Which motor for future turbo?, my first post. Options

[sgray944t]

Well first I will introduce myself as this is my first post. I live in Raleigh, NC and have decided to build up a 914. My dad has lots of experience with Porsches of all types and suggested a 914 as a relatively simple and very fun car. I have been reading this site for a few weeks religously trying to learn everything I can. Im buying a 914 with the intent to swap a 911 motor in it. I am mainly interested in the 3.0 or 3.2 conversion, eventually to turbo. This is where my question comes into play. I have read Iamchappy's thread about turboing his 3.0 motor, and it seems like the 3 liter has no problems accepting boost. However I havent come across anything about turboing a 3.2. Is there any mechanical reason for this, or is it just something no one has documented? The reason I ask is that I am probably going to install the motor in its NA form first, then gather the parts for turbo over time. I think the higher hp of an NA 3.2 would hold me over until its time to turbo, however if turboing 3.2 motors is not ideal, and the 3.0 is a better forced induction motor, I would rather stick with it. My final goal is somewhere around 300hp give or take. At this point I'm thinking that the 3.0 is the better choice because its been turbocharged more often than the 3.2 and therefore I will have more support when problems arrive. Im also fairly sure the 3.0 can give me the power goals I'm looking for relatively easily. But please enlighten me, Im still learning about this 914 thing so I can use any comments you might have. Thanks alot guys!!!

[9144guy]

id have to look at the spec book but i( think) 3.2 l were in the c2/c4 modles and had alot of oil problems, we at the shop have pulled apart 6 c2/4 motors for base gaskets and other seeps, done 3 993 motors for clogged air induction cloges in the heads ,i could findout more, let me know

[sgray944t]

Werent the 964s 3.6 liter? Im not really interested in putting a 3.6 in the car becuase of the added work to make it fit. Plus it raises the cost quite a bit.

[Brando]

The best way is to go with a 911SC 3.0 engine. It is essentially the same as the 930 (1970's 911 tubo) except naturally aspirated. All of the internals are made to work with turbo applications. If you're hankering for a 3.2... with the investment if finding a 3.0 without broken headstuds (~$3000 for a new top end, average) you can get a 3.0 case bored out a bit and then move on to the turbo applications later. You can easily get 250 out of a 930 case with forced induction.

The C2s and C4s of the 80s as stated use a MAF system and have more electronic systems than you want to deal with. More hassle than it's worth for a 3.2L motor. A 3.6L motor is better and worse. They make about 325 at the wheels but are so electronically managed you'll pull your hair out making it work.

This is before making a G30 or G50 trans fit in there. See where I'm going?

Best results would be
3.0L case, punched out to 3.2, turbo'd with 930's induction and exhaust systems. (IMG:http://www.914world.com/bbs2/html/emoticons/smash.gif)

[Brando]

The question I have though, is how much horsepower do you need in a 914? The car's only about 2000lbs on the heavy end. Even with a moderate 200hp 6cyl engine you've got 10lbs:1hp. That's a nice power to weight ratio. With a turbo you'll accelerate a hell of a lot faster. Then you can spend your extra pennies on some nice big 23mm swaybars up front and in back. I'd suggest with that much power getting a roll-cage bolted or welded in there.

[ArtechnikA]

QUOTE (Brando @ Apr 1 2005, 12:37 PM)

with a moderate 200hp 6cyl engine you've got 10lbs:1hp. That's a nice power to weight ratio. With a turbo you'll accelerate a hell of a lot faster.

exactly.

well, sorta.

the turbo motor is heavier, the beefier transmission and driveline parts needed to handle the power are heavier, the bigger brakes you'll need are heavier, the cage you'll want after you scare yourself silly the first time is heavy, and before long, you're back to the 10 lbs/HP you couldda started with...

turbos are fun (and yes, i want one...) but you're never able to get away from the careful balancing act necessary to keep you from going backwards - at great cost...

