td42 twin scroll turbo manifold

[slidenyo]

Anyone no of any for sale?
Murmuring's on the Oz forums that the series 2 trucks got them in 2 piece format.
wanting to match to my twin scroll garrett and twin plenum manifold and big pump

[tweake]

i think i know the manifold you mean. there is also a DTS manifold thats similar.
but afaik its not a true twinscroll manifold. it simply merges the two rear ports to the front 4 ports.

[slidenyo]

Ah bugger trying to get the true benefit of the twin scroll so building an equal length manifold might be the only option. From what I've read it'll spool earlier than a single and deliver lower egts. Pumps getting 1hd 12 mm head and plunger camplate and comp with governor delete and fuel pin rework. Might as well make use of the forces at play to some benefit

[Crash bandicoot]

Twin scroll only stops scavenging, most effective on 4 cylinder banks L4 ,v8 etc, and very efficent on rotary engines..... not so much with 6 cylinder with 2 and 5 being out of sync with the combined compression and exhuast strokes of the other 4 cylinders. The gain is marginal in this senario compared ti an equal length 6 cylinder manifold.

[slidenyo]

I thought is was more to do with using the pulse from each exhaust cycle to good effect by pairing the cylinders equally timed away so that the pulse gets to the turbine without coliding with another? Thinking about it I can trial off the original na manifold with a u bend up to turbo arrangement. Then I don't have to chop the high mount one or build something just yet

[tweake]

unless you really want to try something different i wouldn't bother.
those oz guys have spend huge amount of time and $$$ and none bother with fancy exhaust manifold.
theres a list of improvements to some of the existing manifolds.
they are up to 260+ rwkw outputs easy enough with single turbo and log style manifold. snapping cranks is becoming a problem.

[slidenyo]

Not trying something different as such plenty of truck tractor and even BMW petrol 6's run the twin scroll manifold and turbos trying something that gets done on everything else but not so common on the td42. I have the high mount an kinugawa as a back up but have been also sitting on a pile of truck and tractor turbos for some time

[slidenyo]

Log manifolds are fairly percussive and beating in tune works better than a cacophony of beats shoving each other round before bolting out the gate

[slidenyo]

Sorted denco diesel does just what I'm after

[tweake]

Sorted denco diesel does just what I'm after

hope it does what your after.
its not really a twin scroll manifold but closest you will get. that style is fairly commonly used. my mem theres some tricks to porting it in certain places. worth checking out.

twin scrolls don't really work well with such small turbo's. petrol and big diesels use much bigger turbo's.
just hope your not using a turbo thats to big.

[slidenyo]

It's a garrett off a 4 litre 4 pot tractor so should be close although the twin scroll would work better on the 4, being a cast manifold means no gates . But I have a few more ideas to work through yet.

[tweake]

It's a garrett off a 4 litre 4 pot tractor so should be close although the twin scroll would work better on the 4, being a cast manifold means no gates . But I have a few more ideas to work through yet.

any details on the turbo?

[tuckertrucker]

Twin scroll only stops scavenging, most effective on 4 cylinder banks L4 ,v8 etc, and very efficent on rotary engines..... not so much with 6 cylinder with 2 and 5 being out of sync with the combined compression and exhuast strokes of the other 4 cylinders. The gain is marginal in this senario compared ti an equal length 6 cylinder manifold.

You sure about that mate?? I don't want to go against your almighty wisdom but a mate has a twin scroll on his td42 (replacing the previous garrett he had) and the gain is wicked. The top end performance hasn't really changed much but he is getting 8lb boost at 1200 rpm - he couldnt get that until around 2200 before.

IMO the twin scrolls value comes from its abilty to improve low end performance without loosing the top end power.

come back at me crash if you think im outrageously wrong

[tweake]

You sure about that mate?? I don't want to go against your almighty wisdom but a mate has a twin scroll on his td42 (replacing the previous garrett he had) and the gain is wicked. The top end performance hasn't really changed much but he is getting 8lb boost at 1200 rpm - he couldnt get that until around 2200 before.

IMO the twin scrolls value comes from its abilty to improve low end performance without loosing the top end power.

come back at me crash if you think im outrageously wrong

i'm picking that his turbo was to big and now hes put a smaller one on. i doubt very much the twin scroll on its own would have made much difference. odds are its whatever else he changed at the same time that increased the low rpm boost.

[tuckertrucker]

You sure about that mate?? I don't want to go against your almighty wisdom but a mate has a twin scroll on his td42 (replacing the previous garrett he had) and the gain is wicked. The top end performance hasn't really changed much but he is getting 8lb boost at 1200 rpm - he couldnt get that until around 2200 before.

