2.5DSE Auto trans power handling.

[Martin H]

At the moment this is pretty much a hypothetical problem solving question. It may well have been broached before. As it stands my bog standard 2.5DSE is adequate. For how much longer? I don't know. I have a low boredom threshold and spring is approaching.
IF and it's a reasonably large IF (At the moment) I were to look at increasing engine power I'd probably be looking at getting 140 - 160 BHP

The weak spot on an auto 2.5 with a chipped, de cat engine etc, as I understand it is the gearbox. Vis a vis overheating and associated issues.Yes?

My thoughts on this are as follows.
1/ Fit larger transmission cooler. Possibly small radiator from road car.?
2/ Attach electric cooling fan. Spall or similar.
3/ Use a good quality ATF fluid.

Once all that's done increasing the engines power shouldn't pose too much of an issue.

Does this all sound feasible?
Feedback positive and negative appreciated. (Mostly)

 

[Datatek]

Swap the box for a ZF4HP24 from a 4.6. It's torque that kills the box, the 22 is near the limit as standard.

 

[TCubed]

The issue with the gearbox is that increasing the engine torque chews it up. You should fit the stronger ZF24 box from the 4.6 if you really want to up the power. Datatek is going to do it soon so you should talk to him

 

[TCubed]

Swap the box for a ZF4HP24 from a 4.6. It's torque that kills the box, the 22 is near the limit as standard.

Ah you beat me to it

 

[wammers]

Providing the box is in good condition and the car is driven normally a power and torque increase should do little harm. The 4.0 litre petrol has the same box with 320 Nm of torque and 190 BHP and does not unduly shred boxes. Although the diesel torque curve is somewhat different. However towing with a diesel with that sort of power and torque with it's different torque curve, could cause a few problems. So if you are thinking of increasing the power to tow, forget it.

 

[Martin H]

Towing with the Rangey is never going to be an option. I have the Jeep for towing. So, how's this for an option. Assuming I went for an increase in the BHP dept, Keep the current box in situ and have a Z24 in the shed ready.

Howzat. Seems like a nice easy option.

 

[wammers]

Towing with the Rangey is never going to be an option. I have the Jeep for towing. So, how's this for an option. Assuming I went for an increase in the BHP dept, Keep the current box in situ and have a Z24 in the shed ready.

Howzat. Seems like a nice easy option.

Seems so, but they are not a straight swap. Things to be played with.

 

[Martin H]

Playing with things is what makes life interesting.

 

[tomcat59alan]

Towing with the Rangey is never going to be an option. I have the Jeep for towing. So, how's this for an option. Assuming I went for an increase in the BHP dept, Keep the current box in situ and have a Z24 in the shed ready.

Howzat. Seems like a nice easy option.

Why, you cannot go very far on the Isle of Wight

 

[Martin H]

Why, you cannot go very far on the Isle of Wight

This is true. I'll put a Clio diesel in it.

 

[tomcat59alan]

This is true. I'll put a Clio diesel in it.

Do Renault build a Clio 4x4 ? If they do you can put the gearbox in as well, sorted

 

[TCubed]

Do Renault build a Clio 4x4 ? If they do you can put the gearbox in as well, sorted

There was the scenic 4x4 and it may have had the same engine as was then fitted to a Clio

 

[Datatek]

Seems so, but they are not a straight swap. Things to be played with.

Depending on version the box is a straight swap just the bell housing to change. On some the oil pump also needs changing.

 

[Datatek]

There was the scenic 4x4 and it may have had the same engine as was then fitted to a Clio

Not a real 4 x 4 more like a Gaylander