Right now I have a pretty stock 350 in my 67 with a th350 and a shift kit. I have a aftermarket distributor, holley contender intake, barry grant speed demon 750 (I know its way too much carb but I planed on trying to build the motor up and the carb was too good a deal to pass up). I have headman headers and a nice free flow exhaust. I dont know much at all about the motor but its supposed to be out of an 86 blazer. (I dont know if I trust the previous owner on that information though) Right now as it is sometimes the car runs great and pulls nice sometimes it sucks and is sluggish and boggy. What are thoughts on putting a used TPI setup on the car? Will I be very limited on power when I get heads and a nice cam? I would like the car to run a little more consistant and just dont know if I can get that with my current setup. I imagine if I have a better setup motor for the carb it should be more consistant with some good heads and flow. I think right now when the weather isnt right the carb is just too much and I am fouling up the plugs and why its running sluggish sometimes.

I think I have a complete TPI setup I can get for 300. SO I am thinking about buying that and bolting it on the car seeling the carb and intake and when I can get heads maybe going with a carb setup again. That or going with a nice holley injection setup.

Thanks for the advice.

Zack

There is alot more to a TPI setup than just bolting it on. You have to have a wiring harness and computer.You can use a late 80s F body computer with an aftermarket chip or an aftermarket computer. You will have to put an eletric fuel pump in tank. Have to have throttle cable. Also there are two different types of TPI setups one is Mass air flow this system has a MAF sensor and adapts to change in air flow the other is Speed density and doesnt do well with change. There are other things to consider o2 sensor in exhaust. It would be alot to install for a short time also stock TPI runs out of steam about 4800 to 5000 rpms.With all that said just pick up a Holley 1850 600 cfm or simular carb. and use that. Maybe a good tune up plugs wires etc.Check ignition timng so forth.JMO

I second that...Go with the 600 vac sec Holley or Edelbrok and you will be more than happy. Save that 750 for another build like you said.

TPI conversions are a big job. My experience, through a friend, has been that TPI is great for street driving. My friends motor has reworked heads and larger runners in addition to larger fuel injectors. He has tweaked the computer. The motor is stroked. It has tons of torque between 1000 and 4000RPM, but kind of falls off above 4500 or so. From what we can tell, the fall off is a function of the TPI system more than anything else like cam, heads, exhaust etc.

you need to remember that the factory tpi was designed for a 305, the parts were just dropped onto the 350 and given bigger injectors (a large part of the reason that 5.0 stangs stomped tpi f-bods)

these guys are right: it's a lot of work
the worst part is that aftermarket tpi intakes are expensive (don't waste $ on the runners), you could always mod an lt1 intake but then you still have all the wiring to do

good carb in the meantime and map out a plan to efi the way you want it

good luck

I have to agree with the other guys, it is ALOT of work. Finding a complete, uncut, usable wiring harness, and then everything else that you will do to get it up to par with your current setup on a power basis will cost some serious time and money. The stock plenum, runners, and intake are all too restrictive, and EXPENSIVE. I sold the wiring harness from my 91 on ebay. 153.57 for a bunch of used wires. No computer included! If it helps any, the previous owner had switched it over to a carb setup, as well. I myself would have liked to have it, but just for the look and mileage basically. The stock TPI cuts out on power at about 4500 rpm, and like they said, was originally intended for the 305's. GM had the right idea at the time, but technology has came a long way...I have one of their first attempts at f.i. from the 80's, the crossfire set up. It is good if you want to blow alot of cash on rebuilding it (just like a tpi), and it is easy to tune. BUT, I wish that I'd have saved some money and switched it over to a carb. It would have cost 1/3 of what I spent on injectors, wiring, chips, modules, gaskets, etc., and I had a car that rolled out of the factory with it!

It will look very trick, I do have to say, though. Personally, forget the stock parts and do an Accel Super Ram DFI (good to about 6500+rpm) if you want to make any kind of power with a TPI style setup like that. I think that F.A.S.T. has some fuelie kits, as well, that might be more up your alley. Plug, program, and play is the name of the game. Honestly though, a carb will be easier to install and tweak, and won't cost anywhere near as much.

I haven't heard too much about the Holley systems, but TBI is one way to go. I think that Edelbrock offers a multiport system that provides a much broader torque curve and is just as easy to do as the Holley TBI kits. Alot simpler and cheaper than the other f.i. options. That's my $.02.

[ 12-14-2003, 05:10 PM: Message edited by: HawkZ28 ]

Thanks for the great info guys. That is exactly what I was looking for. It looks like I will pass on the setup and just save up and get what I would really like to do instead and do it right. Just a little tired of the car not running the way I want.

