I HAVE the 89 rs 5.0 5spd with the TBI from what i read i am better off switching to TPI? and how much money and work would this take. or if i am better off modding it into a open air or dual snorkel? and any way how much of a gain is there by switching to open air element or using a dual snorkel

 

TBI to TPI or TPI to TBI, is like swapping similar Tires, speacking of performance.
If you swap the TPI cam, exhaust and air cleaner to the LO3, then fuel it and tune it, ... for what reason would you whant TPI?

Budged and hp goal will be determinants, for upgrades on both TPI and TBI.

Stock air cleaner is not really retricting any power output noticebly at the moment, the open element is really cheap and easy a swap, thats why its frequently the n°1 mod.
In hot circumstances the stock air cleaner outperforms the open element, noticebly, on the stock LO3.

For some cold air cleaner inspiration you can check this out http://www.ramairbox.com/

 

so if i swap the TPI CAM,exhaust and air cleaner would that be as much as a performance upgrade as switching everything to tpi because the iroc-z has a 5.0 with tpi and has bout 220 hp? just wondering if i switch to tpi will my car have that much hp

 

I don't think you understand what Thomas is telling you. Switching to TPI will yield nothing all things tuned properly.

If you want more power you need to replace the factory exhaust from the heads to the tail pipe with pieces made for a 350 TPI sinlge cat. Headers, Y-pipe, cat, and cat back. If you get pipes made for YOUR car you are getting tiny little pipes.

With the restrictive factory exhaust on there you aren't going to make any kind of power.

 

I forgot someting, the TPI cars came with better heads too.

So, if you use the cam, exhaust, heads and air cleaner from the TPI (tuned port injection) engine you mentioned on your LO3 and keep the TBI (trottle body injection), with proper fueling and a ok tune, you will make as much power as the TPI engine you took the mentioned parts from.

Doing the same thing with a 350 and TBI, it will probably outperforme the 350 TPI.

 

so mods i should focus on should be full exhaust and heads cause this car was designed with bad ones and for the intake bout that cold air intake?

 

The TPI ECM ("computer") is also quicker then the TBI ECM.

Dont forget the cam, fueling and the tuning.

Here is whats best for tuning TBI http://dynamicefi.com/

 

This is basically what it takes to match a 91-92 350 gta/z28 with full exhaust upgrade:

LO3, LT1 cam, 46mm bore performer tbi intake manifold, turbocity's 46mm TB, cold air intake, RBob's EBL flash, ACD#EP241 TPI fuel pump, turbocity's VRFPR 16-23psi, LSD differential, GM 3.23, mac headers #TF8692, hoocker #16823 cat back, catco 3" cat, 3 wire heated oxigen sensor.