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Thread: Very lean conditions...

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2010-06-06 15:05:51
Very lean conditions...
So I found out why the car did not make impressive numbers at all. I had my car tuned and when we finally sprayed we were in the high 14:1 AFR area. Tried everything we could to get the AFR's down but no luck at all. 4 bar fuel injectors (stock VE 333's) at max duty and still no luck.

I am running a Zex wet nitrous direct port kit jetted for a 150 shot. I programmed the controller to start spraying 50% @ 4,000rpm's and ramp its way up to 67% which is a 100shot or so. As soon as the nitrous activated the AFR's sky rocketed into very lean conditions. Funny thing was around 6,000rpm's, the sniffer read AFR's nose diving into the 10:1 area or so.

I wired everything up according to the Zex schematics and everything seems to come on just as it should. The car was not making any power over what it laid down all motor. It showed an increase in torque however. We decided to turn off the bottle since we didn't wanna blow a healthy motor. Shouldn't there be some compensation for fuel or is it just time to go for bigger injectors? Any ideas/input are welcome.
2010-06-06 15:24:17

Is this the kit dry or wet?
2010-06-06 15:29:29
Its a wet kit. Only thing I could think is maybe from having the progressive controller fluctuating to prevent the full 150 shot from spraying is causing the fuel solenoid to not provide enough fuel. I know you can change frequency for the solenoids on the controller settings but I left it where it said most solenoids perform best at, 14hz iirc. Definately makes me pretty pissed after spending a fat chunk on nitrous parts.
2010-06-06 15:35:48
What you need is more fuel pressure. At this point I'm running mine around 70psi lol. I turned it up that high so everything would be good with the nitrous, and then adjusted my K-Value via calumsult so that everything would still be good while putting around town.
2010-06-06 15:38:45
This is going to be my next big purchase for my car. I'll either buy this, or just make a similar setup cheaper lol. Totally seperate tunable fuel system for the nitrous setup.

Nitrous Express Next Generation Nitrous Oxide Systems SAFE, STAND ALONE FUEL ENRICHMENT SYSTEM, ADJUSTABLE
2010-06-06 15:39:08
Wish we tried that on the dyno. We had it set to 3 bar where the car made the best power. We upped the fuel pressure to 58-60psi and took away timing to start safe. We did a couple pulls trying everything we thought of and no luck. Plugs should some serious detonation going on!
2010-06-06 15:40:09
Thats pretty serious. Your on a whole other level than I am bro, lol.
2010-06-06 15:43:14
Lol I've been melting Iridium 8's. I doubt yours is nearly as bad as mine was. I finally got mine sorted out and made my first successful trip to the track yesterday. One of the issues with mine is that nitrous expess changed the jets AFTER I got my kit. When you look at their jet charts online for the direct port 4 cylinder kit the jets that came with my kit are rated for 60 psi. The newer kits come with bigger jets for 44psi. Right now my fuel pressure is at 60psi WITH the vaccum hose hooked to the fpr. Unhooked its around 70psi.
2010-06-06 15:44:42
Originally Posted by nismo94tuner
Thats pretty serious. Your on a whole other level than I am bro, lol.

Well it provides some good benefits. Totally seperate tunable setup for the fuel, so I can change ONLY what's going to the nitrous setup, and not affect how the car runs daily. Not to mention, I could use race gas in it, and still have pump gas in the normal tank.
2010-06-06 16:04:54
I will have to check everything out. I have to pull up the instructions from my old computer and see what mine is rated for. I wouldn't doubt if mine was rated the same as yours. I was getting ready to get some 520's for the damn thing and have two different maps for all motor and nitrous. If I can't figure it out looks like i'll have to throw in some pistons, sell the kit, and stay all motor.
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