banski

Hello fellows~~ Merry Christmas~~
i have a question to masters~~~ I have a 93 rx7 with T78 set up.. i bought this car last october and had fun!! unfortunatly my water seals were blown.. so i need to rebuild a motor. this time i wanna go for smaller turbo because my t78 was spooling really really slow...
i found few turbo kit from ebay please tell me about what you guys think. it's gonna help me out a lot!!
this is my first rotary engine so i'm so stupid about this...
this time i want to have about 350HP it's going to be good enough for me.

http://cgi.ebay.com/ebaymotors/93-94...Q5fAccessories

or

http://cgi.ebay.com/ebaymotors/93-94...Q5fAccessories

also if i want 350HP what sizes of injector should i use? thank you guys~~!!

also how much A-spec charges for tuning? I live in chicago so if you know any good shop let me know..

bc_fd3s

iTrader: (2)

Too much turbo for 350WHP.

And I think you need to do some researching here... if you're asking about injector sizes.

Look at a bush bearing T04E .84 or something. 56 or 60 trim if you want quick spool and 350HP.

ScorpionT

iTrader: (3)

That turbonetics would struggle to make 300whp, and the 60-1 would be just fine.

RacerXtreme7

iTrader: (2)

Too bad it's not a real 60-1 in that eBay add. I'd avoid both eBay auction and pretty much avoid ANY ebay turbo related junk unless it's genuine parts (Like Garratt). You already have a single turbo kit on the car and your getting ready to rebuild. I'd street port the engine and leave the T78 on there for now, you'll notice a lot quicker spool-up after the street port. If after that you still want a little quicker spool look for a FULL T4 sized turbo. If your on a budget get a standard journal bearing T04E 57 or 60 trim, or even a 60-1. Stick with a .84 divided turbine housing and a P-trim turbine wheel. Your T78 manifold is a T4 divided foot print so you can keep every thing you have already. If you extra cash get either 3 turbo's I just mentioned in a ball bearing center cartridge (CHRA) or get GT3574 or GT35R with a T4 divided turbine (call A-Spec for those).
Keep in mind, your going to have to re-tune your engine no matter which route you take, even if you keep your T78 and street port the engine, it will still need a re-tune.

~Mike............

Howard Coleman

iTrader: (6)

re the two setups:

both have stage 3 turbine wheels which are too small for the rotary.

the area of the stock (twin) FD setup is 5.25 sq inches.

a stage 3 wheel is 4.522 sq inches.

too much backpressure.

if either of the turbos comes w a stage 5 wheel that would work... 5.408 sq inches.

the 60-1 is mismatched. the compressor wheel is 5.647 sq inches and the turbo is normally sold w a "P" trim turbine wheel at 5.89 sq inches. as offered, the hotside is too small for the cold side.

400 rear wheel rotary hp requires 53 pounds per minute of air.

your T78 measures 7.584 cold by 5.903 hot and makes 72 pounds of air good for 542 rw rotary hp.

suggestions:

TO4E 60 trim 45 pounds at one bar. 50 at 19 psi
cheap. good. must have 360 degree thrust bearing and should be water cooled. internal wastegate or external

GT3076r 49 pounds of air at one bar. ball bearing $. 5.511 cold/4.019 hot

GT3582r 56 at one bar. ball bearing $ 6.386/5.171

GT3574 56 at one bar inexpensive journal bearing (works fine) A-Spec only. 6.386/5.89 a really nice larger turbine wheel for less backpressure and retained heat. (my pick for you)

also w re to the ebay offerings... stay away from HKS "style" wastegates. prone to failure and can cause you to be calling your engine builder again.

howard

banski

Thank you guys~~ thank you thank you so~~ much!!!
i don't know what kind injectors i have.. hmm.. is there anyway i can tell what size injectors i have?
should i talk to one of A-spec tech for my engine rebuild?
i don't know where should i start...

ScorpionT

iTrader: (3)

But remember Howard, not all turbines are created equal. Some will flow more than others of the same size. The stage 3 is a bit small for a rotary, I will agree there. The 60-1 compressor is fine though.

fc3c69

iTrader: (49)

If you want contact Ryan from Shook Motorsports. Good guy located in Rockford (Loves Park) & can help you out. http://shookmotorsports.com/

Howard Coleman

iTrader: (6)

"not all turbines are created equal. Some will flow more than others of the same size."

they are more correlated than not and as such my average areas work well as a starting point. and yes, they do differ as to efficiency. for example, the stage 3 is significantly inferior to the stage 5 based on blade shape.

"The stage 3 is a bit small for a rotary, I will agree there. The 60-1 compressor is fine though."
i agree with you on both points.

"i don't know what kind injectors i have.. "

if you are running a Power FC you could look at Settings 5 page.

BTW, as to your engine... when you breach a coolant seal you have the equivalent of a blown head gasket. on each compression stroke the hot high pressure gasses rush past the breach and in relatively short order they melt the supportive coolant seal ring which is less than an 1/8th inch thick. should the rail be melted the iron becomes junk. so don't drive a leaking motor. further, if the motor sits for a lengthy period with coolant in it the coolant can damage the surface of the iron.

howard

Howard Coleman

iTrader: (6)

" if i want 350HP what sizes of injector should i use?"

even though you want to make 350 you need to run injectors that are capable of servicing the top output of your turbo. that's because you could have a system failure and your turbo could deliver it's max air. (sticking wastegate etc).

if you don't have the fuel you will be dealing w another motor situation.

another reason is you just might want to run a bit more power... hp is addictive

so assuming you go w a GT3582r, or a GT3574...

plan for max air of 62 pounds per minute.

if you run at 11.3 Air Fuel Ratio then you would need 5.486 pounds of fuel. gasoline weighs 6.35 pounds per gallon so that would be .864 gallons per minute or 3270 CC/Minute. you want your injectors to run no more than 84% duty cycle so 3270 times 1.19 = 3892 CC/Minute. if you want to run richer than 11.3 4000 CC/Minute would be the target.

the stock primary injectors deliver 1100 CC and you can bore out the secondaries and get 1300 each which would be 3700.

you could run the stock primaries and switch to what most run, two 1600 secondaries (which generally deliver 1680 each) and you would be at 4460...

howard

rx72c

iTrader: (8)

Ive maxed out two 880cc injectors and two 1700cc injectors run a 10.50 afr on 28psi with a GT3582r.

Above car delivers around 500rwhp.