Pwdr Extreme

You just made an excellent point that I did not think about at all. This is why I joined this forum!

Thanks! I will be calling you in a little bit.
Jerry

Streetk14

I've had both styles of supercharger on my Vettes, and I can honestly say that I was a little disappointed by the sub-4000 rpm performance of my T-trim when I first installed it. But with the 10 psi it made up top (plus a cam & meth), it had a strong top end pull. And for me, it was fun, but it didn't make much extra power in the rev range where I drove most of the time.

You just need to be honest with yourself about your driving style and how you plan to use the car. You hear the argument of "why do you care about power below 3000 RPM? You're just in the wrong gear if you're accelerating at that speed". And for real racing situations, that's true. For street driving with lots of transitional low RPM situations, it isn't. There are a lot of situations where a downshift isn't practical or possible. That's where having that power makes the car a lot more enjoyable. At least to me.

And while a flatter torque curve does put more stress on the engine in the lower rpm range, that really isn't where I'm concerned about my engine destroying itself. RPM is usually the hardest thing on an engine, and I'd think an engine that is being fed more boost at high RPM is going to be the one living the harder life. I think it's a wash as far as the engine stress argument goes.

old motorhead

Well said. 5 or 6psi at 2500 rpm doesn't hurt anything. I does make the car really come alive in street ops though. It gives you the big block feel any time you want it. Even if it doubles the stress on the rotating assembly, you kinda expect that. If you're making more power, you're inducing more stress. That's not too hard to understand.

It would be good if the OP could catch a ride, or better yet, drive both types. They both have their place. Gets back to personal preferences. I prefer to have all the boost that I paid for available at any rpm I choose to use it. Also, that nasty uncontrollable low end torque can be kept at bay by using a little known technique known as throttle manipulation. The right hand pedal isn't an on/off switch. If you're in a situation where you can't use the low end power.....then don't use it. It's nice to have it when you want it though. Makes a heavy 3200 lb Vette feel a thousand lbs lighter

Pwdr Extreme

I think Old Motorhead said it best, would be nice if I could ride or better yet drive both types. I am completely on the fence. I know I will be driving it in "street" situations the majority of the time.

Serious question... Why do pretty much all of the manufacturers use a PD blower or a Turbo? I've never seen a factory Centri except Prochargers in marine applications.

I'm really not worried about buying a new hood and since they don't make a Heartbeat for my car, Whipple seems the way to go for a PD. As mentioned they don't seem to have the popularity they used to? Is it mainly from cost? They seem to be more efficient and HP capable then other PD's?

I haven't ruled out an ECS by any means. On one hand, the car definitely pulls hard, it's just got to be way up in the rpm band to do so, no argument that a centri will make it pull a whole lot harder. On the other hand, personally I'm disappointed in the sub 4k pull. When I want to pass or accelerate, it seems I have to drop 3 (or 4) gears to really get it done. Given my altitude power loss, am I still going to drop a few gears? With a PD the pull is there in any gear, what I needed to hit 3rd to do before, I can now do in overdrive.
For my driving style on the street that sounds like more fun.

Now if a Centri is still adding a noticeable amount albeit not as much down low, maybe I would be happy with that. Will it be enough to overcome what I will be losing down low with the headers and still be a noticeable increase? I know I would be disappointed if the first time I stepped on it without being over 4k it didn't feel any stronger than stock.

I kind of compare it to the bullet bikes I've had. My old ZX6 which was modified was scary fast, but only above 10-11,000rpm. In top gear at interstate speeds, full throttle was flat out boring. Drop 3 or 4 gears and it was a whole new ball game. My new modified ZX14 pulls like a freight train, even in top gear on the interstate. If I drop 3 or 4 gears on it, it's front tire in the air, you better have ate your wheaties, OMG tunnel vision chaos! Needless to say, I enjoy the 14 much more, even though the modified ZX6 was still incredibly fast, I just love that low end punch.

I wish I could feel a Centri.....

edit: I really appreciate all the input!!!!

Pitufina

What some failed to mention is that the ECS kit will produce a lot more torque compared to an A&A kit stock for stock. The trick is in the smaller pulley diameter in the blower combined with a restrictor. It will not be exactly PD torque but very close and the pull on the top will be the icing on the cake. You can find dyno graphs of all the kits available and see it for yourself.
Personally I think the PD stuff works best on heavy applications. My 08 ls3 pre supercharger with cam only and exhaust has been 11.32@124 in the 1/4 and that is with me botching the launch. Why I bring this? Because the cam doesn't start working well until about 2,800-3k and still runs an very good time. The weight of the vette is on your side.
I can't wait to install my ECS kit that it's been sitting in a box now for a few months! Good luck with whatever you decide

EvanZR1

BTW couldn't you do a Heartbeat on an LS2 by swapping to LS3 heads?

Pwdr Extreme

That's what I'd like to find out or feel... Will an ECS give me enough additional low end power that I will be happy with it??

Pwdr Extreme

I really don't know, I'm still new to all this... I'm assuming that would be a pretty expensive swap vs. buying a whipple for an LS2? What advantage if any does a heartbeat have over a whipple ?

MARSC6

If you ever find yourself in northeast PA I would be happy to show you

If spinning through the first few gears is what your looking for that is quite easy.

