3 Liter supercharging options?

[rennch]

Living at mile high altitude, I lose quite a bit of power. Do I have any supercharging options for my 3 liter? It's got very low miles on a rebuild so I thought it might be a good candidate, if someone makes a kit for it. If I were to do it, what other changes would I have to make to the motor or internals?

Thanks!

[rsrmike]

Not sure about your application... Is it a 3.0 SC engine? What type of induction? CIS? What year? version? 930/?? We need details about compression ratio and port sizes, as well as any mods to the motor.

You'll most likely get more help here if you contemplate turbocharging instead of supercharging (assuming you mean a crank driven "blower")

I don't know of any blower kits for an SC available as of now, but there are some great guys doing aftermarket turbos in this forum... Good luck!

[rennch]

It's a stock, euro 79 SC motor. CIS, the whole bit.

[rsrmike]

How do you feel about turbos? I think you may find them an easier path to forced induction in your case...

[JV911SYDNEY]

I know of a couple of supercharged cars here in sydney. One is a '73T tarmac rally car with an SC 3.0. Unfortunately i dont know the details of the set up other than its a positive displacement supercharger from sweden

there are a couple of places in the UK that do kits as TPC Racing in the US

[NathanUK]

I didn't find any kits for my 3.2 carrera, they are for the 964.

[mppickett]

Michael,

Turbochargers usually work better at higher altitudes than superchargers. This is because the amount of boost developed by a supercharger drops as altitude increases and the input air pressure drops. A turbo, on the other hand, automatically adjusts for the reduced ambient air pressure and maintains roughly the same boost at altitude as at sea level. This adjustment is caused by the turbo spinning faster because the exhaust gases are being forced out with less resistance into the thinner air outside. While most airplanes of the '40s used superchargers, you'll find that virtually all modern airplanes use turbos now.

That being said, a blower would work but you'd need a smaller pulley to raise the boost level at your altitude and would need to be careful about detonation when you drove to the low lands.

Mike

Originally Posted by emptyo

Living at mile high altitude, I lose quite a bit of power. Do I have any supercharging options for my 3 liter? It's got very low miles on a rebuild so I thought it might be a good candidate, if someone makes a kit for it. If I were to do it, what other changes would I have to make to the motor or internals?

Thanks!

[rennch]

Mike, thanks for the input.

Is there a turbo kit for the stock SC motor?

[raceman]

Good plan to boost the car, l`m one of several here who tackled the job at home and have had stellar results. The best thing you can do to get started is use the search button on this forum.Do the right searches and you will have hours,literally,of reading and learning. You have one of the easiest cars to boost,parts are plentiful and cheap and a complete system can be done for about $1500.00. First and foremost before you start turning the wrenches your car has to be in good condish,l upgraded my brakes and suspension to turbo spec first but l have bigger plans. You need to get gauges in your cockpit, a wideband controller with guage, boost guage for sure and fuel pressure is very nice to have also. l have the ex.gas temp,cylinder head temp and intake air temp,you really can`t have too much info when you boost a N/A motor. But search.search some more. and then do another search. l did a year or research before l jumped in.

[rennch]

Wow, $1500 seems pretty affordable. What kind of gains can I expect?

[raceman]

For a reliable,rock solid and cool running build you can safely add 100Hp with less then 10 psi of boost.My cars` system added over 150hp and l feel it`s very safe,intake temps are running 10degrees over ambient.The $1500.00 l quoted,you could do it for that and maybe less but you`d have to really shop it for he parts.And do all the work yourself.There are some guys here on this forum who make some really high quality turbo conversion parts,some stuff it`s better to buy new.When you search for info search the other 911 pelican forum,there is a mountain of SC/turbo information

[rennch]

Well, what about the parts? What exactly would I need? I'm a total neophyte to turbos...Ive never owned any sort of turbo car. Where do I even start?

[raceman]

hmmm, you have a LOT of posts..surely you`re familiar with the forum. As l said earlier my strong recommendation is to search,read and search again. l was an internet fiend for over a year before l started buying parts.Compared to 5 years ago you will find a LOT of info right here on this forum. l have a 3.2 Carrera with motronic but the majority of parts you need will be the same: SSI headers or factory style
: M&K turbo "J: pipe with Garrett flange
: Garrett turbo
:Bosch blow off valve ,plastic and cheap but good enough for Porsche
:wastegate, either Porsche or Tial
:CIS fuel distributor rubber hat for boosted use,l think the turbo Volvo unit is a cheap bolt on
:adapter and line for turbo oil feed,ports off oil pressure sender
: turbo oil accumulator tank and adaptor to allow turbo oil drainback into sump
:misc. tubing and couplers for intake plumbing
:***wideband guage/controller***
ptional** fuel pressure, exhaust temp,intake temp,cylinder head temp gauges
ptional**intercooler
l personally haven`t turbo`ed a CIS injected Porsche,other cars with CIS l have. l would recommend a device to retard timing under boost,l use a Jacobs Boostmaster on one of my other turbo machines but MSD makes one too. You may want to fatten up the mixture under boost with a secondary injector, several ways to accomplish this. Now there is another option you can undertake and one l initiated when l first decided to go turbo..buy a complete used porsche 930 set-up and start wrenching. You`ll need a scavenge pump to evacuate the turbo oil but this is $200- and in some ways superior to the gravity drain many of us use.
There are others here that may chime in,guys with SC`s who have done the conversion. l cannot stress enough the importance of control guages beng installed prior to running the car.Knowing the AFR`s is crucial and fuel pressure in my opinion is also a must have,tuning will be a LOT easier when you know what the engine is doing.Air cooled engines should have full instrumentation if you`re boosting a normally aspirated mill,things can seem fine until the melt down....
PS_ start searching and all your questions will be answered

