The V8 Owners Forum -

Hey guy's

Anyone which tb's they use on their tripple throttle setup? I think they use the single Jenvey 48/ 60's... but I'm not sure.

I want to make it myself and hopefully save me some money...

And besides that I will use it for my DAX and I do not have enough space under my bonnet so I have to change it a bit to fit my needs.

Maybe someone here who can take measurements so I know I will be in the right ballpark when I start...

I'm all new to this though so any advice you guy's have would be appreciated.

If you're making your own plenum then i'd size the TBs to match your expected/ future power flow requirements. You may find other cars, (Vaxhull Senator I think has been mentioned) with removable TBs you could use, would be cheaper still than using Jenvey.

My 1.8 K VVC uses a 48mm TB.

Could you go the bike throttle body route and fit 4 bike TBs?

Just some thoughts

Tom.

Hi
For flow a single big hole is better than many small ones, you want as big a ratio of sectional area to wall area as you can get to maximise flow and minimise turbulance through a system. If you are going to progressivly open the TBs in sequence to aid throttle control then It may be worth using more than one, even then I would go for 1 big TB and 1 small one and open the small one first, Vayxhall 2.5 to 3.2 litre V6s use individual throttles, 2 pairs and 2 singles with 55 to 62mm there may be some 68's butterflys depending on application about £20 for a pair off ebay (the ones with throttle pots go for about £45) plus P&P if you are prepared to wait around and collect them over a few weeks.
Best regards
Mike

In some circumstances I can see how multiple TBs might aid distribution but I'm afraid i've long thought this kind of stuff to be a total waste of money. The factory twin plenum setup could be thought to be a little gimmicky too. Obviously achieving a smooth progressive throttle with a single large TB may be a bit trickier but as long as the plenum is large enough and suitably designed I don't think that's a real problem. £/hp wise these things have to be the worse deal out there, making them from carbon is just rubbing salt into the wounds imo. A single aftermarket TB (like those available for TPI smallblocks) on a homemade plenum atop a nicely ported efi inlet could be made to flow just as well and cost a fraction of the money.

Thanks guys. I think I just went for looks instead of thinking it over. Your are right. Besides that it still would be a horror to fit under my bonnet.

The problem I have is that I don't want to saw any holes in my bonnet and the "normal" plenum doesn't fit the way it is fabricated.

the otherone ACT performance sells looks like I could work with.

When making these kind of plenums are there rules/ formulas I should use?
I mean does the volume have to be exact or otherwise the engine will be hard to tune?

Or is it more than just volume?

To be blunt, even if you have a small plenum or the tb mounted in a funny place the engine will still run quite well. Could you mount a throttle onto the front of a rover plenum if you have space issues? All you need is a box with some volume fed by a throttle.

Send an MP to Adamnreeves, he made his own plenum : http://www.v8forum.co.uk/forum/viewtopi ... c&start=45

I have a siemese intake I made on mine:

Phil