Well, the time has come for me to stop being "that guy" that has a 305 but "is getting a 350 from his friends brothers uncles daughters son's firebird". I finally have a 350 from an 87 iroc sitting in a wheel-barrel in my backyard. The hoist and stand have been purchased and this coming weekend it will be time to put it in my basement and get it on that stand to begin it's long journey to extreme fastness.

so I've done some research over the past few years that I've been on these boards, and have made several short-lived decisions regarding the fate of my 350 that i "would be getting blah blah blah". Long story short, I want to know a few things that will help me make a very informed decision as to how to transform this hunk of metal into something well suited to my driving style and needs.

383 - how bad are these really on gas? and how narrow is the power band compared to a 350 with equivalent improvements? I have never gone over 4k rpm in the entire time I've owned my 305 tpi, and I don't see it happening any time soon.

350 - is the hp gain and wider power-band really worth the loss in low-end torque? I understand it might be cheaper to go this route, but money is not an issue, as this project will take however long it needs to take in order to be the best quality finished product it can be.

finally, is it possible to get 500hp at the flywheel with a home-ported tpi and heads?

 

I doubt it.

 

yeah but you'll need a pretty heavy cam, higher compression, a good set of heads, and a little bit of PROM chip skillz

 

With a wide carb and decent intake, long duration cam, and just about everytihg that is contrary to a TPI, it is tough to get much over 430HP out of the flywheel end of a 350 with no boost and plain fuel. I had to go 11:1 to make 423 on the dyno years ago, and that was a "street" engine. You almost certainly aren't going to generate that kind of power under 4,000 RPM. Start changing the bore/stroke, use a roller cam and decent springs, and get volumetric efficiency up, and you'll have a chance. You're still going to have to be turning closer to 6,000 with 350 cubes on pump gas to make that kind of power. Just my guess.

 

350 or 383, cubic inches DOES matter. With a 383 you can use that wild cam from your 350 and it will be a bit more mild. Thus, you can use more cam, have the same driveability, power range, etc... but with the extra cubes you gain more horses, and only drop gas mileage about 1 - 3MPG in comparison (via driving style, bigger cam and more cubes, and possibly change of induction)... it can obviously get worse depending on how wild a cam you want.


If I were shooting for 500hp to the ground N/A, on pump gas... I'd start with as many cubes as I could get (400 block if it were available, otherwise a 383). Some AFR 210 heads, probably a mini ram if I were going FI, wouldnt know on the cam, but it would have to make up for the mini ram probably, and be rather large. Probably 10.5:1 compression since it's aluminum heads.

You'd have good heads and intake, and then you can just change the cam out to suit your horsepower/streetability needs.

Like mentioned earlier, a roller cam is probably your best bet.

 

Ok, so let's say I decide to go the 383/Extrude Honed Base and LTR route. Assuming proper cam and head combo (was looking at the afr 195's) and a proper tune, am I looking at over 500lb/ft and at least 400hp like the tpi shootout led me to believe? or am I missed something in the equation?

Thanks in advance for your help

 

TPI = bad

It is not a performance intake. You can modify it all you want, but at the end of the day you're still struggling with the biggest issue... the design.

It's better and easier to get an aftermarket intake to go there. I just wish the "T-ram" or whatever it was called that they put on the firehawks were still available aftermarket -sigh-

 

350 in a wheelbarrow? Sure it'll have the potential to go fast, but you can only run so fast hanging on to those handles behind it. Then there's the whole nose heavy instibility on that single skinny tire........

 

BA HAHAHAHA

 

And mileage will be excellent for a 350!! Even better than a hybrid.

 

alright, lemme try to salvage this. Anyone have any experience with the TPIS bigmouth system? Any problems I should look out for?

 

Very off topic...but I see you go to UMD...I go there too. Is your car red?

 

I smell a race comming on

 

My car is red :P is yours the other red iroc?