[rennch]

Raceman...

I have been searching, but it's not a lack of info that's the problem. It's TOO much info. Most of which I don't really understand. I was just wondering if there's a tried and true method...like, someone tell me what to get, and I'll get it, install it, and move on, you know? I am not enough of an engine nerd to devise my own scheme for this. Thanks for the info you just posted though...that's great.

[raceman]

okay amigo,l get it. What exhaust do you have now,let`s start there and l`ll help you do this part by part. l think buying or sorting the exhaust is step one,it was for me and it has the function of locating all the subsequent parts. So on to your exhaust,what do you have on there?

[JV911SYDNEY]

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[Porsche Head]

Ihave been toying with the forced induction (turbo vs supercharger) idea for a while, I also drive an 04 VW GTI 1.8t and drive with my brother in his 87 930. My car is a 72 with a 3.0 and a 915 w/7.81 posi so the response I have now is pretty cool I don't want to loose that with a turbo, there are time when I get pissed off driving my VW becuase I am not on boost and want to jump into a whole in traffic and it won't go, then it goes and I too much power too late.

I am still leaning towards a SC to keep the snappy response even though the turbo is much easier to install and can ultimately build more power. I think the Rotrex might be a good option (see link).

http://www.rotrex.com/

[jsveb]

Hi
I am so far in the seach fase as raceman describes it. I have gathered a lot of parts and made up my mind. I will turbo charge an SC engine. In the beginning I really wanted to supercharge the car. I know a fellow club member here in Denmark who charged a Carrera 3.2 using a Rotrex charger (Danish product ) It ran really well, but the charateristics is more like a big old Mercedes than a Porsche. That is why I am now leaning towards a low boost Turbo setup. just my view on the matter.
Best of luck
Jesper

[copbait73]

Originally Posted by Porsche Head

Ihave been toying with the forced induction (turbo vs supercharger) idea for a while, I also drive an 04 VW GTI 1.8t and drive with my brother in his 87 930. My car is a 72 with a 3.0 and a 915 w/7.81 posi so the response I have now is pretty cool I don't want to loose that with a turbo, there are time when I get pissed off driving my VW becuase I am not on boost and want to jump into a whole in traffic and it won't go, then it goes and I too much power too late.

I am still leaning towards a SC to keep the snappy response even though the turbo is much easier to install and can ultimately build more power. I think the Rotrex might be a good option (see link).

http://www.rotrex.com/

I've made a career from turbocharging but given your comments your best option is to sell the 3.0, invest in lighter weight and upgrade to a 3.6LN.A.

[Porsche Head]

Copbait, I understand, everyone is unsure of the new/unknown, however given the efficiancy of the Rotrex (74-76% boost and 90%+ drive) it will keep the temps way down and still provide low-end and top-end. Normal drive intake temps should only increase ~14 deg, I spun the charger by hand and it take much less to turn than an eaton (7.5 to 1 drive ratio for Rotrex).

I plan on adding water injection and a wastegate with controller to help dial it all in.

I received my Rotrex C38-71 a few weeks ago and it is awesome, a little big for what I need but will use the extra boost and bleed of with the wastegate to help make the bottom end more like a whipple/eaton but still have that great top-end.

I just finished the steering box rebuild and am in the process of putting in the new Bilstein struts/21mm TB/928s4 brakes so I may not be able to get to this before the end of the year. I did a lot of research and it seems that these little Rotrex units are very quiet, efficient and can provide very good power provided you match the blower correctly because of the compact size.

Since no one has done this before I will provide updates to the board and hope to address the skeptics out there. I like turbos and drive one every day (04 GTI) but I also like the N/A throttle response and don't want to loose that character especially for such a light and responsive car.


What I have:

Rotrex C38-71
Rotrex Oil cooler and lines
Poly belt pully system for crank and fan
Motor (3.0 w/8.5 CR) w/large intake runner (78)
Boost/vac gauge (installed)

What I need:

Brackets
Water injection
Wastegate
Recirc valve
Plumbing
Time!!!!

Cliff