Is this possible with a Mazda Rotary

[pomoz]

Gday all
Long time no talk... yes still alive and kicking

I was in a pub in Northern Queensland the other day.
A guy was "flapping his gums" about a mate of his who had a Mazda Rotary (not sure RX7-RX8)
He said .... he had TWIN TURBOS AND A SUPERCHARGER on it ....
I being typical quite person .. said nothing until i had it clarified ... who better to clarify for me ..YOU GUYS .. THE GURUS
So when i have my information i then can go back and "Flap my gums) etc etc
Is this possibble and if so .. what benefits would it have ....or is it just a overkill of BS

Many Thanks
Alex 87S3HC na

[paul c]

pomoz said:

I was in a pub in Northern Queensland the other day. A guy was "flapping his gums" about a mate of his who had a Mazda Rotary (not sure RX7-RX8) He said .... he had TWIN TURBOS AND A SUPERCHARGER on it ....

Betcha he meant (or heard wrong) 'CHARGECOOLER'
You can get them for the twin turbo RX's...




Is it actually possible to have a supercharger in line with a turbo on a forced induction system?

[lotusguy]

Hi,

If memory serves me, I believe both Saab and Toyota experimented with this hybrid boosting mix in an effort to minimize turbo lag.

A small supercharger was used with a centrifical clutch which cut out at a certain RPM. This RPM coincided with Turbo spool-up, reducing or eliminating lag.

But, I believe the plumbing issues and problems with reliability of the belt pulley clutch forced an end to the project. Saab went on to study the use of two turbos, a small and larger one. The smaller spooled up more quickly reducing lag where the larger took over to really 'Haul the Freight'. Porsche too used this method, also others.
Happy Motoring! ...Jim'85TE

[princecharming]

Yes, it's definitely possible. Not likely, but definitely possible. In the 80's, there was a hot rodder named Rick Dobbertin. I believe he made a few cars that were featured in Car Craft and Hot Rod magazine which had both twin turbos and a supercharger. Oh and he had nitrous too. Here's a link:

www.supercars.net/garages/ChevyRocks/54v2.html

If I recall, it made a lot of horsepower for its time. However, I believe it was done as more of an engineering marvel than for ultimate performance. If this was the hot setup, more drag racers would be doing it and this is not the case.

[Htown]

Compound forced induction is relatively common in the toyota mr2 crowd. Generally the turbo feeds a twin screw supercharger. The turbo 'pushes' the supercharger to much more acceptable efficiency levels at higher boost settings. Blowers usually become very inefficient when asked to produce big boost on their own.

[squelch]

Well.. yes.. In the Toyota MR-2 community the "Twincharger" is the Holy Grail...
However there is more incorrect information available about it than facts.

Having worked on two of the only running MR-2 Twinchargers I'll shed some FACTS on them.

The SC is used from off idle to around 3500 RPM, enough time to get the turbo to spool up (it's a big ass turbo)
Once the turbo comes on the pipe a set of bypass valves come into play and the turbo feeds the intake, bypassing the supercharger. It is not used in a compound configuration.

So.. Yes.. twincharging is out here...
There are many twin turbo rotarys out there, it would not surprise me if someone fitted a small blower into the mix, but the plumbing colud be complex.

[MadMaxx]

There is a 1JZ powered mk3 in europe who now has a supercharger and single turbo on the car. IIRC, it's a T88 turbo, and he's going to use the blower to spool the turbo. Not bad, looks pretty slick. I'll try to dig up the photo.

[Autocross7]

Hi everyone... as a rotary fan for year (currently drive an 87' RX-7 along with the Lotus), I can not help but put in my 2 bits...

The 3rd gen RX-7's did come with twin turbo chargers on them. They were pretty reliable and worked in much the way described above (1 spooled then the the second -simplified explanation). The "R" series RB-13 in the last of the RX-7's made it one of the fastest production cars in the world - and left out of many a 'standing' per the often anti-asian car journals. As for putting a super charger in with the twin turbos... show me a picture! OR (to quote my Scottish relatives) "Bugger off!". The set up would be a trick at best as the turbos sit rather low on the RB-13's already low place in the bay. I'd picture a long shaft for the belt driven super charger, but then getting that air split to correctly feed the staged turbos...???

Not saying it could not be done.... just would have to see it to believe it...

Drive topless!!!
Cameron

[MadMaxx]

I know it's not a rotary..but still pretty cool

[IMG]www.supras.nl/iB_html/uploads/post-2-46995-mini_enginebay3.jpg[/IMG]

[Htown]

The Turbo Magazine project MR-2 is indeed compound.

fwiw-

squelch said:

Well.. yes.. In the Toyota MR-2 community the "Twincharger" is the Holy Grail... However there is more incorrect information available about it than facts. Having worked on two of the only running MR-2 Twinchargers I'll shed some FACTS on them. The SC is used from off idle to around 3500 RPM, enough time to get the turbo to spool up (it's a big ass turbo) Once the turbo comes on the pipe a set of bypass valves come into play and the turbo feeds the intake, bypassing the supercharger. It is not used in a compound configuration. So.. Yes.. twincharging is out here... There are many twin turbo rotarys out there, it would not surprise me if someone fitted a small blower into the mix, but the plumbing colud be complex.

[maigret]

The Lancia S4 had both a Supercharger and Turbo.
www.stormloader.com/groupb/lancia.html

My Lancia has Supercharger only....wonder how hard it is to add turbo......

[yeller77]

Anyone knows, the 5th law of pub-diatribe is that any statement that begins with "I've got a friend that..." has got to be half BS. Working from that premise, he probably heard "intercooler" and thought "supercharger." IIRC, most of the FD's marketed in Oz were a "Bathurst" model, basically similar to the JDM and ROW "R" models where the 13-BREW motor made 250-"280" hp. While said "friend" MAY be a rotary guru, playing around with forced induction with these motors can be a nightmare of fuel management as they're extremely fragile when it comes to detonation and said gurus regularly blow motors until they get it right. Next time just smile and order up another pint.

Eric
S1,
94 R2 (ASP)

[pomoz]

Gday all
Thank you very much gentlemen ....
I knew you blokes would come up with all the right answers ....
So i am now "fully equipted" to "flap my gums" when this subject is again breached at the pub....
Another saying of mine
"why talk to the monkey when you can go straight to the organ grinder" (me the monkey you the organ grinders)

Many Thanks
Alex 87S3HC na

[squelch]

Htown said:

The Turbo Magazine project MR-2 is indeed compound. fwiw-

I wasn't talking about a one off, I was talking about the original HKS twincharger system. It is not a compound system.