My VR is underperforming - please help!

[daniles 0]

Took my VR to stealth last week to have it remapped after putting schrick 268 cams in, it was put on the rolling road and the best run we got out of it showed 180 bhp compared to standard highlines being around 183bhp. The torque graph also showed all my power was coming in before 3K and then loosing power after 4-4.5 when it should be the other way round. Stealth said the cams were more than likely put in wrong, would anyone agree. My car has already been back in once for underpowering and the mechanic changed a faulty cam shaft sensor and also advanced the cams by one tooth, i'm now thinking the reason the first time it was under powering was because of the sensor and the mechanic should have left the timing alone. Could it be this or could there be another problem i'm missing, would the cams be showing abnormal low down torque if they were one tooth out?

[purple highline monster 0]

get the cams re set, if the inlet and exhaust valves are opening up at the wrong times nothing will be entering or exiting in the right order and stifling the performance, the low down power figure could just be down to it not affecting the inlet or exhaust gas expulsion as low down theres not as much expulsion needed, soon as its flat out its struggling to keep up

[daniles 0]

looks like another trip back to the garage :-(

[VRTrickster 0]

Does you car have any other problems like lumpy idle,cutting out at all?

[daniles 0]

No car was running sweet as a nut you would of never thought there was something wrong with it.

My mechanic has sorted the problem he had in fact got the timing wrong, the crank pulley was not on TDC as the notch had broken off so he assumed another notch was the TDC. Way to check is to check the crank pulley on the belt side there is a mark there too. However it goes to show if you don't know what you're doing it's easy to get it wrong especially when there's two chains to time together and when you run the car you don't even know the timing's out unless you RR it.

If anyone is experiencing the same problem let me know as i'm a bit of a boff when it comes to timing now hehe.

[VRTrickster 0]

I have checked the cams after installation to check the marks, and even took the gearbox out to have a proper look! When I fitted the cams I was concerned that I couldnt seem to get the cam slots to line up spot on but tried it tooth this way ,tooth that way so that had to be as good as it gets? After running it for a while it had lumpy idle and problems starting in damp which turned out to be the coil ,and idle was lumpy. After speaking to Vince several times for advice I decided to strip it again even further and take the box out. The lower chain I haven't moved and in standard form on the rollers the car was producing I healthy 203 bhp, so Id say it was timed correctly!

After taking the box off I could see that the flywheel/crank mark and intermediate lined up perfect. The cam marks how ever were slightly out of parallel by a mm or two! I refitted the chain over and over and still the same result! I then tried a new chain and still the same. When putting a long screw driver down number one and feeling for top dead centre and spinning the engine over till its coming up to tdc, I gently turn it to and past ,and the cams seem to line up at the point it gets to the top and starts going down. So I would say that it is timed correctly yes ?

[vr6turbo 27]

there may be a small amount of adjustment needed to get the

cam tool to slot in, literally a mm or 2

i used a dial gauge on number one cylinder,which will give tdc accurate to a 1000th inch, that way there is no mistake,

i ahve looked on my crank pulley for a mark, there isnt one

the lower cam chain is only important to time up on distributor vr6 engines.

As it drives the oil pump and nothing else on a coilpack vr

fitting of the chain tensioner is important as well, i usually use about a teaspoon and a half of fresh oil poured into the tensioner then replace the plunger and bleed down with a length of .6mm mig wire.

screw the tensioner in by hand ,only the last 3-4 threads need to be tightened with a socket.

sounds like you got it sorted, nice output for a NA car