[street legal go-kart]

buy a 2.0 driver and drive it for a year , go to a few scca autocross events and then revisit this topic.
Even a 3.0 non turbo 914 is a LOT of car. The 2.0 will be about 1/3 the cost of the setup you are thinking about.
Welcome to our madness (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif)

JT

[nebreitling]

QUOTE (street legal go-kart @ Apr 1 2005, 10:06 AM)

buy a 2.0 driver and drive it for a year , go to a few scca autocross events and then revisit this topic. Even a 3.0 non turbo 914 is a LOT of car. The 2.0 will be about 1/3 the cost of the setup you are thinking about. Welcome to our madness (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) JT

(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif) get a taste for it first -- this will sustain you while you put the minimum $15-20k into your project.

i'd love a big turbo'd six -- i say go for it! -- just look before you leap!

and welcome!

[Mueller]

QUOTE

The C2s and C4s of the 80s as stated use a MAF system and have more electronic systems than you want to deal with. More hassle than it's worth for a 3.2L motor. A 3.6L motor is better and worse. They make about 325 at the wheels but are so electronically managed you'll pull your hair out making it work

The C2 (mine is a 91) and C4 didn't start until late '89, they are 3.6 liters and are popular swaps into early 911s...the wiring issue has been resolved with a few companies making kits...the biggest pisser of a 3.6 if want to turbo it is the high compression as delivered from the factory, it is in the 11:1 range...they do have twin-plugs right from the factory so that is a positive (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

The 3.6 motors from the 993 would be nice, that is when they started using hydralic lifters so no more valve adjustments, that is a good thing.....

[Brando]

QUOTE (Mueller @ Apr 1 2005, 10:49 AM)

The C2 (mine is a 91) and C4 didn't start until late '89, they are 3.6 liters and are popular swaps into early 911s...the wiring issue has been resolved with a few companies making kits...the biggest pisser of a 3.6 if want to turbo it is the high compression as delivered from the factory, it is in the 11:1 range...they do have twin-plugs right from the factory so that is a positive (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) The 3.6 motors from the 993 would be nice, that is when they started using hydralic lifters so no more valve adjustments, that is a good thing.....

i missed a 'late' between "in the" and "80s". (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

Up until 89 they still used the 930. Strongest of them all pre-existing the 964.

The 993 and 964 use the same block (964). Only difference is the 993 has air injection into the exhaust, later got varioram and variocam. Turbocharge that and WOAH you'll need new undies. Benefit of those 2 is that they did make a turbo 964, and did make a turbo 993 (equipment already exists).

Fun with the 964 and 993 include: Once the air injectors on a 993 get clogged you get to have a lot of fun not passing smog with a check engine light and a new top end. Or when the drive belt for the twin distributors goes bad. Or when the speed reference sensor goes bad (wont run right). Or the cold-air intake sensor goes awry. Oh wait, that last one's only on 996s and boxsters.

[sgray944t]

I think I got a little too hasty thinking about a turbo six cylinder 914. The thought of it just got me going without really considering all the factors. I WILL have a turbo 914 eventually, but I think I am going to start out with an NA 3.0 and rebuild it myself. Im not so much into the swap just to have and drive, I really want the experience of building up the car. So now my plan is just get the 3.0 in there, enjoy it for awhile, and add turbo way down the road when I have all the parts collected. With a 2300lb weight and a 200hp 3.0liter I should have a weight:power of about 11.5 to 1. That seems pretty quick and capable of running with most cars on the road, as well as out handling them by a large margin. Thanks for all the help and hopefully this thread will be ressurected in a few years when turbo time comes!!

[Series9]

QUOTE (Brando @ Apr 1 2005, 05:34 PM)

Only difference is the 993 has air injection into the exhaust..

There are quite a few differences between the 964 3.6 and the 993 3.6. The 993 engine is a much better motor, IMHO.

I have a Euro 993 3.6 which has no air injectors and has solid lifters (something I was interested in having).

Among other things, I enjoy a MAF Motronic system. The 964 is not MAF based.

There's also a significant difference in HP between 964, 993 and Varioram.

[Brando]

Thanks for clarifying 914RS...

Although, if the 964 is not MAF based... what would it be then? Has volumetric metering of air:fuel and a computer that runs through fuel maps depending on your driving habits. Or is a MAF system only designated to those with manually controllable timing and air/fuel mixture?

