Where should the throttle body be on an intercooled supercharger setup?

[Jem]

Where should the throttle body be on an intercooled supercharger system?

(Eaton M112 on a V8 )

Should it be air filter, AFM, throttle body, supercharger, intercooler then engine?

Or air filter, AFM, supercharger, intercooler, throttle body then engine?

With the throttle body before the intercooler I can see it having a slow throttle response, but with the throttle body after the supercharger I can see there being problems with the supercharger running flat out with the throttle closed and nowhere for the air to go.

Any ideas?

[Martin T]

With the throttle body before the intercooler I can see it having a slow throttle response, but with the throttle body after the supercharger I can see there being problems with the supercharger running flat out with the throttle closed and nowhere for the air to go.

Any ideas?

You get bypass valves - pretty much the same as BOV's for that
If you dont, then on overrun the car jerks all over the place as surges of pressure force the throttle body open.

[Monkey Dust]

I don't have an answer to your question. But the idea of a supercharged V8 Soarer

[Jonny]

Most kits I've seen have the throttle pre-blower, but you have problems with idle droop etc if you have an IC, as you have loads of volume after the throttle.

One solution is to have two throttle bodies, one in the normal place, one pre-blower (have no idea how that works, but it does )

Some light reading for you:

http://forum.miata.net/vb/showthread...7&page=1&pp=25

[Jem]

Most kits I've seen have the throttle pre-blower, but you have problems with idle droop etc if you have an IC, as you have loads of volume after the throttle.

One solution is to have two throttle bodies, one in the normal place, one pre-blower (have no idea how that works, but it does )

Some light reading for you:

http://forum.miata.net/vb/showthread...7&page=1&pp=25

Yep that makes sense, with a positive displacement supercharger the intake into the charger would have to be throttled or you could do it with a big bypass valve to send air back round to the intake of the supercharger.

Running a supercharger with no charge cooling is much easier to plumb, it just replaces the inlet manifold But you are then limited to 6psi.

Independent Throttle Bodies is another option

[Jonny]

I think the general gist of the miata.net thread was that the bypass valve wouldn't be able to cope with the volume of air coming out of the blower - and these are 45ci blowers, not a monster 112ci one like you have

[2 Black Lines]

I'd be going for :

Filer, throttle body, charger, intercooler, engine.

I'd have a look under a Merc Compressor bonnet for some ideas, because there not the easiest to plumb in, ( IIRC the 112 is a rear exit?)

[Jem]

http://cgi.ebay.com/ebaymotors/Cobra...QQcmdZViewItem

[skyshack]

Most kits I've seen have the throttle pre-blower, but you have problems with idle droop etc if you have an IC, as you have loads of volume after the throttle.

One solution is to have two throttle bodies, one in the normal place, one pre-blower (have no idea how that works, but it does )

Some light reading for you:

http://forum.miata.net/vb/showthread...7&page=1&pp=25

Works same as BMW M13.
http://www.gurneyflap.com/bmwturbof1engine.html

and ITBs

Single throttle linkage works all 5 throttles.

By slamming the outer throttle shut compressor sucks on vacuum. Turbo doesn't slow down and can't stall so it has less lag.

Don't look now but there's a Slighty RS13 in PPC that's getting a V8 + Eaton. Just about any modern engine (DOHC 4v/cyl) works better in a RS13 than it did in the donor as the donor is always at least 100Kg overweight. Most old engines aren't worth looking at.

cliffb75's CA18DET 200SX Morris Minor made an appearance too.

RohanC's black S13 also got itself in there.