injector quest
Thread Starter
Racer
Joined: Jun 2001
Posts: 335
Likes: 0
From: MANTEO NC USA
injector quest
i just got a set of 28lb injectors that i am putting in my 86 L98 i have a adjustable fuel pressure regulator. what should i set the fuel pressure at my mods are motor is bored .40 over 52mm tb, heads ported and polished, siasmed runners, slp headers, no cats, flowmaster mufflers, open air lid with k&n air filter, undrive pullies, comp cam .444/.444, and a hypertech stage two chip. i also have a wells maf. compucar in a bag dry shot system (100 shot) but i don't use it all the time..
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: injector quest (DADDY D)
I would definitely run a lower pressure than stock.
On my 355 with a 0.442/0.465 (w/ 1.5) cam and 1.6 rollers, FMS 30 lb/hr injectors were gratuitous overkill. I smoked my Random Tech high flow in about an hours worth of idling/driving/idling.
THe main problem is that you want to keep the FP high enough so you still have good atomization...and I can't tell you what pressure that would be.
Using a scanner and keeping an eye on the BLM values at idle will be your best bet. Good luck, -Matt-
Edit-100 shot of N2O. Hmmm. I would make sure my timing was not advanced any more than at factory specs because with the Hypertech, you can run detonation with a stock setup. The injectors are going to be kinda hard to tune for in a situation like this. Your N2O kit injects juice only and no fuel correct?
[Modified by HighHopes85, 11:06 AM 8/29/2002]
On my 355 with a 0.442/0.465 (w/ 1.5) cam and 1.6 rollers, FMS 30 lb/hr injectors were gratuitous overkill. I smoked my Random Tech high flow in about an hours worth of idling/driving/idling.
THe main problem is that you want to keep the FP high enough so you still have good atomization...and I can't tell you what pressure that would be.
Using a scanner and keeping an eye on the BLM values at idle will be your best bet. Good luck, -Matt-
Edit-100 shot of N2O. Hmmm. I would make sure my timing was not advanced any more than at factory specs because with the Hypertech, you can run detonation with a stock setup. The injectors are going to be kinda hard to tune for in a situation like this. Your N2O kit injects juice only and no fuel correct?
[Modified by HighHopes85, 11:06 AM 8/29/2002]
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: injector quest (DADDY D)
If you can determine the correct fuel pressure with your stock injectors you can use equations on my site to estimate pressure for the new injectors.
You realy need a scan tool to assure that the ECM can compensate at part throttle for increased flow.
You can put the ECM into diagnostic mode (jumper ALDL A&B before starting the engine) and watch the SES flashes to assure that the ECM goes into closed loop mode and runs at stoch A/F during normal and fast idle. This will assure that you don't fry your cat.
You realy need a scan tool to assure that the ECM can compensate at part throttle for increased flow.
You can put the ECM into diagnostic mode (jumper ALDL A&B before starting the engine) and watch the SES flashes to assure that the ECM goes into closed loop mode and runs at stoch A/F during normal and fast idle. This will assure that you don't fry your cat.
