Why isn't compound boost more popular?

[GRFox]

Why isn't compound boost more popular? I saw a car at a car show with a single turbo through the stock Eaton, it made 948RWHP, bone stock with the exception of the turbo and an upgraded fuel system to feed it.

When the car started up, it sounded like a stock Termmy (with the exception of the sound of the massive fuel pump), even when he drove away he feathered it out into 1st and drove away like a stock car. Completley street able with 950 to the wheels.

I get it, you don't really need all that power (or can't really use it) on the street, but with the ability to change tunes and regulate boost I figured you would see t much more often.

I know relatively nothing about it, so maybe there are some major reasons it isn't done that much, I was just curious.

 

[Avispa]

It's just plain impractical without a lot of fabrication is probably why. Reason is it's awfully hard to mount two heat exchangers under the front bumper; and with the engine compartment already crowded with an Eaton or other positive displacement compressor, where are you gonna fit the turbo intercooler?

 

[4601S/C]

If I had cash to burn I'd do it just to have it. Wouldn't run more than 650-700bhp. It would just be awesome to have. The only compound boost car I really paid any attention to was the Hellion one, but if I'm not mistaken they blew that up and didn't make a second attempt. I think their TT kit is still marketed as a compound boost solution though.

 

[b_dike]

They're complex, difficult to tune, unreliable, and extremely expensive. Not to mention you could make more power with a tt setup.

 

[JaybTorchedMach]

They're complex, difficult to tune, unreliable, and extremely expensive. Not to mention you could make more power with a tt setup.

This.

I remember reading somewhere that the supercharger becomes a restriction after a certain point.

 

[GRFox]

They're complex, difficult to tune, unreliable, and extremely expensive. Not to mention you could make more power with a tt setup.

That just about sums it up. LoL

 

[stangfreak]

The amount of total boost that is meant to run the compound is insane. when the kit first came out, people thought, ok, we are going to run a stock upper pulley, make 8lbs through the eaton, then only 10lbs from the turbo, total of 18. doesnt work that way.

There is a HUGE thread on modularfords where the cobra guru's explained how it works. Id rather go with a single power adder IMO

 

[71catruck]

There is a guy in the turbo section for the terminators that did it with a 5.4 and is makeing just under 900 I think. Yes he would probably make more with just the single but he also wouldn't have the same tq curve he does. I believe he is running a 9.2 at over 150 in the 1/4. It's a six speed car and still has a/c and power steering. Raceing isn't all about peak power its about when you make the power.

 

[stangfreak]

There is a guy in the turbo section for the terminators that did it with a 5.4 and is makeing just under 900 I think. Yes he would probably make more with just the single but he also wouldn't have the same tq curve he does. I believe he is running a 9.2 at over 150 in the 1/4. It's a six speed car and still has a/c and power steering. Raceing isn't all about peak power its about when you make the power.

Oh I totally agree. That's why I laugh at the guys who buy a huge twinscrew and run 15 16 lbs or even 17 lbs on a bigger blower, make a huge peak number and think there going to beat everything.

Anyway, yes. The setup will,make more power under the curve but like isaid it's going to be big boost and its just complex. Two people I know ditched the kit. Things kept breaking and there is too much going on.

 

[Jimmysidecarr]

Why isn't compound boost more popular? .

Often wondered the same thing.

Many good points already given though, complexity, limits to the ultimate upper power level, expense and the need for a very high end and robust fuel system capable of delivering large amounts of E85.

I love the idea and think that a properly done compound car would be the ultimate in flexibility. An absolute blast as a street cruiser long distances on 93 octane as well as a killer mile car or top end blast bruiser in general.

All with just a change from 93 to E85, a flip of the the tune via a quick flash, and a cranking up of the adjustable turbo boost controller.

To be done right it would cost some significant ching$.

 

[97snakebite]

Why isn't compound boost more popular? I saw a car at a car show with a single turbo through the stock Eaton, it made 948RWHP, bone stock with the exception of the turbo and an upgraded fuel system to feed it.

When the car started up, it sounded like a stock Termmy (with the exception of the sound of the massive fuel pump), even when he drove away he feathered it out into 1st and drove away like a stock car. Completley street able with 950 to the wheels.

I get it, you don't really need all that power (or can't really use it) on the street, but with the ability to change tunes and regulate boost I figured you would see t much more often.

I know relatively nothing about it, so maybe there are some major reasons it isn't done that much, I was just curious.

i want to see this "stock" motor cobra w/900rwhp..that motor is on borrowed time

 

[71catruck]

It might be on barrowed time but how many people do that with just a big single on a stock motor. I really think a well compound setup would be an amazing street car. Stock drivability and able to crush anything sounds good to me. Me and a friend thought if you could replace the stock boost bypass valve with a bigger one by wielding in a plate like posi did on his ports and having it open up when the turbo starts boosting then you might be able to get rid of the restriction of the blower to. Just an idea.

 

[Jimmysidecarr]

i want to see this "stock" motor cobra w/900rwhp..that motor is on borrowed time

That is a significant portion of the expense issue, stock piston to wall clearance is not something that mile cars and top end cars typically run due the the rapid heating of the pistons at those lofty power levels.

It would be nice on a built motor E85 car though.:beer:

 

[racebronco2]

The compound boost car would have great low end and top end torque. The problem is that most 500hp cars would be faster since you could spin the tires all the way down the 1/4 mile. Only thing that could hold that much power is some slicks. Unless of course you do roll runs starting at 100mph. There was a member recently whom had less than 700rwhp and couldn't hook up til third gear.

 

[71catruck]

I would think a 700 hp compound set up would be easier to control than a 700 turbo. But who knows

 

[ctgreddy]

I like to look around on other car forums from time to time, and I remember when going on a GT forum, they love compound boost, and it looked like a lot of guys would try the normal TT route and then go back to a compound, as it doesn't have the midrange and isn't as fun nor as fast overall. However, this is on GT's, when you spend 150+k on a car, spending 15-20k on a turbo install and lots of tuning isn't shit.

 

[stangfreak]

If you guys a looking for big power all around just get a 4,0 whipple. The gt500 boys re making insane power with these bigger blowers. 1100 and seeing 800rwtq at 3 k rpm.

 

[foofinator]

I'd love to give compound boost a try on my eaton swapped GT.

 

[SVTDice]

I'm currently in the process of helping a guy do a TVS + Twin 66 MM Turbo's. He is very dead set on it, but he already knows its going to cost alot and its going to be alot of down time for it.

All in all I think the idea is kick ass and I hope he breaks 1200 HP. But we shall see.

 

[Digital]

Because only the manliest of men are choosen to be gods of the compound boost.