gbentink Turbo Upgrade Users Thread (2 Viewers)

[TheBigBoy]

So with all this torque we are now getting and clutches slipping all over the place (as is mine so much so I have to replace it now) what clutch should we put in? I spoke to a guy at Exedy and he said the Safari Tuff probably wouldn't cope with my output (680Nm). And I want to get over 700Nm with a new air box too.

Another one I'm considering is Xtreme Outback Offroad Stage 2 with cushioned ceramic discs. The guy there said it should cope with 750Nm.

Has anyone tried a new clutch that actually copes?

Ok, got 2 models sorted now. It all depends on what your using your truck for.

Super heavy duty, high torque cover, heavy duty organic plate (3200lbs clamping force) .... My current custom clutch. Smooth and soft.

And the new 1 coming out.
Super heavy duty, high torque cover, heavy duty ceramic plate cushion (2800lbs clamping force).

The differences.
The organic is fantastic for a every day driver. But the organic wears faster than the ceramic. So after a year of flogging it, the organic will be less clamping force than the ceramic. Although the thicker body of the ceramic plate means less clamping pressure to start with.

HD-ORG - Daily driver/4x4ing
HD-CERCUS - Race and towing

Im yet to see the characteristics of the later clutch. But I cant see it being that much different. The leverage points are moved to keep the pedal soft. Its really only the last bit of clutch engagement that will bite.

 

[jamohamo]

After a lot of research I've decided on the Xtreme Outback Off Road Stage 2 with cushioned ceramic discs. I know it will be more grabby but I've been told it will not let go when I plant the foot and does provide reasonably good drivability without a really heavy pedal. The model number is KTY30001-1B. The next one up from that (the 1BX) is apparently very heavy so no good for 4x4ing or daily driving.

Xtreme Outback Clutches
KTY30001-1A (HD Clutch kit) XTREME KIT-1A ORGANIC - 15% clamp increase, up to 600Nm
KTY30001-1B (DSBHD Clutch Kit) XTREME KIT-1A CERAMIC SPRUNG - 15% clamp increase, up to 750Nm
KTY30001-1BX (DSBXHD Clutch Kit) XTREME KIT-1AX CERAMIC SPRUNG - 75% clamp increase and C/MOLY CASTING - over 800Nm but very heavy pedal

Exedy Clutch
Safari Tuff (organic clutch material) - 25% clamp increase, up to 600Nm

The gearbox is also being rebuilt (synchros mainly, I hope) so I should get it back this time next week and I will let you know if it does the job or not.

 

[TheBigBoy]

So the big question. What hp/torque are you putting down?

 

[jamohamo]

So the big question. What hp/torque are you putting down?

My 1HDT puts out 680Nm and 145kW so the 1B should cope.

 

[mudgudgeon]

I'll just drop this here

From the HZ-T thread

Has anyone investigated a twin disc clutch?

You can run a smaller diameter clutch, so less inertia. But still have far greater surface area, so more friction, greater torque handling capacity and have less pedal effort.

I'm thinking something like a Ford BA Falcon xr6t clutch. with the correct splined centre hub custom fitted it could be the go.
It's a 10.5" clutch, so should fit on the flywheel and inside the bell housing
It would be pricey, but could be a good option.

 

[Dougal]

Clutch inertia is of no concern on a diesel. You want the biggest disc you can easily fit.

The torque capacity isn't surface area. It's radius, surface area, friction and clamp load. Reducing the clutch size is counter productive.

 

[mudgudgeon]

Clutch inertia is of no concern on a diesel. You want the biggest disc you can easily fit.

Why? The way the guys in this thread are tuning these engines are hardly being tuned and used in a manner typical of your diesel powered tractor, water pump, Genset etc.

The torque capacity isn't surface area. It's radius, surface area, friction and clamp load. Reducing the clutch size is counter productive.

So surface are is a significant chunk of that equation yes?

A dual disc clutch can have a significantly smaller diameter, but by doubling up the discs, you have a far greater total friction surface. With the same spring pressure distributed over a smaller area, you have a higher clamping force per square inch.

