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I've lost 10bhp...
Posted: Sun Jan 28, 2007 12:23 pm
by Si_GTi
... so if you could all kindly check your pockets and down the back of the sofa I'd be most grateful
But seriously, the GTi went on the rollers at Aldon Automotive yesterday and she levelled out at
116bhp @ 5425rpm. I'll scan the printout soon and post up the image.
Many of you will know that I have a BMC CDA air filter fitted, along with a Powerflow stainless steel exhaust. I can't be sure at the moment but the exhaust may be a source of the power loss
and I'm reasonably sure there have been several discussions on this forum about aftermarket exhausts and the possibility of an alteration in back pressure equating to a loss in power?
However it could very well be something else so if you have any ideas please let me know. For instance would a new set of HT leads help matters?
Cheers
Posted: Sun Jan 28, 2007 12:50 pm
by Si_GTi
Okay here we are (click for full-size image):
As you can see there are no discernable dips in the power delivery, it simply flattens off at 116bhp
Posted: Sun Jan 28, 2007 2:04 pm
by olop_chris
If you ask nicely, ill lend you the 6bhp that i gained for abit until you find your 10 lost ones
Posted: Sun Jan 28, 2007 2:06 pm
by Dangerous Dave
You may have a simialir problem to andyg where his vvt isn't activating, I'm pretty sure when I rolling roaded mine (don't have the graph anymore) the torque takes a rise at 4k when the vvt kicked in and the power peaked at about 6600revs. It seems yours doesn't have this increase and instead started to tail off from 4k. I know andy is getting errors with vagcom advising that the sensor readings are off. Have you vagcom'd yours recently ?
Could be the back pressure from the exhaust also but it maybe worth while to give it a scan with vagcom, andy got 105bhp on his standard car without vvt working it may be your mods have helped it get another 10bhp without vvt working.
Posted: Sun Jan 28, 2007 2:19 pm
by Si_GTi
Chris's GTi reached peak power at 6344rpm. In answer to the question though, no, I haven't had the car plugged into a vagcom yet but do intend to do so now.
Cheers Dave
Posted: Sun Jan 28, 2007 4:39 pm
by J-GTi
can you feel the pickup the vvt gives when your ragging it? It is very noticible.
Posted: Sun Jan 28, 2007 6:55 pm
by andyg
I drove my car for about 1 year without the VVT ever activating.
You can tell if its not working, you will accellerate from lights and there will be nothing there till about 4k revs, and even then its not mega fast.
With vvt you should be able to spin the wheels from standing start in first and second in the wet easy.
If you vvt isn't working you will loose more than 10bhp, without vvt my car was putting out 100bhp, and terrible torque, your graph is kinda different to what mine was so I dont think its that.
Posted: Sun Jan 28, 2007 9:10 pm
by jezmk4
Your peak power does seem to be very low
would expect it at 6000 ish +
are you sure your throttle is opening all the way?
Posted: Sun Jan 28, 2007 9:26 pm
by Luke'sGti
maybe its cause your Gti isn't silver lol -
only messing - hope you get it sorted - sorry i'm no help
Posted: Sun Jan 28, 2007 9:40 pm
by Mouse_GTI
That's strange. It should be pushing out at least 130bhp I'd of thought. I can't really feel my VVT kick in
Posted: Sun Jan 28, 2007 10:09 pm
by Redline
Peak power should be at 6500rpm
Posted: Sun Jan 28, 2007 11:30 pm
by alexperkins
Probably a stupid question, but what is VVT, and do only GTis have it?
Cheers,
Alex
Posted: Sun Jan 28, 2007 11:34 pm
by ModifiedMadness
Variable Valve Timing, and afaik it's only the GTi's that have it yeah
Posted: Sun Jan 28, 2007 11:55 pm
by hex_da_rex
Being paranoid now... How can you definately tell that the vvt is working?
Posted: Mon Jan 29, 2007 7:08 am
by alexperkins
ModifiedMadness wrote:Variable Valve Timing, and afaik it's only the GTi's that have it yeah
Ah thanx dude. I dnt have to worry about it then
(Well not yet anyway
)
Cheers,
Alex
