K04 Boost spikes ... HELP!!
06-19-2003, 04:56 AM
#12
Although mostly true...
I run K04s now and I'll tell you that I run leanre on the stock ECU than I do on the AMS one. I don't really recommend running the stock program with the K04s for the very reason you cite. too much lag and lean running conditions.
With the AMS(a K03 program, btw) the car is unreal. No real perceptable lag and an incredible top-end. There are some K03 programs that run very well on K04s and AMS is one of them. OCT, I believe, is another. Now of course having a custom program written would be the best way to go since they can account for items like exhaust systems, DPs, etc.
Good Luck!
Joe
With the AMS(a K03 program, btw) the car is unreal. No real perceptable lag and an incredible top-end. There are some K03 programs that run very well on K04s and AMS is one of them. OCT, I believe, is another. Now of course having a custom program written would be the best way to go since they can account for items like exhaust systems, DPs, etc.
Good Luck!
Joe
06-19-2003, 11:51 AM
#13
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I did this and had no problems...
I used O.CT K-04's with stock and APR 93 programs for a few months while getting my act together for stage 4.
I never saw any on-throttle "spikes" in boost at all, but the APR "1 bar" program does request way more than 1 bar of boost at certain points in the power band...
It would be very useful for you to VAG block 115 in 3rd gear at WOT from 1500 or 2000 to redline, as well as for a 1st/2nd/3rd acceleration run so we can see what you are talking about.
I never saw any on-throttle "spikes" in boost at all, but the APR "1 bar" program does request way more than 1 bar of boost at certain points in the power band...
It would be very useful for you to VAG block 115 in 3rd gear at WOT from 1500 or 2000 to redline, as well as for a 1st/2nd/3rd acceleration run so we can see what you are talking about.
06-19-2003, 12:33 PM
#14
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A few observations
The O.CT K-04's have stock mounting flanges and are installed using the same bolts, gaskets, hoses etc.. as the RS4 units. They are a bit different spec-wise in that they provide boost at a lower engine RPM, have a thicker drive shaft, and have the high temp exhaust housing option.
From what I understand, the managment system in our cars is quite complex. I believe however that boost management is fairly simple, there is a request boost level from the ECU and a closed loop system that measures the actual boost and opens or closes the waste gate to achieve and maintain the correct pressure. This is done in a manner that is independent of the type of turbos installed. If your turbos spool slower than the stock units, you may see some increased deviation between request and actual boost level during transients, but my understanding is that if everything is working correctly, delivered=request +/- 50mBar.
It is certainly possible to run lean with larger turbos installed, but with stock ECU, stock exhaust and dp's I doubt you'll toast the motor.
In daily driving, light throttle, etc.. the lambda system corrects for all kinds of things to keep the fuel/air mix in check. At WOT, the air mass is used along with calculated "equivalent" altitude to generate how much fuel to send to the engine. If you run larger than stock turbos, you'll likely pull more air at high revs than the stock units, but this will be measured and therefore more fuel should be delivered.
Where you'll run into big problems is if you exceed the linear range of the injectors (80-90% duty cycle), and the engine is not getting the fuel the injectors are being requested to deliver. This is why some tuners use (and calibrate their fuel maps for) a 5-bar fuel pressure regulator on setups providing up to 375Hp or so. Over this, and most tuners recommend RS4 or other higher volume injectors.
All that said, I have no idea what chip you have, nor whether its WOT maps are well behaved for your install. I'd check with the original tuner, or work with one to be sure your car is running correctly at all operating conditions.
A few things you can measure to get a general feeling of health are timing pull back (from knock detection) and exhaust temp. If either of these are over the specs for a STOCK motor, I'd be concerned.
FYI, in my stage 4 setup I never see over 820 degrees exhaust temp -- even after a 1/2/3/4 WOT run or up my NH "test hill" also at WOT. Also, I virually never see timing pull back under any conditions if my gas is fresh.
I hope that this helps.
From what I understand, the managment system in our cars is quite complex. I believe however that boost management is fairly simple, there is a request boost level from the ECU and a closed loop system that measures the actual boost and opens or closes the waste gate to achieve and maintain the correct pressure. This is done in a manner that is independent of the type of turbos installed. If your turbos spool slower than the stock units, you may see some increased deviation between request and actual boost level during transients, but my understanding is that if everything is working correctly, delivered=request +/- 50mBar.
It is certainly possible to run lean with larger turbos installed, but with stock ECU, stock exhaust and dp's I doubt you'll toast the motor.
In daily driving, light throttle, etc.. the lambda system corrects for all kinds of things to keep the fuel/air mix in check. At WOT, the air mass is used along with calculated "equivalent" altitude to generate how much fuel to send to the engine. If you run larger than stock turbos, you'll likely pull more air at high revs than the stock units, but this will be measured and therefore more fuel should be delivered.
Where you'll run into big problems is if you exceed the linear range of the injectors (80-90% duty cycle), and the engine is not getting the fuel the injectors are being requested to deliver. This is why some tuners use (and calibrate their fuel maps for) a 5-bar fuel pressure regulator on setups providing up to 375Hp or so. Over this, and most tuners recommend RS4 or other higher volume injectors.
