Im running a single setup with a holset hx40, hks twinpower, plugs are 9's.
Im measuring EGT in one runner.

Started tuning on the rototest on 0.9bar and everything went very smooth, made 370rwhp at 7000rpm and 0.87bar..

Going to 1bar and made approx +13rwhp extra on 5500rpm.. (running static load)
when going up to 6000rpm the exhaust temprature started to raise up to over 1100c already at 0.4bar..

Since afr's and knock was fine we tried a pull anyways ignoring the exhaust temp since we didn't believe the numbers... the result of this pull was that i lost 40rwhp..

Checked compression and it is ok, changed plugs and same problem..

on the way home the car starts to misfire more and more..

What could cause this problem? twinpower gone bad? coils?

 

Do a compression check.

 

sounds ignition related if you're experiencing misfires.... check your ignition map

 

ignition map and everything is the same as when it worked...

checked the plugs and T1-L1 are a little bit wet compared to T2-L2 (it is also from first chamber i measure egt).

One theory is that first chamber does not fire accuratly due to weak spark, fuel is then afterburning in the exhaust manifold which should give me the high egt..

Should this affect the AFR im measuring in the downpipe? because they seem to be the same as before..

Where to look first? what is most common to break?

Gustav

 

I wonder if an injector dumping too much fuel can cause this: the extra fuel would be afterburned in the exhaust instead of the combustion chamber, causing the high EGTs.

Dave

 

My EGT sensor in the manifold is broken, when taking it out the long tip is gone.. going straight through the turbo and breaking the internals.. this is why i lost power and the egt's were way off.

The ignition failures has nothing to do with this one.. it came later and i think i know what caused it..