All,

I went yesterday for a dyno tune and came up very disappointed. For reference only, a stock Evo hits around 250 WHP on that dyno.

I have installed: Buschur Stage 1&2, upgraded intercooler, Nisei LICP, GS1 Cams, fpgreen, PTE 780, pump, ceramic coated mani/O2, MBC and ECUFlash.

Here was the best run that I could get..... First run was rated for 311 HP and 296 TQ.



Here is the full run with A/F and Boost:



Here is how the run looked like on DLL, the file for the graph is attached as well.



Please notice the dip in boost between 5000-5500 RPMs!

Any suggestions on what may be causing this type of behaviour? I was expecting over 350 HP with the tune. I will appreciate any comments on this!

Please refer to a DLL from a previous run a few months ago before installing the cams. Please note how the curve used to look like not the peak numbers!

 

what fuel?

 

Otherwise, how does the car feel for driving? Except for the boost problem, the power band does look fairly wide.

 

Your load is dropping where you see it on the dyno. You are physically moving less air through the motor at that point. Its allmost like somebody is lifting on the throttle then getting back in it. Or you have one funky as hell screwed up mivec map. Or any number of things that affect airflow.

 

It is a Evo 9 so more than likely that is some sort of crossover point. When I used to build Honda vtec motors the dyno graphs usually looked like that at the low cam/high cam crossover point before they were optimized. I don't know much about Mivec, but I'm sure there's got to be a way to change it in the program to get rid of that dip.

 

tephra: 93 OCT

C6C6CH3vo: The car pulls real hard below 5000 RPMS. Seems to loose some power for a second and then pickup again. Similar to what it is shown on the graph. It is very noticeable!

dan l: The car was at WOT from 3000 RPMs all the way to the redline. It feels like if I would close the throttle a bit but check the RPMs that they continuosly climbing instead that going backwards. Can you list a couple of items that may affect the airflow? Just want to check on them!

 

Slo_crx1,

Funny! I thought the same thing! It looks like VTEC is engaging in!

I am double checking the MIVEC tables!

 

I would say the dip in boost or something MIVEC involved

 

or in my case where the culprit was the 18lbs wastegate actuator on pump gas and an MBC...i moved to the EBC and my woes went away....which actuator do you have?

 

I would look at the WG actuator and post up a Mivec map. If you would rather not publically post, then pm me.

 

All,

Thanks a lot for sharing hints on my case! Really appreciate your help!

Current WG Actuator and MBC: FP 18Psi WGA with a Forge MBC.

alan678.... What EBC do you switch to?

Here is the Mivec map used for my best run ~329 HP on the DynoJet:

 

Since your boost actually drops its more than likely a boost leak.

Your mivec, timing, and knock numbers can change all day but boost shouldn't.

If you look at your boost curve it appears to grow then leak grow then leak. This is very odd behavior with an MBC.

 

How much preload do you have on the FP actuator? However you said you didn't have this problem before the cams. I would do a boost leak test and check the preload as well.

 

Hi guys!

What do you mean by checking the preload?

I was thinking that the fluctuation was a result of a boost leak. Will do the test this week to see what comes up.

 

sometimes a car will knock on the dyno from bad conditions... did you log the map?


That would explain the dip