I already have this motor in a 71 camaro ss with 3.73 rear that posted a 1/8th time of 7.36. With full exhast and street tires ! I would like to put the engine in my 90 IROC, but not sure about leaving it carbed or getting aftermarket tpi setup for it. This beast has 425 HP ( at crank ) so would I need 30lb injectors ? Any suggestion as to the tpi setup ?

 

Super Ram, Stealth Ram, or Miniram.

 

tahts moving for a street tire car! dont put TPI on it... get TPI harness and run stealth ram or miniram. Superam may actually still choke that motor

 

Thanks for the advice five7kid and Orr89RocZ. I'm leaning in that direction but love the raw power the carb setup makes. Guess fuel economy and driveability count for something in a street car.

 

miniram and stealth ram probly will still deliver the same power output as that carb as long as you use a big throttlebody to not limit the airflow and have a good air intake system

 

Personally id keep the carb. wire it to start and operate smooth and chop all the injection wires and crap.. once ur playing around with that much power gas mileage really isnt worth the money for a stealth ram set up in the long run.. plus depending in the manifold/carb set up if you tune it right you can make just as much power without the tedious hassle of wirering.. u should run faster times on a drag due to the f body weighing somewhere like 800 lbs lighter than the 2nd split bumper gen like yours (providing you swap the 3.73's in along with it) but id be worrying about not tearing my car in half rather than what i should do with my feul set up (thats just me )

 

Hey chaoz28, you might be right. I did consider getting some suspension work done due to the power of that engine. But I got sidetracked with choosing fuel delivery setup. My 71 also has tci streetfighter w/ b&m pro shifter, and a 2300 rpm stall speed converter. And hell yes to the 3:73 rear. I was hoping to get my IROC down the track in under 11 sec. I think I will take your advise and spend my money where it's needed.

 

well how much is a carb/manifold setup? 200 for a intake, 400 for a carb?

stealth ram is 550 plus 80-100 for fuel lines. roughly same price, you just need to spend more time tuning the car with ecm rather than fuel jets/screws. Wiring? there isnt much to wiring on a fuel injected car. its not all that bad with a TPI harness

 

well im thinking in the area more of knock sensors and o2 sensors and other things that might throw an ecu into open loop if it isnt perfectly tuned.. also a stock mas airflow sesnor will not understand it needs what it needs to flow for a 383.. i understand it can be done ive seen it but i say personally go with carb because messing with ecu is not my department mehcnaical work to me is much much easier plus it is soo much easier to work with a carb if he were to decide on a top mounted supercharger or other set ups with forced induction..

 

That's just tuning. Knock sensor or O2 aren't going to kick you into open loop - it goes open loop at WOT, anyway.

'90 TPI doesn't have MAF. SD is the preferred set-up for nastier combos.

 

The maf will do what mafs do, and that is read the amount of air that comes by it. Which of course will be more now.

 

Yeah its just tuning to get everything to run right. From the sounds of it, SD will be very tricky to get running perfect on your setup and wil take much more skill and time to get right. MAF will still require alot of time spent tweaking as well.

 

Bah, keep it carb'd. FI is nice with the upsides of easier starting, economy, and usually more low end torque. But starting just takes a little patience, economy will be a joke anyway, and you'll have plenty of low end torque.

Used performer rpm-100 bucks ebay
650 holley dp-60 bucks ebay
rebuild kit-25 bucks.

If you want a quick car and fuel economy go with an LS1. 2-25k for used engine and trans. Throw a cam in it and you have 450+hp, and still get almost 25mpg.

All depends on how much you drive the car, what the savings in gas money would add up to in a year, and your extent of knowledge of FI systems. For instance you dont want to be pulling your hair out every time something goes wrong or you need to tune.

Thats a real nice motor but the cam doesnt do it any justice. I think with that cam vortec heads might actually get the car quicker in the 1/4.

 

still got to tune it

 

dont take tuning lightly. its alot of work. carbs are simple and you dont need to spend the long dollar to get things right. nasty small blocks and efi are tricky but if thats your thing do it.

 

Just the long hours. And wide-band O2 box. Or dyno tune (what, $100/hour?) Or multiple runs at the track and hope atmospheric conditions aren't affecting your data more than your tuning changes.

 

To get things close, doesnt take too long. Wideband makes it easy.

Constantly perfect jetting is near impossible.

 

idk? just trying to let him know one mans easy is another mans impossible.
I would say location is also a huge factor. I live in maine and dyno tunes for a custom built small block with efi would be hard to fine someone capable of such a thing. Tuning from the ground up efi wise on the track with no experience doing it would be a long difficult activity imo.

 

Either type of system assumes some level of ability from the owner.

Carb tuning is not as easy as falling off a log, as some people seem to imply. Dyno tune handles that if the dyno operator knows what they're doing. Wideband requires the user to know what they're doing, and the intricacies of the carb circuits can be rather daunting if you want to go beyond basic jetting, power valve, and accelerator pump tuning..

There is a bunch of EFI tuning information available on this Board. It will require some study and trial & error on the part of the user, but the expense is basically the initial equipment investment.

 

No doubt about it nothing is easy. I spent the better part of the summer getting my double pumper dialed in. It was a ton of trial and error carb wise to get perfect or damn close. Makes you really appreciate how engines work. If you are just going to swap parts and hope for the best that will only take you so far. Without that experience i personally dont think that i would have been able to jump right into efi at that level. But I was more of a parts changer before the engine swap.

 

Part throttle tuning with a carb can be a real pita. For a daily driver, I would definitely choose EFI.

You know, if I had the money, and a good bit of EFI experience, Id want everything to be EFI. It'd be great to tune the car at the track with a laptop. But, I know how to tune a carb fairly well, its cheaper, and I really like the extra cooling effect it gives me with blow-through.

Re-reading this thread though, I think the original poster is keeping his carb and putting money into more important things.

Hey I just hit thread count 666. Yikes.