hey i am wanting to carb my lt1 for more power......i have heard that you need to change to a regular distributor but why would you have to do that? Couldn't you just leave the optispark the way it is? What would make the opti not work changing to carb, it doesn't make any sense to me. Any help would be appreciated. Thanks
-Jon

 

The Opti can ONLY be run by the LT1 PCM.

BTW; I doubt your gonna get more power by swaping to a carb. It would be better just to sell the LT1 and get a late 80s roller cam GEN I motor to build up.

 

It can be done, but don't expect the big power boost you would get if you were swapping out an old TPI manifold. Basically you can use the opti, but you will need to use a TPS and a MAP sensor for the computer to control the ignition and the transmission if it's an auto.

 

My bad, your right. You can use the Opti. But the PCM is gonna be pissed with most of it's seensors and the fuel injectors gone.

 

Are you joking???? All the carbed car guys at the track are jealous of those of us who have embraced injection and get more pwer with better drivability and economy as well as often going faster because we can REALLY finetune things.

I strongly suggest you do some learning before you go and trash your car.

My car runs 12s in even the hottest and most humid weather this summer threw at it and does so at about 4250lbs with me NA on a stock 100k shortblock, gets upper teens for normal milage and is mellow enough for the wife to take grocery shopping or to tow my fishing boat to the lake. I think nothing of driving a few hours each way to a different dragstrip. A carb wont get you all that. At the local strip all the carbed stuff running the times I am is either outright trailered or only driven on raceday by contrast I have put 5K on my car since the heads and cam the end of April. Embrace the injection and you WILL be further ahead.

 

then why are all the fastest lt1's and ls1's carbed?

 

Joe O isnt carbed.. or last I checked he wasnt, and hes the fastest N/A fbody out there, or at least he used to be (Ive been out of the scene for a while). I think he was using TB as an air horn and running a carbed manifold with a custom MPFI setup.

http://www.gmhightechperformance.com.../photo_02.html

Thats not a carb, its a Throttle Body being used for the sole purpous of regulating air flow through the intake and telling the injectors how mych fuel to dump via a TPS sensor.

Fuel injection is the way to go. I know many fbodys that are running 12's in stock intake trim with MINOR head work and a cam. Hell my car is bottom 13's iin road race suspension trim with nothing more than headers and a small Isky cam with some minor dyno tuning.. and Im sure I can get it to the 12's and still get 20+mog on the highway with more time on the dyno.

Stick with the fuel injection and you will be happier to drive it more often than not.

 

Another consideration is many racers get VERY stuck in their ways and will NOT adapt to newer technology, does not mean what they do is right. Often times that refusal to learn is a giant handcap.

 

Carbed better then fuel injection, thats almsot funny, but ill be nice.
I think this is a good example of how carbed is worse (this imo) Look at the cars from trhe 60's big block motors with 350 horse power, look at the 98 and up ls1's 350 hp(or something in the 300's I dont own ls1 so) out of a 350

 

I've seen very few carbed LT1 or LS1 cars. I do know a friend that put a carb on his LT1 and even with a stall and a bigger cam my stock block LT1 will smoke him every time. The #1 reason I see people swaping fuel injection for carbs is they want to go fast and don't understand FI enough to make it fast.

If you swap to a carb you will destroy the value of the car, never pass emissions (more and more states are requiring it), it will never get good gas milliage, and it will never run as good as it does right now.

 

The new LS7 make 505hp. No 70s big block ever made that, even with the old GROSS HP measuring system. 505HP NEt would be something like 575 HP gross.

 

I completely agree thats the main reason peolpe carb there FI, because they don't know how to make it fast.

 

that might play a big part in it, but i'd say the MAIN reason is cost. at least it would be for me. i agree that for a street car the EFI set up is the way to go if your car is already equiped with it like LT1 cars are, but dollar for dollar at the track you still can't beat an old fashioned intake and carb set up. if you are really wanting to go fast you can't really use much of the factory EFI anyway can you? i'm NOT talking about 12's or even 11's, i mean like sub 10 second times.

 

Compare the cost of converting to the cost of working with what is there and your argument losses credibility, replacing things that don't need to be is probably the number one way people **** away their potential mod budget and end up slower than they should have been.

 

I'm not getting your point, what do you mean we can't use the factory EFI if we want to go fast. You can tune the factory EFI and buy bigger injectors,throttle body, ECT. Not sure what your saying.