tuned port injection

[cvalcore]

Im thinking about converting my 1990 suburban to tpi and keeping the 350 possible pulling it and building a 383 stoker out of it instead of the 454 for mpg reasons but what is involved in the conversion i no where i can get a complete set up for a decent price and possibly a complete engine?? I would really hate putting a big block in my truck and then not wanting to drive it because it cost so much.

[cvalcore]

i put this in the blazer and suburban section but i might get more people looking over here.

Im thinking about converting my 1990 suburban to tpi and keeping the 350 possible pulling it and building a 383 stoker out of it instead of the 454 for mpg reasons but what is involved in the conversion i no where i can get a complete set up for a decent price and possibly a complete engine?? I would really hate putting a big block in my truck and then not wanting to drive it because it cost so much.

[travis401]

the tpi setup is awesome looking, but doesnt flow very well above 4500rpm for even a low output 350. you can correct that with some porting and aftermarket parts, but after all is said and done youll have spent a lot of money to get a tpi setup to feed a healthy 383. for a lot cheaper you can get a holley stealth ram. you can also get a tbi system to feed a 383 for cheap.

[MalibuSSwagon]

Originally Posted by travis401

the tpi setup is awesome looking, but doesnt flow very well above 4500rpm for even a low output 350. you can correct that with some porting and aftermarket parts, but after all is said and done youll have spent a lot of money to get a tpi setup to feed a healthy 383. for a lot cheaper you can get a holley stealth ram. you can also get a tbi system to feed a 383 for cheap.

A truck doesn't spend much if any time above 4500 RPMs. I just converted my C10 to a stock TPI system. I plan on towing and working the truck, not really racing it with an SM465. I did this for reliability and fuel economy reasons.

There are many methods for porting the TPI system to breathe better, and aftermarket parts as well. If you want to go big, you can pickup a Holley stealth ram or a FIRST system.

Not to mention the TPI system looks great, and can be had for fairly cheap. I found mine on craigslist for $50 and picked it up for spares for another project. re-purposed it for my truck and its turning out great.

[cvalcore]

i just want to use it to tow a trailer every once in a while threw the canyons with out the truck struggling its fine around town but as soon as i go through a canyon it kills it and then you throw a trail on it and im giving it hell. i plan on re gearing it with in the next couple of weeks. and that may help out a lot. im not looking for it be supper fast i just want it to have no problem hauling a trailer and go threw canyons with out being floored. im just wondering how much of pain in the butt it is to convert it over i want the least amount of down time possible.

[travis401]

if you dont plan on revving the engine past 4500, a stock tpi setup should be fine. id suggest giving it a nice port anyway just to free up a lil more power potential.

anything over 4500 and the tpi will just fall flat on its face. retro fitting a tpi system is easy. if you can get the wiring harness and computer from a 3rd gen f body or corvette itll be a simple bolt on with a little more work. the tpi system was used in cars when computer control was limited to the engine only, so its pretty simple to swap.

[cvalcore]

i have heard that some years are better than others to run?

[MalibuSSwagon]

For starters you'll want an 87 - 92 TPI to fit your heads. Also you can easily convert your stock TBI harness to run the TPI system.

Sign on at www.thirdgen.org and start browsing the TPI section. Easily the largest source of TPI info out there.

www.chevythunder.com is an excellent resource as well.

Thread on converting TBI harness to run a TPI - http://www.thirdgen.org/techboard/tp...d-density.html

I personally had a Camaro harness that I stripped down and repinned for my application. I went this route since my truck was originally carb'd, and I had the harness. Since you have a 1990, your truck is already wired up for fuel injection. You just need to make the wiring and fuel system changes under the hood, repin the ECM connectors, and replace the fuel pump with a TPI camaro pump.

Honestly it can be pretty overwhelming when you are staring at a pile of wiring, I've been there. Just take your time, do the research, and it is achievable.

Check out my build thread if you'd like some motivation.

[travis401]

the major difference in the years is the earlier setups were map (mass air pressure) set ups, the later ones were maf (mass air flow). they also had some that had a 9th cold start injector.

ive been a member of TGO since 07 for my camaro, so i can attest to the wealth of knowledge on there. just be aware that if you want to sign up and post, youll catch flack for not having a 3rd gen. but some people will still probably help you out.

[hatzie]

Originally Posted by travis401

the major difference in the years is the earlier setups were map (mass air pressure) set ups, the later ones were maf (mass air flow). they also had some that had a 9th cold start injector.

ive been a member of TGO since 07 for my camaro, so i can attest to the wealth of knowledge on there. just be aware that if you want to sign up and post, youll catch flack for not having a 3rd gen. but some people will still probably help you out.

I think you got that backwards. MAF is the older system.

