exhaust and intake for a 1.9 diesel

[richieadkins]

I still have the exhaust flange from the original exhaust so in theory could I chop that square and use flexible hose to connect the downpipe to the backbox?? A reply to this soon would be appreiciated as I am starting the engine swap today!! Wish me luck i think i'm gonna need it!!
Richie

[ringo]

think thats for the inlet ringo..the exhaust manifold should go on no probs..agree with you though..the inlet would be alot better

Doh - i didnt read that properly at all did i !

I'll get my coat.....

Ringo

[weldore]

think thats for the inlet ringo..the exhaust manifold should go on no probs..agree with you though..the inlet would be alot better

Doh - i didnt read that properly at all did i !

I'll get my coat.....

Ringo

..i never read stuff properly mate

I still have the exhaust flange from the original exhaust so in theory could I chop that square and use flexible hose to connect the downpipe to the backbox?? A reply to this soon would be appreiciated as I am starting the engine swap today!! Wish me luck i think i'm gonna need it!!
Richie

i think the link said that the inner diameter was 54mm so you really want the downpipe to be as gooder fit as you possible can so measure the outer diameter of your pipe and hopefull itll be around 54mm...mine are nowhere near that

its made me get me camera out now

ok,the one on the left is the 1y manifold with the flange i made for it bolted on and the one on the right is a spare downpipe i have that is identical to the one on the van...the 1y bore measures 44mm and the one on the right is 34mm


to give you a better idea this is the old pipe in the new flange


and here is the new 90 deg bend in the 1y flange

[camper]

That is a good fit and nice for welding.

[weldore]

[richieadkins]

Did a quick bit of measuring once I got the cs out today the offcut exhaust from the ibiza (which has the the flange still on it) has an o/s diameter of 44.5 as does one of the joins on the exhaust which was on the van so I reckon all I need to do is get some flexy pipe with an internal diameter about the same then I should be ok any body got any thoughts on this.

That join looks like it will work a treat fella all you nee is a nice shiny backbox

[weldore]

that sounds like a plan richie...should be ok i would have thought
shiny back box...hmmm...ill settle for a rusty one at the mo just to see how it performs

[caveman]

I was on vacation last week[ 2400 kms round trip] and the downpipe broke right at the flange. Got buddy to mig it for now but that downpipe is no longer available here. Also the muffler shell is tearing right where the mounting flanges are so it is time to replace the whole thing. As i replaced the 1.7 with 1.9 and in the future will be replacing the pump with a 'super pump' the motor should be able to pull close to 6000 rpms. Therefore i will need to open up the exhaust to take advantage of the revving capability. I'm going to use a dual outlet gas manifold and probably a 2.1 gas muffler. Problem is i also want to install a catalytic converter [ i have 1.9 and tdi ones lying around i can cut up to use ] so there will be a bit of pipe bending etc to do. I don't good access to a mig or tig so i'll have to send it to a muffler shop. Hopefully it'll work out and i'll post some pics. I believe some else on this forum has done this also.

[weldore]

ill be intersted to se the results caveman .....right im confused .ive took the inlet and the exhaust manifolds off today and when i did the engine swap i couldnt see the point of port matching the inlet.i have on the inlet a bore on each of the ducts that is identical in size all the way through to the mating face of the engine.the ports on the engine are D shapes and they accomodate the smaller 0 shaped ones of the inlet manifold.so if air is being drawn through a small hole into a large hole why do i need to try and port the smaller one to match the face of the D shaped one?..had it been the other way around and the air was rushing into the small hole and buffering off the face of the manifold then i can see why it would need to be done then..anyone shed any light?
i dont want to just leave it as is if it wll make a difference,but i dont want to start shaping something if there will be no gain

why,oh why didnt they make the 1y inlet fit in the bloomin engine bay....hmmm i might try and stick it in..ya never know

[weldore]

ok..thats never gonna fit in a month of sundays unless i modify the chassis..and thats not gonna happen any time soon.so ill leave it as is and just get on with sorting the new exhaust downpipe out and see if theres any power gain....the bore in the 1.6 exhaust manifold is minute compared to the 1y...i bet its half the size..not much bigger than one of the inlet ports on the manifold i hope this makes some difference to the pull as i think it must be being compressed right at the manifold when higher revs are needed.i also decided to stick with the original exhaust and just make the downpipe to fit ..my theory is if it had to compressed any of the gasses it would be ok further down the pipe rather than at the point of exit....i keep thinking back to when i had a 125 bike and we removed the restriction washer in the exhaust to give it more poke

[caveman]

After reading your post and seeing the pics of the 1Y manifold, i realized it would be a big improvement and a lot easier just to use a 1Y exhaust manifold. What exactly do you mean in your last post about things not fitting? I did some measurements last night and can see that if i was too use a dual outlet manifold there would barely be enough room to make the 2 pipes run long enough to be effective. I don't want to go through all the trouble and find that my fancy new custom dual exhaust has less power than what i now have. I have learned that getting the math wrong on an exhaust can be an exercise in futility.

[weldore]

i ment the 1y inlet manifold...the exhaust manifold is on and ive made up the downpipe just needs welding fully ..ive lent my mask to a friend and have to wait till 6 till he comes home to get it back ..failing that its blind welding

[caveman]

I just saw your question about matching the inlets. Yes i suppose you could bolt it on the way it is,and it would work, however spending a bit of time to match them may give proper/better intake flow to the head. With a diesel not having a throttle to restrict it upstream, more intake air available will result in more power. The 1.9 can flow quite a bit more than a 1.6 or 1.7 so being able to let it have as much as possible can only be good. So ideally the 1.9 SDI intake would be best but as for fitting it in a T25, well thats for you to decide. Other than the small diameter runners the CS intake is pretty free flowing.
My next question is, how well does the 1Y exhaust manifold fit on a T25 ? Also do you know if a 1X work as well?

[weldore]

the 1y exhaust manifold goes straight on no probs,the only difference is the exhaust flange mounting is more to the left which makes it even better to get to the studs...i dont know about the 1x as ive never seen one.if i get my mask back tonight and i finish off the downpipe and fit it on ill post some pics for you..its looking good so far

[weldore]

well..what can i say...its alot quieter than before and i think i have a few extra horses...im sure i do,it defo seems a bit pokier than before and boy does that new downpipe make a better noise...only thing is it seems to get very very hot..but the other one could have but i just didnt notice it ..ill post some pics if anyone wants to see it tomorrow when its hopefully not raining and brighter