My compound turbo set-up

[wishihadatalon]

With your power curve being so linear, Id say you just made a quicker spooling alternative to just using a larger single turbo, and you are seeing 80lbs/min of flow.......Jesus. Thats like a GT40 reaching full spool at 4500 rpms...Which doesn't happen.

Its also better with the linear torque, because isn't the quick and abrupt changes in torque (like the initial hit of a larger turbo) that puts the most shock and strain on drivetrain parts??

There are dsmers who live in Walker? Just bought my house here

 

[EclipticalGS]

There are dsmers who live in Walker? Just bought my house here

There was just me, now i guess there's two DSM'ers in Walker. Hah!

 

[Slippi84]

Thats too bad the current set up wont see the dyno again. I was really hoping to see it make the claimed 75lbs/min and prove everyone wrong including me. The compounds run on cavs ive seen were very disappointing.

My ride is a "weekend warrior" so street-ability is pretty important. If the compound could make big numbers and keep it streetable id be all over it. So far though im still very skeptical. Not that my opinion matters, just pretty interested. I just have never seen a compound live up to the hype yet.

Nothing against kevin's accomplishments but for comparison those numbers have been made with a single 35r in an awd car and hes spraying on a compound with a massive S475. I think everyone expected 600hp from the set up mentioned in this thread and that's what it laid down and that's about what the 60-1 can do. I guess i was really hoping to see a 750whp dyno run and put all the doubts to rest.

Yeah that's true but he runs 8s now so huge power or not it works. I think people worry to much about dyno sheets. A car with tons of power and no ETs to back it up is like a supermodel with aids. Good to look at but once your inside you regret it.

 

[EclipticalGS]

Yeah that's true but he runs 8s now so huge power or not it works. I think people worry to much about dyno sheets. A car with tons of power and no ETs to back it up is like a supermodel with aids. Good to look at but once your inside you regret it.

I just think people worry too much about overall horsepower, instead of power curves...

When a 1000hp dsm can run 8's with a large single turbo, and Kevin can run 8's with 600~hp with a compound set-up, its more about how linear the power is, because im sure kevins car has a long power-band, and thats continuous acceleration, instead of monster power "bursts" you get with larger singles.

 

[99gst_racer]

Thats too bad the current set up wont see the dyno again. I was really hoping to see it make the claimed 75lbs/min and prove everyone wrong including me. The compounds run on cavs ive seen were very disappointing.

My ride is a "weekend warrior" so street-ability is pretty important. If the compound could make big numbers and keep it streetable id be all over it. So far though im still very skeptical. Not that my opinion matters, just pretty interested. I just have never seen a compound live up to the hype yet.

Nothing against kevin's accomplishments but for comparison those numbers have been made with a single 35r in an awd car and hes spraying on a compound with a massive S475. I think everyone expected 600hp from the set up mentioned in this thread and that's what it laid down and that's about what the 60-1 can do. I guess i was really hoping to see a 750whp dyno run and put all the doubts to rest.

You never know. The next owner very well may dyno it on his car. Hopefully he'll push it harder than I have.

But 609 WHP plus 15% for drivetrain loss, puts it at around 700 HP at the crank. That's roughy 70 lbs/min using the "10hp per 1 lb/min" rule of thumb. So it sounds close to me.

Regarding Kevin's car; also keep in mind that he's making that power through an auto tranny. In a m/t car, his dyno numbers would have been quite a bit higher. And I'm pretty sure he's not spraying anymore. IIRC, he was able to get better spool numbers with the compounds as apposed to using spray to help spool.

I just think people worry too much about overall horsepower, instead of power curves...

When a 1000hp dsm can run 8's with a large single turbo, and Kevin can run 8's with 600~hp with a compound set-up, its more about how linear the power is, because im sure kevins car has a long power-band, and thats continuous acceleration, instead of monster power "bursts" you get with larger singles.

I agree.

This whole project has really open my eyes and taught me the importance of where the power curve is instead of just the peaks.

 

[Slippi84]

WORD!!! That's why I called my project project 9's no compromise not project make a bunch of HP

 

[Chicken Patty]

Power band is everything. Have anyone ever ran a car with the same or more power than them (same car) and has gave it a severe ass kickin'? It's called power band.

 

[viperlp01]

Not sure what your point is here? The compound system spools faster than a 60-1 by itself. And flows more air.

Sorry this is old but the turbos are still spooling at the same speeds. Maybe alittle faster because the amount of exhaust energy increases per manifold pressure. The car just makes more boost faster because of the pressure ratio increase before the 16g.. If you divide the boost numbers that he is making by the pressure ratio between the turbos you would get a close estimate on how fast they(mainly the 16g) are spooling against the rpm. Paul correct me if I am wrong but there is no way the turbos can possibly spool up instantly. You are mainly looking at the spool speed of the 16g as well if I understand it correctly. The 16g would spool up way quicker that the 60-1 but when the 60-1 starts to reach its desired p.r it starts to help the 16g to pushs the boost level up even higher but the 16g is still spooling at its desired "boost level".

