Big Power. What Are The Cons For Over 300rwkw

[6speedXR8]

The biggest issue with upgrades to a production vehicle is that the higher you go with power increases there is usually a trade off. What I mean is higher engine output can increase stress on all the components of the car's driveline. Most Manufacturers build cars to endure most driving conditions and vehicle usage to a high standard. Power upgrades of around 20/30% don't normally pose a problem. When we upgrade our cars beyond this that is where the trade off starts, for example, High performance upgrades to standard engines can result in shorter engine life, Higher than normal fuel consumption, Engine roughness at idle and road speed etc.

Transmission failure in both auto and manual, Clutch failure, Damaged cv joints.

I don't want to get too specific with what can happen but you get the picture. If want to you upgrade your car the best anyone can do is ask around, that is the best thing about forums such as this forum.

As I am a transmission and driveline specialist I find any 5 speed xr6t that has had a power upgrade over 250 rwkw and the vehicle is driven hard the transmission will fail and the clutch will also fail, that is why we have done so much development with Flywheel, Clutch and T56 6speed upgrades for the XR6T.

Mal Wood

[Geeseman]

  TBO240 said:

  HYPOXR said:

I had an APS Phase II in my ute and the engine only lasted 2000kms. It is a 6 speed manual though. It actually threw a rod out of the side of the block. I also had to change the clutch. my ute only made 293rwkw. Now I have had the engine rebuilt or should I say a new engine with a set of rods and left the standard pistons. But the APS kit will be coming out.

running stage 11 with almost stage 111 power ?

something is not right it had to be running excessive boost and leaned out to the max ,recipe for disaster....that's my 2 bob worth

He did mention that the car only has 2000kms on it. As there are so many Phase II kits out there with similar power its unlikely that the components had anything to do with the failure. Phase II injectors are those used for phase II so they can run over 300rwkw. Best case scenario is to ensure you have a few more thousand Ks on the clock before you mod to see if any faults in the engine appear. Its impossible to provide warranty for components that you did not manufacture.

[Geeseman]

  6speedXR8 said:

As I am a transmission and driveline specialist I find any 5 speed xr6t that has had a power upgrade over 250 rwkw and the vehicle is driven hard the transmission will fail and the clutch will also fail, that is why we have done so much development with Flywheel, Clutch and T56 6speed upgrades for the XR6T.

Mal Wood

Thanks for your input Mal.

What power levels are your gearboxes currently working to at maximum?

Also, when have you noticed, in terms of rwkw, do the CV joints fail?

[Geeseman]

For those running over 330rwkw every day it would be interesting to hear what fuel you run and if you use octane booster with every tank of fuel.

Im seeing some detonation due to what I think is the crap fuel quality in sydney (mobil synergy). I'm assuming this gets worse the higher the power. Can anyone confirm?

[WBT56]

  Geeseman said:

  6speedXR8 said:

As I am a transmission and driveline specialist I find any 5 speed xr6t that has had a power upgrade over 250 rwkw and the vehicle is driven hard the transmission will fail and the clutch will also fail, that is why we have done so much development with Flywheel, Clutch and T56 6speed upgrades for the XR6T.

Mal Wood

<{POST_SNAPBACK}>

Thanks for your input Mal.

What power levels are your gearboxes currently working to at maximum?

Also, when have you noticed, in terms of rwkw, do the CV joints fail?

<{POST_SNAPBACK}>

We dont really know what our T56 boxes are really capable of holding, as we have never had a failure to date. We have 12 or 15 running over 800rwhp, (800+ftlbs), and many more running in the 300-400rwkw class. CV joint failures at this stage seem to be more related to wear or poor build quality than outright output. If you have a back end clunk, it will almost certainly not be the diff, check your CV's. Ben.

[macka'sxr6t]

  OwnaXR6T said:

stay tunned for a post from me regarding something else that people are over looking maybe. It nothing to do with engine, depending on word from  melbourne where the work was done. It is meant to be garenteed. And if they don't cover it I will be revealing who they are and what has happened to insure noone uses them for this type of upgrade.

<{POST_SNAPBACK}>

Still waiting :lol:

macka

[Geeseman]

Well to kick this topic off again I have recently had my engine rods and pistons examined to see if there has been any damage from operation at Phase III levels.

The rods and pistons are in perfect condition with no sign of damage. I've been running around 317rwkw for about 4 months, and around 308rwkw before that for at least 5months. While this is not an indication of what can be expected over years of use, it shows that the rods are pretty capable of handling these power levels should the user keep their care tuned properly and use good fuel - at least in the short term.

The block is also in good condition.

[Lawsy]

Well the block should be in good condition, and at your power levels so should the rods and such. I think your power level geese might be some sort of sweet spot for the engine. You are probably at a point that you could run the engine hard all day every day without destroying it.

One thing that caught my attention is a comment from WBT56.

"If you have a back end clunk, it will almost certainly not be the diff, check your CV's"

Everyone has been getting diff replacements for driveline shunt and it DOES NOTHING...

Coincidence? It seems to me that the CV's were probably the culprit the whole time.....

[Geeseman]

Good points Lawsy.

Yes, I feel the engine is fine at the moment with its current power. Upping the RPM as some have done, is what I feel may endanger it but it's surprising how strong the stock rods are.

I've not had any problems with my CVs yet but I'll be looking out to see what happens to them in the future

[macka'sxr6t]

  Geeseman said:

Well to kick this topic off again I have recently had my engine rods and pistons examined to see if there has been any damage from operation at Phase III levels.

The rods and pistons are in perfect condition with no sign of damage. I've been running around 317rwkw for about 4 months, and around 308rwkw before that for at least 5months. While this is not an indication of what can be expected over years of use, it shows that the rods are pretty capable of handling these power levels should the user keep their care tuned properly and use good fuel - at least in the short term.

The block is also in good condition.

<{POST_SNAPBACK}>

Steve ,

While you had it stripped down, I would have put the LP rods in it for future power upgrades.

Nice little bit of insurance

macka