Would it help tremendously for a blown ZZ4 to have a HSR or Miniram instead of TPI ? How much horsepower increase can be seen? Also, it looks like HSR is a lot less than a Miniram ... why is this? Is the miniram that much better or am I not reading clearly?

Its because the miniram is rediculously overpriced.

yes miniram is way overpriced

HSR is a very nice intake and you'll see lots of hp gains over 4500rpms all the way to 5500+. its good to over 6000 in the right application.

you dont lose all that much torque over TPI either, which is nice. you'll lose some, but it flattens the torque curve which is great for driveability at all rpms, and makes for a fun to drive car.

i picked up alot of time switching from TPI to HSR on my stock L98. i can only imagine how much more time you'll get with boost

apparently the setup already has about 420rwhp with zz4/tpi/blower - what can i see with the hsr switch? up to 450rwhp or so perhaps?

i'd say easily 450whp. probly more. where is that 420 whp peak? is it around 4500-5000rpms? does power start dropping off after that?

HSR will pick up where TPI starts to drop off. you'll have another 1000rpms to play with and should definately see the hp curve rise up.

you'll need to tune for it tho

i think i'd better get some forged pistons first

I was a TPI guy for a long time running a Vortec S/C @ 8LB.. I have a good friend who sold me his Miniram with Upgraded Fuel Runner and 58mm BBK Throttle body for a great price.. I will not knock HSR at all. It is a definite noticeable upgrade over TPI though. With my Miniram, and S/C which will now be running at 18lb, low end torque will still there. Have to work on tuning though.

I think the HSR will definitely help you out especially above 4000 when it really starts to shine. We need a better estamite of what rpm peak hp was made to figure out a rough estimate of the gains. But 15hp to the wheels plus raising your rpm band would be my guess though.

I just installed a Stealth ram on my Procharged L98 firebird and you just wouldnt believe the extra power. Theres absolutely no loss of low end torque with the supercharger. After 4k rpms it just starts pulling harder and harder. I love it. I actually hit 6k rpms and it still had more. After ~5000rpms with the tuned port it just make noise and wouldnt make any power. I also have more boost since i'm spinning the supercharger 1200 more rpms. This is going from a ported plenum and siameased base Tpi also. I believe the gains would be even better on a stock tpi setup. It also makes the exhaust a little louder. This can be a good or bad thing. I hope to get to the track again if it ever cools off. Even having a supercharger is no reason for sticking with the long tube runners. I'd say its well worth it.

I've got a 383 and a procharger. Thinking about upgrading the intake as well. cant decide from the HSR, Accel, Or Mini ram. Leaning more towards HSR. So you like how it works on your car??Thanks

I like it on my car. Works great. I want more boost now. I might end up going with a turbo.

I have a ZZ4 with a ported TPI and keep thinking of pulling the motor and going with something bigger when funds allow b/c of course, I want more power. I really want the cheapest option while keeping driveability and thought of the P1SC but never really knew how it would be on the ZZ4 but thought it might not work out that well overall with the TPI/ZZ4. Granted the ZZ4 has Hyperjunk pistons and tiny 58cc heads but 420rwhp wouldn't be too shabby. Question I have is, can the motor (pistons) really survive the long term with 9lbs. boost? I figure if it can work I can always change the intake and heads down the road to maximize the combo. Also, what size injectors are you running with a S/C ZZ4. My current combo is in the sig.

A++++++ for the stealthram especially with a power adder,the ONLY thing about the stealthram i did not care for was the fuel psi reg.those ones are junk,use an aeromtive reg. and its all good.

As much as people like to believe that you can bolt the miracle part onto an engine and gain 100hp and run a second faster, that’s never exactly the case.

The fact is that it really ends up being a question of combination. If the combination isn’t there then you won’t go faster. The fact is that for the power band it was designed to work in and for what it was designed to do, the TPI setup is a very effective design and with very minor clean up isn’t a restriction well in to the 400hp range NA.

Yes, both the miniram (and very similar LT1 manaifold) and the HSR have more power potential than the stock TPI, but both in a _completely_ different power band than the TPI, so the “right” combination will involve completely different parts.

A great example of this is that both GMHTP and one of the more common car mags (either hot rod or car craft) did articals on TPI manifold swaps (one was an HSR, one was an LT1, again, similar to the MR), only one of them made more power, and both ran slower after the swap.

I've always been under the impression that since a centrifugal supercharger spins at a fixed rpm relative to the crank, it will flow nearly the same mass of air no matter what intake you have. A more restrictive top end would just cause the boost guage to read higher, right. Since the supercharger spins at the same rpm no matter what top end you have, the only thing to affect your performance would be changes in compressor efficiency. Since supercharger companies design many of their units to work on stock engines, one of those units would probably perform in its best efficiency range with the stock parts. The best way to do it is to get compressor maps of larger head units and build a motor (and pulley setup) that will perform in the maximum effieciency range of that particular supercharger.

I'm not trying to say a free flowing intake manifold won't add some power, but it will most likely be very little, unless the supercharger in question is highly mismatched to stock parts. If the supercharger is sized properly (for max efficiency at a given pulley ratio) for stock, a high flow intake manifold could, in theory, make you lose power by decreasing the pressure ratio, therefore dropping the compressor peformance below its maximum efficiency range.

If I'm wrong, please explain. I think there are really too many unknowns in this situation.

Like you said.....it is all about the combination of parts. After that it becomes about the fuel and spark tune. Many people think you just bolt on a part and go faster. It takes a lot of tuning to get that part to make more HP that most ignore.

If you have an engine that will rev and stay together along with a loose converter, then the HSR is what you want.

Since my second Holley FPR went out, can you shoot me the P/N for the aeromotive? Does it go outside of the rails, or bolt in place of the Holley?
Thanks, Tony

Wrong! What you say is true for a displacement supercharger, like a roots, but not for a centrifugal supercharger.

A centrifigal supercharger makes boost as a function of RPM. A more restrictive top end reduces flow, and power, but the boost gauge will read about the same as before.

Ttypecamaro’s first half better describes positive displacement blowers and the second half better describes centrifugal blowers.

The fact is that what will really happen in the real world will depend on how the compressor matches the engine, in other words, where on the compressor map you fall. JoBy would generally be right, but if the for example the original combination had an airflow that put it towards the right hand side of the compressor map, and the second combination ended up flowing more, then you’d probably just drop off the right hand side of the compressor map and end up just stirring up hot air, making much less power.

Again, it depends on the combination, not the magic part.

nice set up man!!!!! i think having a miniram or hsr will definately give you a flatter torque curve ,but turbos usually add 1000 to 1500 rpm to your power band on the top end and centrifugal blowers usually follow your naturally asparated torque curve maybe add 500 rpm to it. it depends on where you fall on the compressor map, i have found that turbos are more effective power adders.