Coolant problems are now fixed, all the small bugs seemed to be worked out, now just left with this one.

Car is a Forged (non sleeved) B16A2, 3 layer hg, drag mani with TN T04e .57 trim running a Tial 38mm wg and spring only right now waiting to put in my 3 bar. Boost is at 7psi off the spring.

When the car is cold (warm oil, just not enough temp to crossover) It will pull clean to 6200 (where I let off just to see if it was indeed the problem). Once it warms up fully though, when it tries to cross over into vtec, the car breaks up nicely at 5800 rpms on the stock tach. It will break up and pop for about 200 rpms and then smooth out and pull.

Car has plenty of oil, nothing has been touched management or any other wise aside from the cooling system since the P28 was chipped with Crome. Car started doing this a little before the cooling system was worked on though so nothing I did there could have caused it (that I know of).

Can't get back to my tuner until Monday at the earliest and now that I have narrowed it down the the crossover point, I was wondering if anyone had any info/ideas on what could cause this or if it could be related to my current map? I do not have a wideband in the car but when we tuned it, it was for a straight 11.2 to 11.3 AFR accross the board. Thanks for any help.

 

i had this issue on my car, lost like 40whp at the break up then came back online and made 291whp@8psi. Its all in the tune, i believe i had to end up smoothing out and slightly lowering timing at the crossover point

 

more often than not, vtec crossover breakups are in the tuning.

 

What I thought, thanks for the back up guys. My tuner is a friend of mine as well and he stopped by this afternoon and told me to come in Tuesday at 8 and he had two house set aside to get it out. I just wanted to make sure it was "probably" in the tune and not something mechanical I could have overlooked.

Thanks again.

 

good luck. break ups can come from spark blow out also. gapping the plugs lower could help if that was the problem. this kinda sounds like a tunning issue also though.

 

I was originally thinking spark blow out as well but with the plugs gapped to only 32 and only 7-8 lbs, I just couldn't see it. I hope it is a tuning issue. Every time I take my car to the tuner, it's gets better and quicker anyways lol. Just another 100 bucks or so and it will probably be perfect.

 

I usaly run between .020 - .028 depending on how much boost/power your making.

I'm currently gapped at .023 on a 10psi tune

 

That's some good info man, I am used to N2O tunes, I will throw a new set in there in the AM with a .25 gap just to see what happens before going back, thanks.

 

good luck

 

Hey man, took the plugs out, closed them down the .025 and I will be damned, worked like a champ.

I really appreciate the help becuase I would have never thought to just close em up a little more, I thought .032 would be plenty. Saves me some cash come Tuesday. Thanks again.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jay_Sensing &raquo;</TD></TR><TR><TD CLASS="quote">Hey man, took the plugs out, closed them down the .025 and I will be damned, worked like a champ.

I really appreciate the help becuase I would have never thought to just close em up a little more, I thought .032 would be plenty. Saves me some cash come Tuesday. Thanks again.</TD></TR></TABLE>

no problem, thats what HT is here for