anondude13

http://www.holley.com/HiOctn/ProdLin...FMS/SR/SR.html

ditchbangr

iTrader: (1)

There have been a couple write ups on the HSR in camaro performers and I just got the new chevy high performace issue and they install the hsr on their project camaro. My machinist does alot of dirt track carb. stuff around here. When he did the 406 for me and I dripped off the HSR for it you should have seen his eyes they got as big as 8 *****. It is a pretty trick looking piece, especialy the base. We kinda live out in the sticks I guess, for performance cars here in MN.

ditchbangr

iTrader: (1)

DP

grumpyvette

the one major factor most of you are ignoring is that all the intake manifolds are designed to operate at differant rpm ranges and if the compression and cam used does not exactly match the intakes rpm range the intake will produce far lower numbers!

my PORTED STEALTH RAM produced far better power with both a CRANE 119661 and CROWER 00471 than with cams that worked correctly with the PORTED TPI with high flow runners

grumpyvette

the one major factor most of you are ignoring is that all the intake manifolds are designed to operate at differant rpm ranges and if the compressionratio fails to be correctly matched to the cam and if the cam used does not exactly match the intakes rpm range the intake will produce far lower numbers!
then your also ignoring the fact that once the intake flow exceeds the heads flow potential , the intake will show no significant gains past that level significantly reducing the hp/tq numbers the intake test will show yet the intake still may have far greater potential and the fact that the larger the displacement and higher the compression the more effective the high flow intakes become!

my PORTED STEALTH RAM produced far better power with both a CRANE 119661 and CROWER 00471 than with cams that worked correctly with the PORTED TPI with high flow runners

Rockin-Iroc

You make sense. You are absolutely correct. It's all in the combination. For most people, a perfectly-matched ported TPI would feel very adequate and quick in their street car. But I can completely see the potential of the Stealth Ram. I might try a Stealth Ram myself when I stroke my engine to a 383. I'd also like to get a pair of those Vortec heads. I'll probably get iron and then ceramic coat the combustion chambers like I did the Corvette's big block iron heads. That will add some additional octane tolerance.

DON 88T/A

The Mini-ram "only" peaked at 6200...
I've seen other MR combos pull much higher...if they were using unported trickflows like mentioned way back along with a smaller TB it would have really held back the MR.
The stealhram is a nice peice but was done @6000..yes it would have faired better with a bigger set of heads too...the MR held 500hp for 600+rpm's...
Like said above each intake has its strenghts..put a set of hogged out afr210's on that motor with a solid roller..and then you'll see what the MR is made of.
The fact that the MR only made 50 more hp then the TPI is very telling of how choked it was up top...big cams are great..you need big heads to work with them.

Red Devil

That was from the magazine themselves, so yes, the TFS heads were unported.

Bill Speed

What happens in the octane range? Many magazines hint at just going for a LS1/LT1 or other engine with more modern attributes. Both projects look relatively costly in a car known for traction problems and body flex (unibody! ha)
I'd be looking to stay at 91/90 octane and going to a max 350HP increase, just to keep the car economic, also being a daily driven convertible. Low end torque tends to suit me.
Bill

Rockin-Iroc

This is just my opinion, but if low end torque suits you best, then the stock-style tuned port is probably the best option for you. However, you can update the heads to something like a Vortec head, which will give you the best bang for the buck. And then definitely get a better cam. The stock cam leaves a lot to be desired, it is TOO mild. My stock tuned port responded beautifully to the Iskendarian 270 Mega-Cam. I also zero decked my block and shaved the heads to get 10:1 compression. (This is on a 350).

Maybe at the most, you would want to upgrade the tuned port tubes to larger tubes, but the stock tubes DO build nice torque, and if that's what's important to you, then the above modifications might be good.

GMPP sells a crate motor with Vortec heads that makes 330 hp with only 9.0:1 compression. This is pump gas friendly at any altitude. Some magazine had managed over 400 hp with these heads at a higher 10.4:1 compression. (Hot Rod, I think). So your goal of 350 hp is possible. I'd like to swap my ported stock heads for a set of Vortecs myself. I think I'd see a large gain.

okfoz

The problems I forsee with the Vortec heads is the following:

1) The available lift on them is limited, I think the highest cam lift is about .490, so you need to modify them to accomidate higher lift cams.

2) The bolt pattern is different than the 87-95 standard SBC, and either you have to modify the head to bolt to the intake, or modify the intake, or get a different base (I believe Scoggin-Dickey or something like that makes one).

Otherwise I would have already gotten a set.

John

Dave Farr

for those of us that value the info presented in 3rd gen but prefer trucks, what is the best choice for mid range torque. have an 89 k1500, 5.7l, vortec heads, 700r4, 4.10, 31" tyres, 6000lbs, currently with edelbrocks tbi to mpfi conversion kit and ported tb flowing 640cfm- works well but always liked the tpi looks but not the rpm limit, need to pull to 5500rpm. i like the engine masters competition- its not the peak power, but the area under the curve. was thinking of the hsr but am afraid of loosing too much grunt down low. am going to use an engle hyd roller 477/479 206/212 @ 050-114 deg, too many problems in the past with low vacume and speed density.

robsgta

Go with a stroker crank a 383 or 396 will help pull that truck with a lot more umphhh.

Rockin-Iroc

And switch to TPI. Best truck motor GM ever made...except that they didn't put it in a truck.

I am pretty sure I've seen base plenums for sale from GMPP for the Vortec heads. Plus for a small fee, a good machinist can easily machine the Vortecs for larger springs. Or you can buy them that way, already fitted with larger springs.