Trumpets & Plenum

[jon haines]

I have just aquired a plenum and manifold and want some advice please boys. Firstly the trumpets are very short why? also how do i tell if the plenum is off a flapper or hot wire?

[B@man]

Looks like a flapper, I recall the hotwire injectors are plug directly into the fuel rail without the short bits of rubber pipe.

Not sure on the trumpets, they are short but have a reasonable flare on them ?

[Wedg1e]

Short trumpets tend to move the torque curve further up the rev. range, which may not suit your engine or driving style. Hard to be certain from the pic. but they look like standard diameter trumpets.

[al 350i]

maybe the trumpets have had a REALLY hard life and worn out!!!

[wooly350i]

al 350i said:

maybe the trumpets have had a REALLY hard life and worn out!!!

Nice one.
Boys at v8d did my engine for me and the spec included shortened and enlarged trumpets,the theory behind shortened trumpets I believe increases available air flow in plenum ,more air to suck is better with more fuel to drink which equals loads a money on the petrol forecourt.

[jon haines]

Thanks for the replies guys i think this needs a bit more investigation.

[tweety]

I have a second plenum, that I'm going to polish, which came with an inlet manifold, how do you remove the trumpets to fit more flared ones??..they are stuck fast...

Cheers, Al.

[MarkS1966]

tweety said:

I have a second plenum, that I'm going to polish, which came with an inlet manifold, how do you remove the trumpets to fit more flared ones??..they are stuck fast...

Cheers, Al.

Hi Al,
When I was considering doing this, I checked out this site, in the end I bottled it and didn't bother

http://www.g33.co.uk/tuning.htm

Yes, I know it's a Ginetta site, but the engine's still the Rover V8

Edited by MarkS1966 on Wednesday 13th February 23:46

[tweety]

Hi Mark,

Thanks for the info, that's a really good site...
As it's a spare I'll have a go at getting the trumpets out, just need a blowtorch now then...

Cheers, Al.

[Oz2]

Hi guys
Had a look at the G site, an interesting read.
It mentions the hot water preheat fed from the water pump to the plenum base, now I'm interested in anything that will cool the air in without an intercooler on the supercharger, ive had a look at mine and there appears to be 1 pipe from the pump into the inlet manifold but that's all I can see, I'll have a better look at the weekend.
Has this already been deleted on the TVR setup or am I just not seeing it? It says on the site to remove both pipes and loop them together.
Any info appreciated.
Adam

[MarkS1966]

Oz2 said:

Hi guys
Had a look at the G site, an interesting read.
It mentions the hot water preheat fed from the water pump to the plenum base, now I'm interested in anything that will cool the air in without an intercooler on the supercharger, ive had a look at mine and there appears to be 1 pipe from the pump into the inlet manifold but that's all I can see, I'll have a better look at the weekend.
Has this already been deleted on the TVR setup or am I just not seeing it? It says on the site to remove both pipes and loop them together.
Any info appreciated.
Adam

Hi Adam,
Here's a coule of pics of the underside of my plenum and the "attachment" that fits underneath it.
This is as fitted to my 350, from which I removed the plenum over the weekend to see about having it powder coated.

Hope this helps (at least a little)

Mark

Edited by MarkS1966 on Thursday 14th February 10:22

[B@man]

That's the part that you break through into when you bore the TB out to 72mm
Mines installed in the bin, simplifies the plumbing a bit too !

[Oz2]

Cheers guys
That totally explains it as I don't have one at all, when the plenum was modified by DPR they must have binned then

Even with the plenum insulator fitted my plenum still gets quite hot although cooler than before the only other option is the intercooler and I'm not real keen on that. Roll on winter!!!
Adam

[MarkS1966]

Oz2 said:

Cheers guys
That totally explains it as I don't have one at all, when the plenum was modified by DPR they must have binned then

Even with the plenum insulator fitted my plenum still gets quite hot although cooler than before the only other option is the intercooler and I'm not real keen on that. Roll on winter!!!
Adam

Now you're just showing off!
It's Bloomin freezing here
Seriously though, glad we could help

[Mr Tank]

Hi Jon

Or you could go long, here's a set of F-bay!



Andy

[wub443]

Does ANYONE have one of those modified plenum covers from DPR, they would consider parting with?

[adam quantrill]

Yes and no ;^)

Actually they are just a cut'n'shut with an original plenum throttle body chopped off and a right angle pipe welded on.

Should be quite easy to make one you just need to learn aluminium welding.

[wub443]

Hi Adam

Yea i know its just a cut off standard plenum, but my problem is identifying what the other piece is, that DPR used to make the pipe side of the mating. i have been to an alloy welder / fabricator, but he's said that although he could make the pipe bit out of a pipe and lots of small flat pieces, all welded and then smoothed off, it would much neater, quicker and cheaper to find out what the pipe bit was cut off of, maybe a intercooler of something, and do the same. Especially as i want two of these.

DPR did 100's of these, but even that was not enough to get their own bit cast, so it must be off something else, question is, what?

Also, i take from your message that you do have one of these! Can i persuade you to part with it?