The MAF (Mass Air Flow) sensor system used on the 85-89 Tuned Port Injection is easier to source. The MAF TPI manifold also has provision for a Cold Start Injector. The MAF sensor is a big lump in a tube between the air filter and the throttle body. MAF is self adjusting to some degree so it's much more forgiving of minor problems with the ECU fuel tables. The forgiving nature of MAF makes it ideal for a 383.

Speed density with MAP (Manifold Absolute Pressure) sensor was the later system 90-92. It's a cleaner install because the air filter bolts directly to the throttle body. However Speed Density needs more exact fuel tables than MAF making it more difficult to tune.

The 4500 RPM limit is way overblown. Stock TPI makes some nice torque at much lower RPMs than TBI. Stock TBI 305 is 255ft/lb TPI 305 is 295ft/lb most of that 40ft/lb is the manifold and fuel system. I'd rather have MAF Tuned Port than Throttle Body Injection.

[68Timber]

A tuned port 383 can be a torque monster if you keep the cam mild, no bigger than an XE 268.

EDIT to add, 3rd Gen is a good site for those induction systems and swaps.

[cvalcore]

ok so all in all will it still get better gas millage than 454?

[cvalcore]

the is the 383 im looking at right now
http://www.ebay.com/itm/CHEVY-383-37...#ht_2404wt_989

[68Timber]

Originally Posted by cvalcore

ok so all in all will it still get better gas millage than 454?

Yes it will. That 383 looks to be spec'd nice. A camshaft of that duration will work well with TPI.

[cvalcore]

will a stock TPI work on that engine or will i need a bigger throttle body runners and intake?

[68Timber]

The stock tuned port set up works pretty well and should be fine on that engine. I don't recall the cam specs but I did look at it. If you start buying aftermarket TPI induction parts the price is going to go up fast unless you can get it all used.

[cvalcore]

ok so what ive gathered i can still use the stock ecm i have in the truck now? and i picked up a tpi with 9th injector but i bought some slp runners and a 58mm throttle body from a guy and be told me that i should not run the 9th injector and just plug it and to not run the maf and put map on it? he told me that this is how he runs his rock crawlers. im sure im making this way more difficult than it needs to be but i want to make sure i get it right and that its still emissions legal in utah. also does anyone no what size injectors i should run? im going to port the plenum runners and most likely the stock intake to the heads?

[68Timber]

I wouldn't begin to know how best to tune one, I'd highly recommend thirdgen.org for that. They're the source for modded tuned port engines.

[MalibuSSwagon]

I went with MAP on my truck since I am running the stock mechanical fan. You need to convert to electric fans with MAF since the piping for the intake would hit the stock fan. With MAP you can just stick a filter on the throttle body

[cvalcore]

ok i have a question i just received the engine i posted above and i asked the guy for a dino sheet and he said he would provide it with the engine and it gets here with no dino paper. now if he sends me a dino sheet how do i no its for my engine and not another? i really just want to make sure this engine has what he clams in it with out tearing it down voiding the warranty

[closer9]

Don't mean to steal your thread, but I'm just curious...

For those that added TPI on a carb'd truck. Did you use a late model fuel tank/sender, or just add an inline pump?

I've got everything I need (I think) except wiring and fuel pump. Been looking at Painless etc, but not sure if I want to just find a stock harness to adapt. It will probably be a while before I tackle this. Got several other projects I need to get to first, but would like to do my homework, and collect the rest of the necessary parts as I can.

thanks...

[MalibuSSwagon]

I bought a new EFI tank and fuel sender for an 87+ R/V truck, and a stock TPI Camaro pump. You could use an inline pump with a surge tank.

I did rewire and cut down a stock 85 Camaro TPI harness. Takes some time and research. If you want to go with a new harness, I would suggest Fuel injection Connection. They have TPI harnesses for $245 for a Speed Density harness.

http://fuelinjectionconnection.com/e...s-catalog.html

[closer9]

Thanks, that's what I was hoping. Was just afraid they might have changed something over the years. This will work out good, because I've been told my tank is a perfect fit for getting the tank out of the cab on Dad's 64.

Thanks for the link. I'll check it out.
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[MalibuSSwagon]

square body Blazer tanks are apparently very popular for swaps.

I got a good deal on all my stuff from rockauto.com, even with shipping factored in.

[68Timber]

Originally Posted by cvalcore

ok i have a question i just received the engine i posted above and i asked the guy for a dino sheet and he said he would provide it with the engine and it gets here with no dino paper. now if he sends me a dino sheet how do i no its for my engine and not another? i really just want to make sure this engine has what he clams in it with out tearing it down voiding the warranty

The dyno sheet could have been faked before shipping even if it had been included with the engine. I'd still want the dyno sheet but would install the engine without worrying about that - as long as you did your due diligence before you bought from them.