996 Turbo Uprated Sachs Clutches - Page 3 - Porsche General - PistonHeads UK

What uprated clutches are you guys using and how do you find them? Did you go with sprung centres with single mass flywheels or stay with a dual mass flywheel with a solid centre?

I think ZeroH will have an idea on this as he has tried various options as far as I am aware. What horse power/ torque are you wanting to pit through the clutch ?

Stock clucth, we will see how long it lasts

I've fitted the 740nm version and kept the dual mass flywheel, mine has a very similar feel to the stock clutch, but I believe others have experienced various results with regard to feel, not sure why this should be though when used in same application. Currently holding strong with plenty of hp/torque thrown at it. Edited by EvoSlayer on Thursday 17th February 17:49

Vixpy1 said: Stock clucth, we will see how long it lasts Mine lasted less than 500 miles after flashing it for K16/24s!

EvoSlayer said: Mine lasted less than 500 miles after flashing it for K16/24s! I'm on K24 hybrids so torque should be less

bob'5 said: What uprated clutches are you guys using and how do you find them? Did you go with sprung centres with single mass flywheels or stay with a dual mass flywheel with a solid centre? Really depends on what torque you are planning to put through the clutch TBH, if you can get away with the 740nm clutch, great, the feeling is very much the same. If you need to use the 890nm clutch, then it becomes tricky (I'm sure Mr.Freefall will be along in a minute!) to feel for the biting point, and it does strain the power assistance somewhat, causing the accumulator to fail in short order. The biting point is right at the top of the pedal travel too. A good upgrade would be to convert the clutch system to GT2 specs, as it doesn't have a power clutch, the feel is much better. forget the 1050nm clutch if you want to drive the car on the road again, without dumping the clutch when you want to set off.

Vixpy1 said: I'm on K24 hybrids so torque should be less Cool, more details please... which compressor wheel are you using and what pressure do you run them to? Oh yeah, and what results are you getting? Apologies for all the questions but I was quite happy and thought I'd finished with this mucking about thing but never underestimate the power of the dark side...

EvoSlayer said: Cool, more details please... which compressor wheel are you using and what pressure do you run them to? Oh yeah, and what results are you getting? Apologies for all the questions but I was quite happy and thought I'd finished with this mucking about thing but never underestimate the power of the dark side... The car is presently loaded onto my truck to take to fearnsport tommorow, the turbos are on the passenger seat.

Vixpy1 said: I'm on K24 hybrids so torque should be less How can torque be less when you are using a K24 turbine compared to a K16 ? Your torque will be more. Re clutches, as Mike says, I've had X50, GT2 (They are different), 890nm, and presently 740nm all in my car. Looking for a clutch that can replicate stock feel is not easy at all... the 890nm was horrible frankly - bizarrely, when I asked people about it before I got it, all I got was positive feedback - whats that about ??? Its not just the engagement or bite point but also the judder it generated whilst changing gear. Not sure its well matched to the dmf. The 740 is a bit better but not much... maybe I need to give it more time to bed in. Need to have a feel of your clutch Andy so we can compare notes !!

ZeroH said: . . . need to have a feel of your c*utch Andy . . . . this thread is in serious DANGER of deteriorating!

khushy said: this thread is in serious DANGER of deteriorating! Lol !!!

ZeroH said: Re clutches, as Mike says, I've had X50, GT2 (They are different), 890nm, and presently 740nm all in my car. Looking for a clutch that can replicate stock feel is not easy at all... the 890nm was horrible frankly - bizarrely, when I asked people about it before I got it, all I got was positive feedback - whats that about ??? Its not just the engagement or bite point but also the judder it generated whilst changing gear. Not sure its well matched to the dmf. The 740 is a bit better but not much... maybe I need to give it more time to bed in. We discussed this before, I have had 890NM on two cars, on the hydraulic 993tt with LWFW and on 997GT2 with DMFW and on both the clutch is perfect and on the 993 maybe not as "giving" as stock certainly easy enough for a daily driver once used to it. On the 997GT2 the stock clutch will slip even with an untuned car so it is quite whimpy yet the 890NM one felt virtually the same, not heavier (even without hyadraulics) same take up point and as for "juddering" WTF is that all about ? If your 740NM one has similar shortcomings it sounds like something else is wrong with the set up, maybe mechanically minded on here could give some pointers, you need to get that sorted as a useable clutch can make or break a car's useability (as you know). Lastly, as we sure all clutches sold as "890NM" versions are exact same part numbers from same source ?

