Best prevention for TD5 exhaust manifold ?

Hi all, I have just suffered my first drama with the exhaust manifold studs on my TD5 90. I understand that this is a common problem, especially on modified TD5's.

My vehicle has done 69k and has a "Twisted" ECU box, K&N filter and EGR bypass.

I had driven in hot weather and had just washed the landy with a jet wash. The problem presented itself as a whistle noise (more like a belt squeal) when under load. On investigation 5 out of 10 of the studs had sheared.

The garage i use (independent) managed to get all the sheared studs out without damage to the head. They also confirmed that the manifold had not warped????

I have now fitted a de-cat down pipe in the hope that a more free flowing exhaust may prevent EGT getting too high.

Question?
Is the flow of the exhaust going to have any effect on the temp of the manifold?

Could cold water getting onto the hot exhaust manifold cause enough shrinking to shear studs?

I look forward to your opinion.

Buy a V8,or change your driving habits.

Stop spraying cold water on to a hot manifold. It's not that common but most manifolds will sulk if you dont treat them right. Most problems occur when people go wading and dunk their hot turbo casings and manifolds in cold water, or use the jet wash before letting things cool down.
You might want to keep an eye on your EGT as it is a sure sign of over fuelling especially if you can see it glowing red in the dark.
Removing the CAT will have little effect on EGT as the turbo is the main restriction in the exhaust flow.
I dont know much about the Twisted product.
What level of tune did you go for and what testing was done after it was mapped?
Was it just plug and play or was it a custom map for your engine. Generic tunes are notorious for just dumping more fuel into the cylinders and claiming massive increases with no regard for other issues.
Did you upgrade the intercooler and overide the ECU turbo overboost levels? Especially if you are running more than standard boost.
If it was not done properly then you risk fragging your cylinder head or the whole engine.

Shifty hi, it is the standard plug in box that acts like and extra ECU - the crudest stage 1 tune. My intention was to get better economy and drivability and not too have a race truck, but with the noise from the exhaust and the instant response from the right foot it is hard not to have a bit of a play.
I take it i should ditch the box and get the ECU re-mapped??

TD5 Exhaust manifilds do distort when they get too hot. If you are expecting to use it in demanding temperatures you can fit a temp guage to monitor it, such as flogging your way through soft Saharan sand. Best practice is to allow the engine to cool down naturaly by allowing it some idle time especially after a 'hot' run (aka a thrashing).

If you have removed the viscous fan this will also make things worse as there will be less airflow over the manifold.

anthony5351 said:

Shifty hi, it is the standard plug in box that acts like and extra ECU - the crudest stage 1 tune. My intention was to get better economy and drivability and not too have a race truck, but with the noise from the exhaust and the instant response from the right foot it is hard not to have a bit of a play.
I take it i should ditch the box and get the ECU re-mapped??

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I'm not suggesting you should ditch the box but you do get what you pay for. A plug in generic tune can only ever fool the ECU into the crudest of changes. Most of them work by extending the injector period causing over fueling hence the very hot EGT. They may give you more torque but at what cost and they take no account of all the other variables such as air temp, turbo boost, etc.
Get it done properly by someone who knows what they are doing. I had mine done by Gary at TD5Alive and its bloody brilliant. He can design and test specific stages of tune for what you want and for your actual engine as no two engines are alike even when new. There are others offering a similar service.

yeah, roger that shifty. I wish i had got td5alive to do mine last year, due to being impatient at the eastnor show i had the option of instant plug and play box from twisted performance or a re-map requiring booked in with TD5alive???? "you make your bed-you sleep in it" and all that!

I will keep a tight control on any fun driving for a while until i can afford a remap. The de-cat pipe has been interesting. Apart from a slight difference in exhaust note it also seems to spin the turbo much earlier.

I like the idea of this nanocom thing with TD5 alive able to send files via the internet and then load direct onto the ecu - I am hoping my blackberry will have this application soon...lol.

The decat pipe allows the turbo to respond faster as there is less restriction in the exhaust flow after the turbo. If you want to see a real difference then remove the exhaust after the decat and go for a drive. Its not as noisy as you might think. You will still get slight turbo lag but unless you are into fitting those fancy dump valves and hissing your way down the high street theres not a lot you can do. After all its a Landrover and not a race car.

Shifty1962 said:

The decat pipe allows the turbo to respond faster as there is less restriction in the exhaust flow after the turbo. If you want to see a real difference then remove the exhaust after the decat and go for a drive. Its not as noisy as you might think. You will still get slight turbo lag but unless you are into fitting those fancy dump valves and hissing your way down the high street theres not a lot you can do. After all its a Landrover and not a race car.

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Ooh I do like a challenge, might make it onto Top Gear....

If you want to race a Landy then you need one of these.

Tomcat Motorsport - Home Page

Shifty1962 said:

If you want to race a Landy then you need one of these.

Tomcat Motorsport - Home Page

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nah, I think I'll pass. But I do like mine in top fettle.