91civicEX

D16z6 with a JRSC kit and a header
everything else stock

i took my car out after work at 1030 today to warm it up and smash on it a little. i took it out onto the expresway and floored it in 2nd. went through second fine almost to redline. third went great too. i dont think i took it to redline though. shifted into 4th and after a second it started detonating so i let off.

this whole thing made me uneasy because i have the timing retarded to where i dont have any power under 1500 and it wasnt hot or cold with only me in the car on level ground. my exhaust is still stock as is the cat and i heard backpressure is able to cause detonation.

what is the best way to curb this detonation? pull more timing? get a btc? hondata?
also can anyone quote how much a hondata system is after tuning?

sporkcrx

are you obd0 or obd1?

91civicEX

obd1 with obd 0 injectors.

sporkcrx

Already have a p28 ecu? I'm guessing hondata would be around $500 and then you'd probably need to get injectors. You can also try out uberdata, but hondata is pretty cheap for the peace of mind!

91civicEX

yea ill probably be going with hondata and some bigger injectors then. what about the cat causing detonation? ill be pretty pissed after dropping 500 on hondata when it turns out it was my cat causing detonation. this cat has been through hell.

JonGP4

gut the cat, its cheap and easy.. also what kinda gas are you running, i hope at least 92.. most of the time on my turbo if i put cheap 93 gas.. like diamond shamrock, or citgo.. i'll get detonation.. but i usually run chevron 93 with about 2 or 3 gallons of VP 103 octane.. i rarely detonate on a FMU and stock injectors.. running about 7PSI with a Apexi kit, DOHC ZC

91civicEX

i run 91(highest around here) i think im gonna fil up two gas cans with 100 and throw some in with every fill up. doesnt gutting the cat make the car sound like ****?

illi Adik

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91civicLX &raquo;</TD></TR><TR><TD CLASS="quote">i run 91(highest around here) i think im gonna fil up two gas cans with 100 and throw some in with every fill up. doesnt gutting the cat make the car sound like ****? </TD></TR></TABLE>

Do NOT gut the cat, do get the hondata and bigger injectors though.

91civicEX

so even buying a spare cat to gut would not be worth it? i just passed smog so i have 2 years to play with it.

illi Adik

Are you on stock header/cat/exhaust?

sporkcrx

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91civicLX &raquo;</TD></TR><TR><TD CLASS="quote">so even buying a spare cat to gut would not be worth it? i just passed smog so i have 2 years to play with it.</TD></TR></TABLE>

he he, that's what I do. I have my cat, and then I have my "cat"

I think with the hondata you'll get rid of the detonation. A buddy of mine had a jrsc on his prelude and he'd get pinging if he had his little timing controller too far up.

b16ahybrid

there is a lot more to it then octane and cam timing timing.
air/fuel ratio and ignition curve both play a role in it too.

JohnnieChimpo

Agreed.
Do you have an A/F gauge?
It almost sounds like you are running out of fuel pressure durring your long run.

91civicEX

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jackson4Door &raquo;</TD></TR><TR><TD CLASS="quote">Are you on stock header/cat/exhaust?</TD></TR></TABLE>

stock cat and exhaust. airmass header


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JohnnieChimpo &raquo;</TD></TR><TR><TD CLASS="quote">Agreed.
Do you have an A/F gauge?
It almost sounds like you are running out of fuel pressure durring your long run.</TD></TR></TABLE>

no AF gauge but i have the JR fmu connected that came with the kit. maybe an adjustable FPR would help? wat fuel pressure would be good?

JohnnieChimpo

I must not have been clear on what I was saying.

Years ago I put a bigger intercooler on my Shelby. Boost stayed the same because the computer just held the wastegate shut longer, till the boost came up.

Anyhow. The thing felt like a monster off the line. I hooked my Gtech up and made a few runs. The quarter mile times were the same as before the big intercooler. The 0 to 60 times were better. I was confused. I hooked up my air fuel gauge and watched the car lean out at high rpm. I hooked up my fuel pressure gauge and watched my fuel pressure taper off as the RPMs went up. I figured that the engine was needing more fuel than the pump could push. I switched to a stock type bigger Holley pump and the car ran even better. The air fuel gauge read correct the whole range and the pressure stayed up.

A big top speed run uses a lot more fuel than you'd think and a lot more than an around town blast through the first few gears.

Just check your fuel pressure while you're doing one of these kinds of runs and your air fuel ratio. A lean ratio will cause pinging too. Boosted engines need more fuel for cooling and once you put it to work for a long run the engine will heat up require more cooling fuel.