All that said, I have no idea what chip you have, nor whether its WOT maps are well behaved for your install. I'd check with the original tuner, or work with one to be sure your car is running correctly at all operating conditions.
A few things you can measure to get a general feeling of health are timing pull back (from knock detection) and exhaust temp. If either of these are over the specs for a STOCK motor, I'd be concerned.
FYI, in my stage 4 setup I never see over 820 degrees exhaust temp -- even after a 1/2/3/4 WOT run or up my NH "test hill" also at WOT. Also, I virually never see timing pull back under any conditions if my gas is fresh.
I hope that this helps.
06-19-2003, 12:37 PM
#15
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O.CT uses different code for K-03 and K-04 setups
I agree that the AMS code is nice. I'm kind of an O.CT bigot, but have also been quite impressed with a friends AMS/ABT K-04 setup.
On my car I ran for awhile with O.CT Stage 2 (K-03) software with my K-04's installed, and it ran and logged OK. They have a STRONG preference to running the code that is designed for your exact install.
I also ran the same setup with APR 93 code and did not have as good results.
FYI.
On my car I ran for awhile with O.CT Stage 2 (K-03) software with my K-04's installed, and it ran and logged OK. They have a STRONG preference to running the code that is designed for your exact install.
I also ran the same setup with APR 93 code and did not have as good results.
FYI.
06-20-2003, 06:49 AM
#16
I agree. I have heard that the OCT setup is smooth.
I just couldn't justify the astronomical cost. IMHO, they don't do anything worthwhile to make those turbos any better. Not for that price!
Anyway, seems like you are very pleased with them, so good luck and have fun!!
Joe
Anyway, seems like you are very pleased with them, so good luck and have fun!!
Joe
06-20-2003, 08:50 AM
#17
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It is very smooth, for sure!
If you are measuring O.CT by peak HP/$ then it will look expensive. The O.CT philosophy has more to do with torque, smoothness and elasticity than peak HP.
The price of my setup is pretty much the same as anyone elses K-04/dp/exhaust setup with about a $1500 adder for the O.CT turbos over the RS4 units. After labor and all, this is about 15% of the total, so it was a reasonable investment for me!
You can certainly get the same top end (maybe a bit better) with "stock" RS4 turbos, but you will miss out on a lot of low end grunt that makes the car very drivable on the street.
From what I have read, our motor was made for torque, not HP. The factory made a very big deal of providing a long and table flat torque curve. O.CT preserves this, and just turns up the wick a little!
The thing that impresses me the most is that I get all this with only 1.15bar of boost, and my egt's are very low -- even lower than what I logged when stock. This means to me that all this performance should not cost me a lot on the reliability side. I like that.
Also, if you run O.CT software in a complete Stratmosphere setup, there is a limited lifetime warranty on the turbos for the original owner of the setup. This is unique as far as I can tell in the tuner world.
It sounds like you have thought this through, and I'm sure you'll be happy with whatever you do! It is fun to talk about all this stuff, and even more fun to drive these great cars!
Good luck!
The price of my setup is pretty much the same as anyone elses K-04/dp/exhaust setup with about a $1500 adder for the O.CT turbos over the RS4 units. After labor and all, this is about 15% of the total, so it was a reasonable investment for me!
You can certainly get the same top end (maybe a bit better) with "stock" RS4 turbos, but you will miss out on a lot of low end grunt that makes the car very drivable on the street.
From what I have read, our motor was made for torque, not HP. The factory made a very big deal of providing a long and table flat torque curve. O.CT preserves this, and just turns up the wick a little!
The thing that impresses me the most is that I get all this with only 1.15bar of boost, and my egt's are very low -- even lower than what I logged when stock. This means to me that all this performance should not cost me a lot on the reliability side. I like that.
Also, if you run O.CT software in a complete Stratmosphere setup, there is a limited lifetime warranty on the turbos for the original owner of the setup. This is unique as far as I can tell in the tuner world.
It sounds like you have thought this through, and I'm sure you'll be happy with whatever you do! It is fun to talk about all this stuff, and even more fun to drive these great cars!
Good luck!
06-20-2003, 09:36 AM
#18
I already have the K04 installed
Plus 'piggie pipes' and the AMS/ABT software.
If I had the additional funds to throw at the car, I would've seriously considered the OCT setup. Actually when I spoke to Bob, he told me it would be about $4200 for the turbos alone + the intake tubes + fastening hardware/gaskets. Software I knew would be extra, so I didn't factor that in. Wound up looking closer to $2200 difference in the end. But you do have a warranty and a kick-**** bottom-end, so that much could easily make the price of admission worthwhile!
As always, have fun!
Joe
If I had the additional funds to throw at the car, I would've seriously considered the OCT setup. Actually when I spoke to Bob, he told me it would be about $4200 for the turbos alone + the intake tubes + fastening hardware/gaskets. Software I knew would be extra, so I didn't factor that in. Wound up looking closer to $2200 difference in the end. But you do have a warranty and a kick-**** bottom-end, so that much could easily make the price of admission worthwhile!
As always, have fun!
Joe