Perhaps the final update on the MTM Stage 3++
08-28-2004, 10:33 AM
#1
AudiWorld Super User
Thread Starter
Perhaps the final update on the MTM Stage 3++
Well, we have the car boosting to 15-17psi running the stock N75 valve and I have to say that the car definitely moves but the power delivery is so much different than the K04 (I suppose this was to be expected).
The boost on the larger GT28R turbo is very linear with no spikes. It begins building boost from 0psi to 17psi at 3000rpms. It does not reach peak boost until around 3900rpms.
With the K04 it would quickly spool up from 2500rpms and would peak early at around 3000rpms (28psi) and then quickly settle in at 23psi from 3100 or so up to around 5000rpms and would nicely taper off boost to redline.
This leads to a completely different feel in power. The old K04 felt like a torque monster when powering out of turns because the boost was immediate. The new GT28R needs to have the pedal held to the floor and be driven arount 1000rpms higher in the rev band to get in it's sweet spot.
My conclusions are that for my style of driving I actually favor the smaller K04. On a Solo II track there is little doubt that the K04 will provide better results. Now thinking about big tracks like Sebring, I would actually prefer the K04 as well. Coming out of the gear 2 turns, the K04 would allow me to get out of the corner much quicker. I would probably suffer in the back straits, but the instant power delivery just appears more desirable to me.
Around town, there is no doubt that the K04 is the winner. It is easy to stay in its sweet spot and allows for nearly instant spooling.
I have to say that I am a little upset to have tried this out, but I am actually thinking of returning to the K04 and working on having it ceramic coated and working on hard plumbing the front end of the car as well as running a 3" MAF. Right now, Jet and I are putting down around 280lb/ft of torque TO THE WHEELS on the K04 with the N75K so if I can get a little more tweaking to it, I think it will be my best bet.
All I can say is that perhaps I had to try this out to find out that the grass is not always greener. Others would have told me that I may not be happy with the spooling characteristics of a big turbo and I wouldnt have believed them, so I guess I had to figure this out for myself. Your thoughts are welcomed. Cheers! Mike
<img src="http://pictureposter.audiworld.com/57072/gt28rcompress-1.jpg">
The boost on the larger GT28R turbo is very linear with no spikes. It begins building boost from 0psi to 17psi at 3000rpms. It does not reach peak boost until around 3900rpms.
With the K04 it would quickly spool up from 2500rpms and would peak early at around 3000rpms (28psi) and then quickly settle in at 23psi from 3100 or so up to around 5000rpms and would nicely taper off boost to redline.
This leads to a completely different feel in power. The old K04 felt like a torque monster when powering out of turns because the boost was immediate. The new GT28R needs to have the pedal held to the floor and be driven arount 1000rpms higher in the rev band to get in it's sweet spot.
My conclusions are that for my style of driving I actually favor the smaller K04. On a Solo II track there is little doubt that the K04 will provide better results. Now thinking about big tracks like Sebring, I would actually prefer the K04 as well. Coming out of the gear 2 turns, the K04 would allow me to get out of the corner much quicker. I would probably suffer in the back straits, but the instant power delivery just appears more desirable to me.
Around town, there is no doubt that the K04 is the winner. It is easy to stay in its sweet spot and allows for nearly instant spooling.
I have to say that I am a little upset to have tried this out, but I am actually thinking of returning to the K04 and working on having it ceramic coated and working on hard plumbing the front end of the car as well as running a 3" MAF. Right now, Jet and I are putting down around 280lb/ft of torque TO THE WHEELS on the K04 with the N75K so if I can get a little more tweaking to it, I think it will be my best bet.
All I can say is that perhaps I had to try this out to find out that the grass is not always greener. Others would have told me that I may not be happy with the spooling characteristics of a big turbo and I wouldnt have believed them, so I guess I had to figure this out for myself. Your thoughts are welcomed. Cheers! Mike
<img src="http://pictureposter.audiworld.com/57072/gt28rcompress-1.jpg">
08-28-2004, 11:31 AM
#4
AudiWorld Super User
Thread Starter
Sure...
1. MTM Stage 3 programming
2. TT225 Injectors
3. K04-015
4. Hollow Cat
5. Thermal Race Exhaust
6. N75K
Heres a dyno with the stock N75K only boosting 23psi (it was not the best dyno of the day on this car)...
<img src="http://pictureposter.audiworld.com/57072/dyno6green-gd.jpg">
Heres the Canadian MTM Stage 3 car (Jet Jockeys with the N75K boosting 28psi). Keep in mind his stock N75 torque numbers were reading less than mine...
<img src="http://pictureposter.audiworld.com/57072/mtm3badn75stockcustomintakepipe.jpg">
These numbers on my car are without the modified turbo inlet pipe which gained Jet Jockey about 8hp and 5 torque.
Cheers! Mike
2. TT225 Injectors
3. K04-015
4. Hollow Cat
5. Thermal Race Exhaust
6. N75K
Heres a dyno with the stock N75K only boosting 23psi (it was not the best dyno of the day on this car)...
<img src="http://pictureposter.audiworld.com/57072/dyno6green-gd.jpg">
Heres the Canadian MTM Stage 3 car (Jet Jockeys with the N75K boosting 28psi). Keep in mind his stock N75 torque numbers were reading less than mine...
<img src="http://pictureposter.audiworld.com/57072/mtm3badn75stockcustomintakepipe.jpg">
These numbers on my car are without the modified turbo inlet pipe which gained Jet Jockey about 8hp and 5 torque.
Cheers! Mike
08-28-2004, 11:35 AM
#6
keep in mind that you now have a higher power band...
so while you may think you dont have the "torque monster" of the K04 you really have much more useable RPMS.
You're power band is now 4k-6.5K. Once you are out of first gear... you'll be right there with any shift once you adapt your driving.
Whenever I drive a k03 or k04 car I feel it runs out of breathe just as I was starting to get going... *shrug* give it time. It is very well sized turbo for our cars
You're power band is now 4k-6.5K. Once you are out of first gear... you'll be right there with any shift once you adapt your driving.
Whenever I drive a k03 or k04 car I feel it runs out of breathe just as I was starting to get going... *shrug* give it time. It is very well sized turbo for our cars
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08-28-2004, 11:41 AM
#8
AudiWorld Super User
Thread Starter
These are excellent thoughts...
I was hoping some one would chime in who is running a big turbo. Before I take it off, i'm definitely going to play with it for awhile and make sure I'm making a sound decision. How does it do on Solo II courses? My big problem is that when in the turns I can only downshift to 2 so I end up down in the lower end of the rev band for a lot longer. cheers! Mike
08-28-2004, 11:53 AM
#9
AudiWorld Super User
Thread Starter
You're staying above 225tq for 2100rpms and i'm staying above 225 for 1700rpms...
but lower in the rev band. Plus I peak above 250 tq for 500rpms. You are AT 250 for over 1700rpms. Not sure which I like better. cheers! Mike
08-28-2004, 12:01 PM
#10
people have run them and done very well...
It depends on each course... but in terms of the situation you just mentioned, you may find it will shift as well.
drive the car around for awhile, and get used to the new power delivery.
drive the car around for awhile, and get used to the new power delivery.