Dyno graph - what happened??

[cat007]

What do you all think happened on this dyno graph of my Supra? Why did it drop off so sharply at the end, yet the boost and AFR stay as steady as they had been previous...?

Maybe a bit of wheelspin on the dyno?

She is certainly running pretty rich though.

[d1 mule]

would also be questioning why it only made 240 whp

[cat007]

would also be questioning why it only made 240 whp

Yeah something is *not* right. Not sure what. Wasn't missing. Is running a bit richer than my original 238rwkw dyno.

I have a feeling the timing is way off as I think my harmonic balancer had spun on its rubber. Seems to be about 5-7 degrees out.

Edit: something is *not* right

[Dell'Orto]

Man is that super laggy or did they not rev it right out? I would hazard a guess given your latest questions that your cam timing is out

[cat007]

Man is that super laggy or did they not rev it right out? I would hazard a guess given your latest questions that your cam timing is out

It could that the cam timing is out. I will check #1 pistons TDC and compare it to the cam's alignments.

Here's a scan of my old dyno sheet. Much nicer fuel, and power, and torque. Everything really haha

[cat007]

And the run from today if anyone's interested:

http://youtu.be/wPKrtfudFOQ

[iamawesome]

Seems very odd, did Geoff tune it at all? And just out of curiousity, how did you get put on to him?

[cat007]

Seems very odd, did Geoff tune it at all? And just out of curiousity, how did you get put on to him?

It was a supra club dyno day. So no tuning. Just a power run.

[Dell'Orto]

Yeah look how much later it makes full boost now. Either timing is out or its lost lots of compression

[cat007]

Yeah look how much later it makes full boost now. Either timing is out or its lost lots of compression

Hmm. Guess I should find a compression tester...

[Flannelman]

Whats been changed since the dyno runs?

[cat007]

Whats been changed since the dyno runs?

Vavle Springs and about 6 years of it sitting around. Probably only about 10k on the clock...

[Flannelman]

Whats the new spring rates?

New valve springs mean cam removal. I would be checking cam timing closely, (the intake cam could be retarded one tooth) followed by correctly adjusted throttle - is it getting 100%? No blockages in intake track? Are the air cleaners clean?

[cat007]

Whats the new spring rates?

New valve springs mean cam removal. I would be checking cam timing closely, (the intake cam could be retarded one tooth) followed by correctly adjusted throttle - is it getting 100%? No blockages in intake track? Are the air cleaners clean?

I can't remember the specs exactly but they're matched to the TRD equivalent apparently.

I will double check cam timing.
Throttle position idle and full is adjusted correctly.
No blockages in the intake and the air filter isn't perfect but not exactly dirty either...

[Flannelman]

Just a tip, use a long thin screwdriver down the spark plug hole to see where TDC is if the timing marks are suspect.

[cat007]

Just a tip, use a long thin screwdriver down the spark plug hole to see where TDC is if the timing marks are suspect.

Yeah will do

I'm pretty certain my crank pulley has spun on its rubber so that'll have put the timing off if it has

[QikStarlie]

use the piston stopper method i suggested awhile back. screw driver trick should tell you if its out, but isn't very accurate for setup.

if everything else checks out timing wise both ignition and cam timing. i would start to look for a boost leak

[JZCrazy]

What gear was it Dynoed in?

[cat007]

What gear was it Dynoed in?

4th

[JZCrazy]

Oh hmm