ZF official catalogue below, the 890NM is listed as 883082 with 999764 http://www.zf.com/media/media/document/corporate_2...

TB993tt said: We discussed this before, I have had 890NM on two cars, on the hydraulic 993tt with LWFW and on 997GT2 with DMFW and on both the clutch is perfect and on the 993 maybe not as "giving" as stock certainly easy enough for a daily driver once used to it. On the 997GT2 the stock clutch will slip even with an untuned car so it is quite whimpy yet the 890NM one felt virtually the same, not heavier (even without hyadraulics) same take up point and as for "juddering" WTF is that all about ? If your 740NM one has similar shortcomings it sounds like something else is wrong with the set up, maybe mechanically minded on here could give some pointers, you need to get that sorted as a useable clutch can make or break a car's useability (as you know). Lastly, as we sure all clutches sold as "890NM" versions are exact same part numbers from same source ? +1. Miras, following you that day through Lutterworth was very funny. Watch the people turn around when you were try to put away from junctions was funny You are welcome to test an 890nm on one of our cars so you can see for yourself. We also are doing the GT2 slave conversion. Ken

khushy said: ZeroH said: . . . need to have a feel of your c*utch Andy . . . . this thread is in serious DANGER of deteriorating! http://www.yaya21.co.uk/woman/products/product?Id=1273&ItemId=1388

Toby, Ken, I think I will definitely have to drive another car with the 890nm to get some reflection on this. Toby - the 890nm clutch and pressure plate were sooooo much heavier than the stock GT2 unit that came out of my car - i didn't weigh them but there was a material difference... i just don't think it mated to the dmf well at all in my car. I've been pondering the judder also... but my flywheel (checked twice) is fine, no accumlator or slave issues... nothing obvious comes to mind. I know Andy had some judder which a change of MAF cured, but for the life of me can't think why it would be linked. The fact that Toby is saying his 890nm is stock like has me wondering tho. Will test when we get together next.

And Toby, I agree - the wrong clutch can definitely make you fall out of love with the car !

ZeroH said: How can torque be less when you are using a K24 turbine compared to a K16 ? Your torque will be more. Re clutches, as Mike says, I've had X50, GT2 (They are different), 890nm, and presently 740nm all in my car. Looking for a clutch that can replicate stock feel is not easy at all... the 890nm was horrible frankly - bizarrely, when I asked people about it before I got it, all I got was positive feedback - whats that about ??? Its not just the engagement or bite point but also the judder it generated whilst changing gear. Not sure its well matched to the dmf. The 740 is a bit better but not much... maybe I need to give it more time to bed in. Need to have a feel of your clutch Andy so we can compare notes !! K24 hybrids which i expect to be laggier, more lag = less torque, unless you turn the boost up..

gtphile said: Really depends on what torque you are planning to put through the clutch TBH, if you can get away with the 740nm clutch, great, the feeling is very much the same. If you need to use the 890nm clutch, then it becomes tricky (I'm sure Mr.Freefall will be along in a minute!) to feel for the biting point, and it does strain the power assistance somewhat, causing the accumulator to fail in short order. The biting point is right at the top of the pedal travel too. A good upgrade would be to convert the clutch system to GT2 specs, as it doesn't have a power clutch, the feel is much better. forget the 1050nm clutch if you want to drive the car on the road again, without dumping the clutch when you want to set off. Sach 890Nm will kill the accumulator components of the std 996t clutch. I have had one go, and the second one fitted 500 miles ago is not too happy. The bite point is at the very top, and it’s an On-off feel, no room to feed the clutch in. Personally I don’t like the feel that much, but I can live with it. We're going to test a GT2 slave conversion on my car, I have bought all the bits, a custom made bracket from the USA to sit on the g/Box, and just having a hydraulic hose made to the correct length. I’m also going to fit the 964RS LWFW If you have a K16 flash, K16/16g, K16/K24, K24 turbo with flash, I would go for the 740NM like Miras and EvoSlayer. If you are have a K24 and are going to 1.2bar boost, or K24/18g then the 890 would be better, but the GT2 slave conversion looks the way to go. Once its done I will do a write up for everyone, but most of the cars in the US do this conversion, and they love it and it seems the way to go. If anyone would like to test to see what it is like once done, just shout... Gary

Vixpy1 said: K24 hybrids which i expect to be laggier, more lag = less torque, unless you turn the boost up.. more lag = Big hit of torque when the power comes in. Get your guy to smooth that our Charlie... Mr F

Mr Freefall said: more lag = Big hit of torque when the power comes in. Get your guy to smooth that our Charlie... Mr F Well up at Fearns earlier (Andy had his head up the back of Zero's car) and Matt winced when i mentioned i had a standard clutch.. Better start saving!

