Straight through exhaust on a TD?

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FlyingPete

FlyingPete

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I've spent this afternoon fixing the starter motor on my 90, and in doing so took the downpipe off for better access. Haven't bolted it all back together yet as the rear pipe needs changing. So when I started it up again, I had just the down pipe fitted with no silencers, and it sounds fantastic :D

I've just bought a new rear pipe which I haven't even fitted yet, so obviously that will be going on, but has anyone run their 19J with the middle box removed? I've seen several straight pipe sections for a tdi, but none for the old 19J.
 
Never did take the middle box out, though now the engine's going into a 109 so it will have a custom exhaust system anyway cobbled together from various parts. Will probably have just the small rear box and straight from the downpipe to there.
 
All engines need back pressure, the gain, if any, really isnt worth the effort.
 
My 19j was a straight through after I removed, inadvertantly with the help of rocks, the back end of mine. Sounded nicer, and faster but the reality was I couldn't tell any real difference.

Now it's a 300 Tdi in the same landrover 90 with another short, straight through exhaust and I think it sounds lovely. Again, no idea (arguable as I have no proper data) if it helps power or speed, but I like to think so .. :)

Now Two stroke expansion chambers, they work if you get the maths and angles right, but that's a different topic .. :)
 
Paul D said:
My 19j was a straight through after I removed, inadvertantly with the help of rocks, the back end of mine. Sounded nicer, and faster but the reality was I couldn't tell any real difference.

Now it's a 300 Tdi in the same landrover 90 with another short, straight through exhaust and I think it sounds lovely. Again, no idea (arguable as I have no proper data) if it helps power or speed, but I like to think so .. :)

Now Two stroke expansion chambers, they work if you get the maths and angles right, but that's a different topic .. :)
Click to expand...

I have never found exhausts make much difference to low tuned diesels as regards performance, provided they flow as much gas as intended. The silencing is just to avoid scaring other road users.

As you say, high performance two strokes are completely different, the exhaust back pressure is critical.
 
Turboman said:
I have never found exhausts make much difference to low tuned diesels as regards performance, provided they flow as much gas as intended. The silencing is just to avoid scaring other road users.

As you say, high performance two strokes are completely different, the exhaust back pressure is critical.
Click to expand...

About what I figured ... but I like a throaty sound .. ;)
 
Free flowing or straight thru will promote power and help reduce EGT’s on a turbo diesel.

There is no need for back pressure on a turbo setup. And not on a diesel where the fuelling is not related to air flow.

That said. On an engine that only makes 89hp stock and isn’t really restricted by the stock exhaust. Gains are likely to be minimal. Even a 5% gain in peak HP (which is probably hugely optimistic) would be hardly noticeable from the drivers seat.
 
Turboman said:
I have never found exhausts make much difference to low tuned diesels as regards performance, provided they flow as much gas as intended. The silencing is just to avoid scaring other road users.

As you say, high performance two strokes are completely different, the exhaust back pressure is critical.
Click to expand...
turbo diesels are quieter than normally aspirated as turbo uses the energy, in the 80s all the turboed tractors had wide bore straight through exhausts
 
300bhp/ton said:
Free flowing or straight thru will promote power and help reduce EGT’s on a turbo diesel.

There is no need for back pressure on a turbo setup. And not on a diesel where the fuelling is not related to air flow.

That said. On an engine that only makes 89hp stock and isn’t really restricted by the stock exhaust. Gains are likely to be minimal. Even a 5% gain in peak HP (which is probably hugely optimistic) would be hardly noticeable from the drivers seat.
Click to expand...

I have quite often run old tractors with the exhaust baffles rusted out completely, leaving a straight through set up. TBH, there was no noticeable difference in performance over the standard set up.
 
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