Comptech SC Correct Setup
Thread Starter
Joined: Nov 2003
Posts: 25,566
Likes: 2
From: Heart of England
Comptech SC Correct Setup
I thought I was all sorted for installing my super charger, got it all togther and I was just trying to sort getting it dynoed to set up the FPR. Then some one I repsect posted this
Now I'm 
and concerned.
Is the FPR really dangerous? Why?
Stock boost with an AC is only round 5-6 psi isn't it? How is 7-9 psi boost dangerous?
Surely with the after cooler the charge will be very close to normal temps?
Please reassure me here guys!
yup, you can slightly fine tune your fuel pressure. but let me iterate how important it is to have your car properly tuned.
comptech provides a bandaid fix for the fueling, even that is dangerous but it works somewhat. it hides the boost from the ecu, then the rising rate fuel pressure regulator just ups the fuel pressure to dangerous levels...
but what it doesnt control is your ignition timing. these motors have high compression from the factory, adding 7-9 psi to the factory ignition timing, well is plain dangerous IMO.
sure if you richen it up enough, u can probably cool the charge enough for it not to detonate, but you're on the edge there.
Ive found with the stock ecu, it does pull some timing at the top end anyways (its still too aggressive for boosted appllications). with a supercharger, you dont reach full boost until redline, so in a way it works.
Regardless of whatever you decide, i would try to target a mixture of 11.8-12.0:1 to be conservative.
good luck
comptech provides a bandaid fix for the fueling, even that is dangerous but it works somewhat. it hides the boost from the ecu, then the rising rate fuel pressure regulator just ups the fuel pressure to dangerous levels...
but what it doesnt control is your ignition timing. these motors have high compression from the factory, adding 7-9 psi to the factory ignition timing, well is plain dangerous IMO.
sure if you richen it up enough, u can probably cool the charge enough for it not to detonate, but you're on the edge there.
Ive found with the stock ecu, it does pull some timing at the top end anyways (its still too aggressive for boosted appllications). with a supercharger, you dont reach full boost until redline, so in a way it works.
Regardless of whatever you decide, i would try to target a mixture of 11.8-12.0:1 to be conservative.
good luck
and concerned.Is the FPR really dangerous? Why?
Stock boost with an AC is only round 5-6 psi isn't it? How is 7-9 psi boost dangerous?
Surely with the after cooler the charge will be very close to normal temps?
Please reassure me here guys!
Registered User
Joined: Jun 2004
Posts: 4,712
Likes: 0
From: Phillips Ranch 909!
Dont worry your fine (up to 7 lbs of boost) with the FPR. I will be pushing around 7 lbs non aftercooled and it's safe when the FPR is tuned properly.
What size pulley are you running, stock?
That "unsafe fuel pressures" is a bunch of rubbish. He has no clue what he is talking about!
What size pulley are you running, stock?
That "unsafe fuel pressures" is a bunch of rubbish. He has no clue what he is talking about!
Joined: Oct 2006
Posts: 13,494
Likes: 71
From: Chiswick
well i would definitely try to have you a/f's between 11.1-11.6.. thats what i was always told to do when tuning a boosted engine... i wouldnt see why it would change for this car.... especially with its 11.0:1 or 11.1:1 compression
Registered User
Joined: Jan 2006
Posts: 507
Likes: 0
From: Rockin' in the Med
5-7 psi is 'safe' with a rising rate fpr like the one found in the comptech kit. That's why comptech bundled their kit with one and didn't go for a more complicated/expensive setup with their base kit. There's s2000's on these forums which have done over 100,000 miles with their kit without any problems (there's an 'official' post somewhere). If you stick to the stock comptech kit (read: no aftermarket exhausts etc. which may lean out your afr's more than the fpr can compensate) you'll be fine.
If you're looking to upgrade your pulley to something smaller however, you'd have to consider getting larger injectors and some form of fuel (and ideally timing) management since there's only so much boost you can cater for by upping fuel pressure.
If you're looking to upgrade your pulley to something smaller however, you'd have to consider getting larger injectors and some form of fuel (and ideally timing) management since there's only so much boost you can cater for by upping fuel pressure.
Registered User
Joined: Jun 2004
Posts: 4,712
Likes: 0
From: Phillips Ranch 909!
Originally Posted by mikey k,Nov 9 2006, 08:30 AM
Stock pulley on stock Comptech on stock car
Comptech have done it loads of times
That's why I cannot see what the problem is!
Comptech have done it loads of times
That's why I cannot see what the problem is!
Just enjoy the kit and relax.
Trending Topics
Registered User
Joined: Jan 2006
Posts: 507
Likes: 0
From: Rockin' in the Med
By the way, make sure that you've got the correct fuel pressure and the right afr's across the rev range, as the fpr isn't preset (at least mine wasn't). You'll want to check it out on a dyno or with a wideband logger.
Thread
Thread Starter
Forum
Replies
Last Post
TurboVtk
Archived Member S2000 Classifieds and For Sale
3
Apr 16, 2004 05:50 AM
Reignman
S2000 Under The Hood
1
May 4, 2003 04:47 PM