Dodiox

Christian are the gains shown on the dyno graph with a catless system or a high flow cat system? what are the hp/tq gain differences between both?

Christian.

Not a statistically significant difference that we could measure. Generally speaking, how well the exhaust flows on the 2006 WRX will not impact HP since peak HP is made at higher RPM...the turbo is what is limiting the power output of the motor. I would use a cated high-flow exhaust system...but then, I am one of those save the Earth guys.

Take care,
Christian.

Boost Addict

Hey christian...

Any luck with the 18G? How does it look reliability wise for daily driving?

How would you guys release this? As a package with injectors? anything else needed to compensate for it? How would it be named? Stage 2.5?

Any info would be great regarding this next stage whenever available!

Dodiox

Christian I just put the stage one on my 06 wrx and I have to say that the carsdrive VERY smooth! it also feels stronger a high rpms.
the most noticeable thing is hot the sudden hesitation at 3,600 rpm is gone, now it pulls very smooth and strong. its also very easy to drive now from a start.
great job on it. im getting my cobb exhaust in about a week or 2 and i know that is where the real difference is.
im a very glad customer and i will stick to cobb products.
great job!

Christian.

Various turbos are still being tested. One vehicle has the 18G and is doing well, although we still need more testing time. We will most likely release this as a package with the AP. Just the turbo, a turbo-back exhaust system, a good TMIC, and the AP will be needed. We do not have a final package established yet, we need to get our 2nd TMIC prototype in to put that to the test. We need to establish our internal quality control. We want to make sure all the wastegates on the turbos we sell are actuating within a specification, the oil/anti-freeze gaskets are supplied, instructions written with pictures, etc. We will not be offering injectors with this package for the WRX fuel injectors are slightly larger than the STi and they should be sufficient in flow. Our initial testing showed the Injector Duty Cycles to be in the low 80% range...no need to upgrade the injectors for this turbo. As soon as I have an update I will post our findings.


Sitting at home with a smile on my face...very glad to read your comments. Please continue to enjoy and let me know if you have any questions or concerns. The exhaust should give the motor a good low rumble. Are you going with a turbo-back or the cat-back?

Take care,
Christian.

Boost Addict

Always hard at work! haha... Thanks for the detailed update Christian! Goodluck with the testing!

Dodiox

i'm going with the turboback w/cat. i can't wait.
the car feels like it lost 200-300 pounds im really really happy with the stage 1, the low end torque feels great and 3rd a 4th feel so much better now. also the clutch play with the gas pedal is so much better now specially from a start. i really can't wait to get the stage 2 and feel that nice torque.
i have to say im a cobb fan now.

i would like to know what you think about getting a dyno tune with the stage 2?
i feel like 16 psi is safe so i don't want to go over that. so i wanted to know if you believe that having the car protuned is actually worth it. since pretty much every car has slight differences even if they are the same model i thought that getting a custom tune wouldn't hurt.
would you recommend me doing it? im not really looking for much more power but just making sure that everything is very well tuned according to the set up and the car's actual performance.
thanks for the feedback.

Dodiox

and just to add on to the cobb stage 1 goodies... i got better gas mileage i went thru the tank with 255 miles a tank up to the moment where the gas light comes on and i have been having fun with my car! usually i get around 225-240 miles without getting so much fun. this was pure city. i've got 400 miles on the highway without stage 1, thats up to where the light comes on so ill see how good it is some day with stage 1. im wondering how good the economy map is. mmm

Boost Addict

Just be aware the economy map will not save you much MPG wise, and its definitely NOT recommended to be stomped on AT ALL... I heard its very sensitive and may potentially cause damage if you drive aggressively with it (even to avoid an accident, or what not...) I'm sure Christian can provide a better explanation...

Generally speaking, Ive heard the negatives are not worth the miniscule increase in MPG

Chiketkd

Christian,

I was looking over the hp, tq and afr map for the completely 100% stock 5spd '06 WRX - the lean spike around 3,600rpms really jumped out at me. Would it be wise to stay away from high flow panel filters (e.g. STI panel filter) which would lean out the afr slightly more and risk detonation? Would the addition of a cat-back or TBE on an otherwise stock '06 WRX 'lean out' the afr in anyway?

Christian.

A ProTUNE should be able to give you safe gains since the tuner can analyze how your vehicle is reacting to various changes.

Yes, those stock A/F curves are super scary. The vehicle is around 8-10 psi by that RPM, running ~14.7 AFR!

Since the vehicle has a MAF based mapping system, most changes in volumetric efficiency (intake and exhaust changes) will be compansated for and the vehicle will not lean out.

Take care,
Christian.

Dodiox

i got this from www. jscspeed.com


"02-05 WRX OWNERS READ: On the 02-05 WRX there are no boost spike or creep issues in most cases with the use of an aftermarket downpipe or turboback.
06+ WRX OWNERS READ: On the 06+ WRX there are boost spike or creep issues in all cases with the use of an aftermarket downpipe or turboback. This is because the 2.5L engine pushes so much air. Even with the internal wastegate fully open not enough air can exit to stop spinning the turbo, the result is boost creep or boost spike. With the 06+ WRX, unlike the STi, you cannot fix the problem by just porting the stock turbo wastegate. We suggest porting the stock turbo wastegate AND getting an engine management system to help fix the issue like a UTEC or AccessPORT. With the added costs this will entail 06+ WRX owners may want to consider waiting to get an aftermarket downpipe or turboback after they have upgraded there turbochargers or they may want to consider getting a cat-back exhaust only. "

they are talking about boost spike and creep that you can't fix even with the engine management ALONE?
any info on this christian?

kn0bby8

I have an 06 wrx and it spikes high in 5th gear. I know of someone else who has an 06 and is experiencing the same boost spile issues. Even with the Cobb stage 2 map i get boost spike.

Christian.

We have not witnessed this yet...this does not mean it does not exist, we just have not been able to duplicate boost spikes or boost creep with our 2006 WRX test vehicles. I would be happy to look at datalogs if you have them. If you do, please e-mail me christian@cobbtuning.com with "2006 WRX Boost Spike Datalog" in the subject along with the attached datalog for me to analyze.

Christian.

Christian.

I wanted to post an update. We are about to complete testing on the VF39 turbo and STi TMIC Map for the 2006 WRX MT. The test results have been overall positive. This combination makes much more top end power than the stock turbo assembly, as was expected. When you run a larger turbo power usually shifts to the right (upper RPM ranges), which is exactly what this combination did. The vehicle lost a little bit of bottom end power up to ~3200 RPM, but then made up for that loss with much more power than the factory turbo after that RPM. The gain (3200+ RPM) in the area under the two curves is much larger than the loss (<3199RPM). We could not target as much relative pressure (boost) as our mapping for the Stage2 STi due to the increased cylinder pressure (the WRX has slightly higher static engine compression vs. the STi). Although, the vehicle is very strong in the upper RPM ranges. This dyno graph is an initial graph comparing the torque and horsepower curves of this VF39+STi TMIC package to that of the Stage2 2006 WRX. I do not have an ETA for the release of this map as of yet, but I hope to have the testing complete by the end of this month.

The next turbo we will be testing is the 18G+STi TMIC, I will be sure to keep you updated.

Take care,
Christian.