Exceptional performance comes from innovation.

In order for you guys to be the best you had to build better products than the competition, you did and because you made the most out of what was currently available you guys have been very successful.

Ball-Bearing was a buzzword when it was new I'm sure..... I just wish you were more open to the possibility of there being advantages to running one of these setups, however I know you know much more about this topic than I do, however I feel that this is much more than a fad.

Scorke

 

This all boils down to acceleration. Acceleration is directly related to your torque curve of your engine. Your acceleration will mimic your torque curve. Your car will accelerate hardest at peak TQ and accelerate slower as TQ drops.

You remember what your stock Evo felt like? When you would hit the gas and it would push you back in your seat for a second.... then by 4500 rpms that sensation was gone... That is what a falling TQ curve feels like. Making your turbo spool quicker is just going to multiply that initial push in the seat and then make the disappointment in the upper RPMs that much more...

The force of your motor is multiplied by the gearing in your trans and final drive. The lower the gear, the harder you accelerate. The longer you can keep your car in a lower gear, the longer you can accelerate with the added torque multiplication of that lower gearing. Understanding that will tell you why its more important to be concentrating on upper end power.

In a dyno chart posted in the TS thread in general, there is a torque spike to 512 lbs @ 3800 rpms but the torque is down to 260 lbs by 7000 rpms. After 3800 rpms, this car is accelerating slower and slower... why would anybody want to drive this car?????? Doing the math, you will see that this car NEEDS to be shifted by 6000 rpms to stay in the power band. This is the point where mechanical gearing loses the war with the huge drop in TQ. Doing anything to move the peak torque to a higher rpm would make this car SOOOOoooo much quicker.

Adding to the bottom of the RPM range is exactly the opposite of just about every other mod you do to your car ie cams, intake manifold, larger turbo, freer flowing exhaust, etc.

The bottom line is.... If you want your car to accelerate faster then work on the RPM range that you want to be accelerating hardest in. I am pretty sure everybody here will agree that its not at 4000 rpms.

 

Just to be clear, what I have posted here are MY opinions and not necessarily AMS's position on this subject.

Out of curiosity, do you feel your 35R spools too slow after a shift? Do you feel it hinders your acceleration in any way? IMO, anything 35R and smaller (no matter how poor the manifold its mounted to) spools fast enough. With a proper BOV and a quick shift, boost should be nearly instant. For those with larger turbos (37R and bigger), I could see people wanting to get better spool out of it... unfortunately, this is a trade off for having BIG power up top.

As I have stated several times, OEM builds for the "average" consumer. If an OEM power band is what we all wanted, we would not be modifying our cars. OEM has tried many things to simulate V8 style TQ in small displacement turbo cars. Twin scroll with one large scroll and one small scroll.... two small turbos instead of one larger one.... sequential turbos.... etc... They all worked for what OEM was trying to simulate..... but the second somebody wants more power, these OEM turbos are yanked and replaced with a conventional single turbo.

I am interested in a fair a/b comparison. My initial thought when hearing some guy "dropped 2 seconds off his lap times just by switching to a twin scroll" was how unscientific of a comparison this must be. To drop 2 seconds off lap times is a HUGE feat especially considering the amount of time spent spooling the turbo versus being fully spooled and accelerating. If just the spool up was the reason for the better lap times, his old setup had to be very poor to begin with. Are there dyno charts that we can compare his old setup to versus he new setup that include a log of boost that was run? Are there logs from the track time showing the difference in spool and the fact that boost was the same level? Were the laps at the track on the same day with the same track conditions and the same weather? Was the turbo / kit the ONLY changes made between the lap times?

Find me a link and I will read it over.

 

If twin scroll is a "buzz-word" thank God gravity is a law..

You seem to have made up your mind without doing any testing yourself to back up your claims. Nor do you even seem to care that this could be the future of turbo technology. I think AMS is missing the boat here..

You may not want to dismiss the idea before knowing the full story...

 

We are all guessing until dynosheets are released or someone does testing. Does a single scroll produce more HP up top over a twin? I think Full-Race kits fit some holes in the current turbokits out there as far as direct comparison it's hard for me to believe that a twinscroll offers the same or even more than a single, but we will see.

Twinscroll 4094R for me.

