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Don't want to clog your build thread up to much but the turbo you have chosen isn't a good choice to try and make the power you want. Garret rate them at 1050bhp which is based on 10.5bhp per 10Lbs/min air flow, which is quite difficult to achieve especially with pump fuel. You really need to be using E85 or at worse proper racing fuel. As you only have a 2.0 engine to achieve the power you want you need to run high boost.
If you look at the compressor map the point on the map where peak flow of 100Lb.min occurs is with a pressure ratio of around 2.65.
https://www.garrettmotion.com/wp-content/uploads/2019/06/G35-1050-Comp-Map.jpg
Slope Font Line Parallel Pattern


The pressure ratio is absolute so a pressure ratio of 2.65 occurs when boost is around 1.65 bar. Because of pressure losses through the intake system and intercooler you actually need a higher pressure ratio to achive a specified boost level. If you ask for 2.0 bar boost you are probably running at a PR of around 3.1 -3.2 about 95ls/min max . At 2.5 bar the PR will be more like 3.7 87Lb/min (about 870 bhp). At 3 bar boost the PR will be over the maximum of that compressor map probably 4.3 + so around 75lbs/min roughly 750bhp.
Of course you can run the compressor off the map which results in the wheel overspeeding and the efficiency being low. As the efficiency drops the turbo still makes boost but the air ends up being heated more. This turns the turbo into a hot air generator, loads of meth will help to bring this down but the only way you are going to see 1000bhp+ from a 2.0 engine with that turbo is to run nitrous. This will give you the extra oxygen you need that the turbo can't support.
 

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Discussion Starter · #62 · (Edited)
Hello,
thanks for the reply and the information. We already work with a very reputable tuner Dynodrome that tunes the 1200whp World record Tfsi S3 driven by Ntemos.
At this point we have changed 3 Mechatronic units for testing but none get the pressure as high as we need it to be through out the whole rpm range. It peeks and then it just plunges down.
We have taken the transmission apart cleaned it checked it and at this point we are going to put the OEM basket back on that worked perfectly with no slipping at the 600whp power range. If the issues with the pressure is gone then we need to send the Dodson basket back to them so they can see whats wrong with it.

At this point we are at 2.6bars of boost with 100oct pump fuel and Meth at 700whp an low timing 15 with no returns from the engine.
The reason we stopped there is the clutch pressure issues that we are having after installing the Dodson basket/discs. I dont want to damage it is a very expensive part.

I will keep you posted.
 

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Ok you certainly have people who can get power out of an engine. I usually see between 18 and 18.5 bar of pressure when logging on my gearbox. But it's only a small turbo so torque requests are usually around 550-600Nm max. I still think you will have issues with trying to get over 3 bar boost from the turbo without the turbo seriously overspeeding it generating really high IAT's.
The blade design seems to favour high flow lower boost with higher efficiency.I have a speed sensor on my turbo connected to the Ignitron ECU so I can see wheel speed and it tracks pretty much with the airflow and boost seen on the compressor map.
This is a VCDS log from some testing I was doing with the DSG
Font Screenshot Pattern Parallel Number
 

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Discussion Starter · #64 ·
Today I tested using the OEM basket still the issue persists ! I am starting to think that the transmission cases have some kind of unseen damage ill try finding another complete transmission and installing the Dodson basket there install it on the car see how that reacts. At this point its the only option that I have. If this doesnt work then I will have to check the electronics of the 4x4 that where installed when converted to quattro from FWD.

Still on the hunt!
 

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I think the transmission oil may have been really overheated at some point which is what caused the filter to fail. Can't imagine what else would do it. This could have caused issues elsewhere in the gearbox. Changing the gearbox out for another one will probably sort it. I ouldn't imagine the other electronic modules in the car would be causing an issue. I do know that if the ABS module is an older version without ESP then this can cause issues as the DSG looks for wheel speed sensor readings on the CAN bus to validate shaft speed sensor readings. This will just cause a fault code to be generated and results in a limp mode situation. O n your car everything should be fine.
 

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Discussion Starter · #66 ·
I think the transmission oil may have been really overheated at some point which is what caused the filter to fail. Can't imagine what else would do it. This could have caused issues elsewhere in the gearbox. Changing the gearbox out for another one will probably sort it. I ouldn't imagine the other electronic modules in the car would be causing an issue. I do know that if the ABS module is an older version without ESP then this can cause issues as the DSG looks for wheel speed sensor readings on the CAN bus to validate shaft speed sensor readings. This will just cause a fault code to be generated and results in a limp mode situation. O n your car everything should be fine.
The only fault im having is the clutch speed sensor cant recall the code number gotta check the VCDS! I will let you know thanks for the info ill let the boys know!
 

