New 944S2 cab Turbo finished
12-19-2007, 06:05 PM
#46
Racer
Thread Starter
your welcome Richard, when I first went down this path there was very little info available for high compression mid boost, so hopefully this will be an encouragment for others if they wish to go this option.
I know that its very likely not the 'right' way to do it, but from my perspective its been really effective and as a street car its a lot of fun. If I wanted to track it, I would have gone a different path.
Currently I'm deciding between adding the 3mm cometic HG and 951 rods (they are quite cheap and available) and running 14+psi or upgrading to a late model 968 and starting all over and applying what I have learnt from my car to the new one.
I see you have a 968...........
I know that its very likely not the 'right' way to do it, but from my perspective its been really effective and as a street car its a lot of fun. If I wanted to track it, I would have gone a different path.
Currently I'm deciding between adding the 3mm cometic HG and 951 rods (they are quite cheap and available) and running 14+psi or upgrading to a late model 968 and starting all over and applying what I have learnt from my car to the new one.
I see you have a 968...........
12-23-2007, 04:49 AM
#47
Racer
Thread Starter
Oh dear we have a problem Houston, I blew a head gasket this morning on a very sedate drive, only went on strong boost for a few seconds but when it came back to idle felt like it was on three cylinders....yep confirmed after the plugs came out and a quick compression test as well, plus looking down into the pistons I could see number 1 was wet with coolant and the overflow was bubbling with glee!
Some background on this, about 4 months back prior to going on boost I stuffed up badly, drained the coolant and refilled as part of general maintenance but didnt bleed the system, I ended up with a massively over tremperature head, no actual reading but I know the head was baking...I thought I had got away with it, but maybe this was the initial cause of this recent HG blown.
One other point was I had been hearing strange fuel pump groans....and didnt do anything about it other than go and check on prices for a 044 replacement, another mistake, interesting thing this morning I had the red low fuel light on, so when I pushed it maybe the groaning fuel pump couldnt cope and ran lean....dont know but before she goes back on the road a new pump will be in there regardless.
The strangest thing though I only made a decision on Friday to pull the engine down and put in new forged rods, rod bearings, rings, valve grind and the cometic 3.2mm headgasket, then Sunday this happens...is that fate or what.
So the good news will be more boost, I am going to up the boost to 15psi or more once its back on the road with the forged rods and lower CR, hopefully that will give me some serious mumbo, should push well over 450crank hp then, theres alway a silver lining in every cloud if you look for it....
rgds
mike
Some background on this, about 4 months back prior to going on boost I stuffed up badly, drained the coolant and refilled as part of general maintenance but didnt bleed the system, I ended up with a massively over tremperature head, no actual reading but I know the head was baking...I thought I had got away with it, but maybe this was the initial cause of this recent HG blown.
One other point was I had been hearing strange fuel pump groans....and didnt do anything about it other than go and check on prices for a 044 replacement, another mistake, interesting thing this morning I had the red low fuel light on, so when I pushed it maybe the groaning fuel pump couldnt cope and ran lean....dont know but before she goes back on the road a new pump will be in there regardless.
The strangest thing though I only made a decision on Friday to pull the engine down and put in new forged rods, rod bearings, rings, valve grind and the cometic 3.2mm headgasket, then Sunday this happens...is that fate or what.
So the good news will be more boost, I am going to up the boost to 15psi or more once its back on the road with the forged rods and lower CR, hopefully that will give me some serious mumbo, should push well over 450crank hp then, theres alway a silver lining in every cloud if you look for it....
rgds
mike
12-23-2007, 05:58 PM
#48
Drifting
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Wow, I can't believe I just found this thread. Awesome project, and I'm sorry about the headgasket getting KIA. Hopefully its just the headgasket and you don't have any holes in your cylinders from the lean incident.
The neat thing about the stock sensors on the S2 is that they will allow you to run full sequential injection, and distributorless ignition if you want to go that route (if your EMS will allow it).
