Thread: Cammed my car!

Purchased a set of s4 cams off gspec and installed them. Broke them in following jwt guide. Was very excited to see how the car would pull and it ended up pulling like I loss 20hp. I double check my cam timing, dowel pin at 10 in, 12ex, lobes pointed out, crank on ~0 tdc mark, 20 pins in between cam marks, distributor at 5 o'clock and set timing to 15 i believe(its hard to do with the lopy cams). The car with stocks cams put down ~160 on hotshot headers and felt 2x better then now. Discuss.

Mods are:
jdm de
hotshot wai with pop
thermo spacers
ceramic 2.5 headers
Ur pulleys
fidanza flywheel
vrs 2.5 exhaust w/240 cat, 28 in magnaflow res, apexi ws2 muffler

OEM ECU still "learning"? Maybe, maybe try a reset?

Car had bigger cams you didn't know about to begin with?

Did you redo your ignition timing? Just because you mark it doesn't mean it's going to be the same with bigger cams.

Well, I have never seen a car put down 160WHP on stock cams. The most WHP I have seen on stock cams was 146 WHP.


Most of the cars that I have seen with JWT S4s and S5s have made between 158-167 WHP.


Here is a small tid bit about JDM motors. There are a few JDM motors out there that make 175 HP. These motors cam out of the Autech Pulsar. There is also an Autech P10 that makes 180 HP.

These motors come with bigger cams about the size of S3s and 11 to 1 compression.

I know of one guy who got one of these motors from me. I wounder if you may have gotten one of these motors.

He put it in his car and all he had was a JWT Pop, HS header and 2.5 inch exhaust and he ran 14.3 at 97 MPH.

sounds more like a timing issue, recheck your ignition timing, ive noticed the s3's and s4s tend to like cam timing around 17* too high no good, too low no good. like miko said there are some freak motors out there if you were lucky enough to get one but yeah 160whp on stock cams seems way high, on my old se-r with intake, ssac 2.5 header, 2.5" exhaust, 2 piece UR pulley set, Jun ultralightweight flywheel, stage 3 clutch, and jwt s3's i dynod 155whp 142wtq, to dyno 160whp is crazy if the cams were stock but not soo crazy if you got one of the rare motors, but hey just let the ecu adjust and wait it out for a bit and recheck timing and set to 17* and see what happens

Do you mean personally, or do forum members count?

I agree that 160 seems really high for his mods. I never really noticed that before. I guess the real problem here is that it feels slower to him instead of faster. The freak motor explanation could be it, or a freak day at a freak dyno... Are the S4s supposed to work well with adjustable cam gears? I have little experience with cams but it sounds like ignition timing would be a good thing to check, and cam timing might be another variable if someone else can chime in and say the S4s don't work well with stock cam gears and he shouldn't have even thought about this swap without adjustable cam gears.

Ill probably have some local members recheck everything someday in the mean time i hope it feels better when the ecu adjust. Im pretty sure it wasn't a freak motor, day or dyno. It was on a dynonamics during our dyno day about 4 months ago. Compression checked with stock cams only hit ~180 all across. Ill have to get a digital caliper to measure the old cams. Anybody know the specs for stock cams and S4's?

Are you going to 8k? S4's don't start making power till 6k. If you haven't increased your rev limit, that's why they feel less powerful.

Where are you getting that from

There is no reason to be revving to 8k with S4's installed straight up.


Anyway, I have also found that my old S4'd DE felt alot better with 17* base timing, maybe a tad more. Are you saying that the top end feels worse also? Cause you will lose some bottom end grunt with the S4's, enough for you to notice.

S4's are 1.566" from top to bottom of the lobe.