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The only fault im having is the clutch speed sensor cant recall the code number gotta check the VCDS! I will let you know thanks for the info ill let the boys know!
Please let us know what you find! Chasing a similar issue currently, big slippage in 4th gear or higher when going above 2 bar of boost. Probably just crummy APR DSG software in my case, wish I could hit that 18 bar of clamp pressure. Sadly it barely reaches 13 bar.
 

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Please let us know what you find! Chasing a similar issue currently, big slippage in 4th gear or higher when going above 2 bar of boost. Probably just crummy APR DSG software in my case, wish I could hit that 18 bar of clamp pressure. Sadly it barely reaches 13 bar.
My stock DQ250 did 12- 12.5 bar as stock I am sure. On the TVS site the various holding pressures and capability of the different maps is shown. It's approximately 100Nm per 3 bar clamp pressure.
So 12 bar =400Nm, 15 bar = 500Nm and 18 bar = 600Nm. The stage 4 upgrade is using an upgraded clutch pack which has more discs so more surface area.

Rectangle Font Screenshot Parallel Software


Suprisingly TVS only appear to have 2 dealers in the USA in Florida and California. I have no issues with clutch slip in any gear.
 

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Discussion Starter · #69 ·
Please let us know what you find! Chasing a similar issue currently, big slippage in 4th gear or higher when going above 2 bar of boost. Probably just crummy APR DSG software in my case, wish I could hit that 18 bar of clamp pressure. Sadly it barely reaches 13 bar.
Will get the new transmission on this week hopefully and resolve the issue at hand🤞🤞🤞.

In your case I would:
  1. Check your transmission flash
  2. Check your mechatronic unit
  3. Check your transmission oil viscosity
If these dont fix the issue then start going deeper
  1. Check your plates in the clutch basket just in case they are worn out
  2. Check you transmission oil pump
  3. Check the case's pistons that are built in
  4. Check the 4 seals on the bottom of the clutch basket
  5. Check transmission for potential cracks
Hope we both get the issues sorted out fast cause its getting me crazy not to be able to drive this beast in its full power!
 

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Weird, the clutch should slip at lower gear or when downshifting because it produce more torque. Try doing the basic setting. Maybe the computer just need to relearn.

Make sure not to confuse hard shifting which is caused by faulty DMF from clutch slipping.
 

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Discussion Starter · #71 · (Edited)
So after changing the transmission the tuner got a file in the Mechatronic but it wasnt right and we had the bar of death. Today was the day that we where supposed to flash the correct file but the programmer got Covid and he is quarantined... Oh my days :rolleyes::rolleyes::rolleyes: Another set back then.
 

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Discussion Starter · #72 ·
Wanted to update my project by letting you know that the project is still in limbo since the tuner was almost 3-4 weeks in the ER from COVID but thankfully recovered now and we currently have the mechanic of the build suffering from COVID. So I am still waiting to figure things out:cry::cry::cry:
 

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Discussion Starter · #73 ·
Latest update on the transmission:
We changed the gearbox today and coded the new software. Monday is testing day and I hope that the issues are resolved so we can go on with our build at last now that everyone is back and healthy!
 

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Very interesting read. I have been contemplating a Dq500 swap, but it seems like the dq250 is a lot more capable than I thought. My end goal is 700whp, also tuned by dynodrome. Any idea if a dynodrome tcu tune with golf mk7 R/ 8v S3 clutches would handle that?
 

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Discussion Starter · #75 ·
Very interesting read. I have been contemplating a Dq500 swap, but it seems like the dq250 is a lot more capable than I thought. My end goal is 700whp, also tuned by dynodrome. Any idea if a dynodrome tcu tune with golf mk7 R/ 8v S3 clutches would handle that?
The 8v S3/Golf Mk7R has thicker gears in the transmission. I had OEM clutch internals untill 600whp and beath the living shit out of it for almost 10.000km. (Avoiding launches of course since I wanted the clutch to last). It should be good for 650whp with a stage 3 tune.
 

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Discussion Starter · #77 ·
have caught up on your posts - jeez what a ballache with the transmission! hopefully this replacement box holds up. did you get upgraded clutch packs while you were at it or something or just. stock-o DQ250?
I did get a full upgraded Dodson kit but the issue was probably on the cases not the clutch pack 🤷‍♂️🤷‍♂️🤷‍♂️
 

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Discussion Starter · #78 ·
So hopefully we got good news and the issue is resolved. Had a nice pressure hold today of 18bars after testing with a "can" program for testing purposes. Will hopefully finish the tune next week.
 
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