Which Turbo?

[col_fd3s]

hi guys, my rex has been running a td06 with a 20g exhaust housing and serious boost issues.

the car was mapped to 0.5bar and running 302.4bhp, but anything above 0.5 and on planting your foot down the car would just jerk and jolt.
reworx put this down to the housing being to small to exhaust the gasses quick enough, and suggested getting a 25g housing, but these appear to be rarer than he preverbial, and as i\'ve just cooked my rex, and found what i think is substantial play in the turbo shaft, i want to replace it, but what would you guys recommend going for?

col

[lee mills]

depends what power you want and what your going to use it for ie Street/Trak/Drag im sure plenty of people will give you lots of options but you need to decide what use you want it for before you can make an educated decision

[col_fd3s]

well ideally i want to stay around the 400 mark, but also have it as an every day turbo, that could also be put to good use on the track...

col

[lee mills]

I would suggest a GT35 but somebody with more knowledge will no doubt be along soon to advise you

[nuki]

http://www.rx7store.net/product_p/gt35r%20kit.htm
 
i want that
£1500

[nuki]

http://www.rx7store.net/Garrett_GT35R_Turbo_p/garrett%20gt3582rt4.htm
 
or £780 for u ^_^

[jackaleks]

people have been making good noises about Holset turbos (HX35 seems to be the favourite). they\'re a British company as well (owned by Cummins) so should be a bit less expensive than the competition.
 
that\'s not from personal experience, just from lots of forum lurking

[StavFC]

Bringing this back from the dead like Jesus rather than starting a new one, the HX35 has been mentioned...
Has anyone ACTUALLY TRIED a HX35 on a 13B? They are T3 flange which is not ideal, but messed about with one even on a 5litre V8 and it didnt choke it so the turbine clearly flows bloody well, and compressor wise its as good as a GT35 (proven 600bhp+ on counltess engines, seen 450+ on stock 2litres at under 1.5bar).
 
I happen to have an almost unlimited supply of HX35s, and my manifold needs to come off as its blowing, so no harm welding a T3 flange on, so its tempting.
 
Only want 400-450 at the fly really, so not exactly pushing the thing.
 
PS- On the original post... How on earth would the exhaust housing make the car jerk n jolt?! A hugely choking turbine really doesnt cause that effect?

[BlitzBoy]

PS- On the original post... How on earth would the exhaust housing make the car jerk n jolt?! A hugely choking turbine really doesnt cause that effect?

Seeing as you are a Rotary expert what would it cause?

I guess Reworx who are rotary tuners and have produced countless 9 and 10 second cars dont know what they are talking about ?? :2Rolleyes hmmmmm

I had to go bigger turbo with the bigger exhaust housing as my porting caused the engine to choke at high boost, causing a stumbing/jerking effect that I felt on the last runs with my old turbo

[StavFC]

Im not a rotary expert and freely said on here I dont know them well at all, but I have experience of the fundamentals of turbocharged engine tuning, unlike most it seemed by that pathetic torque/boost argument the other week, lol.
 
My point is im VERY surprised choking through restriction cause jerking and jolting though (unless it was ANOTHER problem caused by the choking, like weak ignition issues), make the car flat as a fart, even cause such high backpressure it dets and hurts things, but surprised it makes it jerk and jolt on a rotary. Ive seen that once or twice on piston engines when choked, but that was only as it was causing valve float and missfiring.
 
Rather than rolleyes and sarcasm, why dont someone who KNOWS (do you? or just replying to argue?) explain why this happens on a rotary when restricted, as im sure we would all like to learn more about the unique issues on a rotary like this seems to be...
 
Or even, someone just answer my HX35 question rather than argue about something else they dont know about.

[BlitzBoy]

Well you entered an argument with your "PS" comment, disclaminig that a small exhaust housing would not give those symptoms and Reworx gave an incorrect diagnoses

yes I do KNOW read my last line in my last post regarding my own experiance with a choking rear housing, too small a housing would stop the exhaust gases to escape correctly from the exhaust port causing the gasses to be carried over to the next inlet charge. SIMPLES lol

[strange_days_uk]

Buy mine, is perfect for you
http://www.mazdarotaryclub.com/forums/showthread.php?t=59332

[StavFC]

yes I do KNOW read my last line in my last post regarding my own experiance with a choking rear housing, too small a housing would stop the exhaust gases to escape correctly from the exhaust port causing the gasses to be carried over to the next inlet charge. SIMPLES lol

Its not "simples". Exhaust gasses not all escaping is backpressure/restriction/choking, what happens on every engine, rotrary or not, simple engine fundamentals.
 
But it doesnt suddenly (ie go from fine to jolting like it has a missfire, without having noticable restriction issues beforehand) cause juddering, jerking, jolting unless it missfires too due to valve float, detonation, weak ignition, etc. Flat as a fart yes, but not drive like its fooked.
 
So why then, if its 100% just a too small turbine and nothing else, and you KNOW, why does it act differently on a rotary, as I dont know?
 
Thats what id like to learn :Thumbs-up

[BlitzBoy]

But it doesnt suddenly (ie go from fine to jolting like it has a missfire, without having noticable restriction issues beforehand) cause juddering, jerking, jolting unless it missfires too due to valve float, detonation, weak ignition, etc. Flat as a fart yes, but not drive like its fooked.
 

If you read his first post correctly, he states its fine up to 0.5 BAR and it has been, its when he tries to increase boost he gets the problems. therefore more fuel and air are going in, but the resultant bigger faster exhaust gasses (Rotaries produce far higher EGTS then Piston engines) cant escape due to the exhaust housing being too small, causing it to be ingested in the next combustion cycle causing the mixture to be fooked hence the symptoms Reworx diagnosed

[jackaleks]

But it doesnt suddenly (ie go from fine to jolting like it has a missfire, without having noticable restriction issues beforehand) cause juddering, jerking, jolting unless it missfires too due to valve float, detonation, weak ignition, etc. Flat as a fart yes, but not drive like its fooked.

wouldn\'t it misfire though? given that a w4nkel\'s combustion chamber is long and thin if there is a load of exhaust still in there as the rotor comes round for the inlet \'stroke\', as Blitz said due to it not being able to escape a restrictive turbine, then surely this could seriously hamper combustion? after all, our engines have leading and trailing plugs to promote a healthy flame becuase of the awkward shape of the combustion chamber.