msgofast

Keen to see if anyone has loged any problems with the variable cam timing on the new age STI engine, log shows that the cam drop out at 4500 ish mostly in 4th? 5th gear it drops out and then comes back in. have been told it is common for the solinoids to fail, but i am yet to hear of anyone having this problem.

Car is a 02 STI S202, less than 20,000miles.

Thanks
Michael

CustomScoobyIOM

Havent heard of this myself.

Interested to know what it is though.

What fuel are you using?

msgofast

With the delta dash you can log the cams retarding back to 0 at 5ish rpm, come back in at 6 ish in 5th, but 4th they stay out, power graph shows the dips in power as well.

car is a Tarmac rally car now, it was imported from Japan and in std form it had this problem which we never noticed till now when we went back to check the first few logs. It now runs ELF and 1.7 bar ( they are 1.4 std), the car is std apart from that, std it was making 40kw more than a STD AU spec STI, and more boost and ECUTEK it is now 70kw better than AU spec but now max power is at 5600rpm, but with the cams dropping out power isn't as good as it could be.

We have sourced some new solenoids and fit them up tomorrow and see what happens. We were told they fail regular and can blow engines due to this. What we found is that when the cams come back in the have a rattle from a spike in lean AFR. But the funny thing is that no one else has seen this?

G TOMO

My mates got an 02 STI with (we think) the same problem, but his dose'nt seem to get on the cams at all, it has a PPP fitted but only makes 250 BHP, and its exactly the same performance as my MY03 WRX side by side.

He is booked in with TSL soon to get get the Delta Dash info,

Let us know if the new solenoids cure the problem.

Good luck !

msgofast

What you would notice with them not working at all is they will be very laggy to drive, boost will come on 1000rpm latter.

find out tonight

msgofast

Tried the new solinoids and nothing changes, still drop out, even tried another Jap spec ECU and still the same, has to be a problem in the cam gears.

dowser

I'd have thought it more likely that the ECU was telling the VVT what to do? What's the IAM on the car? Do you have access to Flash2002 software too? If not, may be worth getting a tuner to look at it with their version - at has a few more VVT control parameters

Richard

msgofast

IAM ?

We have the latest ECUTEK tuning software, MRT has been helping with us tune the car, the cams on the S202 are very different to the std STI and hate to much advance, most it likes is 23deg, where std STI is 35 odd, been in there playing, but nothing helps in the mid rpm, they just drop out.

cheers
Michael

TonyBurns

iTrader: (3)

The cams shouldnt be any different to the JDM STi, the S202 is based on an MY02 Spec C, same engine etc, just lightweight (as per the MY03 limited Spec C's).

Tony

msgofast

The specs list the S202 as having "special inlet cams"

http://babelfish.altavista.com/babel...202%2Ftop.html

Bob Rawle

Mmmm, the S202's I've played with didn't mind cam timing, similar cams to the MY03 STi which absolutely loves timing.

this definately sounds like the ecu is doing something, btw the cams are moved hydraulically using the engine oil. using deltadash monitor the cam solenoid duty cycles and see if they change when this happens, if so its a mapping thing.

bob

TonyBurns

iTrader: (3)

Competition model of in presser WRX STi series, type RA spec C

All i need say

Tony

msgofast

Yes you can see the duty moving around, 30 % up to ~50%, they drop from 48% down to 45% then they drop off, but duty only goes back up to ~50%, amps are around the 400 mark, check these numbers with other STI logs and they look the same. They are happy to go from 0 at idle and up to 25 deg at 3000 rpm under load, full throttle and they drop out at 4-5 ish, some times they come back in at 5-8 degs at 6rpm in 5th and 6th, but drop out again.

The cams are set up to 28 degs and tapper off to 0 at 7000rpm, remember the car is std, exhaust, air filter the lot.

As i said before we tried another Jap spec ECU, same deal.

Maybe they didn't respond to cam timing due to them no going any more advanced, so that's why there were no real gains?

We never had time to pull the cam gears apart, we replaced the solenoids, we tried different weight oil, different size oil filter, the engine oil pressure relief valve is at 7 bar, dropped that to 5 bar, nothing made it better, if anything made it worse, dropping out faster, which makes me think oil pressure in the gears is bleeding off, checked all the filters in the banjo bolts too.



Tony,

Yes they are the same as a spec C,

"Based car
WRX STi type RA spec C
Main standard equipment"

"Private camshaft"

Which is different to the AU spec STI?

Cheers

Michael