I am buying this TPI setup from an 87 TA http://www.thirdgen.org/tec...i-setup-100_0480.jpg it comes off a 350 so it has the 22lb injectors for my 350 now due to me using vortec heads I know i have to swap the lower manifold for a vortec one. What I dont know is since this is bone stock (also has stock ecm and stock harness just not pictured) What else besides intake plumbing and modifing the ECM and harness will I need to do? This isnt going to be happening for some time seeing as the lower manifold is almost 500 bucks I dont have right now. Just trying to get a feel for what Ill need when im ready. Any can anyone point me to a good TPI porting guide online? Thanks for the help.

quote Originally posted by linuxpowered88: I am buying this TPI setup from an 87 TA http://www.thirdgen.org/tec...i-setup-100_0480.jpg it comes off a 350 so it has the 22lb injectors for my 350 now due to me using vortec heads I know i have to swap the lower manifold for a vortec one. What I dont know is since this is bone stock (also has stock ecm and stock harness just not pictured) What else besides intake plumbing and modifing the ECM and harness will I need to do? This isnt going to be happening for some time seeing as the lower manifold is almost 500 bucks I dont have right now. Just trying to get a feel for what Ill need when im ready. Any can anyone point me to a good TPI porting guide online? Thanks for the help.

You should be able to have the lower intake bolt holes (on the stock tpi lower manifold) drilled to accept the vortec pattern. If I remember correctly, its only the two center bolts (on both sides of the intake) that are at a different angle - and the lower intake should be able to be modified so the bolts will work. *****Someone let me / linux know if I am wrong about the bolts****

You can purchase different "proms" to plug directly into the ECM for that motor.

As for porting the TPI... Dont even bother trying to port the tubes. Go to www.tpis.com - There you will find large tube runners, then have the lower intake and upper plenum port matched to the size of the new tubes. ***This is unless you decide to have the tubes "siamesed"*** depending on how wild you want to go.

Check out the www.tpis.com website. There is ALOT of very good information there, and they have a few books / guides that are good reading too. Will be able to give you a really good feel for what youre doing!

I thought the intake runners were different on the vortec heads that using a regular manifold caused enough of a restriction that you would lose horepower/torque from this setup. Also I dont want to go extreme on the port just enough to make sure I dont lose HP over a 600 cfm carb thats all. Ill prob just port match the intake to the new gaskets. Thanks for the info + for you.

The LONG intake runners (tubes) that are the TPI, will KILL any horsepower that you plan to make in the higher rpm's!

Since the intake runners (only air travels through them) are so long, it kills horsepower by basically starving the motor for air at higher rpm's. The benefit though, is ALOT of torque and making ALL of your power in lower rpm's (from 1500 - 4000). The larger tubes from TPIS, or siamesed tubes - will allow you to keep the "look" of the tuned port injection system (I personally love it, although its not the best for making power) while allowing the motor to flow MORE air, and still a little more in higher rpm's allowing the motor to breethe a little better.


The vortec heads [assuming you mean the ones that will fit a SBC motor] are really only different by the (4) center intake manifold bolt holes that are drilled and tapped at a different angle than the older traditional SBC heads. Vortec heads in general are way better than the old style SBC heads because they flow much better! If you really want to make alot of power, it may be a good idea to just stay with the 4bbl carburater...?

Which heads do you have currently? What year / vehicle are they from?

The 96+ Vortec heads use 8 bolts (2 per corner) and are pefectly vertical. There are no center bolt holes and the intake ports are taller than conventional SBC's. Here is an old pic of the vortec bolt pattern:



The angle on the center 4 bolts is an issue from 87-95 vs. the 86 and older intakes, but the overall port size/shape is the same.
To use the TPI with the 96+ vortec heads will require the Vortec lower base and it is $450+.

[This message has been edited by fieroguru (edited 04-25-2008).]

Ive found the lower intake for 400 bucks or so. I dont mind that since i got the TPI setup for CHEAP. here is the engine I have http://www.crateenginedepot...-12496968-P5C53.aspx and these are the heads on said engine http://www.crateenginedepot...2558060-P752C0.aspx. the TRQ doesnt bother me with a 4bbl carb it is rated at crank 330hp and 380lb of trq. You feel the best power around 3500-4000 in my book but isnt weak in the upper end. It seems to be a popular on the stock L98 in the third gen bodies with TPI to put the vortec heads on the engines during rebuilds. They seems to have good results so Im sure that it should have decent power. I dont mind if my numbers stay about the same as long as I dont get SLOW due to this mod.

