Jump to content
SAU Community

Recommended Posts

Hey all,

I took my car down to RE Customs today. Spoke to Ray who was cool and friendly about my results. Basically i got the stock boost level raised to 10 psi. I was told that the engine was knocking. Would knocking occur if the spark plugs weren't regapped? Also when i fully open the throttle the engine seems to splutter (mainly around 5000rpms) before revving clean to redline. Would this be caused by the plugs aswell?

My car is an auto 95 33 gtst. Mods are 3.5 inch cat back and POD. Boost was raised with a bleed valve.

Also what are your opinions on the dyno read out.

Thank you to all that reply.

post-25823-1158307209.jpg

Link to comment
https://www.sau.com.au/forums/topic/134479-got-my-car-dynoed-today/
Share on other sites

shouldnt be knocking with those mods... as mentioned fuel pump would be the only reason as it should be rich as upping the boost

Also maybe look at getting a better bleed valve/boost controller looks like by the time you are making max power it has dropped back to 8.5psi

cant say for sure without seeing your afr but generally with those mods you would see you car richen up a fair bit eg maybe a 11:1 or 11.5:1 if you get the afr and it's above 13:1 i would get it checked out although any good dyno operator should have said something and stopped the dyno session.

But it's an easy task and worth checking anyways pull out your plugs check the gapping and check your coils are in good nick.

if its coffing and farting round 5000 u should gap ur plugs down mine r at .7 sum ppl say its to low but when i had same mods my car was doing this and that gap fixd it 100%

also if in doubt about the fuel pump put a fuel presure reg on it and up the presure to say 45 50 and see if that helps with the pinging if not could be shitty fuel mine knocks (pings) if i run optimax but 98bp ultamate it dosent

I'd think about closing the plug gap to 0.7 or 0.8, but at only 10psi I can't see this being your problem. If your getting a stutter at 5000 I'd be checking plugs, coils, fuel pump and injectors, make sure they are all working OK. I'd also be checking the simple things, air filter, fuel filter etc.

you are definetly hitting rich and retard

dont bother changing plugs or anything else

turn the boost down see if the problem goes away

if so, which im pretty sure it will, time for a piggyback, remap or stand alone ecu

Sorry for the late reply. I run my car on Bp ultimate. Seems to run better than any other fuel. So getting an SAFC should rectify this problem?

Thanks

Well yes but it still seems really low for 10 Psi. I hit 175 with standard boost, std cooler, pod and cat back. I wouldn't up the boost till you at least get a Hi-flow cat and perhaps a dump or split dump pipe. Seal up your plugs to be sure and you should be able to get close to 9Psi without even touching the boost controller.

Your plugs at 0.8 should be fine. Whilst .7 or .6 may seem to fix a problem, it usually only "covers it up". Find the cause of the issues rather than trying to cover them up methinks.

Checked my coilpacks and they seem to be fine, no cracks etc. My plugs are NGK iridiums which are only about 6000kms old. The air filters seems to be fine, its basically new, don't know about the fuel filter though. I haven't changed it since i bought the car 20,000kms ago but it was apparently changed before i purchased it. Gonna look at A/F ratio on monday. Could driving my car around temporary in this state potentially harm my engine? Also can ignition timing be cause of this problem? Does it have to be retarded or advanced when running more boost?

Thanks all

Unfortunately there isn't much you can do to fix the tune of your car without getting a power-fc or some other computer, the computer retards the timing and richens the mixture when it detects the car is running outside the factory specs(more boost).Cars with a catback exhaust can hit rick and retard on a cold night.

Getting A/F ratio chart on monday. Will post up when i have it. Can't afford a power FC at the moment. I'm not looking at going over 190rwkws with the basic mods (turbo back, cat, Intercooler) Just want good street power.

pretty much no-one has paid attention to what he has said. the car is knocking, that is causeing the power dip. not r&r. there is very little chance of the car hitting r&r at 10psi with stock dump/front and cat. it wouldn't flow enough air. if he did, then when he did put a new dump-cat section on it would make it hit at about 9psi. i'd be getting the fuel pressure and timing checked.

i would also be looking at a new controller, as has been said. it shouldn't bleed off that much boost at 10psi.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×
×
  • Create New...