Race vehicles commonly use twin, triple or multiple disc clutches, of far smaller diameter than a single disc clutch. the increased friction surface area from multiple discs, more than makes up for reduction in surface area/radius etc of a single disc. all with reduced (or the same) spring pressure.
this help retain drivability, and no increase in pedal effort for far greater torque capacity.

Mantic offer a 9" twin disc clutch, or a 7" triple disc clutch for use behind LS1 capable of handling ~1300Nm of torque.
Far in excess of what a single disc clutch is capable of.

from Mantic clutch

Diameter Weight No of Discs Torque
9.0in/225mm 33.8lb/15.4kg 2 1010ft lbs/1365Nm
7.25in/185mm 26.6lb/12.1kg 3 984ft lbs/1330Nm
12.0in/300mm 46.0lb/21.0kg 1 781ft lbs/973Nm

 

[mudgudgeon]

centerforce is another manufacturer building twin disc cluthces for high output street cars,

even if the mass of the clutch is unimportant to a diesel, there is not going to be a down side to have a reduced moment of inertia given the size and weight of the standard toyota flywheel.
I would think the improved capacity of the clutch and driveability is going to far exceed any negative (if there is any) in the reduced inertia with a smaller diameter clutch?

 

[Dougal]

Why? The way the guys in this thread are tuning these engines are hardly being tuned and used in a manner typical of your diesel powered tractor, water pump, Genset etc.

Because the more torque you have, the more inertia you need to keep it smooth.
At high torque you need more flywheel mass, not less.

Reducing flywheel inertia is the worst thing you can do to a diesel. It it only useful on screamer engines (8000+rpm) that need rapid rpm gain and loss in a race situation.

So surface are is a significant chunk of that equation yes?

The actual surface area is only a wear concern. The torque capacity concern is the centreline of that surface and the radius it resides on.
Bigger radius gives more torque capacity.

A dual disc clutch can have a significantly smaller diameter, but by doubling up the discs, you have a far greater total friction surface. With the same spring pressure distributed over a smaller area, you have a higher clamping force per square inch.

If you want to fit a dual disc clutch, that's fine. But you'd fit the largest one you can. You can use the doubling in friction faces to get double the torque on the same clamp load (same pedal force).

Race vehicles commonly use twin, triple or multiple disc clutches, of far smaller diameter than a single disc clutch. the increased friction surface area from multiple discs, more than makes up for reduction in surface area/radius etc of a single disc. all with reduced (or the same) spring pressure.
this help retain drivability, and no increase in pedal effort for far greater torque capacity.

Refer to that 8000+rpm screamer I mentioned earlier. Petrol race engines and high torque diesel engines are opposite ends of the spectrum.

 

[mudgudgeon]

the suggestion of the Ford XR6T twin disc was because it is the largest diameter production twin disc clutch I've identified, and therefore, most likely a relatively cost effective exercise to adapt it to a 1HD-T rather than completely reinvent the wheel (or clutch in this case). there are numerous 14" and larger truck clutches, but they won't quite fit within the std bellhousing without use of a big hammer

the XR6T clutch is 267mm diameter vs 300mm for 1HD-T series engines. How much effect is that likely to have on the MOI?

Just putting an idea out there, I'm not in any danger of fitting a dual plate clutch, but if guys are struggling to get a clutch to hold without big down side to driveability (particularly if they are going offroad) maybe it pays to look outside the box?

If a new heavy duty clutch is barely coping, how will it go after being pushed hard for a year? I'd be looking for a more permanent solution in this case. A half arsed solution now is going to cost more inthe long run. A poor man pays twice

 

[Dougal]

The easiest permanent solution is more clamping pressure. Either a different cover plate or one tweaked to give more preload.
If the pedal is then too firm, grow some leg muscles, fit a smaller diameter master cylinder or find a way to put power assist into it.

Given that the stock clutches do more than half the required torque, doubling the clamp pressure will solve the problem and double the pedal force. Before any pedal mitigation measures are taken.

Attempting to get higher friction coefficient into a disc is when they get all grabby and glazed up and crap.