If you are not in a rush I will recommend you to keep looking at thirdgen.com mall for a Vortec lower to show up. I got there my Edelbrock and TPIS runners including TB and plenum all for $400. The TPIS or Edelbrock as you know is more than that alone. There are many people there switching to LSx engines or SuperRams and sell this stuff for cheap but you need to look every single day to catch them. And they do show up often. Vortec heads are ok but don't dream of too much power unless you change the cam too and address the whole air path. Also don't forget a good plenum porting job. I did mine thru Corvette plenums. He does an awesome job. Anyway the right place to look for great porting jobs on anything TPI is thirdgen.com itself. Do a search there. There are tons of threads and links and dyno results. I started with a stock TPI and then modified everything I could. Read here my build threads and dyno results. I think TPI intake is the most beautiful intake setup GM has ever done. Good luck

Original build: https://www.fiero.nl/forum/A...060206-1-046290.html
Upgrades: https://www.fiero.nl/forum/Forum2/HTML/077431.html
Last dyno results: https://www.fiero.nl/forum/Forum1/HTML/064401.html

Video

------------------

Red: TPI V8 + 6-Speed Yellow: Nitrous 3.4 + 4 speed Auto
304rwHP/366rwTQ

Thanks alex i have a plus for you but u have one already. I donut expect any real power increase till i swap to edelbrocks heads and a cam upgrade. I'm doing the tpi swap for easy starting and a lil better mileage when said right foot is not so heavy i can not pick said right foot up till 5k for said shift of gear. I just don't want the TPI to make LESS power is all. As long as I stay where im at im happy with the swap. Hence while I want the mild port etc. When i switch heads I'll go with a bigger TB larger runners and a bigger upper manifold until then im poor.

Ok so next question this setup comes with the stock ECM unit should i just get this re flashed for some stuff or replace it. Im trying to keep cost reasonable but if it needs a different unit then so be it. If I should reflash it what should i remove I dont need the EGR but I dont know what else I should use. Thanks for the help again everyone +'s for those who dont have one already.

quote Originally posted by linuxpowered88: Also what fuel pump should I use since im carb now im using the 4 cyc pump and a regulator to push it down to around 5 psi. I have heard one for a Grand National works well is this true? I am switching to 24lb injectors on the setup if that makes any difference.

You should be able to buy a 'prom' chip that is programmed in "stages" to how your motor is built. I stated this before, www.tpis.com offers the 'prom' chips. At TPIS, they ARE expensive, and maybe someone else will either have one to sell, or be able to tell you where to get one. If the TPI that you have has 'VATS' (vehicle anti-theft system) it will have to be diasbled through the prom chip.

Yes. You can / should use the Grand National fuel pump. I am using it im my 350 / tpi. Take that regulator off that you have on. Put an adjustable fuel pressure regulator on the fuel rail of the TPI, then what pressure to set it at is up to you... Anywhere from 38-50psi.

You do not have to use 24lb/hr injectors. With a mild TPI, its kind of overkill and not needed. (that is what I was told about mine) I have 24lb/hr injectors in my TPI. It runs good. I chose to use the 24's because I had them, and knew for sure that they were good.

Thanks Chris gmtuners is going to burn me a custom chip for far cheaper than tpis chips and he does good work never heard a bad thing about him. Plus he is a fiero guy too. Second thanks for the info on the fuel thats along the lines I was thinking. 3rd a friend has a 97 TA with 24ln injectors and a blown head. He is going to junk the motor since the head is cracked and it seized on him. its too far gone and he has a nasty LS2 going in . So I can prob get the injectors off him. Im running a bit more cam then the stock L98 and and the vortec heads as well and plan to upgrade that next time the engine is out anyway. The injectors on the intake are questionable anyway at best acording to the seller. Thanks for tip about the Anti theft system Ill ask the seller and have gmtuners remove it if need be.

I'm still using 22lbs injectors with all my mods and still works ok at my power level. But if you are going to use bigger just get them now so that they can be taken into consideration on your RPOM tune. That is very important.