Problem: Dyno tuned today, and whenever the car hit vtec, power would drop down dramatically. Had it from 5500 rpm all the way to 7000 rpm, no matter what, it'll lose power.

We checked:

vtec solenoid, dizzy (coil/ignitor), oil level, TPS sensor.

Originally, the TPS sensor was a bit outta wack, throwing a code. However, the car ran better with the code thrown. Once we cleared the code though, the car still sputtered/misfired at vtec. We got a couple of clean runs in, but once we touched the vtec point, the sputtering occurred again. The only thing we think it is now is the cams. I bought some "Blox Type B's" from an HTer. We played with the cam gears, had it advanced and retarded, still no resolution.

Set up:
stock LS sleeves, 81.5mm bore, wiseco pistons, eagle rods, acl bearings, new seals, oem ITR oil pump, water pump, timing belt.
b16 head w/ blox b cams and blox valve train. skunk 2 cam gears.

Weird thing is, I was street tuning a couple of months ago with some GSR cams. everything was fine during the street tune (meaning no vtec issues). Swapped the Type Bs in, and went to the dyno.

Any ideas what you guys think it may be? If you need any more details on the set up, i'll be glad to post it up. The shop is thinking its the cams, I'm still guessing its some sort of electrical issue, and I have a friend who think its an oil pressure problem.

pic of dyno chart:


picture of my headache

 

what r u tuning the car with? Crome? post up your maps.

i had a similiar problem when i was tuning my friends car with crome. i switched to uberdata and the problem went away. does the car sound like its breaking up after VTEC?

also, what size exhuast r u running and how is the dump tube routed? post an engine bay shot if u have one

 

Yea tuning with Crome. I wish i could post up the map, but i dont have it. i can ask my tuner to post it up if you want. The car does sound like its breakin up in vtec, but i dont think its a software issue. It ran fine with Crome when it was with the stock GSR cams. Here's how it sounded on the dyno:
http://smg.photobucket.com/alb...1.flv

and here's one of the few clean passes that i had:
http://smg.photobucket.com/alb...o.flv

Also, my exhaust set up is:

log manifold, 57 trim turbo, 3'' downpipe, and 3'' exhaust. Dump tube is side exit, so the fumes arent directed into the engine bay:

http://img.photobucket.com/alb...5.jpg

 

i had a similar issue and after 1 year we still havent completely figured it out. the main thing you need to check is your oil pressure.

 

My car had the EXACT same problem. It made that nasty fluttering sound right around vtec engagement, and we couldn't figure it out...and the car made no power. I got off the dyno and took the car out for a spin, no break up at all, pulled fine...and broke the tires loose in 3rd gear.

I concluded that the problem was a bad dizzy cap or something that was causing the spark to jump to the pickup for the dyno's tach. If you car pulled fine on the street tunes, then it is probably the same problem that i had.

Hope you get it worked out

 

ask your tuner if he has the newest version of crome installed and also if he is running crome gold. the car i was tuning had the same symptons like yours. it was tuned on crome pro version 1.43 i believe. On another car i tuned, it would run fine under 280 hp (9 psi) whenever the boost was turned up the car would break up. i gapped the plugs really tight, put new ones in, changed plug wires, distributor and we had the same results.

I ran uberdata without making any changes to the car and the car ran mint. Zero breaking up.

i still havent retuned my friends car on crome gold. hopefully the breaking up issue is solved when i retune it on crome gold.


ask ur tuner to test out uberdata or hondata to see if u still get the breaking up. if the car runs fine with this program, ask ur friend to buy crome gold dealer version so he can burn u a chip to see if gold runs any better.

im leaning towards a software problem since i seen it happen to me more than once

 

arent the blox B too big for that set-up??

 

Make a pass on just the LO cam.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AaronJ &raquo;</TD></TR><TR><TD CLASS="quote">My car had the EXACT same problem. It made that nasty fluttering sound right around vtec engagement, and we couldn't figure it out...and the car made no power. I got off the dyno and took the car out for a spin, no break up at all, pulled fine...and broke the tires loose in 3rd gear.

I concluded that the problem was a bad dizzy cap or something that was causing the spark to jump to the pickup for the dyno's tach. If you car pulled fine on the street tunes, then it is probably the same problem that i had.