With going to 15psi, will your intercooler be able to keep up? Keep in mind you are flowing 20% more air than a 951.
How do you like your EMS? Have you worked with any other ones before, or is this your first venture?
I hope you mean you enrich the fuel mixture to aid in cooling. 
The neat thing about the stock sensors on the S2 is that they will allow you to run full sequential injection, and distributorless ignition if you want to go that route (if your EMS will allow it).
With going to 15psi, will your intercooler be able to keep up? Keep in mind you are flowing 20% more air than a 951.
How do you like your EMS? Have you worked with any other ones before, or is this your first venture?
BTW this is where having a standalone is so good, I have set up both mixture and ignition compensation so that as intake temp rises I lean off mixture a few percent and more importantly back off the ignition timing too, same deal with engine temps, so the EMS looks after the rising temps. Downside is you really feel the drop in power as the temps rise. But better than a popped engine.
12-23-2007, 06:33 PM
#49
Racer
Thread Starter
Hi bleucamaro, no holes I did a compression test and I have around 190psi all within 5%, however will find out more in the next few days when it comes apart.
Yep I could run sequential as it has flywheel and cam sensors, my EMS is basic as it was my first experience, next version will go for a lot more control - however this is a great first time EMS so easy to use and control.
On fuel, I did mean reduce as the air increases in temp it goes naturally rich, I just bring it back in to the right AFR run from 15 in cruise down to high 11's on boost, the biggest control as it gets hot is reducing ignition by a few degrees, most my experience is on racing 2 strokes...so I am open to learn always.
You might be right on the intercooler, will monitor that and that could be another upgrade for the future.
rgds
mike
Yep I could run sequential as it has flywheel and cam sensors, my EMS is basic as it was my first experience, next version will go for a lot more control - however this is a great first time EMS so easy to use and control.
On fuel, I did mean reduce as the air increases in temp it goes naturally rich, I just bring it back in to the right AFR run from 15 in cruise down to high 11's on boost, the biggest control as it gets hot is reducing ignition by a few degrees, most my experience is on racing 2 strokes...so I am open to learn always.
You might be right on the intercooler, will monitor that and that could be another upgrade for the future.
rgds
mike
01-02-2008, 01:12 AM
#50
Racer
Thread Starter
Jus a quick update, I have been posting some info on the 944 turbo forum and getting a lot of help from the great guys there too.
I pulled the engine down over the last two days or so, the results are quite sad really, I have piston skirt contact on the bores and from what the consensus of the experts its caused by tight tolerances from factory that Porsche run and the increased heat loading from boost causing expansion and then nipping up.
However now I am over the first sleepless night thinking of what this is going to cost me, I'm excited again, cos I will be onto a new project - my 500hp S2cab.
My baby will certainly be getting much more boost this time around, figure at least 18psi and 500hp no problem.
Next steps, honing the bores, replacing the pistons with low compression forged versions, the forged 951 rods, new clutch & pressure plate, increased capacity radiator and all the replaceable bits during the rebuild.
Luckily my 60-1 turbo can just take this on its limit, have just ordered a new #10 hotside so along with the existing stage 5 turbine wheel that will be ok for 500+, injectors will need upgrading they are 55lb at the moment but on 3.8bar pressure but I think will be pushing the duty cycle limit to run 500hp. The exhaust upgrade I have started will certainly happen and be needed for this hp level, I'm sure there are some other things I'll find on the way too.
So when I started the project I did say I may break something as I tried high compression mid boost and that certainly happened, but it was fun doing it.
Couple of observations, remember this is an S2 3.0 conversion, I have a feeling that if done with a 968 engine this problem would not have surfaced as they run forged pistons and greater clearances as stock, 9M's success is an example of this.
I think sticking to a lower boost maybe 7psi would be sensible and reliable as long as the tuning is spot on, even at this level the transformation is massive and worthwhile doing. If you did go higher boost then the Cometic 3.2mm headgasket would be a must, if maybe I had done this HG change before pushing the boost up I would still be ok now, my assumption...
