Thicker exhaust manifold needed

[Cashpoint]

Conclusion, a friend of mine is now building me a custom one. with 2mm thick stainless steel tubing.

My gt4088 kit came from the RX7 Store. How much is your friend asking for the manifold as if it thick than the one i\'m running i may be interested?

[Looksamc]

Just found this on the net if its any help.

http://www.advancespeedshop.com/cast-iron-turbo-exhaust-manifold-9396-mazda-g17141z6002000-p-665.html

[raceralexuk]

The one Jon (Atomicrex) sells on here are the best you\'ll find.

[jackaleks]

Full Race are probably the best product around, you have to pay for that though

[raceralexuk]

Yeah that\'s pretty nice too.

It\'s twin wastegate flanges are strange though. Very unusual to see on a 13B, I can\'t imagine anybody runs enough boost to need two. Only usually seen on motors running over 3Bar, and it\'s not really viable to try to make a 13 run at that inlet pressure.

[fil_auto]

FDUK me that looks nice, was gonna say it almost looks Ti with those welds / colouring... drool!

V Pretty

[turbotoaster]

Full Race are probably the best product around, you have to pay for that though

for that money though id want a custom made one so that i knew my turbocharger fitted in the engine bay(wasnt touching chassis rail, LIM or filler neck

Yeah that\'s pretty nice too.

It\'s twin wastegate flanges are strange though. Very unusual to see on a 13B, I can\'t imagine anybody runs enough boost to need two. Only usually seen on motors running over 3Bar, and it\'s not really viable to try to make a 13 run at that inlet pressure.

whats the point in having a full divided flange and turbine housing if your going to let the exhaust gas mix before it gets to them?

also dont you understand what wastegates are for, they are to divert exhaust gas AWAY from the turbo so that it doesnt create to much boost pressure, the exact opposite of what your saying.

if the wastegates were to small you would get boost creep where as the engine rises which in turn pumps out more gas the wastegate flow would max out and more air would hit the turbine spinning it up more and creating more boost than you want

[raceralexuk]

That\'s a bit of a strange/agressive way of replying to a post :3Confused
 
Anyway, what I meant was that the volume of exhaust gas on a single turbo 13B running at sensible boost is well within the volume of exhaust gas a normal wastegate can cope with, thus two are not necessary.

Also, keeping the exhaust gases from each rotor separate is not critical with these engines. Twin scroll turbos are being used by "us" because they\'re readily available not necessarily because they\'re best matched to the powerplant.

[turbotoaster]

im sorry......\'not necessarily because they\'re best matched to the powerplant\'

have you seen the research and development mazda went through on the fc when it came to divided housings, ill see if i can find the SAE paper on it, i think mitch might have a copy

they gained greater spool and showed more power at the top end by keeping the exhaust pulses seperate.
i would say rotarys are the actual engine that gain most by being divided

put a turbo on a full bridgeport engine with a small single wastegate and ask it to run 10psi of boost, it will struggle, hence the need for either a large 60mm wastegate or 2 smaller 38/44mm wastegates, since i havent run a dual wastegate setup on a rotary i can only comment on what people have said, that was it was better at controlling boost and responce than a single large wastegate.

[jackaleks]

whoa, where\'d the aggression in here come from?

raceralex: i\'m pretty sure FullRace\'s 13b manifold actually only has one WG flange, at least the only install pics i\'ve seen on RX7Club had two separate runners into one flange. i think the main advantage of having two would probably be boost control response, as you can have the wastegates pretty much on the manifold with no extra runner for the gas to have to travel down... that said, you could probably measure the difference in response times in milliseconds so totally academic!

EDIT: actually, for the money they\'re asking i wouldn\'t be surprised if you could specify stuff like single/dual WG flanges.

[hairyhoover]

Positive boost by 2k and full boost at 3700 rpm

was this on a street or or 1/2 bridge??? what size exhaust housing where you using?
 
Im just in the process of building a engine for this turbo and after seeing the size of it was i worried about spooling with a large street port. I have a 1.19 exhaust housing

[Cashpoint]

Running slightly smaller than yours, 1.06 exhaust housing on large street port