Brake Discs & Throttle Body

robin · Post by **robin** » Mon Nov 26, 2007 10:10 pm

The plastic plenum is fine; going bigger on plenum and throttle body will not improve matters at the bottom of the rev range. There are engines out there making 170 on plastic plenum and 48mm TBs, so it's not mandatory. If you really want to know how little it matters you need to measure relative pressure between manifold and atmosphere at full throttle across the rev range; you'll see the difference is tiny, so the main purpose of any modifications is to better channel and shape the airflow rather than just making the holes bigger.

More work on the head can recover the 135's characteristic (and minor) loss of torque at the bottom of the rev range, but probably not financially sensible from where you are right now.

I doubt the cams are making much difference to the low end performance; it's easy enough to switch back to the standard cams (I'm sure I have some lying around somewhere) if you want to.

Cheers,
Robin

Rich H · Post by **Rich H** » Mon Nov 26, 2007 10:36 pm

Spare standard cams in the shed if anyone wants them

r055 · Post by **r055** » Mon Nov 26, 2007 10:38 pm

RICHARDHUMBLE wrote:Spare standard cams in the shed if anyone wants them

..and ive got his pulleys if anyone wants them...

BiggestNizzy · Post by **BiggestNizzy** » Mon Nov 26, 2007 10:43 pm

robin wrote:
If so, I'll happily pay someone with skillz and access to supplies to get mine reworked.

Cheers,
Robin

interesting idea think I might give that a go as making a small disk is easy and boring it out is easier. If I manage it I will give you a shout.
I will strip my vauxhall number and get a feel for it. I know big to wee steps are worse than wee to big.

it may cost you some beers for the machinist.