Many thanks to all of you who encouraged me along the way, I have learnt a lot and made some mistakes doing this but hopefully this will help others make it better if taking this route.
Happy New year to you all
regards
mike
I pulled the engine down over the last two days or so, the results are quite sad really, I have piston skirt contact on the bores and from what the consensus of the experts its caused by tight tolerances from factory that Porsche run and the increased heat loading from boost causing expansion and then nipping up.
However now I am over the first sleepless night thinking of what this is going to cost me, I'm excited again, cos I will be onto a new project - my 500hp S2cab.
My baby will certainly be getting much more boost this time around, figure at least 18psi and 500hp no problem.
Next steps, honing the bores, replacing the pistons with low compression forged versions, the forged 951 rods, new clutch & pressure plate, increased capacity radiator and all the replaceable bits during the rebuild.
Luckily my 60-1 turbo can just take this on its limit, have just ordered a new #10 hotside so along with the existing stage 5 turbine wheel that will be ok for 500+, injectors will need upgrading they are 55lb at the moment but on 3.8bar pressure but I think will be pushing the duty cycle limit to run 500hp. The exhaust upgrade I have started will certainly happen and be needed for this hp level, I'm sure there are some other things I'll find on the way too.
So when I started the project I did say I may break something as I tried high compression mid boost and that certainly happened, but it was fun doing it.
Couple of observations, remember this is an S2 3.0 conversion, I have a feeling that if done with a 968 engine this problem would not have surfaced as they run forged pistons and greater clearances as stock, 9M's success is an example of this.
I think sticking to a lower boost maybe 7psi would be sensible and reliable as long as the tuning is spot on, even at this level the transformation is massive and worthwhile doing. If you did go higher boost then the Cometic 3.2mm headgasket would be a must, if maybe I had done this HG change before pushing the boost up I would still be ok now, my assumption...
Many thanks to all of you who encouraged me along the way, I have learnt a lot and made some mistakes doing this but hopefully this will help others make it better if taking this route.
Happy New year to you all
regards
mike
05-13-2008, 05:49 AM
#52
Racer
Thread Starter
Hi Arash, lots and lots been happening, but been so busy at work its slow progress.
Pulled the engine down, its in the machine shop still waiting for the pistons to do final hone on Alusil, the bore is 104.5mm, block decked. At the same time I have had the crank machined first oversize, 16v head rebuilt, mild porting and matched to manifolds, new valve guides, new higher rated valve springs. New Wossner rods, new Wossner 8.5:1 pistons, coated with PC-9 on the skirts and Gold coat thermal tops, Just waiting for the pistons to come back from the U.S from Swaines then the machining will be finished - a few weeks I guess. Planning to fit 968 piston squirters too. All new bearings thru the engine, seals, belts, water pump, all new hoses, cam chain, tensioner etc etc.
Rebuilt brakes, new Master Cyl, bias valve, pads etc.
Suspension done, new Konis yellows all round, new lowered sports progressive springs upfront, new 968 MO30 sway bars and bushes.
Ported the existing TO4B 60-1 hifi, stripped & checked internals all like new still, but put new journal bearings in anyway.
Rebuilding the inter-cooler inlet/outlet to go 2.75" OD, matching inter-cooler pipes, part way thru building a new design inlet manifold, this one is build from scratch, new BBK 70mm throttle body, new modern ISV setup inside T/body. New 75lb injectors on 3.8bar, new high flow fuel pump.
Thats about where its at the moment, I feel confident to get my 500 crank HP, the engine will deliver more if I go larger on the turbo, but I think 500hp will be enough. Mind you I have already mapped my standalone fuel/ign to take up to 26psi boost, but will need a new GT35R for that next step - all in time
I will post a complete story in a month or so with full pictures.
thanks for the interest & support.
regards
mike
Pulled the engine down, its in the machine shop still waiting for the pistons to do final hone on Alusil, the bore is 104.5mm, block decked. At the same time I have had the crank machined first oversize, 16v head rebuilt, mild porting and matched to manifolds, new valve guides, new higher rated valve springs. New Wossner rods, new Wossner 8.5:1 pistons, coated with PC-9 on the skirts and Gold coat thermal tops, Just waiting for the pistons to come back from the U.S from Swaines then the machining will be finished - a few weeks I guess. Planning to fit 968 piston squirters too. All new bearings thru the engine, seals, belts, water pump, all new hoses, cam chain, tensioner etc etc.
