Brake Discs & Throttle Body

hiscot · Post by **hiscot** » Tue Oct 30, 2007 5:15 pm

BiggestNizzy wrote:58mm Throttle body ?

http://www.mgfcar.de/throttle/index.htm

:D:D:D

http://www.scottishelises.com/phpbb/vie ... ottle+body

ps that supercharger was for a rover k series the pully is differant than a mini version they only made a few

Rich H · Post by **Rich H** » Tue Oct 30, 2007 6:53 pm

A Rover Tomcat....

Not sure of its proper designation.

BiggestNizzy · Post by **BiggestNizzy** » Tue Oct 30, 2007 10:26 pm

Does anyone know anything about airflow ?

The rear of my new and improved throttle body is bigger than the plenem so you will get a step, this will cause turbulance, can I machine out the plenem chamber ? or does anyone know a fancy way of improving it ?

Victor Meldrew · Post by **Victor Meldrew** » Wed Oct 31, 2007 12:52 am

It doesnt do any harm going to the bigger size when you consider how much cheaper you can pick one up for..

Think mine is a "polished out" 56mm from a rover turbo, or tomcat or whatever.

Noops has one the same, much better than the std plastic one in anyones book. Much cheaper than a 52mm one from Elise parts..

BiggestNizzy · Post by **BiggestNizzy** » Wed Oct 31, 2007 9:01 am

Ahh Rover Tomcat is a 'T' series Turbo engine. the only problem I will have when going to 58mm is at the rear of the throttle body it has a dia of 62mm (i think) and the plenum chamber has a dia of 57mm (i think) this will create a step that is bad for airflow and will negate any advantage from having the bigger throttle body I will have to check to see if I can modify the plenum or the throttle body to remove that restriction. the ideal would be to have them matched. I have got myself some FEA software that deals with flow so if I can get m head round it I will see what I can come up with.

Rich H · Post by **Rich H** » Wed Oct 31, 2007 9:10 am

Do you have an ali plenum?

The placcy one is supposed to be better for airflow if de-flashed (There can be loads of flash inside the pipes) I would look at pening the plenum up a bit, step down in size is bad. A step up in size will kill the chance of laminar flow, but this is probably not a bad thing given the complexity of the airflow through the plenum.

BiggestNizzy · Post by **BiggestNizzy** » Wed Oct 31, 2007 10:03 am

RICHARDHUMBLE wrote:Do you have an ali plenum?

I dunno will have to look, it's a std 1.8 so I have no idea maybe someone can enlighten me.

RICHARDHUMBLE wrote: The placcy one is supposed to be better for airflow if de-flashed (There can be loads of flash inside the pipes) I would look at pening the plenum up a bit, step down in size is bad. A step up in size will kill the chance of laminar flow, but this is probably not a bad thing given the complexity of the airflow through the plenum.

I may have to make an insert to shrink the throttle body down abit all I know is step's are bad.

Rich H · Post by **Rich H** » Wed Oct 31, 2007 10:14 am

Open the plenum a bit, as long as there is no step and the transition is smooth, what you need to avoid is sharp edges.

Victor Meldrew · Post by **Victor Meldrew** » Wed Oct 31, 2007 10:08 pm

The alloy plenum is the same size as the 56mm alloy body. (give or take a millimeter)

The plastic one is a fair bit smaller from what I have seen.

Rich H · Post by **Rich H** » Wed Oct 31, 2007 10:32 pm

I dremeled mine....

BiggestNizzy · Post by **BiggestNizzy** » Wed Oct 31, 2007 11:23 pm

Damn forgot to have a poke at it tonight will take a look at it at the weekend. suspension parts will go away for coating next week so I will have some spare time to fiddle/break other things.

BiggestNizzy · Post by **BiggestNizzy** » Sun Nov 18, 2007 6:14 pm

What is better ?

Aluminium Plenum
Plastic Plenum

Did think about bespoke but I don't have a working knowledge of CFD

I have a plastic plenum but an ally one shouldn't be that hard to pick up. I will also be "blueprinting" it.

YvoTuk · Post by **YvoTuk** » Sun Nov 18, 2007 7:00 pm

Er... the ali plenum is not really worth it imho.

They do deliver extra power, but that's really top end power. For that, you loose torque.
At the end, torque gets you out of a corner, power is nice to mention in the pub

fd · Post by fd » Mon Nov 19, 2007 12:01 am

YvoTuk wrote:Er... the ali plenum is not really worth it imho.

They do deliver extra power, but that's really top end power. For that, you loose torque.
At the end, torque gets you out of a corner, power is nice to mention in the pub

Or another way of saying that is . . .

'power and revs is what makes the car fun to drive and torque is what makes it a diesel . . .'

. . . if you insist on coming out of every corner in the wrong gear you deserve some lack of satisfaction . . .

. . . I have a huge-torque-o-matic diesel and it's great . . . until I drive the elise and realise that it's much, much greater . . .

Oh . . . 48mm (std size ?) alloy TB is all you need for <170bhp . . . you can believe the marketing hype if you like . . . yes the plastique ones are cr@p . . .

Fd

BiggestNizzy · Post by **BiggestNizzy** » Mon Nov 19, 2007 10:46 am

Hmmm
Currently I have a 135 head and lumpy cams off robin and I am in the process of fitting a C20NE Throttle body from a Vauxhall. the car's previous head had been skimmed and as a result of this work all the power is at the top end and I have what feels like bog all at the bottom

yes it is fun when your blasting around high up the rev range but It is also fun to launch off pushing yourself into the seat back. I am wary of having a car that sucks at the bottom but is imence at the top.