Vixpy1 said: K24 hybrids which i expect to be laggier, more lag = less torque, unless you turn the boost up.. I don't follow your lag argument at all.. the stock K24 is far torquier (457lbft) than the stock K16 (413lbft) but also laggier, so not sure of your meaning ??? The lag can be tuned out espec if running the right ancillaries to help the turbos spool. If you have a k16 car like yours, the only reason you would go to K24 hybrids if you have a K16 car already is to flow more at top end.... lag is a secondary consideration here. Just to be clear, you say 24 hybrids, I'm assuming you are referring to the 24 on the turbine side, otherwise you will have 16 hybrids -just to check we are not crossing wires.

Vixpy1 said: Well up at Fearns earlier (Andy had his head up the back of Zero's car) and Matt winced when i mentioned i had a standard clutch.. Better start saving! Yep, the GT2 Slave conversion complete from the US is arround $1100 plus shipping and import tax, then it's about 10-12 hours to fit when the engine is in. When I had my 890 installed I paid best part of £1700 for it fitted. Good luck. Gary

Mr Freefall said: Yep, the GT2 Slave conversion complete from the US is arround $1100 plus shipping and import tax, then it's about 10-12 hours to fit when the engine is in. When I had my 890 installed I paid best part of £1700 for it fitted. Good luck. Gary Are you sure?!... I thought the kit retailed around $800... you can actually just pick up the billet mount and buy the parts here yourself and save a small fortune, that's what I done a few years back!

996TT_STEVO said: Mr Freefall said: Yep, the GT2 Slave conversion complete from the US is arround $1100 plus shipping and import tax, then it's about 10-12 hours to fit when the engine is in. When I had my 890 installed I paid best part of £1700 for it fitted. Good luck. Gary Are you sure?!... I thought the kit retailed around $800... you can actually just pick up the billet mount and buy the parts here yourself and save a small fortune, that's what I done a few years back! Yeh but Steve, Gary did get it done at an expensive place

ZeroH said: I don't follow your lag argument at all.. the stock K24 is far torquier (457lbft) than the stock K16 (413lbft) but also laggier, so not sure of your meaning ??? The lag can be tuned out espec if running the right ancillaries to help the turbos spool. If you have a k16 car like yours, the only reason you would go to K24 hybrids if you have a K16 car already is to flow more at top end.... lag is a secondary consideration here. Just to be clear, you say 24 hybrids, I'm assuming you are referring to the 24 on the turbine side, otherwise you will have 16 hybrids -just to check we are not crossing wires. My turbos are K24's with bigger compressor wheels fitted. Lets take a random engine, say 3.0L, you have 2 turbos, one which makes full boost at 2500rpm, a bigger one which make full boost at say 3000rpm. Generally if you run the same boost on both turbos, the bigger one will make more power but will generally make less peak torque.

996ttalot said: Yeh but Steve, Gary did get it done at an expensive place BTW, Well done

ZeroH said: Need to have a feel of your clutch Andy so we can compare notes !! Ooh er Anytime mate, catchup soon To clarify, I did experience a certain amount of judder in reverse gear only, now whether this was anything to do with that particular ratio/engine speed, who knows, but a fauly MAF was diagnosed/replaced and no more judder. Was it linked, again, who knows.

996ttalot said: 996TT_STEVO said: Mr Freefall said: Yep, the GT2 Slave conversion complete from the US is arround $1100 plus shipping and import tax, then it's about 10-12 hours to fit when the engine is in. When I had my 890 installed I paid best part of £1700 for it fitted. Good luck. Gary Are you sure?!... I thought the kit retailed around $800... you can actually just pick up the billet mount and buy the parts here yourself and save a small fortune, that's what I done a few years back! Yeh but Steve, Gary did get it done at an expensive place Yeah, I think I was paying £100 per hour and being charged by the hour, and the bill was always nearly double what I was quoted for the Job when I went to pay, every time I went there !!!! Just for information:- Slave kit from the US (as a kit is) @ $990 Total customs value: £727.41 Import duty: £16.00 Import VAT: £148.68 Total import duty & VAT due: £164.69 Total landed cost: £892.10 Gary

