FACTORY 3.8 liter 993 ENGINE OPTION X51 DETAILED SPECS
12-23-2015, 11:33 PM
#108
Rennlist Member
Here is my '95 993 M64/70 Cup engine about to go in my '95 Cup clone , when I bought it no front pulley was included , a standard '95 front pulley with A/C fit right on ! I dont recall it being conical at all..<br/>Thanks Bert
12-24-2015, 09:22 AM
#109
point 1 AC console
point 2 MAF & airbox
point 3 IVC
12-24-2015, 12:47 PM
#110
Rennlist Member
Good points all Bill but that is my stock intake as well ,don't have a photo of the type number at this moment and traveling on holiday in LA but the case ,heads ,pistons , crank and all internals are factory .
12-25-2015, 02:06 AM
#112
Rennlist Member
Haha not the first to think so , no mine was built by my buds at
Kundensport in California.
This was converted from my first '96 TT at 17K miles with Motorsport
Centerlock hubs , RSR Bilstein suspension , real Magnesium Centerlock
Speedlines and a host of other stuff ..
Still my favorite ride but it's a compliment to be put on Jochens level
thanks Bert
Kundensport in California.
This was converted from my first '96 TT at 17K miles with Motorsport
Centerlock hubs , RSR Bilstein suspension , real Magnesium Centerlock
Speedlines and a host of other stuff ..
Still my favorite ride but it's a compliment to be put on Jochens level
thanks Bert
12-25-2015, 02:36 AM
#113
Haha not the first to think so , no mine was built by my buds at
Kundensport in California.
This was converted from my first '96 TT at 17K miles with Motorsport
Centerlock hubs , RSR Bilstein suspension , real Magnesium Centerlock
Speedlines and a host of other stuff ..
Still my favorite ride but it's a compliment to be put on Jochens level
thanks Bert
Kundensport in California.
This was converted from my first '96 TT at 17K miles with Motorsport
Centerlock hubs , RSR Bilstein suspension , real Magnesium Centerlock
Speedlines and a host of other stuff ..
Still my favorite ride but it's a compliment to be put on Jochens level
thanks Bert
Last edited by schmidtwerk; 12-25-2015 at 02:36 AM. Reason: Mis spell
12-28-2015, 12:44 PM
#115
Bill,
Had Gamroth stick a bore scope up the drain plug. Indeed regular 993 rods so its a standard 993 crank but with a tapered snout. Oddly he is perplexed by it, he has 2 genuine Cup motors there, neither with the tapered snout crank. He agreed the part number for the crank ending in "70" is cup but neither one had it. There was certainly something the factory didn't like about the standard non balancer pulley in the 3.8 with a triple belt.
Had Gamroth stick a bore scope up the drain plug. Indeed regular 993 rods so its a standard 993 crank but with a tapered snout. Oddly he is perplexed by it, he has 2 genuine Cup motors there, neither with the tapered snout crank. He agreed the part number for the crank ending in "70" is cup but neither one had it. There was certainly something the factory didn't like about the standard non balancer pulley in the 3.8 with a triple belt.
Last edited by schmidtwerk; 12-28-2015 at 12:47 PM. Reason: mis spell
12-28-2015, 04:16 PM
#116
Bill,
Had Gamroth stick a bore scope up the drain plug. Indeed regular 993 rods so its a standard 993 crank but with a tapered snout. Oddly he is perplexed by it, he has 2 genuine Cup motors there, neither with the tapered snout crank. He agreed the part number for the crank ending in "70" is cup but neither one had it. There was certainly something the factory didn't like about the standard non balancer pulley in the 3.8 with a triple belt.
Had Gamroth stick a bore scope up the drain plug. Indeed regular 993 rods so its a standard 993 crank but with a tapered snout. Oddly he is perplexed by it, he has 2 genuine Cup motors there, neither with the tapered snout crank. He agreed the part number for the crank ending in "70" is cup but neither one had it. There was certainly something the factory didn't like about the standard non balancer pulley in the 3.8 with a triple belt.
But there have been one or 2 w/o. Similarly I have seen one 964 Cup that should have the 3 pulley but instead has the RS single pulley, I spoke w/ the owner and his mechanic both swore that it was a stock 964Cup except for the pulley, he has since changed it back to the pure stock form for PCA racing in GTC1
01-02-2016, 01:43 PM
#117
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Thought you guys might find these dyno graphs interesting.
