Joo's 8 throttle base... (RV8)

[900T-R]

Did a search and only found a casual mention by the man himself, none on TCS site so I thought I'd ask here... what is it? Straight replacement for the trumpet base with something on top for an airbox (maybe even the OE plenum top)? Rest of the intake as-is, or mods needed to make it work? Cost, and returns - I guess a bit more/smoother down low especially with a hairy cam, a bit more at the top end and better throttle response?

[v8ian]

Theres a pic of a modified 8 buterfly injection base on here, is that the one??
http://www.mez.co.uk/ms12.html#Michael

[900T-R]

Yeah, that's one's been kicking around for a bit longer I think - Joo may have something similar, or a further development on that theme?

[Markh]

v8ian said:

Theres a pic of a modified 8 buterfly injection base on here, is that the one??
http://www.mez.co.uk/ms12.html#Michael

The one on the site was made by a friend of mine in Norway

[trackcar]

This is an early version on Pasco's car. Made 3 of these now.

http://www.youtube.com/watch?v=YvKP8acievU

[900T-R]

That looks/sounds very nice What does Paul (and for that matter your own 5 litre out of the V8S) have on top of it - standard alloy plenum less TB, or something altogether different?

[Markh]

trackcar said:

This is an early version on Pasco's car. Made 3 of these now.

http://www.youtube.com/watch?v=YvKP8acievU

Hi Joo, so how long until a production model?

Cheers Mark

[AntonyJ]

That looks the bks, saw the pic on Eliot's site a while ago.

Joo, pro's and con's?

[trackcar]

Hi Mark. Don't really know to be honest, raceproved have been hand machining all the ones so far but the next one will be a proper CNC job to production standard, we just need to know that the company chosen can do it to a production standard. All 3 bases so far have run modified large bore std plenum tops. Other stuff just seems to have got in the way of getting this project finished, things like the engine dyno, the cerbera exhausts, the sp6 induction tuning plus stuff that actually earns me money have all meant this project kind of got forgotten but it will get finished at some point.

[v8ian]

Looking at the base from an engineering standpoint, how the hell do you get the spindle bores to be straight, thats a deep hole, do you drill/mill it oversize and fit a set of pre drilled inserts, then ream to fit, or spark errode them,
I have a set of long series drills in the workshop, 8mm dia and 400 long you have to be very careful/lucky to get a 300mm hole that does not wander, even with the most a minute feed, good speed and plenty of suds, its a real problem, even when the drills were new they walked off,

[rev-erend]

Personally - I prefer mine :

[trackcar]

That is VERY impressive rev

v8ian, yes long series drills can wander, one of the pre production versions suffered exactly this.

[rev-erend]

Thanks Jules.. I rather like them..

I spent ages yesterday wiring up the blue leds to enhance the photo's .. trickly little things with all having to be wired in parallel and the current can only flow 1 way.

The problem with the original manifolds seems to me to be the fact that the tightest part of the manifold can only be filed out to about 38mm .. sure the top and trumpets can be 45mm but it's the thinnest part that really counts as the restriction to the air.

The people who are looking for more air would ideally be wanting 45mm all the way thru for a fast road car and 48mm ~ 55mm for race cars.

So - a new casting is really the only way..

Hence the TB's.

[AntonyJ]

Go on then Joo, give us the pros and cons of the TB plenum base.

[v8ian]

If I was in the position of making a throttle base, I would be considering making it slide throttle rather than butterfly, probably do most of the machining in a day as long as the material was at hand. might even be tempted to run them on linear slide bearings rather than teflon strips, sealing the sides would be interesting

[350Matt]

wotcha Rev

That trumpet length looks quite short chap, what revs are you aiming for with peak power?

What cam as well?

[rev-erend]

350Matt said:

wotcha Rev

That trumpet length looks quite short chap, what revs are you aiming for with peak power?

What cam as well?

Though someone might notice..

Got a 256 cam.. running solids, roller rockers and H beam rods with forged pistons..

[eliot]

Markh said:

v8ian said:

Theres a pic of a modified 8 buterfly injection base on here, is that the one??
http://www.mez.co.uk/ms12.html#Michael

The one on the site was made by a friend of mine in Norway

Per dropped me a line the other day and I've updated my page, He said "made these to tame the H404 Cam - they are 44mm diameter and managed 307RWHP"
I've also added the JED tripple plenums to the page today also - the list just gets longer and longer!

[350Matt]

rev-erend said:

350Matt said:

wotcha Rev

That trumpet length looks quite short chap, what revs are you aiming for with peak power?

What cam as well?

Though someone might notice..

Got a 256 cam.. running solids, roller rockers and H beam rods with forged pistons..

Hmmmm so about 7500 -8000 Max revs peak power at 7250?

Excellent..

What have done with the crank?

[rev-erend]

eliot said:

Markh said:

v8ian said:

Theres a pic of a modified 8 buterfly injection base on here, is that the one??
http://www.mez.co.uk/ms12.html#Michael

The one on the site was made by a friend of mine in Norway

Per dropped me a line the other day and I've updated my page, He said "made these to tame the H404 Cam - they are 44mm diameter and managed 307RWHP"
I've also added the JED tripple plenums to the page today also - the list just gets longer and longer!

So - how about adding the Wildcat TB's too .. do you want me to send you some pictures.