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I want to give a quick report on my final positive outcome with the Katech ported TB. Jason Harding has been great to work with and exemplifies customer service.
Last fall I purchased the ported TB. Pricing is great, and Katech is local. I know from my own dyno testing with other ported TBs that horsepower gains would be little, if any, for my CAI only application. However, I figured I'd give the Katech a try as it's the only one that mills down the butterfly shaft...and it's the least expensive option I found and no core charge.
I tried two samples last fall, and I experienced the low-speed, part throttle drivability issues with my A8 as reported by RussM05. I will say the WOT and throttle response were fantastic, and with an M7 I'm sure it wouldn't have been as much of an issue. For my automatic, part throttle and low speed shifting was just too jerky, and it was in a box since last fall. I was too lazy to take Jason up on his refund offer at the time.
RussM05 explains the reasons for this behavior here, but more importantly that there was a new porting profile to address this:
I finally got around to exchanging it for the revised version last week (again without question by Jason). I'm very happy to report that the low speed drivability and light throttle shifting are just like OEM. The throttle response is just as great as I remember in the original version. I'm a VERY happy camper now!
Thanks to Jason for his great service on an extremely small-potatoes transaction in the scheme of Katech's operations. Problems happen, especially in the aftermarket, and they tend to get aired here quickly. The CF vendors who do step up to resolve them don't always get visibility on that part.
Take a look at the second picture in the link in my OP. You can see how much more material the V1 had removed around the blade in the closed position. To my eye, the V2 mostly retains the OEM 'closed' gap around the blade. This is what seems to keep the low/part throttle drivability MAP (like RussM05 said).
Now I've put a few hundred miles on the V2 TB. It drives just like OEM at part throttle and ZERO shift/smoothness issues. Super happy.
For those of us that have the early version, is there an exchange program?
Personally, I only notice a slight hesitation very infrequently. I also have a Halltech CAI and a Faster Proms ported intake. Tune and engine are stock. Have Borla X-pipe but no headers. Perhaps the other intake mods help keep the hesitation at low rpm to a minimum.
For those of us that have the early version, is there an exchange program?
Personally, I only notice a slight hesitation very infrequently. I also have a Halltech CAI and a Faster Proms ported intake. Tune and engine are stock. Have Borla X-pipe but no headers. Perhaps the other intake mods help keep the hesitation at low rpm to a minimum.
We will exchange it for anybody who had an earlier version.
I just installed Katech's throttle body and I'd like to report that throttle response is improved. Of course, I'm sure horsepower is improved but it's relatively small considering. Lastly, idle runs just fine and there is no hesitation at any RPM range. Overall, I'm very happy!
Now it's on to the next mod. LoL
Last edited by NinjamanZ51; 06-25-2016 at 06:52 PM.
what about your 103mm TB? Any info on that other than port matching? Does it require tuning?
No one but a full race car will need a 103 on these cars. The one from them on a stock T.B. ported is all any of these cars need on a track car with any type of drive on the street with the car.
Love my ported on from them works like it should with no problems.
i meant for the LT4, sorry. Would the calibration be given be u for that?
As you mentioned about port matching, the 103 won't fit the LT4 supercharger snout without modification. Or if the aftermarket comes up with a different snout. Calibration will be required.
06-14-2016, 12:30 PM
Katech Ported TB: report on updated porting
