Redlining a diesel

[kaanage]

Will this hurt a diesel since it has a heavier crankshaft, rods and pistons than a petrol engine of the same size? Or will it hurt the unit injector pumps in a PD engine?
I assume the valve gear won't care since the redline is so low.

I sometimes redline it in 1st since the gap between 1st and 2nd is so large.

[mikinoz]

It will protect itself from damage with the limiter.

I don't think your the only one that redlines the TDI. I know I do.

[sabloke]

Not much point in redlining a Diesel since the engine is most effective at about 80% of max rpm. I remember my Astra was an absolute animal at 4,100 rpm and it had the cut-out set at 5,100 rpm.

[Jarred]

as long as you don't exceed the red line, i'm reckon it'll be fine. I'm sure VW tested it above and beyond.

I give mine a good rev everynow and then, power drops off about 850-500 rpm before red, so it doesn't often see it though.

[maxrob200]

Give it heaps (within reason) IMO, clears the turbo vanes and car runs better as well

[poyta]

Like in a Petrol engine you're not really going to blow anything up - just shorten the life of the engine eventually. I'd recommend you change a little before redline though. If you look at dyno graphs you'll see that most diesels drop off heavily in power and torque near redline so there's no use going higher than 4000rpm in most cases and even with the drop in revs when you change gear you'll still be in the meat zone with an early shift because of the relatively flat torque curve of the diesels. I read an article somewhere on the net where they did 0-100 and 400m testing on shift patterns in the diesels and the one's shifting earlier before redline were dramatically faster.

[sabloke]

Go a few kays at 4,000 rpm in third every now and then to get the engine rid of soot. i think the "procedure" is called "the Italian clean"

[kaanage]

Actually, the redlining is occuring sometimes when I downshift form 2nd to 1st a bit too early.

I never go near it on acceleration (never really get near to 90% of the red line, usually potter around 30%)

[stickshift3000]

Actually, the redlining is occuring sometimes when I downshift form 2nd to 1st a bit too early.

Yes that can harm the engine if you're exceeding the redline.

A rev limiter won't stop the engine from spinning over the redline on down changes.

Pistons will hit valves eventually depending on what revs you're seeing. Did this once on my race bike at the track, not fun...

[jazd]

Yes that can harm the engine if you're exceeding the redline.

A rev limiter won't stop the engine from spinning over the redline on down changes.

Pistons will hit valves eventually depending on what revs you're seeing. Did this once on my race bike at the track, not fun...

Except the DSG wont shift down if it will result in too many revs. Maybe he has a manual though.

[poyta]

Actually, the redlining is occuring sometimes when I downshift form 2nd to 1st a bit too early.

I never go near it on acceleration (never really get near to 90% of the red line, usually potter around 30%)

In that case you need to learn how to downshift. What you're saying seems almost next to impossible to do - that would mean you're shifting into first when doing about 50kmh?!?!?! Who does that? I'd image the synchro's in your gearbox would be protesting like mad!!!

[kaanage]

Yes that can harm the engine if you're exceeding the redline.

A rev limiter won't stop the engine from spinning over the redline on down changes.

Pistons will hit valves eventually depending on what revs you're seeing. Did this once on my race bike at the track, not fun...

I haven't actually exceeded it but I have run it right up to the redline on occasion.

I remember John Kocinski getting the boot from Suzuki deliberately lunching his (2 stroke) engine after a race when he was disappointed by it's lack of speed. They could tell by the data logging (plus you can't get a racing 2-stroke to over rev on the throttle).

Except the DSG wont shift down if it will result in too many revs. Maybe he has a manual though.

Yep

In that case you need to learn how to downshift. What you're saying seems almost next to impossible to do - that would mean you're shifting into first when doing about 50kmh?!?!?! Who does that? I'd image the synchro's in your gearbox would be protesting like mad!!!

Eh? I don't think there is any synchromesh on the 1st gear. I thought it only had baulk rings.

[Greg Roles]

I rarely ever see 4k. The car is way faster if you stick to the meaty part of the rev range which in stock form is about 3500. I get out of first pretty much as quick as I can, and then torque through second. For the record, in my testing, redlining 1st gear gave me 8.5's to 100, whereas shifting quickly out of first, then at that 3500 sweet spot saw that drop to mid to high 7's. That was on Vag com, so not accurate, but relatively speaking, it was absolutely faster.

I know what you mean though, nothing worse than selecting a too low a gear and stopping the car with the engine! I do it from time to time, and it's certainly obvious!

[stickshift3000]

I remember John Kocinski getting the boot from Suzuki deliberately lunching his (2 stroke) engine after a race when he was disappointed by it's lack of speed. They could tell by the data logging (plus you can't get a racing 2-stroke to over rev on the throttle).

Yeah I remember that too - John was an angry dude at times. Have heard of others doing it during a race also when not performing well! : 0

I rarely ever see 4k. The car is way faster if you stick to the meaty part of the rev range which in stock form is about 3500.

+1

With the tuning box fitted to my tdi peak torque occurs at around 2k rpm, I don't think I've ever revved it past 4000 revs lol!

[Greg Roles]

Yeah sorry, should have said 2000-3500.