Lost 30hp 6k+ rpm

[tricker_luke]

I had my car tuned and it made 238hp at the wheel, but since found out it was down on power, and it is now making 211hp on the same dyno.

Any ideas why it is losing power? I will get hold of the comparison map but it is only really apparent from 6k+.

I have checked the timing and it seems ok, spark plugs ok, map is ok, vts (vtec spool) activates in kpro and i also unplugged the vtec and there was no tone change so vtec is working.
Maybe vtec activates but doeasn't fully engage?

I have also checked the exhaust system and nothing has collapsed, however the exhaust manifold looks like it has a little bit of soot near one pipe, could that cause 30hp wheel loss?

 

[firthy22]

As I said in the other post Luke, I have the same thing with my manifold and thb my car is running as well and sweet as ever. No noticeable loss in power, especially in vtec but getting a new gasket fitted and sealed tomorrow so will let you know if the car feels any different after. Doubt a slight blow at the head gasket would cause anything like 30bhp loss.

 

[tricker_luke]

Yeh please do let me know. I would not have noticed the power loss but went up against another dc5 with less mods and was dusted.

Just frustrating when it is not something obvious, but I don't know what else to really check. There must be a clue in that it is only really apparent from 6k.

 

[firthy22]

I know this might seem obvious but have you checked your oil level. Low oil can cause problems when vtec is engaged.

 

[tricker_luke]

Oil is checked weekly

 

[coyote_dc5]

Are you sure losses are just 6k up. Looking at the comparison graphs it seems torque loss is pretty much throughout whole range with it being most severe at 5.5k being almost 40ft-lb different. Maybe post the comparison graph up to see what all think :-k As to potential VTEC engage issues, it seems torque loss is actually from word go as low as 2k so maybe barking up wrong tree with that. Without VTEC it would barely break 200bhp i doubt.

 

[C&S Evo7]

can you point me in the direction of the graphs please? or email them to me?

sounds like something is definately not right there

 

[coyote_dc5]

Red curve is Luke and Green is mine on similar bolt on's but with no internal mods.

 

[Rob R]

What mods are you running to get 238bhp at the wheels?

 

[C&S Evo7]

Think he meant flywheel 238 at wheels is huge for no turbo

 

[C&S Evo7]

Ok now I'm a bit confused, how can you show both car' graphs overlaid like that ?

I thought one of the cars had lost power ?

Those graphs look like the red car needs mapping better with that big power dip at vtec point where's the green looks much better

What we really need to see is before and after powerloss graphs of the same car

 

[Rob R]

I was going to say it looks like the red one is mapped on a Dastek Unichip as it appears VTEC engagement is at factory rpm?

Who was it mapped by and what management is it on?

 

[tricker_luke]

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[firthy22]

Had my new gasket fitted today, seems one of the bolts was loose but they fitted the new gasket anyway. Car doesn't seem to blow quite as much but hard to tell with the noise from the decat. Engine sems a fraction smoother now but power difference is negligible so doubt that's what's causing your problem.

Hope you get it sorted soon, Luke, after all the hard work that's gone into the build. Seems a trip back to TDI North might be in order for you.

 

[coyote_dc5]

Just posting Luke's dyno up on his behalf. Solid line was immediately after tune when it was running fine and the dotted is now since its lost power.

 

[raz786]

Who mapped it? Graphs are usually smoother than that I thought.

In the posts above the OP mentioned the Exhaust Manifold looked a little sooty or something, a breakdown of the cat or manifold could cause the loss I would have thought?

I would check this first

 

[tricker_luke]

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[tricker_luke]

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[coyote_dc5]

When's the new rad and tegiwa going on Luke? Any feedback from your builder yet?

 

[tricker_luke]

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