01ITR#700

Looking for info from people who have had considerable time and experience working with Hondata.
I having a weird issue with VTEC crossover on my B18C5(9.3-1 COmperssion, 14.5psi of boost) Running Hondata S200, 12.3 Air/fuel all the way through...
For the longest time I had VTEC set at 5500 RPM's on a pretty generic tune, but it worked great and I made 380whp. Now we finally put it on the dyno and did some tuning, made 423whp, ran great on the dyno, VTEC set at or around 5500. Pulled it off the dyno to drive home and the 1st time I get on it on the street it stutters and hesitates BAD right at 5500? I think of the simple issues 1st: Oil level, it was a hair low so I added oil, same issues. 2nd: Fouled a plug or two from lots of dyno pulls?, put in a brand new set of NGK 8's, no change. 3rd: ran a tiny gap on the plugs thinking spark may be an issue, no change. 4th: tried a brand new set of NGK 9's just for the hell of it, no change.
Now the weird part, it only happens SOMETIMES. It will happen randomely in random gears and random throttle. Almost always happens at 3/4 throttle, but happens a little less at full throttle. We played with VTEC and would only get consistent crossover at 6200 RPM's. That IMNSHO is way too high, I'm losing valuable 10th's having it so high.
Thanks for reading all the way through, thanks for any and all info.
Mark

Edit just for more info: After several stutters and stumbles, it then crosses over and pulls like crazy to redline.

servion

What are you doing for an ignition setup? Have you done the standard stuff like cap, wires, rotor?

Are you running an MSD? It sounds weird, but I've heard a lot of people having very strange problems (similar to this one) when they used MSD ignitions. I remember reading a couple threads where such a problem was corrected with going back to a stock ignition with a blaster ss coil.

I'm personally still running an MSD ignition, but if I get any funny behavior I'm going to pull it and run the blaster SS coil with the stock ignition system.

http://www.boosted-hybrid.com/...t=msd

"I have had bad experiences with MSD ignition systems. The only thing that a Honda needs for 500-600whp level to not blow out the spark is a MSD blaster ss coil and heat range 9 spark plugs gapped to 0.020". The msd boxes are crap, they do nothing for making the spark hotter, or to increase the charging time between firing. The external coils do work though, and only the blaster ss coil is needed. " - boosted hybrid

ladysman

What version of the software is the tuner using?

01ITR#700

I'm running 100% stock ignition right now. Stock wires, cap & rotor, all parts have about 25,000 miles on them. If one of those coponents were faulty why would crossover be fine at 6200 but not 5500? Thats the weird question I guess, right?

I'm not 100% sure what version of the software the tuner used, I'm assuming the newest version.

Thanks for the info so far.
Mark

ladysman

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 01ITR#700 &raquo;</TD></TR><TR><TD CLASS="quote">I'm running 100% stock ignition right now. Stock wires, cap & rotor, all parts have about 25,000 miles on them. If one of those coponents were faulty why would crossover be fine at 6200 but not 5500? Thats the weird question I guess, right?

I'm not 100% sure what version of the software the tuner used, I'm assuming the newest version.

Thanks for the info so far.
Mark</TD></TR></TABLE>

Find out what version and report back.

I would try a new rotor and cap as well. 7 series plugs would be a better choice for your HP IMO. Anything over about 420ish, go to 8's. I doubt this is the issue though.

servion

If it worked fine on the dyno, but its funny now, and it works fine with the high crossover point, my thought is that there is something funny in the high-cam fuel and/or ignition map inbetween 5500 and 6200. Where does your motor make peak torque?

You have the s200, correct?

If it were me, I would start by adding fuel and pulling timing in that range just to see if that will correct the problem. Then, I would gradually set the a/f back to the desired range, and then slowly begin to add timing until it works properly.

Do you have any dyno graphs to post?

ladysman

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by servion &raquo;</TD></TR><TR><TD CLASS="quote">Do you have any dyno graphs to post?</TD></TR></TABLE>

My next question.

01ITR#700

This is the best pull at the end of the day...VTEC working fine...


Thanks for all the info/help.
Mark

ladysman

Where is the AF?

01ITR#700

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ladysman &raquo;</TD></TR><TR><TD CLASS="quote">Where is the AF? </TD></TR></TABLE>

I still have to snap a pic of the air/fuel, I'll get it up tomorrow...FYI it's literally 12.3 straight as an arrow all the way across. Hope that helps.
Thanks.
Mark

Boofster

Have you thought about the actual VTEC system? Pull off you solenoid and flush the filter. Maybe a wire is loose (making it intermittent).

Spunkster

This sounds more like a loose wire somewhere and it is happening at a certain resonance...aka it's vibrational and you have a wiring problem.