Evo 6 suddenly sluggish at high rpm's

[bnr32]

Hey guys need some opinions on this issue thats recently creeped up on me.

The gist of it is im reaching full boost when im supposed to be, and I hear the engine working etc, but there seems to be a lack of power getting to the wheels.

The engine doesnt sound like its misfiring or anything, and its not running rough. Its just when i put my foot down (especially noticeable in 5th gear), everything is happening except me accelerating like i should. From about 0-20% of throttle everything is fine, but at 100% throttle it just feels like its at 20%, even though im getting a full boost reading, and the engine is running louder but still smoothly accelerating albeit very sluggishly.

It just feels as though something is restricting the airflow somewhere along the line. Theres one more thing I should add, sometimes it feels more 'ok' but sometimes its really noticeable.

Ive ran through a few possibilities in my head and figured that its either:
i) fuelling issues?
ii) exhaust leak? (but I havent noticed any abnormal noises)
iii) spark plugs? (this is what I hope it is- but if that was the case I should be experiencing shudder and puffs of black smoke from my exhaust?)
iv) intake leak (but then I shouldnt be hitting full boost as easily as I am)

I know this can only really be solved by bringing it down to my mech but im chin deep in work atm and it probably wont be a while before I can get it properly fixed. So, if any of you guru's have experienced something like this before or have an idea of what it is, please let me know. It could save me some bucks and my mech some time too.

Thanks a bunch and happy CNY!

 

[ehdrian]

clutch?..drive shafts?..

 

[[H] [K] [S]]

check ur hoses.... might be there's a leak or one of the hoses came off/loose.... example vacuum hose - if its loose,came off or leaking , u might suffer from overboosting or somethin.....

 

[EvolutionZ]

clutch slipped? engine rev up but car not accelerating much?

 

[DewA_LavaU]

check all your hoses. maybe leak sumwhere. get new clamp if necessary

 

[flanker c]

stock boost,clutch slip,AF too rich.

 

[Doink]

clutch slip...normal accelerate is ok but when full boost...it will slip...time to change clutch

 

[TitanRev]

like others said. Clutch slip is the culprit.

 

[bnr32]

Hey guys thanks for the suggestions but it's not clutch slip as far as I know. I've experienced it on my old car and it is like the car is falling into neutral all of a sudden right? Ie. Revs going up but caR not moving.

Thing is, now the revs aren't even going up. I can hear the engine working harder and the boost is holding at 1.1 bar but the revs jus slowly creeps up.

---------- Post added 02-19-2010 at 12:02 AM ---------- 6 hour anti-bump limit - Previous post was 02-18-2010 at 11:56 PM ----------

Oh and the car was fine before so it can't be the afr turning too rich all of a sudden? It also leads me to believe that the fuel is combusting fine since the turbo is getting enough exhaust gas to build boost like it should, so that might rule out spark plugs, coils etc?

Maybe it's a leaky gasket or hose though as all the engines work to produce power seems to be mysteriously vanishing. At least I hope that's all it is! Haha

 

[Mistaken_Identity]

Are U usin' any Boost Controller...??

 

[bnr32]

Ya I've got a blitz ebc

 

[Mistaken_Identity]

Last time I've experienced the same problem.... Problem solved after do the reset on the BC....

 

[egiewan]

if u reset the BC, boost will become 0.6 bar only rite? Coz I'm using SBC also. The car feels the best when I reset like MI did, but the boost I set to 1 bar in auto mode. All those gain setting I dun disturb at all haha.

 

[bnr32]

Thanks for the suggestion I'll try it tmr :D btw egiewan maybe u can try playing around with the gain setting as it affects your turbo spool up apparently. If I remember correctly ur supposed to have the gain setting as high as u can without it overboosting at full boost. I never really tried auto before tho so maybe that works too

 

[egiewan]

Thanks for the info. Previously my BC was set in manual mode with the gain setting of 10. I'm on a larger GT2835 turbo with an external wastegate setup with high boost spring in it. The funny thing is with the old setting, my car pulls hard on the higher end but when I drive the car around town, it feels kinda sluggish. So I tried to reset the BC and VOILA! Car feels nice to drive around town haha. Weird rite?