custon throttle bodies
Discussion
eliot said:
WRT to the rover trumpets, Ive got the plenum base from the Belguim and Ive started making a prototype from plastic. Ive also now priced a chunk of ally for it too. You can follow it's progress on the this forum
Has any conclusion been made as to wether the middle four cylinders inlet tract lengths being sorter than the outer four will have any significant effect on the performance?
It's something I've thought about a few times as to how it would work using a flat sheet as opposed to trumpets so you're not pulling air around up the sides of the trumpets, but not entirely sure of an elegant way around it.
Individual "suspended ceilings" to act as the trumpet roof maybe?
Collars around the trumpets?
Regards
Iain
First go will be flat. I was thinking of adding an extra lump to the central 4 trumpets to increase the length, but haven't really looked into it much.
TVR didn't worry too much about it with the taraka(sp) upgrade;
but then again I wouldn't call the OEM TVR 'trumpets' exactly an engineering marvel either.
TVR didn't worry too much about it with the taraka(sp) upgrade;
but then again I wouldn't call the OEM TVR 'trumpets' exactly an engineering marvel either.
Well Ive just about finished blending mine and whilst Im not saying its a great power mod I can see it will make a bit of difference, the only thing I can really think of about the lengths is that theres a shoulder where the trumpets sat onto, this I have blended into the wider part of the hole thats in the base. This, I expect, would still help as the 45mm part of the tube will all be the same length, its only the flared bit that will be different for all of them, ok its not perfect but its not as bad as you might expect. I think the main gain would come from having more head room for the air to gather inside the plenum,
Phil
Phil
Right - that's the sort of thing I had in mind, seems a bit easier to do and based on a known working solution. What's the TB from? (edit - just clocked the file name, so which jag then?)
(Finally started boring out the trumpet base last night, spookily enough)
(Finally started boring out the trumpet base last night, spookily enough)
Edited by eliot on Wednesday 30th August 06:46
let us know how you get on with the twin plenum - if it works, my mate with the griff wants to do the exact same conversion.
I'm still working on the thick spacer approach to what you done with the base, i posted a few progress pics on the v8owners thread.(been busy with my own Edis project..)
I'm still working on the thick spacer approach to what you done with the base, i posted a few progress pics on the v8owners thread.(been busy with my own Edis project..)
look at all the twin plenum rovers of the eighties(Bastos/Unipart)all had throttle bodies on one side,developed by Lotus,they tried both ways and stuck with the twinned idea.
I did this to mine,as buying one is impossible!
just got a few (7! knew I would get it wrong first time
) plenums and cut both necks off of two plenums back to the to main body,
then cut the right side out of one and the left out of another,turned the left/plain side into the right basically creating a closed plenum but keeping the back untouched,
next thing was to cut this right side to accept the two throttle body/neck parts.
All cleaned up with a die grinder and polished out side,jeez,took some work but was noticably cleaner revving over 2500 rpm than the opposed/cut in half welded up type and kept the ribbing/detail on top.
have seen similar on a Norwiegan blokes Marcos RV8 5.2, but they used Jag throttle bodies/flanges welded on to the necks,two huge turbo`s and a Sprintex supercharger running map sensors and owner built ecu showed us a timing slip of 305 km/h. nice!
If memory serves me right the problem with opposed throttle bodies was to do with one affecting the flow of the other opposed throttle plate because of the way the cylinders drew from opposing banks in turn creating a sort of flutter in the plenum just where it opened out into the throttle bodiesas the plenum is narrow.
all the highly tuned engines now seem to have seperate manifolds/intake systems for each bank.
incidentally we(neighbour and I) are in the process of building sliding throttles to a bike,we have solved the sealing problem
,but there are many usability issues.
I did this to mine,as buying one is impossible!
just got a few (7! knew I would get it wrong first time
) plenums and cut both necks off of two plenums back to the to main body, then cut the right side out of one and the left out of another,turned the left/plain side into the right basically creating a closed plenum but keeping the back untouched,
next thing was to cut this right side to accept the two throttle body/neck parts.
All cleaned up with a die grinder and polished out side,jeez,took some work but was noticably cleaner revving over 2500 rpm than the opposed/cut in half welded up type and kept the ribbing/detail on top.
have seen similar on a Norwiegan blokes Marcos RV8 5.2, but they used Jag throttle bodies/flanges welded on to the necks,two huge turbo`s and a Sprintex supercharger running map sensors and owner built ecu showed us a timing slip of 305 km/h. nice!
If memory serves me right the problem with opposed throttle bodies was to do with one affecting the flow of the other opposed throttle plate because of the way the cylinders drew from opposing banks in turn creating a sort of flutter in the plenum just where it opened out into the throttle bodiesas the plenum is narrow.
all the highly tuned engines now seem to have seperate manifolds/intake systems for each bank.
incidentally we(neighbour and I) are in the process of building sliding throttles to a bike,we have solved the sealing problem
,but there are many usability issues. 
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