[Series9]

QUOTE (Brando @ Apr 1 2005, 10:09 PM)

Although, if the 964 is not MAF based... what would it be then?

Your question makes almost no sense.

The 964 3.6 is based on the L-Jet flapper-box system. It's the same as the 1.8 FI, before L-Jet was digital.

[joea9146]

Building the Turbo has a big cool factor, but to build it on a 911 3.0 can get very pricey.
Most 3.0 are close to 25 years old so figure on having to rebuild the motor
which gets pricey, than all the Turbo stuff you need to fabricate..... more $$$
If you do it right you will eaisly spend 10k - 12k.
If you are looking for lots of power and grunt just drop a stock 3.6 motor
into the 914.... lots of power and reliability, and will cost you less in the long run.
Also Big Cool Factor (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
If you still want to turbo a 3.0 find the 3.0 that has the lower compression pistons
I believe the lower compression motors are 8:1, Turbo applications are better with
Lower compression

[sgray944t]

Im rebuilding the motor either way so the age of it does not really concern me that much. I was mostly interested in the 3.0 for turbo becuase the CIS injection easily compensates for boost, and becuase of the available support from members who have turbo 3.0s. Not to me mention there was actually a turbo kit available for the 3.0, so I know it will work relatively simple.
Does any have a diagram or explanation page or something on how the CIS injection works? Im buying a book today on the 911 motors but Im not sure if it explains how the system works.

[ArtechnikA]

QUOTE (sgray944t @ Apr 2 2005, 11:33 AM)

Does any have a diagram or explanation page or something on how the CIS injection works?

there are pages out there, grassshopper, make Google your friend.

here are three good books:

Bosch Fuel Injection & Engine Management
How to Tune & Modify Bosch Fuel Injection
Solving Bosch Continuous Injection System Problems

available at Pelican Parts among other places.

[sgray944t]

Well I just bought Bruce Anderson's book and I did in fact see the "How to Tune and Modify Bosch Fuel Injection" right next to it. Does this book have the same system that comes on the 3.0l in it? The link says K-jetronic and L-jetronic which I've heard on this website before but Im not sure what motor it goes with. Ill have to go look through the book and see whats in there.
Thank you master (IMG:http://www.914world.com/bbs2/html/emoticons/pray.gif)

[Mueller]

QUOTE

Is this book Porsche specific?

no, not really, but CIS is CIS, does not matter what vehicle it is from......just so you know, custom fabrication is going to be needed, there is NOT a kit to install a turbo into a 914 specifically with a /6 motor (or a /4 anymore)...so don't expect to just be able to look in a catalog, buy a part and just bolt it right up to the car.....


I have this book, as well as the others mentioned, you can never have enough reference material .......

[ArtechnikA]

QUOTE (sgray944t @ Apr 2 2005, 04:18 PM)

..."How to Tune and Modify Bosch Fuel Injection" right next to it. Does this book have the same system that comes on the 3.0l in it? The link says K-jetronic and L-jetronic which I've heard on this website before but Im not sure what motor it goes with.

from the descriptive link at the Pelican site:

"Specific testing and tuning guidelines are provided for many foreign cars."

914 1,7 and 2,0: D-Jet
914 1,8: L-Jet (very similar to the system used in 928)
911 T from 1973.5, and all 74+ through (IIRC) 1989 including 911SC: K or KE - Jetronic - also known as CIS or CIS-E.

CIS - Continuous Injection System. K-Jetronic - K is for Kontinuous.

at some point Porsche switched to DME / Motronic

a good websearch for CIS Injection and/or K-Jetronic will turn up many references; adding 'Porsche' to that search will narrow it down. many European cars use one of the Bosch injection systems, and many of the Asian cars use systems developed by or licensed from Bosch.

i know there's a 911-specific site on CIS troubleshooting and testing, but i haven't tracked it down yet. note - most of the stuff you will find in a 911 context involves troubleshooting and fixing stock systems - there aren't a lot of modification references, because CIS is rarely used in a performance application. Porsche used CIS on the 934 only because the FIA rules made them do it.