so the search continues for where i am losing power in my evo, i had it on the dyno and the power was pretty good, however it was on a different style dyno, but the power fell off at about 5500. it slowly dropped, while on the other dyno while my car was running properly the power stayed flat and didnt drop. my mods are, hks 272, hks intake, 3" turboback, 255 fuel pump, ams ic piping, dynoflash ecu, mbc, and rre x clutch. my air fuel and spark were fine on the dyno the other day and i had no knock. i have checked for boost leaks and have none, changed plugs didnt help, did a comperession check and came out fine, checked the turbo for shaft play and it is fine, the turbo wheel is fine, and my car is getting more than enough fuel so its not a fuel system problem. so i am now thinking that there is damage to the stock valvetrain because of my cams wich have been in for 10k and i have a loss of power in my car, a noticible loss, and the power falls off at 5500 when a 272 should keep power pulling all the way up top just like it did when i first got them tuned. so would you suggest that my cars valvetrain is damaged by what i am saying? any help would be appreciated.

anybody?? i dont want to have to spend the money on valvesprings and retainers and come to find out that it wasnt my problem

it can't be your valve springs and retainers. Did you try a leakdown test? Sorry I didn't get back to you in your last PM, but here's a link:

http://www.type2.com/library/engineg/leaktst.htm

That's where I'd start if I were you.

BTW, what did you put down and on what dyno?

i havent tried a leakdown test i just checked out the link, i put down 338 on a dynojet when i first got my car tuned and it was running strong, it just put down 303 on a land and sea but it was running rich so i leaned it to 11:1 and its putting 322 on a land and sea but it stays dead even with a friend who just put down 301 on the same dynojet that i first dynoed on. also may i ask why it couldnt be that my valvesprings are worn out? i have been trying to figure out my problem for a long time and really havent gotten anywhere with it, also what will a leakdown test actually do for me, what will it tell me? thanks for the info

just another thought, could it be your BOV is not holding boost? That's the only thing I can think of really besides doing a leakdown test to give your motor a clean bill of health.

its defintatly not my bov i have been holding boost fine

power loss is not associated with valve springs and retainers. I've never heard of such a thing...only engine failure/damage is associated with faulty valve springs or retainers.

did you dyno at f1dyno? how did you lean out your car? are you running an SAFC as well? I know of someone who dynoed there and put out roughly 380whp with the same mods as you, so I would say 332 is kinda weak on the f1dyno. 338 on the pruven dynojet is definitely healthy. Q put down 336 in his car at that dyno and the thing pulled like a beast after the tune.

a leakdown test is a better test to figure out if your motor is damaged. You'll be able to tell if you have damaged valve guides, damaged valves, blown rings, etc. It is similar to the compression test but think of it as more thorough.

no it wasnt at f1, it was at tdc they do alot of subies, f1 has very inflated numbers becuase they messed with the inertia of the dyno, yeah i just started running an safc2 to see if i was knocking and to use on the dyno if my car was out of tune. i have never tried a leakdown test but i might as well try it because i am getting fed up with the power i am making right now, where could i get a leakdown tester or do you know anyone who has one that i could possibly use? also do you have any suggestions to what you think it may sound like to what is wrong with the motor?

Speaking of DV, which one are you using?
I don't recall but did you say in the other thread that you did a boost leak test?
How many miles do you have?

A leakdown test puts measured air pressure in the cylinder with the valves closed and then measures how much of the pressure is lost. This effectively tests the amount of that is leaking past the piston rings or valves. You can tell valve leak because you will hear the air escaping into the intake or exhaust. Of course the piston needs to be at TDC and the valves ned to be closed for the test.

What intake pipe are you using? Any leaks there will give you unmetered air entering the engine.

leakdown test will be a pain in the *** because you have to remove your intake and exhaust manifolds, but you will know for sure that your motor is fine afterwards. You should be able to buy or rent a tester at autozone.

How long have you been down on power? Have you noticed any unusual oil consumption?

i am running a hks ssqv, i did a boost leak test i ran close to 30psi through all the pipes and lines and everything came out fine, i just hit 31k, and i am running ams ic piping and a hks intake

i have been checking for oil consumption and i havent lost any oil it seems, i have felt a drain of power for almost a month now

dirty filter? but you say it sorta happened all of a sudden...

Holding boost doesn't mean the BOV is any good. If it is leaking you can still make boost and hold it pretty well but the turbo is working overtime and wil start to fall off up top. Also if it is recirc'ed then you have unmetered air re-entering the inlet side. In general this air is hotter going into the turbo then fresh air and therefore has less oxygen and it's temperature will only be compounded by the turbo. This will make it hotter then the normal air the engine sees at the intake.

It's really a long shot but considering that you've covered all your bases, I'd be inclined to think that maybe your valves are damaged...but don't quote me on that, just trying to make an educated guess.