I'm a newbie here, but have found so much interesting help just by reading. I have a 97 Z28, 6 speed. I have removed the LT1 and built it into a 383 using a Scat forged crank, forged 5.7 Scat H beam rods, forged JE pistons, ARP studded 2-bolt mains, Custom ground Comp Cam (consulted Comp), ported stock heads, ARP head studs, Crane Gold roller rockers, Edelbrock headers, Flowmaster single 3" in dual 2 1/2" out cat-back, BBK 58mm throttle body, 42# injectors, Walbro 255lph pump, Vortech V1 w/ approx. 12lbs. of boost (still working on the rest of the Vortech parts), Centerforce DFX clutch. I have the Vortech head unit with the two rear brackets, I am looking for the rest of the parts to install it. If you know of anybody with them I would appreciate a hit. I'd like some advice on who to have burn a chip for this and what your opinions are on this combination or if you can think of anything I am overlooking. The motor is built, I'm just waiting on the throttle body so I can bore out the intake, than the remaining Vortech parts. Is anybody running the DFX clutch? It's back-ordered, so I still have time to change my order if needed. Your opinions would be great!

 

One thing I thought of while reading is that 42 Lb. injectors MIGHT not be enough for a built motor plus 12 lbs. boost.

You may need to move up to some 60 pounders or something once everything is done

 

I agree about the 42# injectors. I would definatley look into some bigger ones. As far as the Vortech brackets you could always order them from Vortech. I see alot of stuff on ebay as well. You said you have a 97, so there are no chips to burn. You have an OBDII PCM. You can have a mail order tune done for it, or get a programmer such as LT1 Edit, HP Tuners (I think they have something for LT1's). I think Tunercat for OBDII's fell through. I had descent luck with a tune from PCM 4 Less and Ion from MadZ28. I opted to ditch the factory PCM and go with a FAST system. I have no idea how it works yet, still building the new motor. Don't skimp on the fuel delivery or you will pay for it, I know. Good luck, Rob.

 

If you think you'll be making over 500rwhp, that single in-tank pump is not going to be enough. I'm over 500 and even with a boost-a-pump my fuel pressure is OK at 10 lbs of boost. I'm also running 60 lb. inj. My target is 15 lbs. boost so I figure I'll need a dual pump setup for that.

Not sure, but aren't the Edelbrock headers shortys? You might want to consider LT headers for more flow.

For my base tune, I had Ion of MadZ28 do it along with a OBD2 to OBD1 conversion. His base tune was good enough for cruising but a dyno tune was necessary to get the fuel and spark optimized.

By the way, what are you doing for an ignition system?

 

All very good information. I should have stuck with my first thoughts and gone with the 60# injectors. Oh well, I'll relist the 42#'s and get some 60's. I'm so use to playing with OBDI on my truck that I didn't even think about the OBDII, thanks I'll check with Ion for that. As for an external fuel pump what do you suggest? I didn't think you could flow more than the in-tank pump would allow to pass it without completely removing it. Why the OBDI conversion Joe? As for ignition currently I have the spark retard box from Vortech/MSD but I am open to suggestions. I know that LT headers would probably be the way to go, but I'm trying to keep it looking as street legal as possible (air pump, cat - or at least cat-looking). By the way, I received an email from Jegs this morning that my DFX has been shipped .
Thank alot for all the great info.

 

Check with Lonnies Performance about his dual intake Walbro setup. One pump stays on constantly while the other one kicks in under boost, around 5# or so. You have a 97 and I sent him a Fuel pump assemebly for a 97 by accident. He said the 97 is its own entity, so I had to send him another one. He might still have it and as far as I know it's ready to bolt in. Tell him it was the one Rob from Hawaii sent him. This would save you the hassle of taking yours out and sending to him. The dual intake is supposed to support 1000RWHP, so that should support you with no problems. That setup will run you about $600. Once again don't skimp on the fuel system. Good luck, Rob.

 

I went for 72# Seimens injectors with and Acceleronics driver. The Peak and hold style injector run great. Very fast opening response. Also, I run 2 Walbro 255 lph pumps. Easy to adjust the WOT PE curve with a Dynojet WB O2 and lt1 edit. (97ss 383 D1) B.

 

Chasmosis1: I went with the OBD1 conversion because I was told it's much easier to tune. Also, the tuning and logging software is cheaper than the OBD2 software.

 

Good deal, thanks

 

My calculator says that 42# injectors are ideally suited for 450 HP engines, where duty cycle does not exceed 80% and Brake Specific (?) Fuel Consumption is set at 60%.

500 HP needs 48#; 550 needs 52#, 600 HP needs 57#.

 

Thanks Ultra Dog, I already sold the 42#er's and ordered the 60#er's.