Porken style S3 mods for the Euro S2
03-17-2012, 01:27 AM
#1
Nordschleife Master
Thread Starter
Porken style S3 mods for the Euro S2
Why do a 16v S2 instead of a 32v S3?
Ultimately I think its because the modded motors are going to have distinct characters, similar in absolute performance level, but with the S3 having a flatter torque curve, and the S2 more of a top end monster. It will be a question of personal preference, some in each camp.
The S2 is potentially cheaper, half the cams, half the valves and related parts.
SOHC maybe easier to work on than DOHC, less complicated.
Preference for the spider to the organ pipe intake.
Ability to pass a smog visual as an early motor.
************************ Target system (my view so far)
US 85/86 brains with o2 circuits, custom chips.
US 85/86 IAC valve, and S4 fuel pressure regulator, maybe upgrade to modern rail style injectors in a more convenient fuel rate.
Stock Euro S intake, maybe with cleanup porting, and spacers to remove gap between legs and plenum.
Euro S heads, with cleanup porting, welded cams first shot at passing smog 242 duration .506 lift on intake.
US 85/86 short block, stock to start with, maybe later with one of Greg's new cranks and/or 104mm 968 pistons.
US 85/86 exhaust manifolds, one of Greg's tuned catted exhausts.
My goal is less absolute power or dyno numbers, more ripping fun to drive.
Ultimately I think its because the modded motors are going to have distinct characters, similar in absolute performance level, but with the S3 having a flatter torque curve, and the S2 more of a top end monster. It will be a question of personal preference, some in each camp.
The S2 is potentially cheaper, half the cams, half the valves and related parts.
SOHC maybe easier to work on than DOHC, less complicated.
Preference for the spider to the organ pipe intake.
Ability to pass a smog visual as an early motor.
************************ Target system (my view so far)
US 85/86 brains with o2 circuits, custom chips.
US 85/86 IAC valve, and S4 fuel pressure regulator, maybe upgrade to modern rail style injectors in a more convenient fuel rate.
Stock Euro S intake, maybe with cleanup porting, and spacers to remove gap between legs and plenum.
Euro S heads, with cleanup porting, welded cams first shot at passing smog 242 duration .506 lift on intake.
US 85/86 short block, stock to start with, maybe later with one of Greg's new cranks and/or 104mm 968 pistons.
US 85/86 exhaust manifolds, one of Greg's tuned catted exhausts.
My goal is less absolute power or dyno numbers, more ripping fun to drive.
03-17-2012, 01:34 AM
#2
Race Car
The S2 also sounds better...
:-)
You characterize it accurately- 16V seems to really depend on steep cam profiles, maybe to compensate for displacement...but it makes for a very strong bias toward the upper rpm range...great for the track...notsomuch for the more casual street driver.
One question will be..likely % gain, whether on dyno or 'rip' factor, for all the effort to assemble and harmonize the respective parts..
:-)
You characterize it accurately- 16V seems to really depend on steep cam profiles, maybe to compensate for displacement...but it makes for a very strong bias toward the upper rpm range...great for the track...notsomuch for the more casual street driver.
One question will be..likely % gain, whether on dyno or 'rip' factor, for all the effort to assemble and harmonize the respective parts..
03-17-2012, 01:46 AM
#3
Nordschleife Master
Thread Starter
I suspect the potential candidate car will have some issue with the existing engine, so what you are looking at are incremental increases in cost over a stock rebuild.
What I've heard about past attempts with a hotter than Euro S cam is that its hard to tune diddling with mixture on the MAF and adjustable FPR, but its a wild fast ride. Sharktuning should improve every aspect.
What I've heard about past attempts with a hotter than Euro S cam is that its hard to tune diddling with mixture on the MAF and adjustable FPR, but its a wild fast ride. Sharktuning should improve every aspect.
03-17-2012, 10:09 AM
#4
Rennlist Member
I have a question on 16v Euro mods. (I have a 1985 Euro). 928 Motorsports offers an offset key for the cam gear to achieve better lower end performance.
Has anyone tried this simple modification?....and is there any real difference? What is the compromise?
