How to: Turbo Manifold design, need your thoughts

[RAd28]

just had another crazy idea for mounting the twins... what if you were to mount them with the base flange (close to) parallel to the side of the block like my first idea, BUT make the axis of the turbos (close to) vertical...

*thinking out loud* => challenge would be the intake side of things, but i can't see why some tricky pipe work couldn't get past that... i can only picture what the front turbo would look like mounted this way, the rear turbo's inlet housing is rotated about 30deg rel to the exhaust housing, so options are, both the same, one way or the other, or both different, one way or the other...

have i missed out on anything?

[jonra23]

Mount the front one low and rear one high, exhaust from front out under the rear turbo, inlet from front over the top of front turbo.

regards.
jon

[1jzracing]

they have to be dead level or they blow smoke ... made that mistake b4 even 5 degrees is too much

i have seen 1 high 1 low b4 and it looked awsome might be wort looking into, ill try to find pics tonight

[pilot]

There is exactly an article in Garret´s home page about this (June 2006: TURBOCHARGER INSTALLATION INSTRUCTIONS) here:

http://www.turbobygarrett.com/turbob...ws_letter.html

[RAd28]

1jzracing - you refering to rotating the axis of the turbos? that's a good point, had thought about oil and water, but didn't consider oil seeping through the seals... although shouldn't the seal have enough strenght to cope with the angle? i mean the oil is under pressure anyway... do you know why it blows smoke?

one high, one low... sounds interesting. definatly worth looking into...

~EDIT:

on that garrett page it says about oil pressure, and seal leakage from the pressure being too high, sure this couldn't have been the problem 1jzracing? from my understanding, ball bearing turbos need a restrictor on the oil flow... are you sure it was from the angle of the turbo? not something else?

[1jzracing]

check these pics out for one up one down

as for the oil the seal on a turbo its nothing more that a little slip ring similar to a piston ring and there is a laberinth type of oil slinger on the shaft so it flicks most of the oil off as it spins befor it gets to the ring which isnt a real tight fit. its not like a rubber seal there isnt all that much stopping the oil, so any angle on the shaft and the oil litterally just runs out onto the turbine

ps.. it could have been any of those things it was years ago, did try restrictors etc and it just always smoked when it was idling even tried replacement turbos, they were twin rb20 units on a 1j mounted at a slight angle.... went well

[Forcefed6]

Here are some more pics of one up, one down on a 1GGTE... Also in an ra28. This will give you a little idea of how much space there isn't...

THis car used to belong to an old Toymods member...

[RAd28]

wow... cool, thanks for that... looks like lots of work... hmmm guess a decent single really is the way to go...

[Gold28]

Thats Phils old car. Made plenty of power but I think he had problems with one of the turbos not getting enough oil.

The standard manifolds on a 1G ain't all that bad. Pull them off and have a look, they have nice long runners, good collectors and generous bends. A little cleanup of the casting and they are quite good. Heck Josh is running the standard exhaust manifolds and a Y piece with a big single on top and it is making 280rwkw. There is not too many custom manifolds that are making thoes numbers.

The problem with the 1G turbo setup is the collector chokes the life out of them. I had thought of making a short stumpy adapter to turn the rear turbo around to face forward and have separate dump pipes. Sounds good in theory and would give you better turbo spooling and possibly better top end due to better breathing but space in a RA28 is the killer, you will have fun trying to get the front dump pipe past the rear turbo and the rear dump past the master cylinder. Worth a try if you want to stuff around with it though. You also have to stuff around with the compressor piping and the oil/water feeds. A lot of work for possibly only a small gain. But then again people spend good money getting hiflowed turbos for a 10% gain so why not. Surely there is that much in improved maniflods.

If that makes any sense at all it's a miracle. This beer has gone straight to my head....

[Forcefed6]

Yes that was Phil's car. The problem I think he had, was not an oil supply problem, but was a return problem as the lower turbo was below the oil return on the block. We found this out when it did the seals on that turbo because the electric pump that was there to pump the oil uphill died. We fixed this problem by removing the sump and adding a return into the top of the sump which is just below the turbo.

The setup worked well, and if kinda what inspired me to do mine that way.

[RAd28]

The problem with the 1G turbo setup is the collector chokes the life out of them. I had thought of making a short stumpy adapter to turn the rear turbo around to face forward and have separate dump pipes. Sounds good in theory and would give you better turbo spooling and possibly better top end due to better breathing but space in a RA28 is the killer, you will have fun trying to get the front dump pipe past the rear turbo and the rear dump past the master cylinder. Worth a try if you want to stuff around with it though. You also have to stuff around with the compressor piping and the oil/water feeds. A lot of work for possibly only a small gain. But then again people spend good money getting hiflowed turbos for a 10% gain so why not. Surely there is that much in improved maniflods.

i had thought of doing the same thing for mine, and yeah, as you mentioned there is stuff all room in the engine bay... i'm curious about the idea of joining both sections of the manifold with a 'Y' Piece... sounds abit like a bandaid mod, i'd be concerned with heigh under the bonnet, ... but 280kw sounds alright, what turbo?

the one up one down idea seems like too much work for just a street car.. maybe if i ever make it to the track

[TheToyman75]

Rad28,

What series 1G do you have and what was it putting out before ? The single turbo upgrade will end up being the most cost effective and there is always a turbo that will provide the desired result in relation to when it comes on boost.

As for long verse's short runners there are many complex theory's and calculation you can do but personally I opt for the simple version. The harder the hit on the exhaust wheel the better the boost.

A hot expanding gas will impact the exhaust wheel harder than a colder one. In theory this will yield a quicker boost response than a longer runner.

The higher the velocity of the exhaust gas hitting the exhaust wheel again the harder the hit, the shorter the pipework, the less friction to slow it down.

2 small points in a really big topic

[RAd28]

it's a GENIII 1G, no idea what it was putting out before... just stock power, only had an exhaust, and FMIC non standard, some beefier plug leads, and a malpassi fuel reg, but nothing else.

i can understand MOST of the theories relating to exhaust gasses, i guess the main question is is it really worth taking them all into consideration for the sake of time, effort, and above all, money? do you really get that much gain? or would it be better to save a few bucks, and buy a boost controller or something else for example.

[Gold28]

YES!!!!!

Buy a boost controller, even just a cheap bleed valve and run it at say 15psi, it will transform your car. Until you get bored with that, I wouldn't even consider changing turbos or stuffing around with manifolds. Most gen3's at that boost will make around the 140-15rwkw mark which is plenty for a RA28 road car.

[TheToyman75]

it's a GENIII 1G, no idea what it was putting out before... just stock power, only had an exhaust, and FMIC non standard, some beefier plug leads, and a malpassi fuel reg, but nothing else.

i can understand MOST of the theories relating to exhaust gasses, i guess the main question is is it really worth taking them all into consideration for the sake of time, effort, and above all, money? do you really get that much gain? or would it be better to save a few bucks, and buy a boost controller or something else for example.

Why the hell would you put a Malpassi reg on it ???

Will you really get that much gain froma Turbo and manifold upgrade... Yes (Look at Josh KE30 for Example) BUT I agree with Anthony. The Gen3 1G is a pretty impressive package for a 2.0l, in stock trim its not bad but with a good exhaust and efficient intercooler they respond great to some more boost. My last RA28 turned 144.2kw at only 12PSI.

As suggested you can just fit a bleed valve (Around $100) to up the boost and see if its what your after. A good electronic boost controller will give you a better result again of course.

mmm maybe I should just get another 1G.........