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      09-29-2011, 02:11 PM   #23
ZCP M3
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Okay, let me drop a bit of knowledge here. It's all about power under the curve and thus the ability to generate lots of torque at all RPMs. Twincharging is only advantageous if the turbos are overly large and take a long time to spool up.

Take a look at a 135/335/1M dyno graph. Max torque is available almost anywhere in the rev range and damn near down to idle.

Now take a look at a Supra dyno graph with a turbo that is very large. It clearly doesn't spool, even under load from the dyno (which will make it spool faster), until about 4000rpm. This is where twincharging would help.



You want the supercharger to provide low end torque until the turbos are up to speed. The N54 has the turbos up to speed at around 1500rpm. If we say the supercharger makes 7PSI boost at 7k RPM, you will have less than 1.5PSI of boost until the turbos are pushing out all 14.5PSI or whatever they provide. So 99.9999% of the time, the supercharger would actually cost you horsepower due to parasitic drag. You'd see a benefit from idle to 1500rpm in first gear.

Now the follow up argument is that the supercharger will increase throttle response and to a point it will. But with MDM enabled, the N54 uses the wastegate to keep the turbos spooled up for quick response.

Unless you plan on increasing the turbo size and introducing more lag into the system (and can't utilize the MDM wastegate tuning), the s/c isn't going to pay off for the added complexity. And the same thing applies, once the turbos are spooled the charger provides little benefit.

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      09-29-2011, 11:41 PM   #24
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The Ronin exige is my favourite example of a homebrewed twin charged system. This car has a 1.8L 2ZZ toyota engine built from the ground up. The entire super/turbo system is custom. This car is absolutely insane... and so is the owner



yeah lightspeed

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      10-24-2011, 07:53 PM   #25
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Hi guys I'm the nut case 680 whp ronin exige..
I had a great run last Sunday up hill with a 1M and I gotta say I was impressed with the car and the driver behind the wheel..... He pushed it for all it had and knew when enough was enough, it's good to see egos kept in check..
We had a nice sprited drive up and over the hill, again I was impressed to see him toss the 1M into the twisties without lossin a beat...

If anyone has a question on compound charging feel free to ask away, Id be happy to help out if I can...

I did own a M1 at one time...

Cheers,

Frank
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      10-24-2011, 08:29 PM   #26
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Why?
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      10-24-2011, 08:47 PM   #27
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Hi guys I'm the nut case 680 whp ronin exige..
Nice car. Good color.
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      10-24-2011, 09:14 PM   #28
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Why what ?

Thanks the color is a Ferrari grigio medio..
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      10-24-2011, 09:34 PM   #29
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That exige is badass. I can watch those vids all day long. What is the weight w/o driver?
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      10-24-2011, 09:45 PM   #30
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If we say the supercharger makes 7PSI boost at 7k RPM, you will have less than 1.5PSI of boost until the turbos are pushing out all 14.5PSI or whatever they provide. So 99.9999% of the time, the supercharger would actually cost you horsepower due to parasitic drag. You'd see a benefit from idle to 1500rpm in first gear.

Now the follow up argument is that the supercharger will increase throttle response and to a point it will. But with MDM enabled, the N54 uses the wastegate to keep the turbos spooled up for quick response.

Unless you plan on increasing the turbo size and introducing more lag into the system (and can't utilize the MDM wastegate tuning), the s/c isn't going to pay off for the added complexity. And the same thing applies, once the turbos are spooled the charger provides little benefit.

First off the supercharger makes whatever boost it's displacement and rpm will allow so if it's 7 psi at 1,000 rpm it will be 7 psi. at 8,000 rpm...
It does not rob HP when compounded since the presure out put from the turbo offsets the parasitic losses and helps to spin the blower... There is no free ride but if you want instant throttle responce and zero turbo lag this is the only way to go....
There is no 1.8ltr gasoline engine making 420 ft tq at 3,800 rpm that I know of on 91 octane.
You can not get the power from small turbos alone, if you want big power you need a larger turbine housing to rid the exhaust gas pressure and heat and with that you get lag.... Unless you keep your foot planted you will always have lag in the real world with a big turbo setup alone...
It is the superchargers instant pressure and the exhaust heat and pressure that will spool the larger turbo....
My car at 70 mph cruises at 3,000 rpm if I touch the throttle I get an instant 16 psi.of boost by the time it hits 3,700 rpm I have 35 psi. I have never been in any car with this kind of responce..
Remember it's only 1.8 ltr and pulls like a freight train al the way to it's 10,000 rpm redline in any gear....