IMO the twin scrolls value comes from its abilty to improve low end performance without loosing the top end power.

come back at me crash if you think im outrageously wrong

i'm picking that his turbo was to big and now hes put a smaller one on. i doubt very much the twin scroll on its own would have made much difference. odds are its whatever else he changed at the same time that increased the low rpm boost.

yeah fair enough mate. My understanding was that although you wouldn't easily be able to get an even balance of exhaust gas pulses from a 6 cyl, I understood that the secondary flow of exhaust gas flowing over the lower section of the turbine gave the turbine enhanced pressure (or flow) at low rpms - hence the increased performance. As far as I was aware he kept the AR50 compressor but it was the turbine which was changed??

[Twodiffs]

8lb boost at 1200rpm is very little to be honest.

[turoa]

8lb boost at 1200rpm is very little to be honest.

What would you call good for the likes of a td42?

[Twodiffs]

Standard boost with the aussies guys and aftermarket setups is upwards of 30 psi by 1900 - 2200rpm. At 1200rpm anywhere between 10 - 16psi. Just with built turbo, pump and ic. Not twin scroll.

[Crash bandicoot]

Twin scroll only stops scavenging, most effective on 4 cylinder banks L4 ,v8 etc, and very efficent on rotary engines..... not so much with 6 cylinder with 2 and 5 being out of sync with the combined compression and exhuast strokes of the other 4 cylinders. The gain is marginal in this senario compared ti an equal length 6 cylinder manifold.

You sure about that mate?? I don't want to go against your almighty wisdom but a mate has a twin scroll on his td42 (replacing the previous garrett he had) and the gain is wicked. The top end performance hasn't really changed much but he is getting 8lb boost at 1200 rpm - he couldnt get that until around 2200 before.

IMO the twin scrolls value comes from its abilty to improve low end performance without loosing the top end power.

come back at me crash if you think im outrageously wrong

im not saying wrong, just letting ya know itll be the garret spooling early which they are renowned for,.the manifold. not so much on a straight six configuration

[tuckertrucker]

Standard boost with the aussies guys and aftermarket setups is upwards of 30 psi by 1900 - 2200rpm. At 1200rpm anywhere between 10 - 16psi. Just with built turbo, pump and ic. Not twin scroll.

yeah but the aussies go pretty hard with their patrols. my boost doesnt start till around 1700 so i thiought 8lb at 1200 was awesome.

but in saying that, i am lookin at new setups to get those sort of figures youre talkin of

[Twodiffs]

Standard boost with the aussies guys and aftermarket setups is upwards of 30 psi by 1900 - 2200rpm. At 1200rpm anywhere between 10 - 16psi. Just with built turbo, pump and ic. Not twin scroll.

yeah but the aussies go pretty hard with their patrols. my boost doesnt start till around 1700 so i thiought 8lb at 1200 was awesome.

but in saying that, i am lookin at new setups to get those sort of figures youre talkin of

Is that with the Garrett? - I thought the factory HT18's were putting out that sort of psi up to a maximum of 15psi?. Crash will know.

At 1700rpm I'm probably hitting 20psi...definitely 24psi by 2200
Don't discount the ole TD42 as they handle more than what people think they can, have been running 30 psi for over 3yrs now.

[slidenyo]

what pump what turbo and what egts Mr twodiffs ?

[Twodiffs]

Td05 from United Fuel Injection in Perth, DC3 pump from Diesel Central in Qld and top mount air to air. Inlet manifold and airbox mods. Pump is 11mm and I'm only using half of its capability.
Max egts 550 post turbo under heavy load otherwise rarely goes over 350-450.

[DaveM]

Custom turbo manifold?

[Twodiffs]

Standard dts manifold and dump.

[tuckertrucker]

Standard boost with the aussies guys and aftermarket setups is upwards of 30 psi by 1900 - 2200rpm. At 1200rpm anywhere between 10 - 16psi. Just with built turbo, pump and ic. Not twin scroll.

yeah but the aussies go pretty hard with their patrols. my boost doesnt start till around 1700 so i thiought 8lb at 1200 was awesome.

but in saying that, i am lookin at new setups to get those sort of figures youre talkin of

Is that with the Garrett? - I thought the factory HT18's were putting out that sort of psi up to a maximum of 15psi?. Crash will know.

At 1700rpm I'm probably hitting 20psi...definitely 24psi by 2200
Don't discount the ole TD42 as they handle more than what people think they can, have been running 30 psi for over 3yrs now.

yeah with the garrett I'm not really seeing much boost till 1700 ish. When the funds allow Ill be chopping and changing. But I've got a boat to sort out first, then the manual conversion, and then Ill look at getting this power.


PS sorry for hijacjing the thread a little bit