I know this will invite a wide range of suggestions and even disagreements, but is there anything close to a consensus on which of several SC might be the best or at least a good choice for my particular engine, car, desires and future plans.

I currently have a 417ci stroker LS3 putting out about 625 HP (flywheel) in my '81 Camaro. Short block built by Livernois Motorsports with all forged components and 11:1 compression. I built the rest with TrickFlow heads, LSXR intake, long tube headers, 239/251/113 cam, etc. Other than tricky tuning, its been running great for 3 years in both SD and MAF mode. Well built 4L65E, Strange/FORD 9" differential, DSE quadralink rear suspension, etc.

Now its time for a bit more power. I was considering a well built LS7, but that costs about $22K and maxes out at 700HP. And my goal is about 750.

All the plumbing and appearance keeps me away from a Turbo setup. I have settled on a roots-type SC with built-in air-to-water cooling. The car will be driven mostly on the street for fun and very occasionally at the drag strip; and I have other cars for road course racing.

Last, I may later swap this engine (with SC) into my C6 Vette and therefore would prefer something that will fit a C6. (And then get an LS7 for the Camaro.)

After some research, here are my preferences in order, but that will likely change based on your feedback.

Magnuson Heartbeat - Gets great reviews and fits a C6.

Whipple - Don't know much about it, but seems very efficient.

GM LS9 SC - Looks cheaper, but may have lower limits for future HP.

I am NOT inclined to consider the Kenne Bell because I'm pretty sure there isn't room for a rear-feed system. I want a front feed.

I am NOT inclined to consider the E-Force Edelbrock because of marginal reviews and lower limit for future HP.

Am I missing any other major options?

I also need advice on PCM/ECM and DBW.
I'm currently using a '02 "411" PCM with a 24X crank and drive-by-cable.
Is this compatible with any SC kits?
I suspect I will need to change the crank to 58x, go DBW and/or get the HP Dominator.

I'm looking forward to your suggestions. Thank you.
(BTW - I'm a moderator in the Auto Transmission and PCM Tuning sections.)

 

Why not consider a centrifugal setup? They're typically far more efficient than a roots or screw.

 

Joe, I don't want to add an air-to-air cooler to the car.
Also, I'm constantly experimenting - this is the 3rd engine in the car, the 3rd LS intake, the 4th rear differential, many trans experiments, etc. So a centrifugal SC might be next, or a Turbo, but I'm going roots first.

 

You don't have to add an intercooler with a centri setup. Even without an intercooler, it'll generate less heat than a roots will, and make more power. Although it looks like you're adding an A/W in with your blower choice.

From your above comments, it looks like you've narrowed it down to a Magnuson Heartbeat already.

 

Oddly, whilst the twin screw is undoubtedly the more efficient blower, there seems to be a lot of hate across the forums for the Whipples lately.

And one way or another you would want cooling, whether that's Maggie, Whipple, Turbo, Centri....

So what odds does that aspect make ? Would you really intend to run a Maggie on a 11:1 CR build with no charge cooling ? What fuel do you intend to use ?

As for apperances, it would be kind of impossible to hide a Maggie, and centri's would be hard to make disappear.

However if you have a little room down low, the likes of the AGP Gen5 kit, or Huron also offer a similar kit....you can pretty much make turbos invisible when you open the hood.

Yes you would still have some visible plumbing and whatever form of chargecooling you opt for, but generally that's minimal.

 

Joe, no I have not narrowed it down. If a bunch of you were critical of the Magnuson, I would take that into account.
Stevie, thanks for the "summary" of the Whipples.
Since stock LS3 run 11:1 CR and accept SCs for an extra 150HP or so, I hope I can too. Not looking to add more than 150HP with the current pistons and CR. I only want to run 93 gas. I like the look of a Magnuson as there is minimal plumbing on the sides.

I have not ruled out a Turbo. Perhaps a C6 specific kit would fit my Gen 2. The car has lots of room in many places, but of course the frame is totally different from a Gen 5/6 for which most SC kits are made. (With the radiator out, I can sit in the engine compartment in front of the engine!)

Therefore plenty of room for an air-to-air cooler for either a Centrifugal or a Turbo, but also (ugly) plumbing. Hence this is not my first choice, but certainly possible.

Perhaps I should get Turbo kit suggestions here and then ask on my Gen 2 forum if anyone has fit one in a Gen 2. I also plan to install the DSE front suspension system and therefore perhaps ask DSE for info on Turbo kits which would fit that.

Please keep the comments coming. They are all very much appreciated. Thanks again.

 

My 2 pennies.....

I've been doing a lot of research the last 2 months on twin screw type SC'ers. I like the way they have instant response, instant BIG torque and very simple and clean installment of everything.