Why do you think a single disc clutch isn't capable of high torque?

 

[Hulsty]

Anyone spoken to these guys? Apparently they do some good stuff for hi po TD42 clutches, not sure what torque a grunty TD42 puts out but it must be near what a 1HD does.

http://www.npcperformance.com.au/

 

[mudgudgeon]

in this thread alone there is several mentions of clutch slipping with the increased output.
TBB has mentioned a few posts up that some HD clutches available will not be driveable (relative) offroad.

Have you spent much time driving a manual 80series in traffic, or steep rocky terrain?
They already have a heavy pedal action, my 80series had a vacuum assisted clutch, and still had a heavy action, and that's coming from a lad that is a 6'6" 115kg former athlete with fairly substantial leg muscle mass already

I'm not sure what your point is in saying a stock clutch does half the torque?
How does doubling pedal effort and then spending money to reduce the pedal effort give a better outcome versus a twin disc clutch that will not increase pedal effort, yet provide a vast change to torque capability?

Obviously there is cost involved in both.
To me, changing one thing (ie altering the clutch), then changing another (master cylinder, power assistance, steroids for leg muscles etc) to deal with the first change doesn't make sense if it is possible to solve the first problem with a tested of the shelf (more or less) item without creating another unwanted problem.

apart from reducing overall mass(given the added components, there may not be a reduction in mass) and a change the MOI, if the change in the MOI is not large, what would be the downside of a twin disc clutch?

From info above after market HD clutches are rated from 600nm to 750-800Nm
with very heavy pedal, or other poor characteristics.

If 1300Nm can be handled by a twin disc 9" clutch, what rating is a twin disc 10.5"clutch going to provide?

I'd love to do some calculations, but dont have full pecs of a stock clutch or the Ford example and dont fully understand the equations anyway.

 

[mudgudgeon]

Anyone spoken to these guys? Apparently they do some good stuff for hi po TD42 clutches, not sure what torque a grunty TD42 puts out but it must be near what a 1HD does.

http://www.npcperformance.com.au/

the images on their home page are a twin disc clutch

 

[TheBigBoy]

I think is getting to the point of starting a new thread about clutches. This is a Gturbo user thread after all.

My 2 cents worth. How have these companies rated it to NM? Clutches work off clamping pressure! I totally disagree that a heavy duty clutch mean a heavier pedal. You change the leverage points to A. Give more clamping pressure, and B. the more leverage allows for a soft clutch feel. The clutch I currently have is a 3200lb clutch and feels as soft as factory. I will really put it through its paces soon and test it.

 

[Mitch92]

I've spoken to someone at NPC a few weeks ago and they recommend I get a 1hdt,ft,fte flywheel and machine it flat and re-drill it to suit a chev 6.5l diesel clutch. They said it would be 70% stronger than an exceedy safari tuff clutch.

 

[Mitch92]

Capable of 1000nm

 

[58bernie]

I know nothing about clutches except mine can be made to smell, real quick, reading with interest.

 

[jamohamo]

Doesn't higher clamping pressure have an adverse affect on bearings though? It sounds like the ideal would be to have it as close to a normal clutch as possible at low revs (under 1600) and then the grabbing factor at high revs (2000+). It's only at higher revs mine was letting go because that is when the torque would increase markedly. Do clutches exist that actuate depending on rpm?

 

[mudbludger]

Thread started, its even "official" so must be legit

Bernie lets see what you come up with for the clutch, maybe odor eater makes one for the smell?

The knock on effect of installing these turbos is not surprising, the shortcomings of standard equipment soon becomes apparent. I am left wondering if an exhaust (over 3") and injector upgrade thread will soon grow around this turbo along with all the others....

Once upon a time I was happy with my std turbo, 14lb boost, 3" exhaust, little bit extra fuel and cross country top mount. And you know what? life was good and I felt complete, but nooooooooo Graeme just had to come along and reboot my power addiction.


Now i work a second job to fund intake, intercooler and pump improvements then stay awake at night e-stalking you fellow addicts till three in the morning.........