In the shop at the moment is a 993 Carrera 4S with Porsche upgraded X51 engine which we have just prepared for the new owner. Described by the vendor as:
"1996 993 Carrera 4S with the rare X51 3.8-litre Performance Kit Exclusive engine upgrade - in other words, it has a 993 RS engine. Capacity went from 3600cc to 3746cc thanks to an increase in bore from 100mm to 102mm and RS cylinder heads to match. Combined with reprofiled camshafts, a revised DMS control and a rigid alternator drive, this raised the power of the Varioram engine from 285bhp at 6100rpm 300bhp at 6600rpm. Torque went up from 340Nm at 5250rpm to 355Nm at 5400rpm. It was an expensive upgrade and, as such, only a handful of 993s in the UK were so-equipped, which makes this a very rare Porsche."
Fair enough? No....
As ever at Ninemeister, it's always better not just to take someone else's word for it when it comes to engine performance, so with the new owner's permission we disconnected the 4wd and ran the engine up on the dyno. The initial results were very disappointing but that was quickly traced to a bad batch of fuel, so once refilled we ran it up again and found potential issues with the operation of the variorum and resonance flap. Suffice to say we thought we could do better with a remap, so here is the before/after result with remap showing the difference when the intake system is working correctly. Final result was 320hp and 282lbft (382Nm), which is about as good as it gets for a remapped factory RS engine.
In the shop at the moment is a 993 Carrera 4S with Porsche upgraded X51 engine which we have just prepared for the new owner. Described by the vendor as:
"1996 993 Carrera 4S with the rare X51 3.8-litre Performance Kit Exclusive engine upgrade - in other words, it has a 993 RS engine. Capacity went from 3600cc to 3746cc thanks to an increase in bore from 100mm to 102mm and RS cylinder heads to match. Combined with reprofiled camshafts, a revised DMS control and a rigid alternator drive, this raised the power of the Varioram engine from 285bhp at 6100rpm 300bhp at 6600rpm. Torque went up from 340Nm at 5250rpm to 355Nm at 5400rpm. It was an expensive upgrade and, as such, only a handful of 993s in the UK were so-equipped, which makes this a very rare Porsche."
Fair enough? No....
As ever at Ninemeister, it's always better not just to take someone else's word for it when it comes to engine performance, so with the new owner's permission we disconnected the 4wd and ran the engine up on the dyno. The initial results were very disappointing but that was quickly traced to a bad batch of fuel, so once refilled we ran it up again and found potential issues with the operation of the variorum and resonance flap. Suffice to say we thought we could do better with a remap, so here is the before/after result with remap showing the difference when the intake system is working correctly. Final result was 320hp and 282lbft (382Nm), which is about as good as it gets for a remapped factory RS engine.
01-02-2016, 02:10 PM
#118
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Where it gets more interesting (in my opinion) is when you compare the result to the equivalent 9m 993Vr +3, a similar 3.75 litre engine with 9m billet heads, 9m Sport cams, 9m modified stock Vr intake with 100 cell cats and remap. In this application the high velocity ports of the 9m head significantly out-perform the large port, high flow, low velocity 993RS head, increasing the VE (volumetric efficiency) right across the rpm range which increases the peak torque from 282lbft (382Nm) to 326lbft (442Nm) at peak. That's a huge difference.
I can (barely) understand why the RS head was made for homologation reasons, the engineers probably thinking they would need huge 46mm intake ports (stock 993 are 43mm) to achieve their performance objective for the RSR, but when you relate this dyno comparison to the X51 engine, it still puzzles me why Porsche specified the RS head for the kit. I've always been convinced that the stock Vr heads on a 3.75 engine with RS cams would achieve the same power but with more mid range torque, the good news is that sometime towards the end of January we will be testing that exact combination. Naturally the resulting dyno graph will be interesting in more ways than one and might save someone a fortune if they are contemplating the X51 conversion for their 993 and also question the logic of new cylinder heads.
The new 9m built engine is built and ready to be installed in a 993C2 that has undergone a full body restoration and which is currently sat in the build shop waiting on new suspension and the engine. More on this as soon as the 993 is finished.
I can (barely) understand why the RS head was made for homologation reasons, the engineers probably thinking they would need huge 46mm intake ports (stock 993 are 43mm) to achieve their performance objective for the RSR, but when you relate this dyno comparison to the X51 engine, it still puzzles me why Porsche specified the RS head for the kit. I've always been convinced that the stock Vr heads on a 3.75 engine with RS cams would achieve the same power but with more mid range torque, the good news is that sometime towards the end of January we will be testing that exact combination. Naturally the resulting dyno graph will be interesting in more ways than one and might save someone a fortune if they are contemplating the X51 conversion for their 993 and also question the logic of new cylinder heads.
The new 9m built engine is built and ready to be installed in a 993C2 that has undergone a full body restoration and which is currently sat in the build shop waiting on new suspension and the engine. More on this as soon as the 993 is finished.