 

[91stocker]

good to look at but once your inside you regret it.

haha true true

 

[Kevin Jewer]

One thing that I did notice is that the less boost the primary runs, the slower the overall spool of the system. So that shoots down your "spooling sooner with less PR with the 16g" theory.

This is true. The higher the PR on the small turbo the bigger the "motor" seems to the big turbo (exhaust gas output). A 2 liter with 30 psi on the small turbo is now a 6 liter. A 6 liter will spool a given turbo "faster" than a 2 liter. In my setup at 45 psi the big turbo does 17 psi, the large turbo does 28 psi. People keep trying to tell me this is backwards, but this is how it has to work. More boost from the small turbo is better.


The following is not directed specically at 91stocker, but I'm goind to touch on each of these points just to go through the exercise.

Nothing against kevin's accomplishments but for comparison those numbers have been made with a single 35r in an awd car

I think you mean a single AWD car with a 35r. The average "decent" 35R car runs 10-11s. Also, FWIW, my average 60 foot time isn't much different than that of an average AWD with slicks. I'm still sorting out the rear suspension on this car. it will go at least 3 tenths faster with the same power. If every AWD car with a 35R could run high 8s no one would ever run anything bigger. I also run relatively low boost, and I don't tune to the edge to make a shitload of power at low boost. I want to race this car, not fix it all the time. I wouldn't compare my times to anyone elses for that reason, never mind the auto tranny.

and hes spraying

False, you've missed the whole point of why I did the conversion to compound turbo and why I want to have Paul's babies...

on a compound with a massive S475.

The turbo is massive indeed, which only proves just how well this setup works. In the case of the 60-1 a 2 liter could spool it without compounding and the debate revolves around how fast each setup spools it. In the case of a T6 1.32 475, it's a case of spooling at 4500-5000 rpm vs not spooling at all (ok, 8000+ rpm and 12 seconds down track in a very high gear with a loose converter, same thing).

To recap, my car went faster with the compounds and no nitrous than a single turbo with nitrous to spool, at the same boost. The fastest my car went on my local track on the single 42R was 150.0. The second run ever on the compound setup went 153.8 at the same boost. It also dynoed ~20 more peak whp on the same boost through the auto, which isn't a lot for the nearly 4 mph gain (curve vs peak). How this can not live up to anyone's definition of "successful" is beyond me. I guess you have to resort to comparing GM auto trannies to Mitsu 5 speeds and one-off results on a particular turbo to pull it off, but then I question the motivation behind it.

Compound turbos are not for everyone! If they're not for you, that's fine. But if you're going to argue that they don't work very well for my application you're going to have to work pretty hard to convince me.

 

[99gst_racer]

False, you've missed the whole point of why I did the conversion to compound turbo and why I want to have Paul's babies...

You must be logged in to view this image or video.

 

[Slippi84]

YouTube - Marc's 2JZ Turbo Compound Setup

 

[viperlp01]

Paul and Kevin <3's Haters

 

[91stocker]

Hey nothing wrong with a little back and forth

Its pretty interesting, lots of good info.

 

[GORBS88]

You never know. The next owner very well may dyno it on his car. Hopefully he'll push it harder than I have.

But 609 WHP plus 15% for drivetrain loss, puts it at around 700 HP at the crank. That's roughy 70 lbs/min using the "10hp per 1 lb/min" rule of thumb. So it sounds close to me.

Just a question about this statement, How does the amount of power you lose through drivetrain loss go UP as you make more power over stock.?? The amount of power lost through drivetrain loss doesn't go up! Stock we lose around 30-40Hp, NOT 91hp!

 

[slipstream808]

Just a question about this statement, How does the amount of power you lose through drivetrain loss go UP as you make more power over stock.?? The amount of power lost through drivetrain loss doesn't go up! Stock we lose around 30-40Hp, NOT 91hp!

Eh, best is to not open that can of worms. The percent is a PURE estimate. Differs from individual car to individual car. Drivetrain losses come in two forms. Constant losses that happen during cruising and acceleration losses that occur during acceleration in addition to constant losses. Truth is, based on what RPM you are at in your car's specific powerband, the drivetrain losses will vary. In the end though it isn't a constant value. More acceleration through the drivetrain results in more power lost.

Realistically you'd have to dyno your car as well as dyno the engine and compare the graphs to get percentage losses. When it is all said and done I like whp better and I think most people that really like their cars do as well because all that power and torque have to go through your entire drivetrain for you to feel it.

