge air temp
to BELOW AMBIENT temp.

You say you can show it. Post a link where it is discussed in a forum or other web site BY THE OWNER OF THE CAR.
I know its possible and I know what it takes to achieve that level of performance.

Yup the twin Buick GM turbos work very well. (TWIN being the key word.)

sorry i never even saw this reply
heads have 1.72 intake valves

The block and heads came out of a 80 chev pickup(not original motor) and near as we can tell, it has 150k on it. Has dogcrap 991 small valve truck heads with 76cc chambers and 1.72 intake and 1.5 exh. valves. Should be 8.6 to 1 with 4 valve relief flat tops that are .022 in the hole and a .038 gasket.

no water to air cooler here here is the thread
http://www.theturboforums.com/smf/th...art-2-to-come/

and if u dont want to take 3 years to read all couple hundred pages or so

For those of you who dont want to go blind reading all this, the old used up motor was pulled out intact and running perfectly after going 9.37@150! Best power number was 738 whp @ 25 psi and a 75 shot of NOS. Ring gap ended being .090 on the top ring when i finally pulled a piston out of the hole. Yikes! :doh:

[Project89]

pups is there anyway u can take a video of u driving the car, sometimes being able to see and hear is worth 1000 words

whats ur plug gap? noone has even asked , ur going to need around a .022-.026 plug gap

if ur at .032-.045 thats going to be a big part of ur problem

gear gears gears this is going to be another issue u have way to much gear plain and simple

u know the turbos is not an issue specially if it takes 30 seconds to spin down, the ex housing on that gt45 is massive and a 355sbc even with outstanding heads wont choke it

ur ex system on the other hand could choke it

what is ur timing under boost? ur only going to want about 20-22* is were it would be at with intercooling and aditional 2-3* if running meth injection, if no form of intercooling and using pump gas 18-20* from 5 psi and up is a good place to start

[Pupsvette76]

Timing is locked at 34 but I hear not ping I been having an issue with my intercooler whenever I run the charge thru it the motor produces no boost 0 psi for some reason with the charge pipe right to the bonnet of the tb I can crank it to whatever I want... I also have water inj not fully operational yet though spark plug gap is at .030 I planned to gap them down to .025 and yeah my gears are not a match for this motor I know plan to swap them out around Christmas time

[Pupsvette76]

Not sure what gear would fit best I was thinking along the lines of. 3.55

[Project89]

Originally Posted by Pupsvette76

Not sure what gear would fit best I was thinking along the lines of. 3.55

are u still having trouble reving over 4k? if so what does it do , does the motor just fall on its face, or is it starting to miss and pop and bang?

if needed i can post a video of what it sounds like if the plug gap is to big and the ignition system isnt upto the task.my friends car i tuned would have the same symptoms at around 4,500 it wouldnt rev past there at all and would bang and pop.

went from .032 plug gap to .022 and its been flawless ever since.

what intercooler are u using is it something out of a junkyard car?if not whats the core size ?

genrally ur going to want something in the 32x12x4 range though a 32x12x3 will work for moderate hp levels

remind me again what car this is in and what trans ? 3:55 or one step down would prolly be a really good match . i do recall u saying no more then 5 psi in first gear. once u do a gear swap u will get alot more boost in first

[Pupsvette76]

Its a 70 nova with a turboed sbc 355 and a turbo 350 trans and 4.88 gears on a spool It doesn't pop or bang at all it just ceases to keep climbing in rpm and in fact if I hold the pedal Down even when it doesn't climb it will actually start to drop In rpm plug gap is .030 it's a new intercooler not sure exactly what core size I believe it's 27in long and 3in deep

[Project89]

Originally Posted by Pupsvette76

Its a 70 nova with a turboed sbc 355 and a turbo 350 trans and 4.88 gears on a spool It doesn't pop or bang at all it just ceases to keep climbing in rpm and in fact if I hold the pedal Down even when it doesn't climb it will actually start to drop In rpm plug gap is .030 it's a new intercooler not sure exactly what core size I believe it's 27in long and 3in deep

ok let me post some videos for u in a lil bit, keep in mind the downpipe is only about 2.5 ft long so the noise u do hear would be very hard to hear if it had a full ex.

see if it kinda acts like what ur engine is doing.


have u checked the same for wiped lobes, possible rocker stud pulling out.bent push rod etc

will it rev in nutral or park?

whats the fuel system have for line size /pump what size injector

[Pupsvette76]

I have checked for wiped lobes and the cam is fine and all rockers were tight so that indicates no loose studs and I didn't notice and bent pushrods it does the same thing in neutral it will rev to 4800-5 and then stop no banging no rev limit sound just stop and then if I hold it then it will actually go back down the fuel system is a 255gph pump I bought the better pump with the kit 62lbs injectors with -8 feed line -6 return

[Project89]

what is ur afr when it does this, right off the bat u can eliminate the turbo and plug gap, since it does it in nuetral as well as gear, the turbo wont build boost during free rev.

still go ahead and tighten the plug gap anyways though

i would look into fuel system issues, for sure, get a fuel presure gauge and rev the motor up and see if fuel presure is droping


even with crappy heads he thing should deff rev up over 4800, hell even the cfi camaro motors will rev up higher then that and they have very very tiny ports

[Pupsvette76]

Ok just an update I messed around with the fi today and got it pretty dialed in didn't do much tuning just kinda changing some preset settings and it will now hot like 5300 still low since the rev limiter is at 7k... But anyway I went into my log files and my afr at WOT will hit 9 for like a millisecond and then rebound and search for the target afr which is about 12 at WOT fuel pressure never drops off lowest number I saw was like 42 and I have it set to 45 boost refernced