I recently had my KO4s rebuilt with 997TT compressor wheels and I've just had the worst luck sense. Overall, I don't feel that the car is pulling nearly as much with the stock KO4s. Are there some troubleshooting steps I can run through to atleast find out why?

 

What kind of tune is your ECU currently running?

 

This is what I'm not sure about. I've asked a few times and I don't know if I've missed the answer in some message or if I just don't understand. I purchased the car already a stage 3 from someone. I don't know what if any tuning has been done to it. I also dont know how to go about purchasing a tune and getting it into the car. Any advice would be appreciated.

Thanks!

 

I'd bet it is a hardware issue as opposed to a software issue. I'd log the car.

 

Well, do some searching on the board, but I'll give you a few tidbits. The ECU controls (among LOTS of other things) the fuel map, boost pressure, and timing. When you bought your car (assuming it is truly stage 3), it had been tuned for the upgraded turbos. In other words, it was tuned to run like an RS4.

When I say "tuned" I mean, the ECU was programmed to take advantage of the larger turbos (eg. build more boost, adjust for a new boost threshold, etc...)

Now, I don't know much about 997 hybrids, but I don't think anyone makes a standard ECU flash or chip for this flavor of turbo mod. That being said, you're most likely running a stage 3 RS4 K04 tune on your 997 hybrids.

Does that make sense? You need to get your ECU tuned for the upgraded turbos. Also, is the engine stock? You might want to look into putting some money into upgrading the engine. At least getting upgraded rods. The stock 2.7 prolly can't handle the extra power created from the 997 hybrids -- if it's tuned properly.

 

I think so. I got PM from 10secS4, I'll see what he can do.

When you mention rods, which rods exactly? How much do they generally run? Does the engine have to be taken out to change them out?

Thanks!

 

That would be the connecting rods. (crank to piston)
They are thought to be the weakest link in the bottom end.
Yeah, the engine has to come out.

I wonder if it's a WG adjustment issue...

 

So, I thought I'd specify a bit more since I don't really have any hard numbers to go off of and just a feeling. I already mentioned that it doesn't pull as much. But deeper into it with my original KO4s I would hear the turbos spool a lot more than I hear the rebuilt ones. I would hear the "woosh" while accelerating where with the rebuilt turbos I just hear the engine reving. Again, all while I don't feel nearly as much pull. With the old ones the car would accelerate so hard that I could feel the steering kind of pull in either direction, not it doesn't even come close to that.

Will an updated ECU help with this type of problem? I'm assuming yes since it might tell the injectors to spray more fuel causing more boost. Is this correct?

Thanks again for putting up with my ignorance.

 

Sounds like a tuning issue.
Do you have a boost gauge? If so, is it reading the same.
Like Deb38 said above you need to log the car
I'm curious to see what your requested boost vs. actual is.
An updated ECU tune would most likely fix your problems.

 

Unfortuneately, I don't have a boost gauge. I've been meaning to get one. What requests a specific level of boost and how? The ECU?