Supercharger for S2
02-08-2008, 07:50 AM
#47
Racer
You can run around 7- 8psi on the stock S2 engine without internal changes, this is on the edge so it can go wrong unless you are careful. This is the cheapest, but fragile if you dont get the tuning right
A Cometic headgasket 3.2mm drops compression to about 9.3:1, you can run about 9-10psi on that quite ok, keep you pistons and rods stock, this is better than above but you still need to get the tuning right.
Shorter rods, has been done, depending on rod length you can choose compression, still the issue with stock pistons & tuning though.
All the above will need larger injectors and some method to tune, chip tuning, piggy back or standalone.
Otherwise new forged pistons & forged rods either 951 RARST or aftermarket, this is the best option, now you can go for a lot more power, however you will need a lot more addons & very likely a full standalone EMS.
This is a great engine to turbo, very powerful when turboed but you will really need to know what your doing and have some decent money aside.
regards
mike
A Cometic headgasket 3.2mm drops compression to about 9.3:1, you can run about 9-10psi on that quite ok, keep you pistons and rods stock, this is better than above but you still need to get the tuning right.
Shorter rods, has been done, depending on rod length you can choose compression, still the issue with stock pistons & tuning though.
All the above will need larger injectors and some method to tune, chip tuning, piggy back or standalone.
Otherwise new forged pistons & forged rods either 951 RARST or aftermarket, this is the best option, now you can go for a lot more power, however you will need a lot more addons & very likely a full standalone EMS.
This is a great engine to turbo, very powerful when turboed but you will really need to know what your doing and have some decent money aside.
regards
mike
02-08-2008, 10:00 AM
#48
Advanced
Join Date: Feb 2008
Location: UK
Posts: 95
Likes: 0
Received 0 Likes
on
0 Posts
You can run around 7- 8psi on the stock S2 engine without internal changes, this is on the edge so it can go wrong unless you are careful. This is the cheapest, but fragile if you dont get the tuning right
A Cometic headgasket 3.2mm drops compression to about 9.3:1, you can run about 9-10psi on that quite ok, keep you pistons and rods stock, this is better than above but you still need to get the tuning right.
Shorter rods, has been done, depending on rod length you can choose compression, still the issue with stock pistons & tuning though.
All the above will need larger injectors and some method to tune, chip tuning, piggy back or standalone.
Otherwise new forged pistons & forged rods either 951 RARST or aftermarket, this is the best option, now you can go for a lot more power, however you will need a lot more addons & very likely a full standalone EMS.
This is a great engine to turbo, very powerful when turboed but you will really need to know what your doing and have some decent money aside.
regards
mike
A Cometic headgasket 3.2mm drops compression to about 9.3:1, you can run about 9-10psi on that quite ok, keep you pistons and rods stock, this is better than above but you still need to get the tuning right.
Shorter rods, has been done, depending on rod length you can choose compression, still the issue with stock pistons & tuning though.
All the above will need larger injectors and some method to tune, chip tuning, piggy back or standalone.
Otherwise new forged pistons & forged rods either 951 RARST or aftermarket, this is the best option, now you can go for a lot more power, however you will need a lot more addons & very likely a full standalone EMS.
This is a great engine to turbo, very powerful when turboed but you will really need to know what your doing and have some decent money aside.
regards
mike
I've read your thread on turbo-ing the S2 cab and admire what you've done.
I am glad you looked at this thread
So according to you, if I use the Cometic HG I dont need to do anything with the pistons/rods... I will need larger injectors in any case, correct?
I can't remember what did you do tuninng wise on your engine, did you go standalone?
Do I get a Porsche specialist to do the tuning right?
I dont really want to go overboard with the power. As a matter of fact all I am after is just a bit more torque from the car, say between 250-300 lbft. I am used to the torquey engine of my TDI passat hence the desire
Rob
02-08-2008, 01:56 PM
#49
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
You can run around 7- 8psi on the stock S2 engine without internal changes, this is on the edge so it can go wrong unless you are careful. This is the cheapest, but fragile if you dont get the tuning right
A Cometic headgasket 3.2mm drops compression to about 9.3:1, you can run about 9-10psi on that quite ok, keep you pistons and rods stock, this is better than above but you still need to get the tuning right.
Shorter rods, has been done, depending on rod length you can choose compression, still the issue with stock pistons & tuning though.
All the above will need larger injectors and some method to tune, chip tuning, piggy back or standalone.
