968 turbo-ing methods
#31
Rennlist Member
Hybri_944, Sorry it took a minute to get back to you. My fastest speed is 194 mph. That's with a newly calibrated 220 mph speedo from North Hollywood. Only tried it once though. that's enough.
#32
Rennlist Member
2mm shorter rods lower the compression a 2 valve head from 11:1 to 8.5:1 with some dishing. It does not lower it from 9:1 to 8,5:1. The 4.5mm shorter rods will be way too short. Usually Phs mods power the compression to 9:1 as they use a 16 valve head most of the times. I am using a 2.7 head and prefer having lower compression to having some more hp up top from a 16 valve head.
#33
Rennlist Member
Wow, I never thought to look int he 968 board for turbo info. Go figure. So, as for turbo charging a 968, I have two questions related to this thread:
1. The new Mahle low-compression 3.0 liter pistons would eliminate the need to shave pistons, no? (Although I understand stronger stock length rods are still a good idea.)
2. Would an intercooler like the one sold by speedforce racing, which mounts in front of the radiator, work on the 968, to eliminate the need to change the latch mount, etc.?
Also, I trust a stock 951 intercooler would work in the front of an 944S2? Yes? If so, is the S2 with Mahle low compression pistions and a 2.7 head and 951 plumbing the easiest route to 3 liter turbodom?
1. The new Mahle low-compression 3.0 liter pistons would eliminate the need to shave pistons, no? (Although I understand stronger stock length rods are still a good idea.)
2. Would an intercooler like the one sold by speedforce racing, which mounts in front of the radiator, work on the 968, to eliminate the need to change the latch mount, etc.?
Also, I trust a stock 951 intercooler would work in the front of an 944S2? Yes? If so, is the S2 with Mahle low compression pistions and a 2.7 head and 951 plumbing the easiest route to 3 liter turbodom?
#34
Three Wheelin'
1. The new Mahle low-compression 3.0 liter pistons would eliminate the need to shave pistons...
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Yep,
That's right...And you might as well put in some Carillo rods as long as you're in there!
Jason
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Yep,
That's right...And you might as well put in some Carillo rods as long as you're in there!
Jason
#35
Three Wheelin'
Also, I trust a stock 951 intercooler would work in the front of an 944S2? Yes? If so, is the S2 with Mahle low compression pistions and a 2.7 head and 951 plumbing the easiest route to 3 liter turbodom?
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I think Raj has an easier solution...but, I'll let him speak for himself.
Jason
_____________________________________________________
I think Raj has an easier solution...but, I'll let him speak for himself.
Jason
#37
Rennlist Member
Turbocab, the static compression of the new mahle pistons when used with a 2.7 head is 8:1. This ofcourse goes up if used with a 16 valve head and you don't have the valve relief's of the 16 valve head.
Tom, ideally the 944S2 would be the ideal car to make a 3.0 turbo just for that reason. It has all the bodywork in place to install a factory intercooler which wil also save you some serious $$$.
The SFR solution is a good one as well and has been tested in street apps but not sure if its been tested on the track. We are going the SFR route for the intercooler on a friend's cab as he did not want any mods done to the latches and wants a sleeper look.
Tom, ideally the 944S2 would be the ideal car to make a 3.0 turbo just for that reason. It has all the bodywork in place to install a factory intercooler which wil also save you some serious $$$.
The SFR solution is a good one as well and has been tested in street apps but not sure if its been tested on the track. We are going the SFR route for the intercooler on a friend's cab as he did not want any mods done to the latches and wants a sleeper look.
#38
Raj:
It appears that the new Mahle turbo pistons are manufactured for the 2v head. This means that the piston dish will be "offset" to one side of the piston to match the 2v head. If this is true they will not mantain optimum squish with the 16v head. Did some one has seen the pistons?
It appears that the new Mahle turbo pistons are manufactured for the 2v head. This means that the piston dish will be "offset" to one side of the piston to match the 2v head. If this is true they will not mantain optimum squish with the 16v head. Did some one has seen the pistons?
#39
Rennlist Member
Ok, if I started with an S2, what about the DME and wiring harness? Can I make the S2 DME and wiring harnesses work with the 951 motor set up -- somehow? Seems like there would be a lot to re-wire if I used the 951 DME and KLR. I wonder if it is easiest just to put a 3 liter in a 951?
#40
Rennlist Member
Turbocab, I have seen these pistons and compared them against the spares I have for my turbo RS engine and dimensionally they are the exact same and have a dish for the 2 valve head. The idea for these pistons was to remanufacture them if 944 turbo owners wanted to go to 3.0 or if 3.0 owners wanted to turbocharge using a 2 valve head. I don't think the idea was to use these pistons with a 16 valve head. For that you will still have to go the tried and trusted route of shorter rods and dished/shaved pistons.
Tom, btw not sure if you remember me from the heydays going back 6 yrs on the email forum . As far as using the S2 as a basis, you can go either way. The 944 turbo setup will require you swapping your clutch housing and clutch setup to a 944 turbo as well. If you stick to a 944 S2 setup, you will run into problems getting your reference sensor to work as on a 16 valve head it is triggered by the cam pulley. You will not have this option with a 2.7 na head and you cannot run the 2nd trigger from your flywheel cause it does not have the magnetic sensor on it.
