Rouge A-Tune review

[Mike Goebel]

Finally got it all installed last night.

Parts List:
1988 Turbo S K26/8 (Evergreen stock rebuild)
Rouge A-Tune: $326 Rouge A-Tune
MBC: Grimspeed $100 GrimmSpeed
46mm Tial Flange $16 Driftmotion
Down Pipe: Ebay $40 including shipping
46 Tial WG: $$$$ but I did manage to get it for about $100 less than new from a lovely Rennlister selling a new one.

BTW did you know the chip is symmetrical and can be installed backwards?? I do now!! Needed to adjust the TPS so that idle is triggered later than was set before. There is still a problem with engine returning to idle after a throttle blip. Blip to 3000 RPM and the rpm drops quickly to about 1200 stops then to 1100 stops and hunts a little bit until it finally settles in at about 1000ish. Idle at that rpm is very smooth. Much better than with out Rouge chip. I did set the idle per Clarks and but no improvement. Not sure what gives at the moment.

The Grimspeed MBC is a really nice piece. Nicely finished and easy to set as it has both detents and marks on the unit. Installing the Tial 46 was different than I had envisioned. Didn't know I was going to need to make a new interface flange for the exit side of the WG. BTW got a Tip on Rennlist from Tom M'Guinn where to purchase a 46 flange super cheap. Making the downpipe work is not too bad if you have a hacksaw, hammer and a welder near by. Should have bought a welder tho and did it myself. Make note to get a welder soon!! haha.

Driving and tuning: All Boost readings from factory 944 Dash gauge. I have compared it to a cheap HF gauge and they pretty much agreed up to 2 BAR. Pulls were done in both 2nd and 3rd gear. 3rd of course feels stronger then second.

Made a few passes with the MBC set to min boost and reached about 1.5 BAR. Cranked it up a full turn and got maybe 1.7 BAR. A few more boost increase adjustments and got to just under 2 BAR. Car feels moderately stronger from about 3000-5500 RPM. Boost drops off somewhere after than but I'm not going to look down for that long to get any good readings. For about $650 (Chip & FPR & MBC & Dump Pipe) I can't imagine a better improvement. $650 doesn't include the Tial 46 but that was really optional and I wanted it!!! Will install VDO Boost gauge in a bit and get some better readings. Will also install Lambda sensor too. In the end I think 15-16 psi will be just fine for street car and might even be able to keep up with a new Camry in a flat out drag race too .

Mike G.

[Mike Goebel]

Boost increase update. Cranked up the NBC about a full turn. Boost is definitely in the two bar range since the factory gauge pegs somewhere around 4000 to 5000 RPM. But then it still drops off after 5000 RPM for sure.. So I’m a little confused when I hear these claims of reaching full boost before 3000 RPM and holding all the way to red line. BTW the car is a semi rocket ship. Rolling on the throttle in first gear produces wheel spin in the 4000 RPM range. Drag raced one of those new X5 BMWs last night. He couldn’t even pull on me. Pretty sure before the boost increase he would’ve just walked on me.

Thanks
Mike G.

[nize]

are you certain you have a k26/8 ? the spool lag (3k) sounds about right but the drop at 5k rpm sounds like a k26/6.

-water plumbing to to cool the turbo is good?
-intercooler is cold and well vented to keep cool?
-cat removed?

you mention MBC so i'm assuming you aren't using the dual-solenoid setup, which means as boost builds it will overcome the wg spring pressure and bleed boost at higher RPM. some people overcome this by using a higher pressure wg spring but that over-rides the failsafe so i highly recommend against this and suggest using an electronic boost controller with dual solenoid to both spool early and hold boost to redline. refer to this thread:
http://forums.pelicanparts.com/porsche-944-turbo-turbo-s/1048045-wg-tests-8.html#post11029395

[Mike Goebel]

Originally Posted by nize

1) are you certain you have a k26/8?
2) -water plumbing to to cool the turbo is good?
3) -intercooler is cold and well vented to keep cool?
4) -cat removed?
5) You mention MBC so I'm assuming you aren't using the dual-solenoid setup?
6) Means as boost builds it will overcome the wg spring pressure and bleed boost at higher RPM.

1) Yes
2) Yes
3) Yes
4) NO!
5) Yes
6) Exhaust backpressure helps keep the Tial WG closed.

Mike G.

[nize]

try removing the cat. it really serves no purpose on the 951.