Ive been trying to stay TPI but lately I think Im gonna go over to the dark side. It seems like too much work with all the porting and whatnot that has to be done. Dealing with the MAF and all, plus my headers for some reason came with the o2 sensor hole filled in so I would have to bore tht out to make the system run right. Not to mention that the after market parts are way expensive. With the set-up I have and the big cam I cant get enough air into the TPI to burn all the fuel needed without porting it to hell and buying a new throttle body. Why bother when I can just drop a 750 cfm Holley on it with a hi-rise intake and be done with it.

I just thought I would mention it becasue maybe Im overlooking something important and you guys could "open my eyes" so to speak. I would also like information on which carbs are the best becasue I seem to get mixed responses maybe I should set up a poll. Or maybe someone could offer me a good price on an intake and carb set-up.

 

Darth,
For me going to carb is not even an option. I am gonna stay fuel injected and I'll tell you why. Based on the datalogs of my car, its so easy to diagnose whats wrong with the car. You switch to carb and then you have no clue whats going on inside your engine. i.e. You have no idea what your fuel mixture is unless you do WOT cut offs and then read the plugs. I just plug in a laptop and find out exactly how rich or lean I am then I burn a chip and fix the problem. I dropped .7 and gained 4 mph with 1 reburn of my chip. My buddy Dan has a carbed car and has fought with it to gain .5 after about 3 or 4 trips to the racetrack. I did it between visits.

Also, without new heads or ported stock heads, you are not gonna max out the airflow capacity of the TPI. The heads simply don't flow enough to be choked by the TPI. In factory form they flow an anemic 195 cfm @ .500 lift which is where they begin to port stall... meaning they level off at .500 lift and over. Using factory TPI pieces kevin91Z has gotten solidly into the 12's. Simply swapping to a carb is basically the "easy" way out of learning to make a perfctly capable setup go fast. I saw "easy" because to me it would only complicate things. Not having those all important sensors and the laptop to read them would leave me guessing. I don't like guessing when I have a motor worth a few thousand dollars on my broke *** budget.


Not trying to dissuade you, just giving you the reaction of a guy who is diehard Fuel injected.

Best wishes with your decision.

 

There ya go.
Not one person to the best of my knowledge has done the swap to a carb and not be happy. I made the swap and I am very pleased, of course I didn't have God's gift to performance TPI ( ). Tuning software is much cheaper ($30) for a jet kit. And tuning is very easy to do with some common sense and a vaccuum gauge.

 

I guess it all goes back to my background I grew up around a bunch of guys that have been building race cars since the 70's and needless to say they are all die hard carb guys. I dont really know anyone to help me out with FI. My uncle made a backyard built 327 with a single holley 800cfm carb go mid 10's in a 55 bel air that prolly weighed twice as much as my camaro. Oh yea and that was a daily driver. When I have resources like this close by its hard to ignore them.

 

I agree with RedIROCZ28. It all depends on where your point of view is. My father was all about carbs in his youth, and now he is a die-hard EFI guy. EFI has a steeper learning curve, but once you learn it, its much easier. And yes it has a higher price, but the ability to hook up a computer to your car to read what the engine is doing pays for itself.

I would really advise against hacking up a TPI car to go carb. Sell it to someone who wants a TPI car, and go hack up a carb or TBI car. ;-) Maybe you can even find someone who wants to trade you cuz they're sick of their carb car.

By the way, I have a TPIS intake and runners on my car now. I went a best of 13.23 @ 107.18 with the stock port-matched intake and runners on my previous engine.

 

If you wanna go 13.30's @ 105 MPH....

89 305 TPI engine
Put a Edelbrock Performer intake with a Holley 600 carb on it
Lokar cables
Fuel pressure regulator set at 9 PSI
SLP headers
3.73 gear
Nitto Drags
Nitrous Express LT1 kit converted to a carb plate with 100 HP jets
NGK 1 step colder plugs
Had timing at 8 degrees base...which is high i think but it worked fine

15lbs of juice later, it still runs 13.30 at 105...i'm happy enough and the trans even shifts nice till

Plan is to back off f the timing to find more power possibly, lose a few more pounds off the car...Hopefully it will go 12's like that. Either way, it will see 150hp jets before winter...Video's to come..

 

You crazy animal!

 

Im not goping to hack up the TPI actually I was gonna take it off and work on it slowaly as I had the money and resources. If I decide I dont like the carbs performance Ill put the refreshed and built TPI system back on.

It seems to be split about 50-50 at the moment some people teliing me to go for it some telling me not to.

 

It's your car, so you have to do what you want with it. I like the TPI, and wouldn't go from that to carb, at least not in a 3rd gen. I wouldn't want it on my Chevelle though. I guess everything has it's place. What are you using the car for? Racing mostly? street?

 

Its my daily driver but I dont drive like 1000's of miles per week becasue I ussualy stay on campus so gas isnt a huge issue but I wouldnt like drop twin dominators on it and ruin my milage completely.

 

I did the opposite, went from carb to TPI. Main reasons were fuel economy and looks.
It wasn't all that hard.
My carb setup, http://www.transamws6.com/pics/transam/Edelbrock.jpg

My TPI setup, http://www.transamws6.com/pics/transam/engine.jpg

My current project is building up my LT4 and dropping that into my 86 Trans Am.