Thanks for taking the video Carlos!

The car made 125.7whp @5900rpm and on my last pull made 136whp @ 7k rpm. As you can see the dyno plot is all over the place. Everyone seemed to think it was due to valve float. The engine has very mild work done to it..

-Full SFR exhaust and no cat
-Run was made with FRWilk's chip however i had it switched off and was using the stock fuel map
-Rebuilt head with 5 angle valve job but with original springs
-Engine is in pretty good tune.. all new vac lines and hoses, Magnecore wires..relativley new cap and rotor and maybe 10k miles on the FPR.
-Stock airbox and paper filter
-A/C delete
-Engine has 99,800 miles on it
-Pull done in 4th gear on load type dyno

So what do you guys think, is valve lift to blame here? What else should i look into?



Can i change the valve springs with the head still on the car? Im not really too concerned..car feels fine really. I need to funnel money into the turbo anyhow..

BTW Carlos, can you email me the full resolution video?

 

i want to see a dyno of the turbo! I have a coupon somewhere for a dyno at farnbacher. i won it at metro's holiday party last year. it expires at the end of the year.

i also won a season of autocross. of course i screwed up and missed one, and then upped and moved in the middle of the season. Putz!! yep thats me.

 

Jon, do you mean valve float? Not that I know the answer anyway, I'm just trying to understand it. For whatever it's worth, I thought valve float was simply a high-rpm problem...

All that aside, 130+ rwhp is really very good I would say!

 

Whoops yes, i meant valve float.

Tom, mail me the coupon and ill try and give Farnbacher a call .

 

i just asked jill where it is and got a blank look, then 'it is in a box'. you saw the house in lido. there was the boxes in that house plus a PODS full of boxes. She will give a once over look.

 

No problem Tom. Not a huge deal if you can find it or not. I figure the car will probably make around 225whp with the current mods..which if i remember was just the exhaust, chips and boost enhancer. Still need to fix that broken stud. Still have to install a wideband, boost gauge and put a proper boost controller in there..also want to get rid of those Autothortiy chips.

 

It looks somewhat like spark knock.

Do you know what your AFR was? Is that Standard correction, or SAE?

 

Standard correction . Please enlighten me, what is spark knock? Is this the same as detonation or a little different?

 

Sorry Jon, detonation. It could also be that timing map on the aftermarket chip.

If they gave you STD correction and not SAE, I might go somewhere else next time. Most shops won't even print out STD for you anymore, as SAE represents more realistic conditions.

If it's running strong and you can't hear any knock, I might not even worry about it.

 

It should do a little bit more than mine...

 

You think Carlos? Im really not sure, just sort of a conservative guess. 3'' SFR exhaust and no cat, Autothroity Stage 2 chips, LBE, cant remember if anything else was done. I definetley want to get rid of the chips though..have heard not so great things about them in the upper RPM range.

Email me the video if you get the chance... jjeng951 at gmail dot com

 

definitely seems like somethings not right, but I don't know about valve float - I'm pretty sure that in an interference engine, valve float will lead to a destroyed head

Have you checked the gaskets on your intake by any chance? Could be a leak somewhere there maybe, but then again, that would probably have a tangible effect on driveability, and it sounds like the car drives fine, so maybe its a problem with the dyno calibration

 

nope i dont think so because 3 other cars also ran that same dyno and he was in the middle

 

I love the Interweb speculation from the kids on this thread.

J.R. dynoes his F1 vintage Cosworths on THIS dyno.
Anthony dynoes his GRAND AM Hondas on THIS dyno.
If this dyno op says its a spring problem, ITS A SPRING PROBLEM.

I'll tell you a story...
The last time one of J.R.'s customers F1 cars was in for mis-fire.
3.5 liter Cosworth.
Car kept coughing at 9,000, and this is an 11,000 RPM engine.
He told Geoff to HOLD IT UNDER LOAD AT 8,000 RPM.
"You TRYING to blow this thing up?", he says.
"Hold it at 8,000"
Just so you guys understand - this means foot flat on the floor, but the dyno stops it at 8,000 RPM. That makes heat.
So they did.
Coolant started coming out of the right bank.
Problem found - weak headgasket.
Try to do THAT on a Dynojet.