Otherwise new forged pistons & forged rods either 951 RARST or aftermarket, this is the best option, now you can go for a lot more power, however you will need a lot more addons & very likely a full standalone EMS.
This is a great engine to turbo, very powerful when turboed but you will really need to know what your doing and have some decent money aside.
regards
mike
A Cometic headgasket 3.2mm drops compression to about 9.3:1, you can run about 9-10psi on that quite ok, keep you pistons and rods stock, this is better than above but you still need to get the tuning right.
Shorter rods, has been done, depending on rod length you can choose compression, still the issue with stock pistons & tuning though.
All the above will need larger injectors and some method to tune, chip tuning, piggy back or standalone.
Otherwise new forged pistons & forged rods either 951 RARST or aftermarket, this is the best option, now you can go for a lot more power, however you will need a lot more addons & very likely a full standalone EMS.
This is a great engine to turbo, very powerful when turboed but you will really need to know what your doing and have some decent money aside.
regards
mike
02-08-2008, 02:20 PM
#50
Burning Brakes
Just at a glance I would say this is possible. If you remove the hood and attach the engine to a hoist and bring up the slack, then pull the lower crossmember and drop the oilpan, and you should be able to work on your back with the engine hanging over you, the crank and the rods and pistons should slip out! If you were going to do that I would replace the rod bearings while you were there.
You might be able to device your own engine hoist that would hold the engine in place without having to remove the hood. A good 4X4 could probably handle it. It would suck if it fell on your face though!
You might be able to device your own engine hoist that would hold the engine in place without having to remove the hood. A good 4X4 could probably handle it. It would suck if it fell on your face though!
02-08-2008, 02:25 PM
#51
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
Just at a glance I would say this is possible. If you remove the hood and attach the engine to a hoist and bring up the slack, then pull the lower crossmember and drop the oilpan, and you should be able to work on your back with the engine hanging over you, the crank and the rods and pistons should slip out! If you were going to do that I would replace the rod bearings while you were there.
You might be able to device your own engine hoist that would hold the engine in place without having to remove the hood. A good 4X4 could probably handle it. It would suck if it fell on your face though!
You might be able to device your own engine hoist that would hold the engine in place without having to remove the hood. A good 4X4 could probably handle it. It would suck if it fell on your face though!
02-08-2008, 02:43 PM
#52
Burning Brakes
Well that big lower crossmember (the big aluminum one) bolts to the engine, and also bolts to the frame. It interferes with getting the oil pan off so it has to be removed. Once you remove that crossmember there is nothing to support the engine.
Im not saying actually pull the engine from the car, but the hoist will need to be there in order to hold the engine in it's installed posistion. Nothing will need to be disconnected besides the lower crossmember and the oilpan. Again I am almost certain the pan cant be pulled with the crossmember in the way. Lindsey Racing sells a crossmember that is split into three pieces so that you dont have to fully remove the crossmember, and therefore you dont have to support the engine.
Im not saying actually pull the engine from the car, but the hoist will need to be there in order to hold the engine in it's installed posistion. Nothing will need to be disconnected besides the lower crossmember and the oilpan. Again I am almost certain the pan cant be pulled with the crossmember in the way. Lindsey Racing sells a crossmember that is split into three pieces so that you dont have to fully remove the crossmember, and therefore you dont have to support the engine.
02-08-2008, 02:46 PM
#53
Nordschleife Master
There is alot more in play then a simple reduction in compression when you start to build power around the 3.0L block. I have ran into this issue and I can assure you others have as well. The problem to some level can be delt with by the use of forged pistons due to there larger expansion rates but regardless the piston skirt length is just to short on the N/A pistons. There is also a issue that comes up with the block windows as you increase skirt length on the 3.0L block. Now, that being said there are advantages and disadvantages to useing a 3.0L block not all aspects are better for high power output but in terms of block rigidity its a much stronger block then the 2.5L. As some people on here have said with the SFR setup (ghetto) you are going to run into belt issues around 13-15 psi (from what I have read) now, it makes much more sense to switch to a cog belt setup as well as a larger blower. How can you do this with the limited space? Easy, you start relocation and removal of everything. So, without alot of work its just not a simple bolt something on and make power. Infact in many ways a 2.5l N/A is a much better motor for bolton power due to compression/piston design/headbolts/etc.. etc..
