TPI vs LT1 - LT4

[Guest Hauptmann03]

John Baechtel's book "Chevy TPI Fuel Injection Swapper's Guide" has some powerfull arguments in favor of the TPI such as Plentiful, Cheap, Lots of support, Cheaper, Good potential through hot street motor (All but the most extreme racing output) and super low and mid-range torque. What more can one ask? Baechtel actually states that the TPI will run with the LT series when properly maintained and tuned. He says they are plentiful and all kinds of parts are readily available.

What do you experts think about this?

Thank you,

[Guest 73TPIZ]

I'm no expert, but the torque the TPI generates with just my 305 is a blast around town and does ok at the track. Best part is i don't have to spin mine to 6500 to make HP. she pulls high 12's shifting @ 5000 and that's enough to piss off the f-bodies, the fox bodies, and even some of the new y-bodies (camaros, mustangs, and 'vettes).

 

And don't forget the visuals................

 

[Dan Juday]

O.k. I'll comment. I put a 305 tpi in my Z as well. Ths last summer I put a (an?) LT1 in a friends Tomahawk (280Z with Cobra body). The low down torque of the tpi is great. But having driven both cars there is no doubt in my mind that LT1 is superior. I have Baechtel's book as well and frankly it is out dated. LT1 upgrade parts are more plentiful and cheaper dollar-to-horsepower than the fading tpi stuff. The computer is easier and cheaper to reprogram.

 

The LT1 comes from the the f-bodies with aluminum heads and T56's bolted to them. Now that the LS1 is becoming more available in the yards the prices of LT1's are dropping and will continue to. Heck, the Camaro guys are pulling there LT1's and swapping in LS1's.

 

The one area the tpi has over the LT1, IMHO is looks. I love that big bad finned plenum stuck up in the air by those eight sexy curvy induction tubes. You do the LT1 swap and I'll park right next to you at MSA and pop the hood, but I wont meet up with you later to race.

[Guest zfan]

I have a question re: the LT1 injection system. Can it be made to run on the earlier non LT1, non fuel injection blocks?

 

I have a 383 sbc chevy with a weiand dual plane intake and 750 proform dp carb and would love to go fuel injection. I wouldn't want TPI because my motor is ment to spin to 6300-6500.

 

Mike

[Guest dpiatkin]

Hey Zfan, here is a link for the "LT-1" intake and he says that you can use it on all sorts of critters !! chek out his website, good info,and prices !

http://www.lt1intake.com/services.htm

[Guest 73TPIZ]

But Daddy, I like the dinosaurs. Why did they have to die.

 

because they were slow...............................

[baddriver]

I have that book, and I know where you are coming from, but the book basically states that you need to replace the runners, fuel injectors, intake, throttle body, etc in order to make good horsepower. When you get done with all the changes recommended to make the TPI 'competitive,' there's almost nothing from the original tpi left!

 

The LT-1 makes good horsepower out of the box, not after you add $2,000 in accessories, and that's the appeal. I found that book to be more of an advertisement for aftermarket parts than anything else. It has some great info, and it's certainly correct that if you already have a TPI, you can make it competitive with an LT1, but if you are out shopping for engines, the LT1 is hard to beat.

[baddriver]

Zfan,

 

I think that you could get the early, non-sequential system to work with a non- LT1 engine, but there are two big problems I see with that. One is that the distributor design is very different, and I don't know if you can make the LT1 computer work with an older distributor (well, I'm sure you could, but not easily) The other is the crank position sensor, which you won't have on the older SB. I don't think the early LT1 engines had the CPS, so they might work, but the later engines certainly need one.

 

And you would need to modify the intake manifold to fit on the older block. No, scratch that, since the new manifold has no water passages, you would have to modify an existing older FI manifold to accept the injectors. All together, yeah, it could be done, but it's probably not the easiest way to get FI.

 

You could get a TPI, replace the runners with siamesed runners, a big throttle body, etc and have a system, but you might as well buy a stealth ram like Grumpy is always suggesting for the money you'd spend.

[fl327]

waste of time trying to get tpi to rev up even like stock Lt1.

power made with tpi is for low to mid rpm thats it, even with siamesed runner big tb and the air foil, still going to run out of breath anywhere past 5500, and im being optimistic there. Can still put together 12 second maybe 11s in a z though, as its not hard to make 300hp with a 350, just have to make 300 before 5k rpm, not hard to do. Entire donor cars are anywhere from 100-1200 and up running decent enough to swap out. Its a pretty good deal for efi and an overdrive trans. If they came with turbos, I do the swap again

[Guest zfan]

Thanks Guys! I guess I will just wait for something better to come along.

 

Mike

[fl327]

ps. the spider plenum of the tpi does look good.