Vixpy1 said: My turbos are K24's with bigger compressor wheels fitted. Lets take a random engine, say 3.0L, you have 2 turbos, one which makes full boost at 2500rpm, a bigger one which make full boost at say 3000rpm. Generally if you run the same boost on both turbos, the bigger one will make more power but will generally make less peak torque. Charlie, didnt realise you had gone up to K24's. are you using the 18g wheel or the k26 wheel? if you have, your std clutch will be fried in 500 miles! If you have a 5bar fpr being put in, do not map the boost over 1.2bar. With std injectors, there is not enough dutycyle left in the stock fuel system to handle more boost. 1.1 -1.2 is the max really, otherwise the AFR's will be high. The information is on this site for on how to check the AFR, dutycycle, and knock sensor. You should check all 3 when the map is done. Hey, it back to old school, 3rd gear run WOT, just like the TVR's Good luck with your project! Gary

Vixpy1 said: My turbos are K24's with bigger compressor wheels fitted. Lets take a random engine, say 3.0L, you have 2 turbos, one which makes full boost at 2500rpm, a bigger one which make full boost at say 3000rpm. Generally if you run the same boost on both turbos, the bigger one will make more power but will generally make less peak torque. Your example is too convenient - in the real world a bigger turbo will make more torque and more power - thats the whole point !! In any event, I'd be interested to hear what compressor wheel you have on your 24hybrid ? If its not a k26 or 18g what is it and what are its flow characteristics ? Do you know what hp they are supposed to be good for ?

I don't know, but the Sherlock Holmes in me think he has bought these. Spill Vixpy!!! Confession is good for the soul. http://www.pistonheads.com/sales/2416338.htm

_gez_ said: I don't know, but the Sherlock Holmes in me think he has bought these. Spill Vixpy!!! Confession is good for the soul. http://www.pistonheads.com/sales/2416338.htm Those be the turbos, they came from the states when they were new, we know they have a bigger compressor wheel, more than that not alot. Guess we will see when they are fitted to the car next week

Vixpy1 said: Those be the turbos, they came from the states when they were new, we know they have a bigger compressor wheel, more than that not alot. Guess we will see when they are fitted to the car next week Interesting - well, the work was all done with KKK parts so it should be spot on. Whatever they are, I'm sure Matt will get the best out of them.

ZeroH said: Interesting - well, the work was all done with KKK parts so it should be spot on. Whatever they are, I'm sure Matt will get the best out of them. Feel free to have a look at them when you pick up your car.

ZeroH said: Interesting - well, the work was all done with KKK parts so it should be spot on. Whatever they are, I'm sure Matt will get the best out of them. They are 5mm bigger so I would say they are the K26 wheel. A good map should see you OK here. But, you will be maxing out the dutycycle with a 5 bar fpr and Std injectors, so dont set the boost too high. 1.2 bar will see you with 625BHP roughly Gary

Mr Freefall said: They are 5mm bigger so I would say they are the K26 wheel. A good map should see you OK here. But, you will be maxing out the dutycycle with a 5 bar fpr and Std injectors, so dont set the boost too high. 1.2 bar will see you with 625BHP roughly Gary Oh I think that will do me

Found an interesting thread about decoding the KKK turbo codes. So you 2478 wheel has an exducer size of 24 x (2") = 61mm and the inducer is 78% of that size = 47.5mm http://www.924board.org/viewtopic.php?t=15595 What it all means.. Haven't got a clue but a reckon it will be faster than what you have now!!! And to take it back on-topic, you'll probably need a new uprated clutch soon!! Another interesting link (for me anyway!) http://www.turbomaster.info/eng/applications/compr... Edited by _gez_ on Sunday 20th February 20:51

Mr Freefall said: They are 5mm bigger so I would say they are the K26 wheel. A good map should see you OK here. But, you will be maxing out the dutycycle with a 5 bar fpr and Std injectors, so dont set the boost too high. 1.2 bar will see you with 625BHP roughly Gary Apparantly its not the K26... tho not sure how exactly to verify... will do some homework ! 625hp is what Ruf achieve with their nardo, which has the intake piping and various other bits that all add up so not sure Vixpy is gonna get that far with just these turbos (tho i am assuming they are sub k26), but in any event, I'm sure the performance times will tell a story.