I spoke to a Whipple rep in depth about their 2.9 (only front air feed they make), the 3.3 and 4.0, 4.5 (all rear air feed). Since the 3.3, 4.0 and 4.5 will not fit in my 1998 Trans Am because of the rear air feed inlets, they are out.

That left the 2.9. The Whipple rep said there's almost no way to make 1,000 RWHP. It would be a freak of a set up if it did.......and friggin expensive as hell.
The smaller 2.3L LSA and Heartbeat SC'ers make the same and even more than the larger 2.9 Whipple. There's something wrong with Whipple SC'ers....they just don;t make good power for their size.... Borowski Racing Engines, Steve Morris and a few other badass race shops said Whipples are just not the best....

Just get a TVS 2300 or LSA....and make more power. Or look into the Kenne bell stuff to make more power.


NOW.....I have a kit waiting to pay for.....the new Harrop 2650 SC'er. Its a big boy. I am waiting for a local guy to put his car on the dyno next week to see what it makes. The Aussies have already made roughly 1,000 RWHP on 14psi and 98 octane on a 416ci....but I heard they also don't give accurate dyno numbers..

Its possible they will make 1,100 or 1,200 RWHP. Magnuson claims their Camaro with their 2650 version SC'er makes 1,123 RWHP. But some people say its not true.

Just wait a little longer......see what the Harrop 2650 makes. If it really flows 25% more than a TVS2300, it will make well over 1,000 RWHP.

Centri SC'ers to me.....are a joke how loud they are. Its ridiculous noise to me, I could never use one on a street car. If the Harrop 2650 does NOT make over 1,000 RWHP, I'll just go ahead and install the single turbo kit I have. But I would love to have a 1,000+ RWHP positive Displacement SC'er.....best of all worlds.

.

 

If you have room for low mounted twins...you could pretty much have both turbos well hidden and also the IC plumbing too. Especially if it was a dual in each side with a single out.

Or if you are opting for a water based cooler..again if you've lots of room it shouldnt be too hard to hide that away with just a water rad up front ?

Huron Speed offer a variety of turbo kits for cars these days, so it wouldnt do any harm to check out what they have to offer.

 

Here are pics of the current engine compartment from top and bottom and a close-up of where the exhaust headers come out. Click the pics for a closeup.

Note that the exhaust headers are very close to the frame rails, which I suspect wouldn't leave much room for a Turbo. I'm certainly not interested in fabricating my own turbo plumbing. If I go Turbo, its gotta be a kit.

 

LS6427: Thanks for your "2 pennies" which might really be worth more than $2K.
I didn't know the Centrifugal were so much louder. While the car is already quite loud with its dual 3" exhaust, no cats and Pyres race mufflers (basically glass packs) I don't want more engine noise.

And thanks for the feedback (or at least opinion) on the Whipples. I'm currently just aiming for 750HP; otherwise I will need to switch to a 4L80E and possibly lower the CR.

Please keep the ideas coming; this is starting to give me enough info to see what the Gen 2 people are doing; at least those with LS swaps.

 

Centris can be loud for sure...but dont really think that is unexpected considering the speeds the internal gears can be spinning.
But true, it is not for some. My YSi was pretty loud although some of the helical gear units would probably be quieter. And likewise if spinning them slower. But overall they are great performance adders.

Some random pics of the Gen5 turbo kits if you havent seen them already. ( hopefully links work )

http://www.camaro5.com/forums/pictur...ctureid=117311

http://www.camaro5.com/forums/attach...1&d=1477520567

With everything hidden down low...it keeps everything neat and tidy up above.

I DIY'd my own car on a similar idea although my turbos would be a little higher and tucked in closer to the bellhousing, using welded/adapted truck manifolds.

AGP use their own cast adaptor that bolts to stock LS3 manifolds

 

Maybe I missed it but what fuel are you going to run?

I think a positive displacement blower is a great choice for street driving, I run an LSA supercharged S10 on E85 as a daily driver when the weather is good. Hard to beat the instant low end torque and they are small enough that it fits under my stock hood and I wouldn't hesitate to drive it on long trips.

With 11.5 to 1 compression you're going to be boost limited so the LS9 supercharger would be a possibility but you can't really turn the boost down like you can with a turbo but you can get it ported and spin it faster if needed on the future. You can set it up to prevent over boost though.
There are plenty making 800+ with them. Size wise they are only slightly taller than the stock LS3 intake.

I also run the Holley Dominator and use the 7" Dash for all gauges and love it.
It's easy to use and tune, Does everything I need it to and more.
Some of the things it can do that the stock ECU is lacking.
Programable inputs/outputs
Logging
Programable safeties
Multiple tunes at the flip of a switch.
Flex fuel (some OEM ecus are capable)
Paddle shift
24x or 58x use
Built in wide band
You can display anything and everything it gets a signal from or sends a signal to.
Virtual on screen toggle switch panel (With Holley dash)
Holley upgrades software on a regular basis for free.
The only thing I miss is cruise control.