Has anyone tried this simple modification?....and is there any real difference? What is the compromise?
03-17-2012, 11:19 AM
#5
Race Car
Yes, I recall someone located some Mercedes cam keys that afford a little offset. They would basically retard the cams a couple degrees, shifting the power curve to the left. So you should see an earlier HP/Tq peak, but the top end will also fall off earlier. If the only change made is the cam timing.
Make sure that it is advertised to fit up to your model year, and isn't for 4.5L. Not much piston/valve clearance to play with in there!
Make sure that it is advertised to fit up to your model year, and isn't for 4.5L. Not much piston/valve clearance to play with in there!
03-17-2012, 11:39 AM
#6
Rennlist Member
Mike, time out for a reality check:
Euro S2 engines (M28.21) are 4.7L 10.4:1 compression and spec'ed at 300-310 bhp depending on year.
USA (M28.19) was also 4.7L, 9.3:1 compression, and 242 bhp.
Seems to me that Porsche already did what you are proposing.
And if you do the arithmetic, the Euro is right up there with the GT in terms of hp/liter.
Now what exactly is it, that you want to accomplish with the S2 Euro? Seems to me that you've already got a pretty nice motor....
Euro S2 engines (M28.21) are 4.7L 10.4:1 compression and spec'ed at 300-310 bhp depending on year.
USA (M28.19) was also 4.7L, 9.3:1 compression, and 242 bhp.
Seems to me that Porsche already did what you are proposing.
And if you do the arithmetic, the Euro is right up there with the GT in terms of hp/liter.
Now what exactly is it, that you want to accomplish with the S2 Euro? Seems to me that you've already got a pretty nice motor....
03-17-2012, 09:45 PM
#7
Mike, time out for a reality check:
Euro S2 engines (M28.21) are 4.7L 10.4:1 compression and spec'ed at 300-310 bhp depending on year.
USA (M28.19) was also 4.7L, 9.3:1 compression, and 242 bhp.
Seems to me that Porsche already did what you are proposing.
And if you do the arithmetic, the Euro is right up there with the GT in terms of hp/liter.
Now what exactly is it, that you want to accomplish with the S2 Euro? Seems to me that you've already got a pretty nice motor....
Euro S2 engines (M28.21) are 4.7L 10.4:1 compression and spec'ed at 300-310 bhp depending on year.
USA (M28.19) was also 4.7L, 9.3:1 compression, and 242 bhp.
Seems to me that Porsche already did what you are proposing.
And if you do the arithmetic, the Euro is right up there with the GT in terms of hp/liter.
Now what exactly is it, that you want to accomplish with the S2 Euro? Seems to me that you've already got a pretty nice motor....
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03-18-2012, 02:49 AM
#8
Nordschleife Master
Thread Starter
Mike, time out for a reality check:
Euro S2 engines (M28.21) are 4.7L 10.4:1 compression and spec'ed at 300-310 bhp depending on year.
USA (M28.19) was also 4.7L, 9.3:1 compression, and 242 bhp.
Seems to me that Porsche already did what you are proposing.
And if you do the arithmetic, the Euro is right up there with the GT in terms of hp/liter.
Now what exactly is it, that you want to accomplish with the S2 Euro? Seems to me that you've already got a pretty nice motor....
Euro S2 engines (M28.21) are 4.7L 10.4:1 compression and spec'ed at 300-310 bhp depending on year.
USA (M28.19) was also 4.7L, 9.3:1 compression, and 242 bhp.
Seems to me that Porsche already did what you are proposing.
And if you do the arithmetic, the Euro is right up there with the GT in terms of hp/liter.
Now what exactly is it, that you want to accomplish with the S2 Euro? Seems to me that you've already got a pretty nice motor....
Truth is I'm just looking at low hanging fruit, not seriously pushing the envelope or breaking any wallets. I see gains from lots to some in this order;
Exhaust, IMHO factory designed to limit power with inoffensive sound.
Cams, stock US is LAME, Euro S not lame, but not close to full potential.
Sharktuning and other chip mods.
Displacement, more cubes, more breathing room around intake valves.
Tweaking, thermal coating, cold intake air tricks, etc.
