72mm Plenum Conversion?

[thenick]

Hi all,

After speaking to the guys at Top Gear Automotive the other day, i've been thinking about uprating my plenum to the 72mm bore with larger butterfly. I have already upgraded the filter, induction pipes, trumpets and base and am about to remove the AFM when I install the Emerald ECU so would be quite interested in doing the plenum as well. The Top Gear boys say Power used to do a conversion but couldn't remember what was involved or how much it was, they were however impressed by the results. My questions are, does anyone know who still does this conversion and how much it costs? Also would it really be worth it?

Thanks,

Nick

[kevin63]

I know it's not what you asked but, a guy in our region put a twin port pleneum chamber on his V8, apparently it was used on the V8 touring cars a few years ago but they may be a bit rare, could be another option for you.
the car is on here under body off restoration http://www.advancedautomotivedevelopments.com/

Edited by kevin63 on Saturday 17th November 20:07

[GreenV8S]

ACT do a range of upgrade, from an exchange plenum top with bigger throttle, multiple throttles, bigger trumpets etc.

[thenick]

Ah thanks Pete, I knew Tim did twin and triple conversions but wasn't aware he did standard upgrades, i'll give him a ring and see what he says.. I already have his 45mm superflare trumpets and base along with the induction stuff, would this conversion make much difference? Engine is a 450 also with MC1 cam, sports manifolds, decat and Emerald ECU (well the ECU isnt on yet but it will be soon).

[rev-erend]

V8 developments do the 72mm conversion..

[trackcar]

A 72mm plenum is good for 270hp before it starts to become a restriction. Its a very good cost effective conversion. Most places charge about 250 pounds to convert i think, but they come up on ebay regularly for half that.

[Boosted LS1]

Can't you bore out the choke and fit your own larger butterfly, allowing for a bit of clearance?

Boosted.

[eliot]

Boosted LS1 said:

Can't you bore out the choke and fit your own larger butterfly, allowing for a bit of clearance?

Boosted.

Ive done a few now. Look in my manifold archive;
http://www.mez.co.uk/ms12.html (under 72mm plenum)

[Hoover.]

There was a chap at the Griff Growl.. (Eaun I think)... was demonstrating a larger bore plenium, with larger butterflies, and a totally diff AFM.... apparently giving road test good reports:

They put it on Mrs FlipFlopGriff's car.

I think the chap has done some testing since and may be offering it up as package.

I don't know how to contact the bloke directly, but he knows Derek of Absolute Shocks...

Hoover

[cmr2payne]

TVR Powers website says

PLENUM TOP / AIR INTAKE
The plenum top is bored out to over 70m/m and a larger brass butterfly is fitted along with a specially machined aluminium bell mouth to increase intake volume.

[hodgo]

i'm also looking at similar upgrades to my 450, collecting the pieces at the moment before swapping them all over in one go. To piggy-bag on the orginial question, would a 450 trumpet base and inlet manifold be the same as on a 500 i.e. 45mm dia for trumpets? i'm need to understand if i can use my orginial kit otherwise I'll need to search around for surplus bits and bobs.

[OscarT]

Same as 500.

[Johno]

Get John Eales to do your 72mm for you, cheapest by far and does a top job. He did mine for less than they go for on Fleabay . . .

[Gaffer]

Hoover. said:

There was a chap at the Griff Growl.. (Eaun I think)... was demonstrating a larger bore plenium, with larger butterflies, and a totally diff AFM.... apparently giving road test good reports:

They put it on Mrs FlipFlopGriff's car.

I think the chap has done some testing since and may be offering it up as package.

I don't know how to contact the bloke directly, but he knows Derek of Absolute Shocks...

Hoover

Ooo I know, I know I know

Its Eann and he can be contacted via Ian @ TorqueRVT 01606 831 244

One will be going on Daisy when she comes off the road at Christmas.

Claire

Edited by Gaffer on Monday 19th November 10:29

[TVRleigh_BBWR]

eliot said:

Ive done a few now. Look in my manifold archive;
http://www.mez.co.uk/ms12.html (under 72mm plenum)

This is the guy who sells them on eBay. and by the info on his site knows his stuff.

And yes its a good idea to get one before you put the emerald on then you can get the most of it, as you can then get the emerald tuned to use its full potential

You may want to get larger trumpets and inlet base, also to get the most out of it, else you just going to create bottle necks.

[thenick]

Already got them! Thanks though, I shall give the guy a mail and see what he says...

[Hoover.]

Gaffer said:

Hoover. said:

There was a chap at the Griff Growl.. (Eaun I think)... was demonstrating a larger bore plenium, with larger butterflies, and a totally diff AFM.... apparently giving road test good reports:

They put it on Mrs FlipFlopGriff's car.

I think the chap has done some testing since and may be offering it up as package.

I don't know how to contact the bloke directly, but he knows Derek of Absolute Shocks...

Hoover

Ooo I know, I know I know

Its Eann and he can be contacted via Ian @ TorqueRVT 01606 831 244

One will be going on Daisy when she comes off the road at Christmas.

Claire

Edited by Gaffer on Monday 19th November 10:29

That will be the chap... I knew it was not an every day spelling of his name.... do you know if there any before n after figures ref torque/bhp/ etc ?????

[Gaffer]

I can send him a message if you want as I have no ideas of figures.

Claire

[Meatball]

Hoover. said:

Gaffer said:

Hoover. said:

There was a chap at the Griff Growl.. (Eaun I think)... was demonstrating a larger bore plenium, with larger butterflies, and a totally diff AFM.... apparently giving road test good reports:

They put it on Mrs FlipFlopGriff's car.

I think the chap has done some testing since and may be offering it up as package.

I don't know how to contact the bloke directly, but he knows Derek of Absolute Shocks...

Hoover

Ooo I know, I know I know

Its Eann and he can be contacted via Ian @ TorqueRVT 01606 831 244

One will be going on Daisy when she comes off the road at Christmas.

Claire

Edited by Gaffer on Monday 19th November 10:29

That will be the chap... I knew it was not an every day spelling of his name.... do you know if there any before n after figures ref torque/bhp/ etc ?????

Hoover, i fitted Eanns straight through afm on my moddified 450 chim and gained 7 - 8 bhp from memory and it was tested before and after on the same rollers.

[Meatball]

Can you go any larger than 72mm on a alloy plenum?