Supercharger Applications - Older 911s

domtoni · Post by **domtoni** » Thu Oct 19, 2006 12:21 pm

Sorry to bother you, but if the larger community could give me some advise, I would be most appreciative.

My company is developing a two speed drive for a mechanical supercharger. The first supercharger unit is from Rotrex, which is basically a modified turbocharger. Small, compact, and quiet.

The two speed drive gives increased RPM at low engine speeds, and once the desired speed is hit, the drive goes into a one to one drive mode.

We have built two cars, a 4.6 Mustang and a 1.8 liter Chevrolet Lacetti (gas of a car).

Is this the kind of performance option you guys would love to have? We think it should be installed by an authorized fitter as most people don't have ability to do it themselves.

The unit in the Mustang will be shown at the upcoming SEMA show in Las Vegas later this month.

All comments will be appreciated?

Best Regards
Dom Toni

__________________
dom toni 911E

impmad2000 · Post by **impmad2000** » Thu Oct 19, 2006 12:39 pm

Boost is good

Got any spares lying around.
Once I have the imp running on Megasquirt, I'd love to try a bit of positive manifold pressure.
Is the Rotrex smaller than the Rootes blower type ? I've driven both turbo and supercharged cars, and the driveability of the supercharger is seamless.
In the long run, 911 back up and running, all EFI'd up, I'd consider boosting that too (low pressure only). Long way to go on that front though.
I'd be happy to DIY install BTW, but I've played around with turbo systems before. Risks of a holed piston are higher though...
Good luck
Tim

2.4TE · Post by **2.4TE** » Thu Oct 19, 2006 12:43 pm

Dom- sounds like a fun project! Not for my 911, but I had a frogeye Sprite I used to hillclimb and always wanted to supercharge it. I wasn't alone; several others are interested in supercharging those early A series engines. In all cases, I suspect it would be DIY though.

Nige · Post by **Nige** » Thu Oct 19, 2006 12:53 pm

Ever since owning a Polo G40 I've hankered after another supercharged motor. Sounds interesting to me

domtoni · Post by **domtoni** » Thu Oct 19, 2006 1:03 pm

Let me give you all a bit more information.

We built a 4.6 liter Mustang. The two speed drive gave effectively 50% more horsepower in lower RPM ranges and gave the car 50% more at the top end.

If I could get 50% more from my modest 2.0 E, then I should be able to smoke all of those RS guys !!!

We don't have any extra units laying around now, but should have some production units in 3 - 4 months.

Impmad, let try to send you a picture of the unit via e-mail.

domtoni · Post by **domtoni** » Thu Oct 19, 2006 1:08 pm

Let me give you all a bit more information.

We built a 4.6 liter Mustang. The two speed drive gave effectively 50% more horsepower in lower RPM ranges and gave the car 50% more at the top end.

If I could get 50% more from my modest 2.0 E, then I should be able to smoke all of those RS guys !!!

We don't have any extra units laying around now, but should have some production units in 3 - 4 months.

Impmad, let try to send you a picture of the unit via e-mail.

2.4TE · Post by **2.4TE** » Thu Oct 19, 2006 1:08 pm

Dom,

Would it work with MFI?

domtoni · Post by **domtoni** » Thu Oct 19, 2006 1:12 pm

Dr. Dave,

The unit will work with MFI.

As I understand the Americans use MFI pumps on their iron, supercharge them, and just turn the fuel delivery up. Not the most fuel efficient solution.

To insure one does not blow up the motor, I guess one just monitors the exhaust emissions, and make sure the motor is not running lean.

I am not an engine engineer, so I say this from my limited knowledge base. I trust Porsche motors are strong.

impmad2000 · Post by **impmad2000** » Thu Oct 19, 2006 1:49 pm

2.4TE wrote:Dom,
Would it work with MFI?

I'd have thought it is possible, but not as easy as some. Bosch K-Jet (CIS) with its metering head copes quite well with adding a super/turbo charger. As the metering head includes the additional air pumped in, it correspondingly adds the correct ratio of fuel. MFI would need a revised fuel metering cam I guess.
Cheers
Tim

2.4TE · Post by **2.4TE** » Thu Oct 19, 2006 1:55 pm

Tim,

"MFI would need a revised fuel metering cam I guess"

Yes, I would think so too.

Matt black70 · Post by **Matt black70** » Thu Oct 19, 2006 11:02 pm

Hi Dom
I'll have a chat to Gary about it if i remember in a couple of weeks time.It's a shame you can't make the 31st.I'll measure my dizzy at the weekend and give you a call.
All the best Matt

james911rs · Post by **james911rs** » Fri Oct 20, 2006 1:16 pm

Dom Toni
Have you talked to Supercharger services at Trysull, whish is only 15minutes from you. They make superchargers for 1930's cars, but i talked to them about doing a twin supercharger conversion on my car for about £3500. But my car would have been the guinea pig, so the more who have it done the cheaper it would be. They are worth chat to as they are so local to you.