02-08-2008, 06:23 PM
#54
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
There is alot more in play then a simple reduction in compression when you start to build power around the 3.0L block. I have ran into this issue and I can assure you others have as well. The problem to some level can be delt with by the use of forged pistons due to there larger expansion rates but regardless the piston skirt length is just to short on the N/A pistons. There is also a issue that comes up with the block windows as you increase skirt length on the 3.0L block. Now, that being said there are advantages and disadvantages to useing a 3.0L block not all aspects are better for high power output but in terms of block rigidity its a much stronger block then the 2.5L. As some people on here have said with the SFR setup (ghetto) you are going to run into belt issues around 13-15 psi (from what I have read) now, it makes much more sense to switch to a cog belt setup as well as a larger blower. How can you do this with the limited space? Easy, you start relocation and removal of everything. So, without alot of work its just not a simple bolt something on and make power. Infact in many ways a 2.5l N/A is a much better motor for bolton power due to compression/piston design/headbolts/etc.. etc..
maybe thats why porsche used the 2.5l engine for its 968 turbo?
02-08-2008, 06:58 PM
#55
Advanced
Join Date: Feb 2008
Location: UK
Posts: 95
Likes: 0
Received 0 Likes
on
0 Posts
02-08-2008, 08:28 PM
#57
Racer
Rob, when I did my engine conversion I did it partly because I thought it could be done without major expenditure and I love to play with engines as a hobby. I then pushed the engine further out of curiosity what I could get it to produce, unfortunately it blew a headgasket, no big deal, but the engine had had a previous hard life and as someone else mentioned on this thread you have to have a sound engine before taking this on.
I used 55lb injectors and a standalone, lots of fabrication work too. I also tuned & installed the EMS myself. If you have to use someone to do this its going to cost.
On the 968 forum I read that one of the guys had used a stock chip to tune with similar boost I had, but this was a lot of money too, think it was Raj.
I nearly used a SMT6 piggy back, but as I was planning to push the power I thought it better having complete control over the engine, rather than just signal massaging.
I would without hesitation do this conversion again, if I wanted a reasonable gain round about 330hp crank, the car is amazing on 8psi and high compression - IMHO a perfect street car.
regards
mike
I used 55lb injectors and a standalone, lots of fabrication work too. I also tuned & installed the EMS myself. If you have to use someone to do this its going to cost.
On the 968 forum I read that one of the guys had used a stock chip to tune with similar boost I had, but this was a lot of money too, think it was Raj.
I nearly used a SMT6 piggy back, but as I was planning to push the power I thought it better having complete control over the engine, rather than just signal massaging.
I would without hesitation do this conversion again, if I wanted a reasonable gain round about 330hp crank, the car is amazing on 8psi and high compression - IMHO a perfect street car.
regards
mike
02-08-2008, 08:30 PM
#58
Nordschleife Master
02-08-2008, 08:31 PM
#59
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
what was the cause of the blowout?
Rob, when I did my engine conversion I did it partly because I thought it could be done without major expenditure and I love to play with engines as a hobby. I then pushed the engine further out of curiosity what I could get it to produce, unfortunately it blew a headgasket, no big deal, but the engine had had a previous hard life and as someone else mentioned on this thread you have to have a sound engine before taking this on.
I used 55lb injectors and a standalone, lots of fabrication work too. I also tuned & installed the EMS myself. If you have to use someone to do this its going to cost.
On the 968 forum I read that one of the guys had used a stock chip to tune with similar boost I had, but this was a lot of money too, think it was Raj.
I nearly used a SMT6 piggy back, but as I was planning to push the power I thought it better having complete control over the engine, rather than just signal massaging.
I would without hesitation do this conversion again, if I wanted a reasonable gain round about 330hp crank, the car is amazing on 8psi and high compression - IMHO a perfect street car.
regards
mike
I used 55lb injectors and a standalone, lots of fabrication work too. I also tuned & installed the EMS myself. If you have to use someone to do this its going to cost.
On the 968 forum I read that one of the guys had used a stock chip to tune with similar boost I had, but this was a lot of money too, think it was Raj.
I nearly used a SMT6 piggy back, but as I was planning to push the power I thought it better having complete control over the engine, rather than just signal massaging.
I would without hesitation do this conversion again, if I wanted a reasonable gain round about 330hp crank, the car is amazing on 8psi and high compression - IMHO a perfect street car.
regards
mike
02-08-2008, 11:57 PM
#60
Racer
not totally sure but the headgasket did not burn through just a break between the waterjacket & cyl 1. The overal HG condition was quite poor. If the rest of the engine had been in good condition I would have put a 3.2mm Cometic in and run her up to 12-13psi. But when I saw the state of the internals I just went a different route.
rgds
mike
rgds
mike
