What are the best mods to make a tpi 305 faster. I have a 1986 iroc z all atock except for a flowmaster catback system. I was wondering which mods would be the best for my car and give me the best performance.
All info is greatly appreciated

 

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spend $300-350 bucks on a cam, port your heads, headers, and exhaust, port(remove the screen to your maf) your mass air flow sensor. problem solved. Comp cams sells cams designed for tpi, you could also call and have them cut one for you.

 

I was told an L98 cam would give 25 extra HP. I guess thats the only difference between the 86 305 and the one a few years later rated at much more power. And is there any proof of gutting the screens gives HP? I didn't feel a difference.

 

How do i look at a sig?

 

I would NOT gut the screens out of the MAF. Very little, if any, flow diference, while exposing the most important part of the system to damage for the rest of it's life, and further more, possibly slightly throwing off the ECM's calibration.

Cam, Exhuast, and... (devil eyes....) a 350

I'm kidding, but yeah, cam, exhuast, gears, converter, then maybe look into some intake/heads.

 

Which cam would u guys suggest, I would like to have a nice lopey idle if i were to swap cams. Would nitrous be a good idea after swapping the cam, exhaust, intake, converter.

 

Just how far do you want to go with this 305? Having a cam with a "Lopey" idle would suggest you want something to run in a higher RPM range, and if that's the case - you will need to define your goals before any of us can suggest any specific parts or strategies.

I wasn't under the impression you wanted to go nuts with this thing, just get a little more power to the ground.

 

Headers/Y-Pipe-High Flow Cat-3" Catback

High Flow Air Filter-Cold Air-Bigger Throttle Body-Modified Intake Manifold/Runners

3 Piece Underdrive Pulley Set-Crank,Alternator,Water Pump


50 + Horsepower and tons of torque.

 

Im not looking to make this a full on race car but i want this car to run pretty good. Down the road i know i will ditch the 305 for something bigger. But for know i would like this car to be respectably fast. I would be willing to do the following mods cam,exhaust,intake,heads, and also I was thinking of running nitrous to give it an extra boost. I am looking for around 250-300 hp to the ground. Also I do not have posi so I would definately like to put a limited slip diff in.

 

If you like porting port out the lower intake and the pleuim and clean up the dips in the runners. The lower intake is a big bottle neck same with the pleium. In the process buy a fuel pressure regulator and install that. All for under $200 just invest lots of time porting. It depends though if you want more hp at high rpm this is a good start. I'm doing this to my car right now, so far so good. Hopefully a couple hours a day and a few weeks later i'll be back on the road.

 

Several magazines have shown that Vortec heads and a big camshaft will put the 305 over 300hp (carburated). With stock TPI, I guess you're a lot more restricted on the horsepower side, but TPI is really good at making toque.

 

the screens are fine to take out there are no worries as long as you run a air filter. However do not cut the fins. They are used to flow air past certain parts of the wire and make the air hit it evely. It directs the air. There was a very noticeable difference when i took my screens off. Do thaty with a cold air intake headers, 255 fuel pump and an adjustable fuel pressure regulator. these are awesome starter mods

 

forgot if you go my way port the upper intake and clean you egr while you do an afpr. quitea few extra FREE horsepower

 

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The sig is just the persons signature usually posted after their first post in a thread, however, sometimes they are not turned on or on all the time. Look at the sig means, check out my signature attched to this message.

This my sig below:

 

Vortec heads are still a NO-GO with TPI correct? At least without major machining I mean - not a bolt-up swap right?

 

i have read some where there is a baseplate which it will work off of if anyone knows which one it is post it. It wasn't cheap

 

Here's the baseplate $399
http://www.sdpc2000.com/catalog/1460...-Baseplate.htm

 

On a semi-stock 305 it's a waste, plain and simple, and opens the possibility of problems that you really don't need. Why take the chance for no gain?

Removing the rear screen does indeed open it up to damage, no air filter is going to save it if you have a backfire. There are two schools of thought with regard to the front screen, search and make up your own mind.

Your '86 is a hyd. flat tappet cam, get a cam kit out of summit and you'll see a nice increase. For about $300 you can get the Comp k-kits that have cam, lifters, springs, retainers, locks, seals, timing chain, and lube. You can get just the cam and lifters for somewhere around $80 or just the cam for $50 for the Summit ones IIRC.

 

Not so sure I understand how the rear MAS screen will save the filament with a backfire either......It's not a very fine screen and even if it was, flames would probably go right through anyway. Am I missing something?

P.S. I've had my screens off with no problems so far.

K

 

It's not the flames that would do it (even if they reached that far), it's the wave front that would kill it.