Compound charging works and it works better than any turbo alone setup...
Oh yeah my charge temps are never more than 10*f above ambient at 35 psi. due to my chargecooling setup... Here is a 27 psi.pull on 91 octane
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      10-24-2011, 09:45 PM   #31
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Quote:
Originally Posted by ronin exige View Post
Why what ?

Thanks the color is a Ferrari grigio medio..
Why twin charge a 1m, seems like you can get plenty of power without it for the chassis, but your exige is awesome.
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      10-24-2011, 09:50 PM   #32
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That exige is badass. I can watch those vids all day long. What is the weight w/o driver?
Thanks it's 2150 with a full tank..
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      10-24-2011, 09:56 PM   #33
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Originally Posted by ZCP M3 View Post
...
But with MDM enabled, the N54 uses the wastegate to keep the turbos spooled up for quick response.

Unless you plan on increasing the turbo size and introducing more lag into the system (and can't utilize the MDM wastegate tuning), the s/c isn't going to pay off for the added complexity. And the same thing applies, once the turbos are spooled the charger provides little benefit.

M mode closes the wastegates and not MDM. I'm a little anal about 1M details.
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      10-24-2011, 09:56 PM   #34
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Originally Posted by SpencerMH View Post
Why twin charge a 1m, seems like you can get plenty of power without it for the chassis, but your exige is awesome.
Oh I'm not sayin you should, i think it's cool as is and I've seen it pushed to it's limits..
I just came across this while surfin to find out more about the 1M after seein it do it's thing by a skilled driver...

I don't think you'd want 800 hp in a car with such a short wheelbase and high CG.
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      10-24-2011, 10:13 PM   #35
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Quote:
Originally Posted by ronin exige View Post
Thanks the color is a Ferrari grigio medio..
Good taste. I went with Lamborghini Grigio Telesto for mine:


I highly approve of your car- any links to a build thread?
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      10-24-2011, 11:07 PM   #36
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Everything about my car is on www.Lotussport.org the good the bad and the ugly... Fron melted pistons to blown gearboxes, I was gonna say tranys but I'm new here...

I followed the old Porsche satin rim look..
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      10-24-2011, 11:19 PM   #37
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Such a sick whip
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      10-25-2011, 12:21 AM   #38
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Quote:
Originally Posted by blueshark View Post
Could a supercharger be paired with the existing turbocharging units?
A lot has already been said here especially about sizing correctly. Generally, you supercharge for low end, then have big turbos that pick up the boost at higher RPM. The problem is that the 1M uses tiny turbos to reduce lag, so to do it right you would have add the supercharger and go with bigger turbos. There is also not a lot of room. Bigger turbos by themselves would increase lag and probably overwhelm the already iffy charge pipe. Finally, the current tires can barely handle the torque on this monster, so you will have to address that or go to Costco and buy a bulk pack of diapers so you drive this proposed beast without messing up the seat. : )
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      10-25-2011, 12:26 AM   #39
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I'm sure the charge pipe will be the least of your worries if moving to a compound charging setup on the 1M.
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      10-25-2011, 12:35 AM   #40
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I'm sure the charge pipe will be the least of your worries if moving to a compound charging setup on the 1M.
: )

Yes, the diapers would more important. Just trying to expand that the effects of one change will impact a lot of other parts of the drivetrain.
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      10-25-2011, 12:37 AM   #41
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Quote:
Originally Posted by ZCP M3 View Post
Okay, let me drop a bit of knowledge here. It's all about power under the curve and thus the ability to generate lots of torque at all RPMs. Twincharging is only advantageous if the turbos are overly large and take a long time to spool up.

