Slide Throttle intakes?

[rs4pro3]

ok, wasn't sure where to toss this as it dosn't apply to just the m20, M30, M50 etc... But to Slide throttle intakes in general. I've heard that they arn't very good for street use and basically are a race use only item. One of these reasons is due to the fact that they leak air between chambers making for very poor response in the mid throttle ranges, but at WOT you better hang on:finger:
Now say you could make it so each Chamber was sealed from the one next to it, do you guys think they could still be used reliably on a street engine? I'm just trying to cure some curiosity.:?:

In case you are wondering this is a slide throttle intake

Instead of a butterfly the throttle slides out of the way, leaving no restriction at WOT.

[mspiegle]

I've seen something like that for twin-screw superchargers. Its a special TB that mounts to the back of the SC. Instead of an actually throttle plate, it has a top half and bottom half. As you open the throttle, the top half goes up and the bottom half goes down. At WOT, both halves are fully extended and not blocking any of the intake stream. Unfortunately... they cost around $2K i think (which is strange since it isn't a horribly complicated device), so I never got one for my 928.

[RobertK]

I understand the concept but I don't understand the comment about leaking air between chambers.

[rs4pro3]

Well to aid in the ability of the middle plate to be able to slide ussualy small roller bearings are used, this leaves a small gap between the Top, bottom and middle sliding plate. That air can leak threw. Causing the same affect as a vacume leak would when you are at part throttle or at idle.

[uflnuceng]

How about screwing each metal plate into like a low friction plastic plate, so the plates glide on plastic. Kinda like what those "mover men" things you put under entertainment centers and they just glide around, but something more heat resistant of course. If you only had the one throttle plate like on the M20, M30, etc, then I guess you would only have one hole and hense no leaking between chambers?

Interesting concept.

[rs4pro3]

What I was thinking of was multiple Teflon strips around each chamber, Slide throttles have been around for along time, Motorsport teams used them on the M49 in the E9 CSl race cars, and so did some of the teams on the S14's. In a race engine part throttle modulation dosn't matter as much and they typically used bearings on one side and Teflon on the other to try to seal as best as possible.

[RobertK]

Of course you would have to find an interested way to rig the TPS or use some kind of stand alone engine management.

[rs4pro3]

Ya, I've heard of Linear TPS's before but haven't researched it any.

[AdamF 88iS]

There were a lot of slide throttles used on S14s back in teh Grp A days. Those cars used Alpha/N engine managment with no air metering device, so vac leaks didn't make any difference for them.

Interested to see your solution.

[ragehardintothebendies]

I'm sure I've seen a setup like that on an old 911 too.

[uflnuceng]

Of course you would have to find an interested way to rig the TPS or use some kind of stand alone engine management.

Well... in theory couldn't you just change the orientation of a would-be stock TPS? Instead of it being on the side of the normal throttle body, you could put it on the end where the throttle cable is. I don't think it would be that difficult to set up (in theory... but communism works in theory to so...)

[AdamF 88iS]

Of course you would have to find an interested way to rig the TPS or use some kind of stand alone engine management.

You dont actually have to use a TPS, all you need is a contact for idle and wide open... thats all the TPS does anyway. Put a contact at each end of the slide and thats it.

[rs4pro3]

True I was thinking more along the lines of rigging up on of the E34 style Variable switchs, and running a MAF and the appropriate piggy back.
I have to do some design projects at school so I figured why not try it, I'm not sure yet if the school's lab any CNC machines, I walked by today and noticed 3 manual mills, and possibly a CNC but couldn't get in the lab. I just transfered here, I guese I could use my old school's machine as the Lab tech was glad for someone to be ussing it finally. Multi throttle intakes have always gotten my attention, and a slide throttle intake seems like a good alternative that dosn't require as much space.
Here are a few small pics of the E9's setup I know Alpina and Schnitzer made the intakes, and I've found a little info on them, and also have a guys phone number who has owned a few.(haven't had a chance to call him yet)

And the good old M49

[RobertK]

Picture no worky

[xLibelle]

Interesting idea... this seems very do-able.
Visions of S14 style airbox into ITP (individual throttle plates(?)) on a M50 dance in my head

instead of idle and wot positions alone, a tps can be done up with a one-turn 2k pot (or whatever size would be required) with cog on gear track OR a spring-loaded belt around that cog.
If anyone is SERIOUS about putting such a thing together, i have some resources.