 

[GORBS88]

Eh, best is to not open that can of worms. The percent is a PURE estimate. Differs from individual car to individual car. Drivetrain losses come in two forms. Constant losses that happen during cruising and acceleration losses that occur during acceleration in addition to constant losses. Truth is, based on what RPM you are at in your car's specific powerband, the drivetrain losses will vary. In the end though it isn't a constant value. More acceleration through the drivetrain results in more power lost.

Realistically you'd have to dyno your car as well as dyno the engine and compare the graphs to get percentage losses. When it is all said and done I like whp better and I think most people that really like their cars do as well because all that power and torque have to go through your entire drivetrain for you to feel it.

Oh, I totally agree. BUT my point to this matter is our cars make around 200 crank HP and put down around 160awhp take or give. SO IF it's around 30-40 hp then how does it increase?
You can't take the 15% number and continue to use it, otherwise when your making 1000Hp your loses are around 150? I think not.

I'm not trying to rain on anyones parade at all just trying to get the facts.

 

[Kevin Jewer]

Hey nothing wrong with a little back and forth

Its pretty interesting, lots of good info.

That's the spirit! I'm glad the thread is alive and well again, a good debate will keep it going.

Oh, I totally agree. BUT my point to this matter is our cars make around 200 crank HP and put down around 160awhp take or give. SO IF it's around 30-40 hp then how does it increase?
You can't take the 15% number and continue to use it, otherwise when your making 1000Hp your loses are around 150? I think not.

Some of the losses are constant, some are proportional to input (percentage). It will take someone smarter than me to separate all of the components of the total drivetrain loss into each category and add it all up, but for some quick examples losses like oil seal drag are probably constant, while losses like those from the inertia of the rotating mass are probably proportional.

 

[slipstream808]

I'm not trying to rain on anyones parade at all just trying to get the facts.

Here is a link that while not explaining the details, is an eye-opener as to what is going on.

Drivetrain loss, explained - 8th Generation Honda Civic Forum

 

[jrohner]

Just a question about this statement, How does the amount of power you lose through drivetrain loss go UP as you make more power over stock.?? The amount of power lost through drivetrain loss doesn't go up! Stock we lose around 30-40Hp, NOT 91hp!

More power does mean more load and friction on the drivetrain, meaning more hp losses.

 

[pazsion]

well since both turbos are spinning..the air is simply pulled through.. not much pressure should build up until high rpms, or shifts..

the smaller turbo will spin faster, sooner then the big one.. the big one compresses a lot more air then the little one.. so there is a huge ammount of pressure heading back to the little one..where things compress even more.. maybe in the future some active oil/water cooled turbos will be needed..

turbos are generally built pretty hefty.. @30psi internal stresses can exceed 300lbs psi when you reduce the size of outlet pipe or go into a smaller turbo, that increases. but so does volume of air, and velocity of that air. with a setup like this, the air might actually have some cavitation.. on the tiny turbo end..as the stock blades struggle to move the air.. makeing the first turbo a powered turbo could help with many things.. but would add to complexity/maintance etc.. keep it simple as much as you can.. the more crap you throw in there the more things can go wrong..

this is very pretty i wanna hear it run and race XD

 

[donniekak]

Oh, I totally agree. BUT my point to this matter is our cars make around 200 crank HP and put down around 160awhp take or give. SO IF it's around 30-40 hp then how does it increase?
You can't take the 15% number and continue to use it, otherwise when your making 1000Hp your loses are around 150? I think not.

I'm not trying to rain on anyones parade at all just trying to get the facts.

A simple explanation for part of the increase is helical gears. The more torque you push through them the harder the want to push axially away from each other, increasing the load, and power loss of the tapered roller bearings. Also when a 800hp car accelerates, the rpms of the gearbox(and all other rotating parts) accelerate faster than on a stock car. An example would be measuring the force it takes to go from 3000, to 7000 rpm's in the period of time it takes in a stock car. Versus accelerating the same rotating mass the same rpm sweep, in a faster time frame.

 

[Winglessflight]

Don't get me wrong, I absolutely love the idea of a much fatter torque and power curve created by the compounded turbo setup, but, just to play devil's advocate, couldn't most of this be accomplished by using the same large turbo on a higher compression engine? You'd get the NA kick (little as it may be on a 4 cylinder) but you'll also get the quicker spool, not to mention saving ~50 lbs on the front axle. I do realize that tuning to the edge would be a little nerve racking. It's all just for the sake of argument, and maybe i can learn something I didn't know.

 

[Kevin Jewer]

The extra compression won't do anything appreciable for spool, and the few % extra torque doesn't add up to nearly as much as a 30 psi kick start from the small turbo.

 

[keltalon]

[QUOTE
Compound turbos are not for everyone! If they're not for you, that's fine. But if you're going to argue that they don't work very well for my application you're going to have to work pretty hard to convince me. [/QUOTE]

Well said. I know I really don't have to add to all the complements you have recieved alrealdy but for your hard innovative work. Just ignore the hater and thanks