_gez_ said: Found an interesting thread about decoding the KKK turbo codes. So you 2478 wheel has an exducer size of 24 x (2") = 61mm and the inducer is 78% of that size = 47.5mm http://www.924board.org/viewtopic.php?t=15595 What it all means.. Haven't got a clue but a reckon it will be faster than what you have now!!! And to take it back on-topic, you'll probably need a new uprated clutch soon!! Another interesting link (for me anyway!) http://www.turbomaster.info/eng/applications/compr... Edited by _gez_ on Sunday 20th February 20:51 From another forum Here are the spec of a k26/6 turbo i bought as a core for a hybrid i plan on doing. -Compressor housing: I.D. of inlet = 1 13/16” O.D. of inlet =2” O.D. of outlet = 2” -Compressor wheel: Inducer dim: 1 ¾” (44 mm) Major dim: 2 9/16” ( 64mm) -Turbine housing #6: Inlet I.D.= 1 15/16” Outlet = 1 7/8” -Turbine wheel #6 : Inducer dim: 1 7/8” (48mm) major dim: 2 7/16” (54mm) They're the same family of turbo. K24 and K26 share the same centers. The next size up is the from the K26 is K27 through K29 HTH Gary

just fitted a Sachs 890nm clutch to my modified 996 turbo. Improved performance, more responsive, but often stalls as i try to engage 1st gear on slight incline. Anyone else experience this? Its really annoying. Anything my garage can do to adjust take up/grab point?

It shouldn't be like that unless maybe they have installed a LWFW? If so any good tuner can adjust your tune to compensate for the LWFW just takes getting used to I have Sachs 890nm with dual mass fly wheel and its like stock. Maybe bite point a little it higher and you have to come off it a bit more progressively than a normal clutch as assisted clutch is so feather light its easy to be clumsy. Reverse is a little awkward to modulate thats just a feature of the clutch.

henry boxer said: just fitted a Sachs 890nm clutch to my modified 996 turbo. Improved performance, more responsive, but often stalls as i try to engage 1st gear on slight incline. Anyone else experience this? Its really annoying. Anything my garage can do to adjust take up/grab point? Hi did you manage to resolve this? Did you change the flywheel or just the clutch? About to replace my clutch

Sometimes an aluminium f/w can exhibit just enough flex to create that resonance. At high torque levels there's a good argument to go with billet steel.

I owned a highly modified 996 turbo which had a Sachs 890Nm clutch and a billet aluminum lightweight flywheel. Between about 1800 and 2300 rpm under load the resonant frequency from it sounded like the engine was knackered. It was possible to drive around it but I think it is worthwhile buying a matched clutch and flywheel combination that is proven to not have these characteristics. Edited by BAMoFo on Wednesday 12th October 15:39

I've a Sachs 890 clutch, 996 turbo modified by techart and recent DMS Ecu tune. 560 BHP, and approx 600 ft lbs of torque. Never felt entirely happy with it, although it certainly accessed the available torque, which the standard clutch couldnt quite handle. Starting the cart on any slight incline, was difficult not to stall, and reversing occassionally juddery. So considering going back to a stock clutch, but then I wont be able to access all the power on tap. Any advice out there? Maybe the set-up wasnt quite right. I've read so many different takes on this. Basically I love the fact I can use the power available, so that apart from first gear in traffic, and hill starts the car is a delight.

I've a Sachs 890 clutch, 996 turbo modified by techart and recent DMS Ecu tune. 560 BHP, and approx 600 ft lbs of torque. Never felt entirely happy with it, although it certainly accessed the available torque, which the standard clutch couldnt quite handle. Starting the cart on any slight incline, was difficult not to stall, and reversing occassionally juddery. So considering going back to a stock clutch, but then I wont be able to access all the power on tap. Any advice out there? Maybe the set-up wasnt quite right. I've read so many different takes on this. Basically I love the fact I can use the power available, so that apart from first gear in traffic, and hill starts the car is a delight. BTW the TechArt modification included old style 16/24 turbos, so good torque lower down and not so much top end, which suits my driving style! So 'change the clutch?' or keep and look into other options to limit occassional juddering in reverse and hill starts??

henry boxer said: I've a Sachs 890 clutch, 996 turbo modified by techart and recent DMS Ecu tune. 560 BHP, and approx 600 ft lbs of torque. Never felt entirely happy with it, although it certainly accessed the available torque, which the standard clutch couldnt quite handle. Starting the cart on any slight incline, was difficult not to stall, and reversing occassionally juddery. So considering going back to a stock clutch, but then I wont be able to access all the power on tap. Any advice out there? Maybe the set-up wasnt quite right. I've read so many different takes on this. Basically I love the fact I can use the power available, so that apart from first gear in traffic, and hill starts the car is a delight. IMO - you'd never fit a clutch that cant handle the torque you have. Its pointless, you'd constantly be living on edge of worrying about it slipping and overheating = dead clutch. Be as well de-tuning the car if going back to a stock rated clutch. I have the Sachs 890 in my 996 Turbo and find it OK. Yes its a little heavy and digital but easy enough to live with it. Just use a little more revs