Its catch 22, you go 16 valves, you need custom intake, exhaust but can keep your electronics and make more hp. You go with 8 valves, you can pretty much everything from a 951 but it will require you changing to 951 electronics as well for trigger purposes.
We are just getting started with a 16 valve conversion. Will let you guys know how it works out. It will use 968 electronics with custom plumbing/intercooling. The shortblock is from my current engine so it will be interesting to see how the same shortblock reacts to a 16 valve head.
Tom, btw not sure if you remember me from the heydays going back 6 yrs on the email forum . As far as using the S2 as a basis, you can go either way. The 944 turbo setup will require you swapping your clutch housing and clutch setup to a 944 turbo as well. If you stick to a 944 S2 setup, you will run into problems getting your reference sensor to work as on a 16 valve head it is triggered by the cam pulley. You will not have this option with a 2.7 na head and you cannot run the 2nd trigger from your flywheel cause it does not have the magnetic sensor on it.
Its catch 22, you go 16 valves, you need custom intake, exhaust but can keep your electronics and make more hp. You go with 8 valves, you can pretty much everything from a 951 but it will require you changing to 951 electronics as well for trigger purposes.
We are just getting started with a 16 valve conversion. Will let you guys know how it works out. It will use 968 electronics with custom plumbing/intercooling. The shortblock is from my current engine so it will be interesting to see how the same shortblock reacts to a 16 valve head.
#41
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Tom,
I have heard from John Milledge, that Mahle now makes a 3.o liter 16v pistons. I too am converting a 968 3.0 liter 16v VarioCam, into a Turbo, to put in my 944T. So you can use these pistons, or go the Bore & Sleeve route. I think I am going to go the B&S route.
I have a flywheel from an S2 that has the proper teeth on it for the sensor, but it is the wrong size for the 944T clutch setup. I am having some shops check to see if it can be machined out to a bigger mm to mate to the 944T setup. If any one knows please post. I am going to have Tim, from SFR, marry a 944T & 968 intake manifold together and use the 968 Throttle body. This will give me a stock look , and help keep the initial costs down; I can always put another intake on it when I recover from the costs.
If we send Tim 2 intakes, maybe he can cut us a good price. He is also going to modify the 968 exhaust to fit up to my stock 944T crossover. Again to keep costs down, for replacement later.
M
I have heard from John Milledge, that Mahle now makes a 3.o liter 16v pistons. I too am converting a 968 3.0 liter 16v VarioCam, into a Turbo, to put in my 944T. So you can use these pistons, or go the Bore & Sleeve route. I think I am going to go the B&S route.
I have a flywheel from an S2 that has the proper teeth on it for the sensor, but it is the wrong size for the 944T clutch setup. I am having some shops check to see if it can be machined out to a bigger mm to mate to the 944T setup. If any one knows please post. I am going to have Tim, from SFR, marry a 944T & 968 intake manifold together and use the 968 Throttle body. This will give me a stock look , and help keep the initial costs down; I can always put another intake on it when I recover from the costs.
If we send Tim 2 intakes, maybe he can cut us a good price. He is also going to modify the 968 exhaust to fit up to my stock 944T crossover. Again to keep costs down, for replacement later.
M
#42
Rennlist Member
Raj,
6 years ago? Jeez, time flies. We must be old guys now. Sounds like you finally sorted out that pesky ARM1.
BTW, Scott Gomes took the time to send me a helpful e-mail about my planned project. Anyone ever work with him?
6 years ago? Jeez, time flies. We must be old guys now. Sounds like you finally sorted out that pesky ARM1.
BTW, Scott Gomes took the time to send me a helpful e-mail about my planned project. Anyone ever work with him?
#43
Rennlist Member
Tom, I never worked with him anything but we have spent a few evenings up in boston talking about cars and stuff. We even went to a go kart track and I had him!
He was very nice and curteous the entire time and was accompanied by his GF.
Yeah, so much for that arm1. Surprised how everyone remembers me from that episode, lol. Nice to hear from you again .
I wonder what Scott's take is on the project. He would be one to have 1st hand experience with all this. I will have it in another 3 months .
He was very nice and curteous the entire time and was accompanied by his GF.
Yeah, so much for that arm1. Surprised how everyone remembers me from that episode, lol. Nice to hear from you again .
I wonder what Scott's take is on the project. He would be one to have 1st hand experience with all this. I will have it in another 3 months .
#44
Three Wheelin'
I'm also going with the Mahle 3.0 pistons.
I'm also going with a 2.5 8v head. Raj had one for me, but I got a new one from Germany instead...so call me a scardy cat! I must say that Raj has been very helpful steering me in the right direction during this process.
Raj, I hope you understand, but, I got it at a great price, so I couldn't refuse!
So, I've got my 968 head, with the variocam, available which I'm going to put on the boards pretty soon. If anybody is interested, let me know.
I'll also have the complete exhaust system, too!
Raj, are you still interested?
Jason
I'm also going with a 2.5 8v head. Raj had one for me, but I got a new one from Germany instead...so call me a scardy cat! I must say that Raj has been very helpful steering me in the right direction during this process.
Raj, I hope you understand, but, I got it at a great price, so I couldn't refuse!
So, I've got my 968 head, with the variocam, available which I'm going to put on the boards pretty soon. If anybody is interested, let me know.
I'll also have the complete exhaust system, too!
Raj, are you still interested?
Jason