Quick question. I know dump pipes play a big part of sport cars but what about diesels?
My FD33T engine is nearly ready to be installed and I looking into the dump pipe / exhaust atm. My thoughts are going 3 inch the whole way from turbo back and removing the cat. Would it too loud? Is it worth going the 3 inch straight from turbo?
The turbo I got is a GT2554RLs which has the same 5 stud bolt pattern on the exhaust outlet manifold as Nissan s13/ s14 I believe . Sr20det.
exhaust pipe i take it is what you are asking, You wont have a cat in your system. I would just fit 2 inch pipe with a flow through muffler.
A dump pipe is where your turbo lets pressure through on over boost
cheers
blaze
Hi Blaze.
The purpose of a dump / down pipe straight off the turbo is to reduce lag and helps the turbo spin longer. Maybe you thinking off something else?
My question is most people go 3 inch dump pipe but im wondering if there would be any benefit to a diesel but now that I think about it a turbo is still a turbo, diesel or not. So a 3 inch dump pipe would still be the way to go.
Cheers
Mick
Hi Blaze. The purpose of a dump / down pipe straight off the turbo is to reduce lag and helps the turbo spin longer. Maybe you thinking off something else? My question is most people go 3 inch dump pipe but im wondering if there would be any benefit to a diesel but now that I think about it a turbo is still a turbo, diesel or not. So a 3 inch dump pipe would still be the way to go. Cheers Mick
Hi Mick
I am no expert on turbos. But diesels do not have a throttle and so the turbo does not slow down so much and does not lag much when you put the foot down. So that big dump pipe does not seem to be necessary like the hot petrol engines believe in having. And there is no cat to remove either on a diesel. (unless you are missing your favourite moggy ??)
My thoughts would be to just put a sensible large pipe in and a free flow muffler to suit and the same size out to the back. A turbo does not need much muffling. A 3" pipe is hard to fit in and involves much more work and expense even to fit under a bus. Wasted IMHO. Go with a 2.5".
Jaahn
-- Edited by Jaahn on Wednesday 9th of September 2020 06:04:03 PM
Cheers for the input Jaahn.
Seems there's a few different opinions out there. I spoke with a truck guy today and he said just try get the biggest pipe you can straight after the turbo and then reduce down after the dump pipe to 2.5 inch with a straight through muffler.
I looked at the ED33 engine and the FD33T engine whilst both still in the engine bay and there was quite a bit more room to play with with the FD33T engine.
A new 2.5 inch dump pipe is about $100 and I could get a second hand 3 inch dump for $100 also. Decisions decisions. Haha
Mick
And there is no cat to remove either on a diesel.
Strange, my 2008 Patrol has a cat on the exhaust. Ive been filling it up with diesel since I bought it new.
And there is no cat to remove either on a diesel. Strange, my 2008 Patrol has a cat on the exhaust. Ive been filling it up with diesel since I bought it new.
And there is no cat to remove either on a diesel. Strange, my 2008 Patrol has a cat on the exhaust. Ive been filling it up with diesel since I bought it new.
the bus in question is pre 2000
cheers blaze
To make a sweeping statement that there is no cat on a diesel is misleading. Maybe Im just being pedantic.
Best to make dump pipe the same size as turbine . If anything slightly larger . Exhaust is spinning and need to change lateral direction . The first 200mm especially with internal wastegate gives these uneven gass a chance to merge with less turbulence. A divider between gate and turbine helps big time . Std the gate enters dump pipe at tight 90* angle . Causing turbulence to dump pipe . To make things more critical. Theres often a 90* bend on dump pipe close to turbo .
The purpose of a dump / down pipe straight off the turbo is to reduce lag and helps the turbo spin longer. Maybe you thinking off something else?
My question is most people go 3 inch dump pipe but im wondering if there would be any benefit to a diesel but now that I think about it a turbo is still a turbo, diesel or not. So a 3 inch dump pipe would still be the way to go.
Cheers
Mick
