Streetk14

Normally, the bypass valve allows air to bypass the rotors. But in this application, it should allow some extra air to be forced in by the turbos. The engine really isn't going to even need help from the blower at higher rpms, so the less restriction present the better.

This will be interesting, that's for sure.

chuntington101

A 1.5 inch bypass valve will flow virtually no air. once the air travels past the throttle body and into the SC it WILL have an effect on the air.

All you are doing with the bypass valve is looking to equalize out the boost pressure pre and post rotor. That way the SC is not actually doing anything to the air and will thus add very little heat to the air or drag to the engine. air will still be going through the rotors.

The question i have is how can you FULLY do this and retain the functionality of the original bypass valve (low rpm / throttle load valve open, WOT valve closed)?

White_Lightning

been there done that.... /mullet.

Streetk14

Agreed that the valve is going to help allow the boost from the turbos to be equalized inside the blower manifold area, but with so much air being stuffed in there, I'm wondering how the blower will really work. A TVS blower doesn't really compress air; it just moves it.

Of course, a bypass valve normally works at light throttle and low airflow. It's NORMAL function is to let air bypass the rotors. This compound boost thing is a different animal.

I wouldn't say the extra volume the valve will provide is worthless, though. I haven't measured my bypass valve, but even if it's 1.5" diameter it should help get more charge air from the turbos into the lower manifold area with less fight. Maybe we're talking 50 rwhp.... who knows. Just my guess that it will be beneficial.

jon6.0

Another thing to keep in mind with a manual trans ZL1 is that they can no lift shift. When you do that the bypass valve stays closed to preserve boost in the manifold during the shift.

jon6.0

If it were my car I would be selling the Heartbeat and using a ported LS3 or a Holley manifold with those twin 66's.

Unreal

Agreed, and the owner said that. If it doesn't work, he will just ditch the blower and run the turbos. He wants to see if the blower will make torque from 1500-3500. It really is an experiment. I know on some cars it works great, and others it doesn't. I've seen a 1000rwhp twin turbo compound 03/04 cobra that ran good. It will be interesting to see how the heartbeat handles it.

I really don't know how they are doing the bypass. Maybe up front it will just force feed ~10psi into the heartbeat and see what happens.

Unreal

Agreed, and the owner said that. If it doesn't work, he will just ditch the blower and run the turbos. He wants to see if the blower will make torque from 1500-3500. It really is an experiment. I know on some cars it works great, and others it doesn't. I've seen a 1000rwhp twin turbo compound 03/04 cobra that ran good. It will be interesting to see how the heartbeat handles it.

I really don't know how they are doing the bypass. Maybe up front it will just force feed ~10psi into the heartbeat and see what happens.

ZO6er

interesting...

Unreal

Car is silly. Should be tuned by end of the week. Hits 20psi instantly at just about any RPM. On spring pressure it sees 14psi, blower alone was 12psi, a little turn up on the controller and it just shoots to anything you want, and has a nice flat boost curve. Hits 20psi without even trying. So far all seems good. IATs are good. On 100+ day it hits ~150F end of a run. No meth so far, but that is coming. Overall it turned out awesome.

Unreal

https://www.youtube.com/watch?v=-5NF...ature=youtu.be

Perfectly flat 14psi of boost right now. Blower alone was 11 so turbos are doing 3 extra. Just getting it dialed in there. Felt good at 20psi. Goes there instantly and just holds to redline.

monsta01

I'd like more details on the Heartbeat setup that made 750whp. Is that a guess or was it actually dynoed? How much boost did it take to make that power?

timmyZ06

That is it?

timmyZ06

That must be the most ignorante and retarded thing i read lately!!!
Of course torque is useless, specially on the street, Carol Shelby was drunk when he said: HP sells cars, torque win race!

Unreal

Actually made that.

Smallest pulley, 434ci ERL motor, Trickflow heads, best of everything. Has big custom heat exchanger, 6 gallon ice water tank, etc.

Was out tuning it all day yesterday. From 14 to 20psi. Feels good. Runs solid. Should have it on the dyno in the next 2-3 days. Put a boost gauge pre blower to see what the turbos are doing.

Blower makes 11psi without the turbos. At 14psi the pre blower boost is 1.5-2lbs. At 20psi the preblower boost is ~5psi. So the blower is basically doubling whatever the turbos put into it +10-11 is what we are seeing. Power band is great. Get that instant hit at 2k, then full boost from turbos by 3400rpm or so.

And yes, in all the racing/beat freeway pulls car never sees below 4k rpm so the power from 2-4k isn't exactly helping win races since it never sees that RPM, but if you don't want to down shift to pass someone on the freeway, it is nice.

Unreal

Car is on the way back to owner. Been a long learning experience. Car didn't make much power (~800rwhp). The blower is just a restriction once you try to up the boost. Even with the bypass open the air has to go through the tiny intercooler bricks and air just backs up. Can't get much more than 800rwhp of air through the heartbeat intercooler. 14psi to 23psi, air flow would just stall. Pulling the intercooler out solved that but then IATs were 270+ and just pegged the sensor out. Also fought with TB issues for weeks. The blower kept sucking the TB shut . Finally had to weld an airfoil into the TB to prevent that.

When owner gets it back, he is probably pulling the blower and going just turbo. The shop in Texas he deals with just did a 416ci with twins that made 1000/1000 with ease, and a killer power band on low boost, so his 434 with more cam/heads/turbo/etc should blow those numbers away.

His other option is to pull the heartbeat and put on a whipple since the bypass valve bypasses the intercoolers which seems to be the only way to get big power on a compound setup.

Detoxx03

I'd just pull it off and leave it off.

Unreal

He is leaning that way. I'm sure once he feels what 1300+rwhp of turbo fun is, 750-800rwhp of blower is going to feel pretty lame.

monsta01

When he made 1000+ with nitrous was he using a post blower setup or pre blower? Man I can't imagine more than 800whp in a Vette. People are crazy. And I am a big speed junkie.

Unreal

I'll have to ask. I think it was a combo of both. It was something like a 350 or 400 shot which wouldn't be a single nozzle.