Without adding to stroke or bore (beyond a 5.0L instead of 4.7L) I think the stock Euro S maybe 250 rwhp can be bumped to maybe 330 rwhp. Going to a 104mm bore or longer stoke adding to that number proportionate to the added displacement.
My stock US 83 is a very fun car to drive, due mostly to the 5 spd, and hits a performance point that is "nice". With a "bit" of caution I can floor this car every day through first and second, almost all the time, and not expect to get a ticket, but still have fun.
My 85 Euro S motor is stock, US manifolds, shot in the dark Y pipe and high flow catted simple exhaust, maybe 260 rwhp on a guess. This car spins wheels and generally begs for felony arrest. If I had good sense I would drive these two and be happy.
I do not have good sense. 330 rwhp in a lightened accessories etc removed car will be a handful on the street, and that is the plan.
03-18-2012, 02:55 PM
#9
I live in reality, but I don't dream there.
Truth is I'm just looking at low hanging fruit, not seriously pushing the envelope or breaking any wallets. I see gains from lots to some in this order;
Exhaust, IMHO factory designed to limit power with inoffensive sound.
Cams, stock US is LAME, Euro S not lame, but not close to full potential.
Sharktuning and other chip mods.
Displacement, more cubes, more breathing room around intake valves.
Tweaking, thermal coating, cold intake air tricks, etc.
Without adding to stroke or bore (beyond a 5.0L instead of 4.7L) I think the stock Euro S maybe 250 rwhp can be bumped to maybe 330 rwhp. Going to a 104mm bore or longer stoke adding to that number proportionate to the added displacement.
My stock US 83 is a very fun car to drive, due mostly to the 5 spd, and hits a performance point that is "nice". With a "bit" of caution I can floor this car every day through first and second, almost all the time, and not expect to get a ticket, but still have fun.
My 85 Euro S motor is stock, US manifolds, shot in the dark Y pipe and high flow catted simple exhaust, maybe 260 rwhp on a guess. This car spins wheels and generally begs for felony arrest. If I had good sense I would drive these two and be happy.
I do not have good sense. 330 rwhp in a lightened accessories etc removed car will be a handful on the street, and that is the plan.
Truth is I'm just looking at low hanging fruit, not seriously pushing the envelope or breaking any wallets. I see gains from lots to some in this order;
Exhaust, IMHO factory designed to limit power with inoffensive sound.
Cams, stock US is LAME, Euro S not lame, but not close to full potential.
Sharktuning and other chip mods.
Displacement, more cubes, more breathing room around intake valves.
Tweaking, thermal coating, cold intake air tricks, etc.
Without adding to stroke or bore (beyond a 5.0L instead of 4.7L) I think the stock Euro S maybe 250 rwhp can be bumped to maybe 330 rwhp. Going to a 104mm bore or longer stoke adding to that number proportionate to the added displacement.
My stock US 83 is a very fun car to drive, due mostly to the 5 spd, and hits a performance point that is "nice". With a "bit" of caution I can floor this car every day through first and second, almost all the time, and not expect to get a ticket, but still have fun.
My 85 Euro S motor is stock, US manifolds, shot in the dark Y pipe and high flow catted simple exhaust, maybe 260 rwhp on a guess. This car spins wheels and generally begs for felony arrest. If I had good sense I would drive these two and be happy.
I do not have good sense. 330 rwhp in a lightened accessories etc removed car will be a handful on the street, and that is the plan.
+1! could not agree more.
03-18-2012, 04:46 PM
#10
Rennlist Member
Would love if some ECU mods could be done to the S2. I have an S2 and I have the SharkTuner2 as well, but it would be beyond me to make this work. :-)
03-18-2012, 07:33 PM
#11
Pro
Some of us can only do 'plug and play'
....but we really wanna play.
....but we really wanna play.
03-18-2012, 08:09 PM
#12
Nordschleife Master
Thread Starter
I wonder if it would be practical to use an S4 ignition brain in an S2 with the US 85/86 fuel injection brain?
More code space for fun, quality knock detection, but keep the reliable early injection brain.
More code space for fun, quality knock detection, but keep the reliable early injection brain.