 

He mentioned 93 pump fuel.

Which at that CR....is pushing most boost options fairly hard. Or more pushing the fuel rather than the boost options.

It will need to be a lowish boost setup and also with good chargecooling ( even despite the low boost )

 

Or Hurons TT offering for same vehicle

https://huronspeed.com/5th-gen-camaro-ss-twin-turbo/

They also do a kit for a C5 but it is more akin to the old APS kit and looking at where your headers pass the suspension mounts....that would maybe not fit.

 

LosingIt: Thank you (!) for all the info, especially about the Holley Dominator. I just might make that my first project; I especially like the idea of switchable tunes and running off the wide-bands. I have the stock narrow-band O2 sensors and wide band sensors with gauges for each bank. Didn't know the max potential of the LS9 SC.

Stevie: You are temping me with a Turbo setup! If you could measure the distance between the Gen-4 frame rails at the widest distance around the two turbos, that would help me determine if one of those low-turbo setups would work in my Gen-2.

 

A large twin screw at that CR on pump is asking to go boom. Even the twin screw will need a huge heat exchanger.....which is basically sticking an intercooler up front just thinner....defeating you're argument for wanting a twin screw blower cause no intercooler. If you have a cam that will bleed boost it'll help but you're sticking a giant pump on top of the motor...it's gonna make heat.

The centrifugal is your ticket to keeping it alive since the boost is linear. You already have a loud car...you're just missing the whistle. Not to mention centrifugal blowers are available with helical cut gears to quite them down. As far as piping kept at a minimum, you also want a blower since there is no "hot side". They're low mounted typically and kept out of the way.

 

ddnspider: Thanks for jumping in. I certainly understand what you are saying, but please explain why the Gen 5/6 kits designed for stock 11:1 CR don't go "boom". Is it the total HP that causes problems or is it the amount of boost. I'm assuming its the amount of boost and I think that just 6 - 7 psi will be enough to reach my goals.

I also read that centrifugal SC under-perform a roots/screw at low RPM and over-perform at high RPM. Not sure I want that.

Thinking about this discussion thread (a lot) and my recent and existing BMWs, I'm shying away from a turbo setup due to the lag. Despite all their engineering they still have noticeable lag and I hate that. (I have more cars that I list in the signature.)

dnspider: You mentioned "a cam that will bleed boost". How much overlap are you suggesting? Obviously I'm going to change to a much lower (or zero) overlap cam from my current 19* overlap. I have installed the Edelbrock 4255 cam cover for quick cam changes and will experiment with cams too.

Seems that everyone is suggesting E85. Is that a requirement with the Gen 5/6 kits to keep them from going boom?

 

Stock LS3 compression is 10.7:1 not 11.1:1

If it were me I’d do a simple D1SC kit with a flex fuel setup and call it a day. It will easily make 750whp, run cooler, and be more efficient.

I’ve been pushing the LS3 for a long time and swapping to a flex fuel setup was one of the best mods I’ve ever done.

 

Will try to answer each question you had to me in a diff paragraph:

Do you have links to people putting on new twin screw style blowers without head exchangers and living a long time on 93 only? I haven't seen any as everyone always chooses to run either meth or E85 or has a huge heat exchanger. Your specific demands rule out just about everyone whose done this before.

The total hp is not an issue for me as we just did 19 psi on a 78/75 5.3 93 octane only setup, but with proper FMIC keeping the IAT's in check. I think at that CR and boost level you'll be generating a ton of heat and combustion pressure.

Roots/twin screw make full boost practically off idle and taper off at high rpm typically. Centrifugal makes boost faster than a turbo, but slower than a roots/twin screw and increases boost all the way to redline. This will help with traction as well as being easier on internal parts. With a high CR and 93 pump only, linear increase in boost will make tuning easier as well as prevent immediate spikes in combustion pressure. A properly spec'd turbo setup will minimize lag so I wouldn't rule out turbo lag, but yes in general a blower setup can make some boost quicker (IME).

For a cam, depending on your turbo/blower choice and RPM range, that would dictate what I would choose for overlap. I have a Futral F13 that is like 2* of overlap and believe it works very well with my D1SC. You can be more aggressive on overlap IMO with a blower vs. a turbo since there is no hotside and turbine A/R and backpressure to deal with assuming a sufficiently large header/exhaust system.

Again, others may feel differently, but this is my opinion.

 

If your goal is only 150 extra HP, I would probably just skip the confusion and go for an LSA or LS9 blower. Magnuson would be my 2nd choice.

I'm still partial to a Centri overall. Just more efficient, less heat generated.