Hope you get it worked out</TD></TR></TABLE>

havent had a chance to make a pull on the street. i'll check that once the weather clears up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b20vtech &raquo;</TD></TR><TR><TD CLASS="quote">arent the blox B too big for that set-up??</TD></TR></TABLE>

i thought so too, but many people have ran some great all motor cams on their turbo set up and have had success. For instance, my tuner, made this post:

https://honda-tech.com/zerothread?id=2154196

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Outkast95LS &raquo;</TD></TR><TR><TD CLASS="quote">

havent had a chance to make a pull on the street. i'll check that once the weather clears up. </TD></TR></TABLE>

I would suggest doing it as soon as you can, because i would put money on that it would solve your problem, it also makes sense to, since you said when you were street tuning it there was never a problem.

 

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

I would suggest doing it as soon as you can, because i would put money on that it would solve your problem, it also makes sense to, since you said when you were street tuning it there was never a problem. </TD></TR></TABLE>

True that. A huge storm just came into the Nor Cal area.. gonna wait til it passes and when the roads become dry. Hopefully within this week.

 

also look into a new manifold. the cams will allow more air into the motor but that log manifold is probably restricting the flow outta the engine

 

Maybe if enough of these pop up people will start listening to me about log manifolds and big cams....

It's not gonna work, change the manifold or put stock cams back in it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Maybe if enough of these pop up people will start listening to me about log manifolds and big cams....

It's not gonna work, change the manifold or put stock cams back in it. </TD></TR></TABLE>

Does the restrictive log manifold cause the exhaust gas to back up?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Maybe if enough of these pop up people will start listening to me about log manifolds and big cams....

It's not gonna work, change the manifold or put stock cams back in it. </TD></TR></TABLE>

it makes some sense but why does the power pick back up, if it were the manifold wouldnt the power be affected till redline?

 

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

it makes some sense but why does the power pick back up, if it were the manifold wouldnt the power be affected till redline?</TD></TR></TABLE>
It has to do with flow effiecency.

Think of a hose with a slight kink in it. You're pressing 5psi of water through, and its flowing fine. You then ramp the pressure up to 20psi. Your kink is going to cause severe reversion and with enough psi movement, you may even get the water to start flowing through at 20psi, but it's not going to seamless.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Maybe if enough of these pop up people will start listening to me about log manifolds and big cams....

It's not gonna work, change the manifold or put stock cams back in it. </TD></TR></TABLE>

not sure what you mean by "pop up people" but thanks for the advice. i'll probably change out the cams when i get some free time. do u think some ITR/CTR cams or some Blox A's would work fine with my log manifold?

 

lol, sorry, If enough of these pop up (threads), people....

Put stock GSR cams in it if you're going to keep the log manifold. Maybe even B16 cams.

 

What intake manifold and throttle body are you using with those cams? If they are stock, it could be that they are too restrictive for the shorter duration cams.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gogunkergorilla &raquo;</TD></TR><TR><TD CLASS="quote">What intake manifold and throttle body are you using with those cams? If they are stock, it could be that they are too restrictive for the shorter duration cams.</TD></TR></TABLE>

blox IM and a 64mm tb.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">lol, sorry, If enough of these pop up (threads), people....

Put stock GSR cams in it if you're going to keep the log manifold. Maybe even B16 cams.</TD></TR></TABLE>

I am definitely gonna go with the cam because its too big and i think that why ur power is all over the place put ur gsr or itr/ctr cam back it I think it should fix the problem

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Maybe if enough of these pop up people will start listening to me about log manifolds and big cams....

It's not gonna work, change the manifold or put stock cams back in it. </TD></TR></TABLE>

Do u think a ramhorn manifold or an equal length manifold will help solve this issue? From a cost benefit scenario, would you think it's wiser for me to just throw the GSR cams back in and keep with the log manifold, or fork out the extra cash for a equal length manifold and keep the blox b's in? Thanks for your advice, by the way.

 

I'd stick with the cams and put a good manifold on it, it will work wonders. Post back up the results if you do it, i bet the gains will be huge!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">I'd stick with the cams and put a good manifold on it, it will work wonders. Post back up the results if you do it, i bet the gains will be huge!</TD></TR></TABLE>

Thanks. Looks like i'll have to start saving up