Thanks again

Zack

here it is from the horses mouth, lol.
cost? alot work? alot benifit? alot

cost of the tpi system is kind of high usually arouund $400. a painless wiring harness is around $300 i think.
custom reprograming of your computer $150
electric fuel pump-$160, new distributor $100 used
misc sensors $100. special ends to connect with the high pressure fuel lines $70 new aluminum fuel $35 another $100 on misc stuff.

work, alot, run a new fuel line, install new fuel electric fuel pump and high pressure filter, install a new wiring harness and mount all the new relays and computer. install the tpi manifold and new distributor, weld in o2 sensor, install a knock sensor in the block, install a check engine light, and if you put in a new 700r4 trans hook up the torgue converter lock up wires, fabricate a several switches to let the computer know if the car is in drive or neutral (not a netral saftey switch either) if you have a/c run the wires to let the comp. know when the a/c is on.
benifit. car starts and runs like a new 2002 ss camaro. no fouled plugs or carb adj. tpi provide a lot more usable torque for every day driving (at the expense of upper rpm power), 20 + mpg, although alot of that is due to the 700r4 over drive trans. it controls the electric cooling fans and adj the idle for the a/c and when you take the car out of netral and put it in park. so,if you want an every day driver with perfect cold and hot weather driving then tpi is the ticket. if you want a drag car and only drive it every once in a while stick with the carb. if you do not have a friend that is a very good on fuel injection or some type of support that can come to your house and help you, stay away from tpi. it is a trouble free system, but the install can get very technical and be a real nightmare. i love mine and it looks cool, but i would have never tried it with my ( ford svt mechanic) friend.

Look into the new Holley street ram or stealth ram.

My 70 RS/SS has early TPI fitted with an aftermarket (Haltech) fuel only ECM. The engine is fairly well modified, aftermarket heads, tough cam etc (none of which I have the exact specs on from the prev owner) - but its a quick street car with a 4 speed and 3.9:1 12 bolt posi in the back.
With TPI (aftermarket throttlebody), I have great low speed torque and a huge fat mid range that feels strong to 5000rpm. After 5000, you're basically wasting your time and by 5200rpm you can feel it run into a wall as it runs out of air.
This makes a great street engine as I shift at 4800-5000 and I end up right back in the middle of that fat mid range torque.
The TPI also gives me a very drivable car, and I have got some reasonable economy on a trip (given the nature of the engine mods and the 3.9 gears).
I've been so impressed with the TPI and the real time tuning ability of the Haltech computer, that I picked up another TPI (off an 89 GTA Trans Am 350) and I'll be using that set-up on a 400SBC that I'm building up for my daily driver - 76 T/A which is currently running a 350SBC.

i just read all of this string and almost dont beleive what im reading ..the reason small blocks fall off about 4000-4800 is the cam,remember economy, midrange, and race cams, its not the tpi i know guys turning 8K rpm regularly (maybe not every corner they come to but they aint driving miss daisy) on some small blocks and there tpi's are right there with them ...i have a tpi on my 67 and do my own programming to it ,nothing to radical of course and havent had any problems..what happens is the ecm calibration is limited to airflow of the maf on older systems but by a program scale once that is reached the programmer can extend any parameters he wants to compensate.. there a little work to put on but in my opinion well worth it..plus for the price that you paid for that high dollar chip you could be programmer your own.. graemlins/beers.gif

http://us.f2.yahoofs.com/users/3f3331f1_5014/bc/My+Photos/__sr_/done+finish+wire+loom+and+cons---1.jpg?phuIP5_ABcnRVOya

why tpi it when you can ls1 it

69 project (http://members.aol. com/getyopapion/Welcome.html)

I've had two third gen's with factory TPI. They are a little sensitive to temperature, they make more power when the manifold is cold. If you get the engine hot and let it sit and heat soak the power drops a little.

Take a look at the jetting of your current carb. It may be off a little and engine power varies with weather conditions, both humiditiy temperatures and barometric pressure. Plus your current jetting may favor one condition and not another.

If your manifold has a plenum divider, it can handle a 750 quite easily.

David

We are running an 87 Vette with ported intake base, plenum ,runners and heads , 3" daul exhaust shorty 15/8 headers a TPIS ZZ9 roller cam 282 in Dur. 287 ex. Dur. .483 in lift 520 ex. lift 11.5 to 1 comp. car pulls like a big block from 1500 to 5500 but after that just runs out of steam.The tuned port was designed for torque which is what it does best.