Rebuilt brakes, new Master Cyl, bias valve, pads etc.
Suspension done, new Konis yellows all round, new lowered sports progressive springs upfront, new 968 MO30 sway bars and bushes.
Ported the existing TO4B 60-1 hifi, stripped & checked internals all like new still, but put new journal bearings in anyway.
Rebuilding the inter-cooler inlet/outlet to go 2.75" OD, matching inter-cooler pipes, part way thru building a new design inlet manifold, this one is build from scratch, new BBK 70mm throttle body, new modern ISV setup inside T/body. New 75lb injectors on 3.8bar, new high flow fuel pump.
Thats about where its at the moment, I feel confident to get my 500 crank HP, the engine will deliver more if I go larger on the turbo, but I think 500hp will be enough. Mind you I have already mapped my standalone fuel/ign to take up to 26psi boost, but will need a new GT35R for that next step - all in time
I will post a complete story in a month or so with full pictures.
thanks for the interest & support.
regards
mike
05-14-2008, 01:07 AM
#53
RL Community Team
Rennlist Member
Rennlist Member
Hi Mike,
I'm glad to hear it's coming along. And coming along well! It sounds like you've given it the whirlwind upgrading! Man, that could be a record on the meanest 16v turbo cab ever. I've recently been seriously reconsidering my choice to go 8v. I'm thinking I want to try it like you did. Especially now that I've learned how to weld, those 2 manifolds don't scare me at all.
I know how life can be sudden and intense, I hope it all goes well. Cheers and be sure to keep us posted
!
I'm glad to hear it's coming along. And coming along well! It sounds like you've given it the whirlwind upgrading! Man, that could be a record on the meanest 16v turbo cab ever. I've recently been seriously reconsidering my choice to go 8v. I'm thinking I want to try it like you did. Especially now that I've learned how to weld, those 2 manifolds don't scare me at all.
I know how life can be sudden and intense, I hope it all goes well. Cheers and be sure to keep us posted
!
05-27-2008, 06:30 AM
#55
Burning Brakes
Wow, I've been looking for this sort thread for years.
I knew it could be done and I was on the verge of doing it when I decided I need a car with ABS to do this on and now I fell in cosmetic upgrades so deep that it will be sometime before I can look at this again. https://rennlist.com/forums/924-931-944-951-968-forum/427241-upgrading-my-my-my-baby.html
Thanks soooo much for sharing.
I knew it could be done and I was on the verge of doing it when I decided I need a car with ABS to do this on and now I fell in cosmetic upgrades so deep that it will be sometime before I can look at this again. https://rennlist.com/forums/924-931-944-951-968-forum/427241-upgrading-my-my-my-baby.html
Thanks soooo much for sharing.
06-15-2008, 05:57 PM
#57
Drifting
Join Date: Apr 2005
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Holy Moly, I haven't checked this in a while, looks like you'll have a beast on your hands. Can't wait to see it together.
If it were my build, I'd still be nervous about the intercooler. Just make sure your intake air temp (IAT) sensor is up to par and located near the head.
Best of luck on this!
If it were my build, I'd still be nervous about the intercooler. Just make sure your intake air temp (IAT) sensor is up to par and located near the head.
Best of luck on this!
10-15-2014, 04:30 PM
#58
very interesting, thank you for sharing.
08-24-2017, 08:57 AM
#59
Drifting
Mike - this is awesome and kudos to you for trying! Based on your experience, would a low boost (3-4 psi) turbo work well for an otherwise stock 968 motor on the track? I don't want high power, just a little bit more than stock.
