I went to the dyno this past weekend

B16 block, built bottom end, 9.3:1 compression, SC61, GSR cams (I think), 84.5 mm bore, 3" exhuast, 2.5" rev hard dp flared to 3", RC 750cc, JE intake mani, Tial 38mm, inline pro, greddy type 31 IC.

AFR was very conservative 11:1, timing was not aggressive at all. Here's the dyno graph, when VTEC was engaged at 5500 RPM I lost 40 whp and then couldn't make power past 7500 RPM.

This was at .8bar spring, but if you look at the boost graph, she didn't go past 9.7 psi, .8 bar = 11.6 psi ????

<FONT SIZE="3">H E L P</FONT>






Modified by FredoSP at 6:43 PM 6/27/2004

 

first off are you sure it .8bar spring.

 

This was tunned by Boosted Hybrid, Jeff knows his stuff, so please no bullshit.

He will have to post, as Im not 100% what he did, but from what I remember when VTEC was enabled at 5500 rpm I lost 40 whp.

Jeff thinks it could be something with the cams or valve timing.

Did I really buy GSR cams, I dont know. Are these all motor cams?

Why dont I make power past 7500 RPM? NO CELS, Guys I'm lost on this one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18bturbo &raquo;</TD></TR><TR><TD CLASS="quote">first off are you sure it .8bar spring. </TD></TR></TABLE>

Well even still with that setup he should of made at least 300whp

And also when the cam gears were adjusted I think Fred gained like 40whp?!?!
Thats crazy for just a 2degrees change

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18bturbo &raquo;</TD></TR><TR><TD CLASS="quote">first off are you sure it .8bar spring. </TD></TR></TABLE>

eekk ... I hope so, thats what I bought from Ben

 

what did you change after you did your 355whp tune?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MachAF &raquo;</TD></TR><TR><TD CLASS="quote">what did you change after you did your 355whp tune?</TD></TR></TABLE>

What's im my sig, that's my goal for whp, so for the moment ignore that

 

what's the timing at?

 

I remember Jeff saying 19, but dont quote me

 

Any pictures of the GSR camshafts?

 

Could the max psi due to the pressure drop across the piping and i/c. If the wastegate is plugged in at the compressor, the psi has to be a little more than at the tb or intake manifold.

 

This may show my complete ignorance but could there be some way the vtec is operationg at low rpm and shutting off when it hits the vtec point? Either that or the cam timing is way off and hitting vtec just aggrivates the situation. Make a full pull with the vtec disconnected and compare numbers.

 

no pics, I got them used on here a long time ago

the wastegate vac line is connect to the compressor side of the turbo, so you def have a point, but .8 bar is 11.6 psi. I didnt think the type 31 had a big pressure drop.

Earl, Jeff has some saved logs with no VTEC, i think I have a video, and you can hear the VTEC at 5500 or 6000 depending upon the run we did. I'll try to get it up ASAP.

Thanks so far, we'll get to the bottom of this.

 

Hrmmm...

To me it sounds like its either the cams, or the cam timing (or a combination of both). The cams are what is going to determine where your torque curve is.

Do you have any other cams you can swap in?

you may also want to try lowering the vtec engagement point.

 

ok for the "not hitting .8 bar" thing it's probally pressure drop accross your intercooler due to the fact that your WG isnt hooked up after it. I'd say get a .9 or 1 bar spring in it and it should run the boost you want to after the IC
edit: someone said this already ****

 

yeah .. anyone want to donate some cams?

 

that looks very similar to mine.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by doughboy247 &raquo;</TD></TR><TR><TD CLASS="quote">what's the timing at?</TD></TR></TABLE>

The timing is at 14 degrees btdc static, under boost the timing is right around 20 degrees. Adding more timing didn't yield any significant gains.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">This may show my complete ignorance but could there be some way the vtec is operationg at low rpm and shutting off when it hits the vtec point? Either that or the cam timing is way off and hitting vtec just aggrivates the situation. Make a full pull with the vtec disconnected and compare numbers.</TD></TR></TABLE>

I initially tuned the low cam fuel and timing maps with vtec disengaged. The car made approximately 200whp with the torque falling off right around 6500, which is typical of the low cam. When vtec engagment was placed at various rpm points, the engine was staying on the high cam the entire time. I initially thought that it could be falling off to the low cam at high rpm, but the datalogs proved that vtec was engaged the entire time. Moving the vtec point to 4000 rpm created approximately 55-60 whp loss. The higher I moved the vtec point, the less whp loss at the vtec engagment. The sweet spot for the vtec engagment was approximately 5700 rpm. I tried dialing out some overlap by adjusting the cam gears -2 intake, +2 exhaust, which yielded close to 40whp gain. The cam gear adjustment horsepower gain is displayed in the dynographs that FredoSP posted. There are no boost leaks within the charge piping. The cams give the torque curve its characteristic shape, which is what leads me to believe that the cams are not GSR cams.

 

Damn lately a lot of customers have left your shop disappointed. I'm not trying to bash your shop or anything. I guess it's the cars that have been going to your shop.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by june &raquo;</TD></TR><TR><TD CLASS="quote">Damn lately a lot of customers have left your shop disappointed. I'm not trying to bash your shop or anything. I guess it's the cars that have been going to your shop.
</TD></TR></TABLE>

i dont think you can chalk up everything to the tuner...lots of variables are out of his hands

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gritsak &raquo;</TD></TR><TR><TD CLASS="quote">

i dont think you can chalk up everything to the tuner...lots of variables are out of his hands</TD></TR></TABLE>
Read up top and tell me where does it say tuner?? I said customer cars.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by june &raquo;</TD></TR><TR><TD CLASS="quote">
Read up top and tell me where does it say tuner?? I said customer cars. </TD></TR></TABLE>

well maybe customers should bring in half *** cars and expect tuning to magically make the car fast and they wouldnt be dissapointed not referring to this guy though

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by june &raquo;</TD></TR><TR><TD CLASS="quote">Damn lately a lot of customers have left your shop disappointed. I'm not trying to bash your shop or anything. I guess it's the cars that have been going to your shop.
</TD></TR></TABLE>

When there are mechanical or electrical wiring issues with a car that comes for a tuning appointment, there's only so much I can do with the tuning aspect. A lot of the cars that come to the shop end up finding out there are issues with their set ups once they get there and those issues need to be resolved before I tune anything. When you run into issues like all motor cams on a forced induction set up, bad sensors, bad wiring, heads lifting off blocks due to improper torque specs, and timing belts being off a tooth (not issues that FredoSP is experiencing), you aren't going to have a perfect tuning session. I have had about 20 tuning appointments in the last 3 weeks and only three had issues like the ones I just mentioned.

 

Modified by june at 12:47 AM 6/28/2004

 

This has nothing to do with FredoSP's thread, he has a problem and needs an answer.