Take a look at a 135/335/1M dyno graph. Max torque is available almost anywhere in the rev range and damn near down to idle.

Now take a look at a Supra dyno graph with a turbo that is very large. It clearly doesn't spool, even under load from the dyno (which will make it spool faster), until about 4000rpm. This is where twincharging would help.



You want the supercharger to provide low end torque until the turbos are up to speed. The N54 has the turbos up to speed at around 1500rpm. If we say the supercharger makes 7PSI boost at 7k RPM, you will have less than 1.5PSI of boost until the turbos are pushing out all 14.5PSI or whatever they provide. So 99.9999% of the time, the supercharger would actually cost you horsepower due to parasitic drag. You'd see a benefit from idle to 1500rpm in first gear.

Now the follow up argument is that the supercharger will increase throttle response and to a point it will. But with MDM enabled, the N54 uses the wastegate to keep the turbos spooled up for quick response.

Unless you plan on increasing the turbo size and introducing more lag into the system (and can't utilize the MDM wastegate tuning), the s/c isn't going to pay off for the added complexity. And the same thing applies, once the turbos are spooled the charger provides little benefit.
Dang! I scrolled through the car pics and missed this one in the middle. Sorry man... you had already said it exactly, thank you! Beautifully done!
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      10-25-2011, 12:48 AM   #42
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Originally Posted by nachob View Post
A lot has already been said here especially about sizing correctly. Generally, you supercharge for low end, then have big turbos that pick up the boost at higher RPM. The problem is that the 1M uses tiny turbos to reduce lag, so to do it right you would have add the supercharger and go with bigger turbos. There is also not a lot of room. Bigger turbos by themselves would increase lag and probably overwhelm the already iffy charge pipe. Finally, the current tires can barely handle the torque on this monster, so you will have to address that or go to Costco and buy a bulk pack of diapers so you drive this proposed beast without messing up the seat. : )
Wrong..
In a compound setup the supercharger is for the entire RPM range, it spools the turbo at any RPM. The larger turbo is needed for increased CFM for power and the larger turbine housing is needed to allow for the exhaust gas to flow out you don't restrict the flow with a small turbine housing.
I'm just tryin to give the facts on compound charging.. Too many guys get it wrong.

Also dyno sheets don't tell you anything when it comes to the responce on the road in different gears..They only show you what you will get if you leave it in one gear with the throttle floored..
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      10-25-2011, 01:02 AM   #43
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Quote:
Originally Posted by ronin exige View Post
Wrong..
In a compound setup the supercharger is for the entire RPM range, it spools the turbo at any RPM. The larger turbo is needed for increased CFM for power and the larger turbine housing is to allow for the exhaust gas to flow out you don't restrict the flow with a small turbine housing.
I'm just tryin to give the facts on compound charging.. Too many guys get it wrong.
Of course it's for the entire range?????? You can't shut off turbos?????? The turbos are not limited by crank speed so they can continue making boosts after the supercharger can't anymore????? Yes, the supercharger fills the low end void whilst the turbos come into their own??? Not sure what is wrong about that????
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      10-25-2011, 01:22 AM   #44
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Of course it's for the entire range?????? You can't shut off turbos?????? The turbos are not limited by crank speed so they can continue making boosts after the supercharger can't anymore????? Yes, the supercharger fills the low end void whilst the turbos come into their own??? Not sure what is wrong about that????
The supercharger spools the turbo at all RPMs it doesn't stop or go into bypass.
The supercharger alone boost output is detrmined by pulley size it doesn't go up or down with rpm, it works as a boost multiplier with the turbo...The larger turbo is also flowing air at every RPM it just doesn't flow enough CFM to create useable boost at low RPM...Put them together and you get as much airflow as you can use when ever you want it at almost any RPM..
My turbo flows into the supercharger - chargecooler and then intake manifold...
This may give you a better idea what happens with the boost..
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Last edited by ronin exige; 10-25-2011 at 01:29 AM.
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