 

I disagree with your comments above. My EVO made peak, TQ at about 3200 RPM, a stock EVO at about 3500 RPM. The force you feel pushing you back in your seat is the CHANGE in acceleration. Torque is directly related to CHANGE in acceleration. But, it's not the change that makes you go fast, it is the terminal acceleration rate you can achieve, and how long you can hold that acceleration rate before neededing to shift. This correlates with horsepower.

A somewhat stock car with a GT35R making 450whp/300TQ racing against a fully built car running a FPGreen making 450whp/400TQ will both perform similarly in the quarter mile, as the high end of the HP range between 6000-8000 rpms is all that matters. Anywhere else, though, and the FPGreen car will kill the 35R car. . .

With your idea that torque is the key to acceleration (meaning being faster down the track), then anyone with a stock turbo'd EVO should shift at 5500 rpm so that they fall back down to the torque peak -- but that's not how it works.

And NO, everyone here WON'T agree that 4000rpm is not the key place to try to make extra power. Not everyone lives their lives a quarter mile at a time. In autocross low end power is key, and in road racing mid-rpm power is key to a fast car.

EVOlutionary

 

Wrong again. Maybe it's because AMS doesn't sell them that you ignore them, but this is where Buschur and FP's 20G line comes in. With proper mods and an EvoGreen you can make 450whp, 450TQ and the dyno graph will very much resemble a stock EVO, only 200HP and 200TQ higher anywhere past 3500 RPMS.

 

The force you feel pushing you back in your seat is change in SPEED. This is also known as ACCELERATION.

 

This is turning into a pissing contest...perhaps this thread would be better suited if we had AMS' official weigh-in on this since Ivan has already stated these views are his own, and not necessarily AMS'.

 

If that's the case, then why is it not faster to short shift a stock EVO at 5000 or 5500 rpm so that you stay in peak torque longer??

 

Peak TQ only tells a portion of the story. You need to look at the TQ curve and gearing to answer that question. When you shift up a gear you are losing the force multiplication of the gears. It may be better to continue in that lower gear even though TQ is dropping. At some point, torque will either drop enough to make better to shift up a gear or you run out of mechanical RPM and need to shift.

I would need a dyno chart showing TQ v RPM to plot out a line chart to determine what RPM to shift at in each gear for maximum acceleration.

 

While a twin-scroll setup should benefit from slightly earlier spoolup, the main advantage for road-racing purposes is the improved response of the turbo. I can definitely see this being advantageous on a road course, since there will be times when you want the earlier spool and better response from a twin-scroll setup, either when coming out of low-speed corners or when going through longer turns where you don't want to have to shift until you hit the next straight. IMO, twin-scroll will do nothing for drag racers.

I have approached Martin in regards to custom building a TS setup for me, but it doesn't look like I'll have the funds anytime soon. F'ing real-estate market is killing me ...

l8r)

 

He's right engine torque is just a force times a moment arm. That moment arm is the sum of all the gear ratios currently being used ( i.e. 1/2/3/4/5 gear, final drive, and tire diameter). The torque divided by your moment minus the force of drag,rotation parts friction and rolling resistance gives you the force that drives you forward. That force divided by your mass equals your acceleration (f/m=a). The time rate of change of that force ( the slope of your torque curve) is your change in acceleration (which I have heard being referred to as jerk).
So torque determines how quick a car is and can help determine top speed if not redline limited.


-Fred

 

I'm sure AMS will someday test this design if they see that it could potentially help performance. Until then take THIS into consideration....

AMS has the highest hp producing t3 flanged turbo kit...not twin scrolled
AMS has the quickest and fastest T3 flanged turbo kit...not twin scrolled
AMS has the quickest and fastest drag EVO 8 in the world...not twin scrolled
AMS has one of the quickest and fastest time attack EVO's in the world and guess what...not twin scrolled

If there is such a buzz about how great it is...why doesn't someone come out and beat AMS on the track or at the dyno with a twin scrolled setup? All this thread has been is hear-say. There have been no numbers, no track results, NOTHING! The only thing for me to look at is what works and AMS seems to have that under control. If AMS knocks 2 seconds off their time attack car by switching a turbine housing it would be a miracle..do you know why? Because their current kit is PROPERLY DESIGNED now!

 

Twin scroll is about improved throttle response earlier spool.