I forgot to mention like what people already said -cold/dense air makes alot more actual hp and can easilly blow a motor.They ussually run lean and break pistons. If your car pushed,lets say 850rwhp -uncorrected on a 80 degree's day,it would probly make 950-1000rwhp uncorrected on a 35 degree day becuase the air is dense and you'll probly see more boost.

Either way,the heads have to come off to see the extent of the damage.

 

I agree that you will make much more actual hp in colder/denser air, but the air/fuel ratio should remain consistent as long as the fuel system is up to task as it would correct for both boost level and air temperature.

(assuming this car is tuned speed density)

 

Did I read this right that you started and ran the car with compression tester in there? Thats not how you do it, you crank it with the starter only..

That much metal on a plug and you are screwed, not surprising really making that much power on 91..

 

yea I read that too and bought fell outta my chair.

 

Just adding something here.......
Actually, there is some validity to a 'running' compression test, but I don't think that was his intention..... A running test shows more of the 'dynamics' of the engine - the engines ability to actually pump air or breath. A 'static' cranking test really only shows the engines ability to 'seal' air.

Ex: You can have a broken exhaust valve spring and the engine can still pass a cranking test, or better yet (seen several of these) you can have a camshaft (ex: OHC) off by 1 tooth in a timing belt engine that will show crankinig in spec, but have a lower dynamic/running compression. Even a worn intake lobe will mislead you. Really depends how many times you bump it over......The first pump is the one you really want to watch. Gotta love modern day engine diagnostics, lots of good tools out there today. Although a trusy old vacuum gauge and compression tester can get the job knowing how to use them effectively.

Actually just had this the other week on a 99 Cadillac Catera that had bank 1 misfires on cylinders 1,3,5 at idle and ran good off idle down the road. When the upper intake was off to replace the intake gaskets we did a cranking compression test (no throttle plates) and ALL the cylinders pumped 200 psi.

This was a twin overhead cam abortion, I mean Opel, engine and the exhaust cam was off 1 tooth, hence the reason why it cranked compression O.K. - only thing that will affect the cranking (static) number is the IVC, which was right where it was supposed to be.

When using a Vetronix 5100 scope and psi transducer to look at cylinder pressure events - while the engine was running (electronic compression gauge), the engine vacuum pulses indicated the problem as obvious as the nose on your face.

It all depends what you are looking for. In his case, a leakdown test would be my next step. or even use a smoke machine - they work great!

 

Last year, my friend did a compression test on his motorcycle. He called me to tell me the results. At the end of the conversation, he said, "by the way, what rpm do you check compression at?" I had to laugh. . .

 

This is the way I have allways done it.

Remove all the plugs from the engine also so it will spin over easy and with a charger hooked up so the battery drain doesnt reflect on your readings.

 

Well the damage is done and theres nothing I can do about it now.

No one told me (im not blaming anyone, but its the point of myself being naive to FI) that I would run leaner...

I assumed with the tuning software, the way it worked is when it was reading more boost it would adjust fuel for me... I guess it doesnt work that way, lol.

and I figured that I wouldnt have any detonation issues since it was cooler out.

 

Here's the thing: You shouldn't have this problem!! You're right, the fuel should have adjusted!

Did you retune recently or something? What exactly did you change?

Did you have an A/F meter on your A-pillar? How are/were you tuned, speed density? Your fuel setup definitely hefty, and you have 96# injectors I think.. What's your fuel setup again?

 

Well I had the car last winter and it ran perfectly fine.

I did send it back last summer and it was retuned by futral...

I have a wideband, but its been giving me an er1 error so its been broken for a bit.

Im speed density tuned on a 3 bar setup. Fuel setup should be good for 1000+rwhp easily from what I understand. im running 75# RC engineering inj's.

Im on stock pcm though, no bs3.

 

If you run out of injector or fuel pump when its cool out all the PCM self adjusting in the world wont help. Neither will it help with detonation from lack of octane at those power levels..

 

I'm not a FI guru, so I don't know how those 75#ers will do... I would've thought you went 85+

What's the ER1 error? And what fuel pump(s) do you have?

 

If you were reaching 110% duty cycle while being dyno'd on a regular 70-80+ degree spring/summer/fall day, when temps dropped you were WAY short on fuel. That is likely what caused your failure.

 

that was what it was showing during the last time I dynoed at the 47* temperature...

Fuel pump I was using is the aeromotive eliminator pump.

If Im running lean, would my fuel pressure have dropped at all during the run?

Or is it just the mixture that changes so FP would stay constant?

 

Biggest ones I could use at the time on stock pcm were those 75#ers...

 

if you have a 3bar speed density tune then the A/F should have stayed constant...unless you maxed something out which is the only thing that makes sense to me.that car in GMHT(blown ss) was running out of fuel and <800rwhp with 1 eliminator and they had to add another.so im going to assume u either ran out of pump or injectors and that happened because it was so cold out=more dense=more hp=more fuel required to keep the same A/F ratio

 

I remember you posting the 110% duty cycle part now.... Yep... You ran out of fuel.

You went wrong in two key areas here:

1) Playing around without an A/F gauge.
2) Little injectors and no fuel management - we can't dog you too much for this one since BS3 is $2k

Live and learn, and buy the right parts the first go round. Hopefully it's not a big setback (money-wise).... But you've gotta think for yourself when it comes to FI... Maxed injectors, no A/F meter? There's no way I'd even get into boost knowing those two things.

 

Thats an easy fix...... if you would of read the owners manual it says that means the sensor is gone... replace it..... mine did that to me and i replaced it.. $79 and it was fixed...



Not with an Injector driver box...... I know im running 96#ers with a stock 98 PCM.





Thats exactly what Stenod was told when they WERE going to choose that pump for my car..... they were told it was to small and wouldnt support the power.... That why they went with the Pro Series Pump.


Havent you ever been told you dont want to go over 80% duty cycle on an injector????????
@ 110% damn ..


Kyle

 

Well I dont know exactly what to say. Futral told me he did this setup on 90% of the cars he builds, so I trust he chose the right components...

The eliminator FP is rated to 1100HP FI I believe, so I would think I would be good there...

I understand about the injector box... But if i remember correctly, Allan said not to get it for some reason, whether it was that if I were to spend the money on something to just get BS3, or that we would be fine with what we had and he would tune for it...

I dont know anything about tuning, so I cant speak on his behalf.

 

And yes I know the 80% rule, but this 110% DC from what i understand was only for a split second here and there when the car was dynoed.