Pwdr Extreme

PA is a little far for a weekend trip, although I have been there several times.

Looking at the pic by your name, my car looks to be identical only a convertible, even our wheels look the same.

Not really looking to spin through all the gears (although seeing a ZR1 light em up at interstate speeds was impressive). Just wanting more pull than it has now in the 2-3k range, I'm certain the ECS will have it covered from 4k on up. Anybody with a boost gauge tell me how much boost at 2k,3k,4k, etc?

Speaking of spinning, will TCS still work correctly with the extra power? Girlfriend is already scared to drive it, lol

old motorhead

About the only advantage that a Heartbeat has over a Whipple is the packaging. The HB will pull a little harder on the bottom end. Whipple will pull harder up top. The "easy" hp on a Maggie probably tops out at 675 to 700. A Whipple can probably get you a hundred more before having to spend money on extra ribs on the belt, hd tensioners, o/d crank pulleys, etc. That's about where you need a "built" motor and lots of drivetrain upgrades anyway.

Have you priced a 2.9L Whipple, A Heartbeat Maggie, and a jackshaft Maggie? What are your power goals?

Detoxx03

Don't be fooled with all of the low end stuff. A centri will make enough low end to put you in a guard rail if you aren't careful. No it doesn't make as much as a pd blower would but there is also no need for it that early either. I know the next argument will be the fun factor. Let me tell you something if you aren't having fun in a modded corvette just sell it already cause that's a stupid argument. Oh and car corporations use the pd for packaging simplicity.

Streetk14

To answer a few questions you asked:

1) You could swap to LS3 heads and run a Heartbeat. LS3 heads are cheap and will also help you make more power. There is the added labor that either you or someone else would be doing, though.

2) A jackshaft Maggie blower is another option for an LS2, though it requires a hood change.

3) If you're looking for a mild blower setup (i.e. sub-10 psi), then I don't see too much advantage to a Whipple. It just seems to be that Whipple hasn't really been supporting the Vette market, and not too many guys have their system. That would be my biggest concern. They do seem to be popular on the 5th gen Camaros, though.

4) You need to take into context the opinions you get on different setups. A lot of guys with ECS kits are running an "unrestricted" setup that makes a ton of boost and requires meth injection. With ~14 psi up top, they still make some boost down low. A restricted ECS kit is another option, but I haven't seen too many boost curves for those. I try not to comment on things I haven't personally dealt with.

5) I had a T-trim blower (same as an SL1500 heads unit) with a 3.4" pulley. That's about 1 pulley size less aggressive than the ECS kits run. At peak power @ 6550 rpm on the dyno, my engine made 10.66 psi of boost. At 5000 RPM, it was making 7 psi. At 4000 RPM, it was making 5 psi. At 3000 RPM, it was at 3.0-3.5 psi. At a little over 2000 RPM, it was making around 2 psi. That should give you the idea of the boost curve. At 3000 RPM, I picked up about 60 RWTQ, so there are gains down low -- just not what you might expect for a blower.

6) My Heartbeat blower made right at 7 psi @ 6500 RPM on the same dyno. At 2000 RPM, it's making a little over 5 psi. By 2500, it's around 6 psi. It carries that boost (6.5-7 psi) all the way to redline. While I also added headers at the same time, I saw gains of 165 RWTQ at 3000 RPM. Instead of my engine making 200 RWHP at 3000 RPM, it is now making 300 RWHP. That's power you feel during regular driving. At 4000 RPM, my stock engine made 290 RWHP. With the Heartbeat, it made 410 RWHP. Like a larger engine, the gains vs. stock remain pretty constant as the RPM rise. Keep in mind this is a mild setup with low boost and no meth or cam.

^^^^ Those are the facts from my two builds.

Streetk14

I think there's quite a few other reasons besides packaging. And I don't consider 3000-4000 RPM to be low RPM stuff, but that's just me.

Detoxx03

It's not high either.

Pwdr Extreme

Streetk14, what kind of power are currently at with your no meth no cam Heartbeat? My goal is to be 550rwhp minimum, 575-600 would be perfect. It seems the general consensus from reading that 600 is the "magic" number before needing tons of modifications.

Since I'm up around 5,000' 91 octane is the best I can get. If I could achieve 575ish with no meth and no cam I'd be thrilled, if I need a cam I'm not opposed at all but I don't want to go too radical. If the cam is more or less free hp, I'll gladly put one in.

What's the main advantage of a heartbeat over the other PD's that are available for the LS2? Considering my power goals do I need to swap heads to get there?

MARSC6

This is my old graph with the ECS kit and headers on a LS2.



Same kit without the restrictor plate and the addition of meth and the ECS stage 1 fuel system. Motor still completely stock.



Traction control will help some but it is easily overwhelmed. It can't be relied on.

Pwdr Extreme

Those are very impressive numbers indeed. How much boost overall when you added meth?

old motorhead

Yup, the absolute best traction control is an educated/experienced right foot. My wife drives my Vette quite often. After all, it is actually "our" Vette. Anyone can drive it around all day without getting into boost. I can actually accelerate quite briskly without getting into boost. The "p/d blower is always in boost/on kill and therefore very inefficient" argument is laughable. Haven't heard that one in this thread yet, but hey.... we're only into page 2 of this discussion

MARSC6

It peaks at about 14PSI at the upper rpms..