Well, I've gone and done it....

[white90]

re:

In terms of readings, I've got the temp up to 680 holding the vehicle in 3rd up a steep hill. Really the limit for a road engine is arround 730 but if you're less worried about shortening the life of the engine you can use 800 as the absolute limit.

if you see 800 on your gauge your manifold will be cracked for sure.

a mate has destroyed x2 TDI ones at temps below 800 anyrhing above 700 is risking damage.

Tony

[will_warne]

re:

In terms of readings, I've got the temp up to 680 holding the vehicle in 3rd up a steep hill. Really the limit for a road engine is arround 730 but if you're less worried about shortening the life of the engine you can use 800 as the absolute limit.

if you see 800 on your gauge your manifold will be cracked for sure.

a mate has destroyed x2 TDI ones at temps below 800 anyrhing above 700 is risking damage.

Tony

Tony, the 800 figure was the upper limit given to my by one of the directors of this company (they are going to do the tuning on the engine). IIRC, rally vehicles run up to 1200. However, he made me aware that was an absolute upper limit for tuning purposes NOT the upper limit for everyday driving. The way I use the vehicle means I want low and mid range grunt and I won't be using full throttle off road for more than a few seconds.

[FridgeFreezer]

I won't be using full throttle off road for more than a few seconds.

...if ever

[white90]

Will you won't hit the upper limit at all offroading it is long hills under full power where the temp reaches its max.

I stand by my previous post below 700 is the safest area.

rally vehicles are in a different league with special materials and regular rebuilds at someone elses expense.

[SimonPearson]

Si, why? Tuning diesels is fine as long as you don't go OTT. Given the EGT figures I get right now I've got loads of scope to improve.

Just a theory of mine - don't mess with a Tdi (or derivative) as they don't like being messed with.

Simonr blew his up, you blew yours up, Les Brock blew his up (although he says it may have been faulty when he got it), and 2 frineds of mine not on this Forum blew their up too!

We all know how it goes... "Oh I'll get a big intercooler, maybe up the boost a little, maybe twiddle the diesel injector pump a little...... "

BANG!

Oooops...

[Turbocharger]

Will you won't hit the upper limit at all offroading it is long hills under full power where the temp reaches its max.

I'm not so sure Tony - the Thermoguard unit has inbuilt damping (and a very heavy thermocouple) so if there's a step change in the gas temperature, the reading responds as quickly as the unit allows, getting closer to the answer exponentially more slowly.

Re temps, I'd treat 700 as a workaday limit for medium term durability (my max is 735 and I'm not doing that again!). The 1050°C turbos which are in the development pipeline are very specially designed with lots of CFD to keep the blade temperature lower than that. Tdi turbos aren't like this.

I think messing with the engine is fine so long as you accept the risks and understand what you're doing. Oh, and take heed of the people who've found the limits by blowing up their engines first

[will_warne]

I'm not so sure Tony - the Thermoguard unit has inbuilt damping (and a very heavy thermocouple) so if there's a step change in the gas temperature, the reading responds as quickly as the unit allows, getting closer to the answer exponentially more slowly.

Re temps, I'd treat 700 as a workaday limit for medium term durability (my max is 735 and I'm not doing that again!). The 1050°C turbos which are in the development pipeline are very specially designed with lots of CFD to keep the blade temperature lower than that. Tdi turbos aren't like this.

I think messing with the engine is fine so long as you accept the risks and understand what you're doing. Oh, and take heed of the people who've found the limits by blowing up their engines first

Don't get me wrong, TC, I'm very aware that there are big risks tuning an engine; things can go bang in a very expensive way I know EGT is the big killer on Tdi's so I'll use mine accordingly; if it gets high I'll just back off. However, the vehicle isn't really an everyday vehicle anymore so I'm prepared to sacrifice some engine life for power; If I can get 70-100k / 5-7 years out of the engine before a rebuild I'll be happy with the engine life. When I got my max reading I was trying to get that and I really was pushing the vehicle harder than I normally would. The other thing to think about is that if the vehicle has more mid range grunt then I won't need to rev it so much meaning lower overall EGT: I find the EGT is considerably higher at high revs (makes sence really) so keeping revs down is a good thing as it'll mean less stress on the bottom end too.

Anyway, I'll just have to see how the tuning goes. The reason I'm leaving it to professionals is so they can decide what's sensible. Having seen their handywork I have a lot of confidence in them and, rest assured, I won't be running to 800 when I use the vehicle, I don't see the need. Driving a competition vehicle at high speed isn't a terribly good idea

[white90]

I'm not so sure Tony - the Thermoguard unit has inbuilt damping (and a very heavy thermocouple) so if there's a step change in the gas temperature, the reading responds as quickly as the unit allows, getting closer to the answer exponentially more slowly.

Re temps, I'd treat 700 as a workaday limit for medium term durability (my max is 735 and I'm not doing that again!). The 1050°C turbos which are in the development pipeline are very specially designed with lots of CFD to keep the blade temperature lower than that. Tdi turbos aren't like this.

I think messing with the engine is fine so long as you accept the risks and understand what you're doing. Oh, and take heed of the people who've found the limits by blowing up their engines first

well John after having the EGT fitted for some time in all conditions, it never gets near max offroading only on long climbs on the road.

Billy has bust x2 manifolds running high boostr and too much tweeking of the pump once the gauge was fitted he hasn't bust any more.

I too think messing about is fine and have altered all mt TDI's to date without failures.

blowing a TDI will be less of a heart ache thean destroying a 6k TGV.

Mine has the Alisport intercooler/21psi boost and pump adjustments and has been this way for well over a year with no detrimental results other than MPG which is 24 on a long run last week.

[will_warne]

well John after having the EGT fitted for some time in all conditions, it never gets near max offroading only on long climbs on the road.

Billy has bust x2 manifolds running high boostr and too much tweeking of the pump once the gauge was fitted he hasn't bust any more.

I too think messing about is fine and have altered all mt TDI's to date without failures.

blowing a TDI will be less of a heart ache thean destroying a 6k TGV.

Mine has the Alisport intercooler/21psi boost and pump adjustments and has been this way for well over a year with no detrimental results other than MPG which is 24 on a long run last week.

Tony, I wouldn't dream of mucking about with an expensive diesel engine without an EGT gauge; you then know when to stop. I probably won't drive the vehicle much faster on road, I just want the power off it. Interestingly Si White reckons my truck is slightly slower than his (same gearing allbeit that he has an LT77 and 200Tdi) so that suggest I've lost a few bhp in the auto conversion.

[Tonk]

no detrimental results other than MPG which is 24 on a long run last week.

hmmmm, i think that fuel consumption is good, i worked mine out the other day at 15 mpg

[MogLite]

hmmmm, i think that fuel consumption is good, i worked mine out the other day at 15 mpg

My Ibex is about the same !!

Must be the way Alex does it - but it flies, and that counts

[Tonk]

i've gotta back mine off a bit (fuelling that is) gets way too close to the danger zone and i'm sure will pull beyond.

[FITZ]

Tony, I wouldn't dream of mucking about with an expensive diesel engine without an EGT gauge; you then know when to stop. I probably won't drive the vehicle much faster on road, I just want the power off it. Interestingly Si White reckons my truck is slightly slower than his (same gearing allbeit that he has an LT77 and 200Tdi) so that suggest I've lost a few bhp in the auto conversion.

Manual gearboxes lose are around 15bhp. The ZF 4HP22 loses around 20bhp and the TorqueFlite 727 loses around 40bhp.