850 T5 Revs between gear change

[jam]

My "new" 850 T5 has a few issues which I am currently working on, performance etc is great but since getting it at the weekend I have noticed during gear changes the revs drop really slow, idle is @ 900?

[Jod T5]

Originally Posted by jam

My "new" 850 T5 has a few issues which I am currently working on, performance etc is great but since getting it at the weekend I have noticed during gear changes the revs drop really slow, idle is @ 900?

In my experience the 850 T5 is slow to drop revs between gears especially at WOT.., i have always put this down to a inefficiency of the recirculating valve system. Of course with a turbo charged engine the ability for the inlet side to loose built up boost is paramount...I found an improvement with a Dump valve...Ultimately it is something i have learned to live with, tho it does sometimes effect quick gear changes...
If you want areas to look at i would consider checking the recirc to inlet manifold pipe and consider cleaning the throttle body, cable drum and Idle valve.....
A idle of 900 RPM is perfect....
Cheers
Jod

[liuleichan]

Also worth noting that the IACV will be majorly involved in the control of revs when lifting the throttle.

[jam]

Thanks all, I've got the heavy accelerator problem too, i'll have a look this weekend. Also looking to drop the oil are there any issue with non original filters? Ta

[Jod T5]

Originally Posted by jam

Thanks all, I've got the heavy accelerator problem too, i'll have a look this weekend. Also looking to drop the oil are there any issue with non original filters? Ta

The genuine filters have a one way valve in them which helps to maintain oil pressure...They are also well priced inm comparisson to pattern parts...
I would always use a genuine filter as i would not be sure what pattern filters are up to OEM specification...
Cheers
Jod

[jam]

Cheers for that! genuine it is, btw oil debate again! 10/40semi ok I also change my cars every 6 months anyway as I get genuine vauxhall very cheap

[goldyy]

Originally Posted by jam

My "new" 850 T5 has a few issues which I am currently working on, performance etc is great but since getting it at the weekend I have noticed during gear changes the revs drop really slow, idle is @ 900?

My 850 2.5 20v has this problem.
I have tied all things and the only way I "cured" it was to disconnect the plug to the idle valve.It now idles @750and does not increase revs when cold but rev lag has gone which makes it more driveable AND it uses less fuel

[saturnuranus]

Originally Posted by goldyy

My 850 2.5 20v has this problem.
I have tied all things and the only way I "cured" it was to disconnect the plug to the idle valve.It now idles @750and does not increase revs when cold but rev lag has gone which makes it more driveable AND it uses less fuel

I noticed a similar effect by removing the ABS ECU. Apart from the speedo not working the revs fell off almost instantly when depressing the clutch which allowed me to swap gears as I always dreamed

Think I'd rather have the ABS and speedo working though...

This video of an 850 at The 'Ring seems to demonstrate the sort of gearchanges we'd like. I certainly couldn't manage anything that snappy in my T5.

+ YouTube Video

[goldyy]

Cool.One day?

[jam]

cheers for that, had a similar problem in a mk2 golf gti a few years ago same cure disconnecting the idle valve - not good on cold mornings tho'