roel03

Is anyone running this setup and can give me their thoughts? My car is an AP1 with exhaust/HFC/intake. The main goal is to lower VTEC.

I sent an email to Karcepts and they said this will lower VTEC to 4000rpm and give me a nice power bump throughout the RPM range. However I couldn't find any real world reviews and impressions.

Thanks for any of your help!

HawkeyeGeoff

I have it....basically 90% of what you'd get out of a custom tune. Everything seems legit...more power....lower VTEC...drives smooth and as it should. Not much else to say about it. If you're not going to do a standalone+forced induction, just do this with the ol' Greddy Emanage to save yourself some money.

Nice thing is since you have an AP1 you really don't need a wideband. Just plug and play.

engifineer

It works well. I have had mine for 2 autox seasons. I will have to dig up my dyno, but it was actually surprising how much the peak went up (127 at the wheels), but that is really not what it is tuned for. It does a great job of bringing up the bottom end. Notes on mine:

I am running the PLM header, K&N intake and berk 63mm cat. The rest of my exhaust is stock.
When I first installed, I did not have the header, intake or cat yet. Very noticeable drop in power around 3000 rpm. So I would not run this without having the header upgraded. By very noticable, I mean the 20mph to 70mph time was slower than stock due to the dip. Once the header and cat was installed this went away completely and the car feels great.

At first, you are going to notice that VTEC does not "feel" as strong when it engages. You will not notice a sudden bump in power when it comes it at 4500 rpm, but overall it is making more power across the band. It just does not feel as abrupt at lower rpm.

Brian is great to work with and provides plenty of support for his stuff. I am happy to give him a good word!

roel03

Talking with them, they said that having the header doesn't make much of a difference, but the cat is huge. I think your symptoms were from having the stock cat installed.

Wish I bought it a few weeks ago so I could have it in time for this weekend's Sebring event.

engifineer

I have a hard time believing it was just the cat. I am running the stock size cat, not a larger one. But who knows.I did not try running the header, then adding the cat so I do not have data points. But typically, a huge dip in the middle of the power band sounds a lot more like a header than a cat to me. Especially when not going to a larger ID CAT.

But, you will know for sure if you install with the stock header, so let us know. It is a VERY noticeable dip in power, so if the header is not the big impact, then you will not feel it. If it is, you will be buying a header in a week, trust me :P

engifineer

Would have been interesting to test it with a test pipe too ... but class rules in STR prevent you from removing it, so I did not even try it. And either way, why I am not a full on tree hugger by any means, I do try to leave my emissions equipment intact and in place on my street cars if I can, so I have no interest in running it catless.

Fokker

While not a large difference the stock header is ~60mm ID while the most common HFC are 63.5 or 70mm ID, so there is some pipe diameter to be gained. Normally any VTEC engagement drop with a stock cat doesn't perform well.

engifineer

I also purchased the Boomslang harness with mine. I recommend it. It is a very well built harness and makes the install easy. I think it took about 20 min to install the ECU and harness. Hardest part was stuffing all the wiring and such around the stock ECU and getting the kick panel back on properly, but not too bad.

flanders

Stock header collector is 54.6mm inside diameter, it does perform very well though compared to the huge bottleneck in the stock cat.

Chibo

I am running this setup with the Boomslang harness, the difference is night and day over stock. OEM header, Berk HFC, AEM intake, completely stock exhaust / motor otherwise. The car really does pull on stock tune cars judging by straights on track.

I recommend it to everyone that asks about the car, it is great and I can't recommend it enough, especially for people that need to deal with OBD compliance.