tracar91

iTrader: (1)

I'm in the middle of my LS1 swap into my street/ track day 1991 Z28. I am to the point of making a decision on my induction system. Going from my 350 TPI setup I realize I'll be losing alot of low end torque (I will miss that) in order to gain HP and revs at the top end.

I use the car on nice days, weekends for car shows or autocross, and 3-5 weekends a year for open track days on various road courses. I very occasionally will take it down the drag strip. Within a couple years I'd like to compete in the NASA time trials for Ohio/Indiana and a high speed road race like the Silver State Classic.

My choices are these:

1) leave the LS1 intake on and pay $ to get the wiring harnesses combined. This allows LS6 or Fast intake as time and budget allow, and HP need requires.

2) Go to a GMPP intake and carb, using the MSD wiring system. about the same cost, a little simpler wiring, possibly less tuning flexibility (haven't done a lot of research on this option)

In your opinion which option is better based on:
1) Ease of installation
2) Low end Torque
3) Drivability/ reliability
4) Future modability

bczee

iTrader: (12)

Question?.. have you drove many 4th gen F-Body with the LS1? or other Gen III/IV engine.. If you did, I think that many of your question would be answered.

1) People say they go to the Carb setup because of ease of installation of Gen III/IV engine, It maybe a few step easier, but in the long run, EFI will be the way to go and the rewards will out weight the Carb for your usage and for many of the your other questions will be answered.

2) If you get a good tune with EFI, you can tune and recover most if not all of that low end torque you think you will be losing from the TPI setup if not more.

3) EFI all the way.. cold moring startups are a just get in and turn the key! Driving in different elavations are handled by the PCM and its sensors.

4) both Carb and EFI have many advantages and are getting to the point of endless "Future Modability"

Don't get me wrong, I still drive my 84' Z28 L69 / T5 (been upgraded to balanced 350 with World SRII head, CAM and Edelbrock Intake.) setup.. but you have to go with what you learn yourself, and I can see and drive both Carb and EFI, so I have my options.

67rsss

iTrader: (4)

Even if you decide to buy a new custom harness for $750, you are still ahead costwise. I would keep the Fuel Injection (obviously since we did). I don't think you will be dissapointed with the low end torque, or the mid-band, or the high end either. The Gen III is a torque beast. We can start out in third gear without the engine even noticing. The wiring can be scary at first, but take your time, and ask questions. It isn't too bad at all, and you are swapping into a popular vehicle, so plenty of people are qualified to answer your questions. When you can afford to change to an LS6 intake, do it! Take a good look at some of the third gen swaps on the board, and don't hesitate to ask questions whenever you can't find an answer! Really isn't a bad swap at all, and you will love the reliability, power, and startup of the fuel injection.

Stu Cool

iTrader: (13)

GO EFI, If you are a little uncertain, then go with someone like Speartech to mod or build your harness. 4 wires, plug and play. Then as time and $ allows get some tuning software and start learning. These motors have such a great flat torque curve, you won't believe how hard they pull from almost any RPM. I think it's called power under the curve. Plus, if you put any significant amount of miles on it, you will appreciate the fuel mileage.

"You can't even buy a weed eater with a carburetor anymore!" - Warren Johnson (complaining about still having to run carbs in Pro Stock)

Pat

NemeSS

iTrader: (127)

go with ls6 intake, easiest to replace ls1 intake,
unless you are going for max effort or forced induction
no need for vic or fast.