mad boost

 

Gears Mr. Big, its all in the gears......lol, who am I shitty, I'll bow down now.....but I live in a relatively small city (compared to the states) and 400Hp is basically unheard of in a "ricer" so I'll be kind **** here :P

 

lol....ok maztang ur ryte...dint think bout that

 

Im running a 12a Turbo. Hoping for between 250-300rwhp when it gets tuned. Specs are as follows

12aT Jap Spec
Large Extend port and enlarged exhaust ports
Series 5 Plenum
4 *550cc Injectors (will be pushing their limit)
Series 5 Hi Flow Turbo (T04 front wheel)
Large Front mount Intercooler
Microtech LTX8 and Bosch Coils
Blitz Blow off valve

Currently Running 4psi before the tune. In the next week or so i hope to get the brass button clutch and fuel pump setup put in, both essential before the dyno. Then comes the tune with 15psi

Hopefully i dont kill the driveline too quickly as im running the standard series 2 gearbox and open center diff Guess this means no drag racing/slicks for me!!

Should be fun, seems reasonably quick now with 4 psi, enoguh to get it all crossed up between gears anyway!!

 

if your going to go to all that trouble, why not a 13B? it'll be earier!

 

god

 

damn

 

multi

 

posts! is i mod read this please delete this and the 3 b4 it.

 

Why not 13b? I already had a 12a Turbo motor in my car. It was either get that fully rebuilt or get a 13b import engine. I chose the 12a, i need it to be as reliable as possible, hence the rebuild

Also, it should make adequate power for me for now.

 

"You can never have enough power. I remember when we had Group B cars... THEN we had enough power!"
Juha Kankkunen - Rally of Argentina '02

 

Well, it must have been streetable since he drove it on the street all the time. I don't think it was making that much in street trim though. The 400+hp figures were on big boost and race fuel. That's not to say it can't be done by any means. There's people on this forum with more power than that on pump fuel.

 

Direct Freak, what info do you have on that 500hp 12a. I made a simialer setup except carb'd weber blowthrough. I ran too much boost and cracked the endplate dowl area. How much is that guy running? Ofcourse, I'm only using a S4 turbo with streetporting on the 12a. I think with 15psi boost, I was in the 220hp range.

 

You sure the cracked end-plate wasn't caused by detonation?

 

Well, if it was, I didn't have any problems with any audible detonation, smooth/damn fast running at high boost(10-15psi). I noticed that I had the sideplate to rotor housing sliding marks also which means its too much combustion pressure(ilustration on the Mazdatrix overboost results page). Apex seals are completely fine from the tare down, everything else too. Seems clear to me dowling is nessessary for that high of boost on 12a plates. S4 and newer turbo intended engines have stronger dowl area's then 12a's apparrently.

 

Much of the info was originally posted in the TII in GSL-SE thread.

As far as your car goes, I would say you had some leaning out of your engine. It's very easy to overspin and overheat the S4 Turbo. His car was extremely well tuned with a Haltech F9 as well.

Barnsey,
Your NEVER going to get the power levels you are looking for from the stock 12AT. You're gonna need to upgrade that turbo.

 

Well that is discouraging on the S4 turbo, I have thought it has been a pretty good match with a mildport 12a's flow ability. I have had pretty good luck with it yet-so-far(when it wasn't cracked yet) and is plenty impressive at 10-12psi on a mildport 12a, so maybe I'll simply keep it at that level for the for-seeable future. I also have since converted my jetting richer to run E85(ethanol 85% 15%gasoline, rated 105octane for lower risk of detonation with decent timing). I'm not running the biggest intercooler either which probably doesn't despense enough heat for that boost very long. I really do like the results though of a FREEEE turbo I have and can readily replace it with another good S4 unit if needed. I have heard they are ~ok for up to 15psi when everything else is correct, is that a fair assessment?

So it is your opinion that more then likely, my problem was related to detonation and not excessive combustion pressure? Thankfully, the inner water seals were fine and held. Endplate cracking is ofcourse a problem when the oil leaks through.

 

It will be above 250. Its not the standard turbo!! The series 5 turbo is not small, the comp cover has been machined out to fit the t04 wheel. The engine ports have also been greatly enlarged. It should get dynoed sometime this or next week, i'll let you know how it goes. My mechanic is confident that it will make that sort of power, he has used the same combo before

 

I apologize, I just re-read youe previous post with your turbo specs. I thought you were using the stock 12AT compressor..

Yes, the S5 Turbo isn't bad at all. You should reach your goals.

WACKY,

What kind of inercooler are you running? Have you wrapped your DP? Any heat-shields?

 

does the 12at have strong enough apex seals from the factory to run these kinda numbers?

 

There's nothing wrong with the stock apex seals! Since 1974 there have been only two types of seals used by Mazda. 3mm two-piece from 74-85 and 2mm three-piece from 86 onwards. (not sure what renisis uses but they're shorter.) Either of these seals will handle a hell of a lot more hp than 250 assuming the tune is good and there's on detonation.

 

I still say 400 rwhp from a street 12a is not going to happen. its hard anuff to get a 13b to that much as revhed stated above about ajc13b. not to say that you can not get more hp than that out of a 12a, its been done. somewhere around 300 hp in a 12a you reach a point of negative return. 1st you have engine life 300+hp 12a = short time. 2nd cost in $$ to do it gets much higher than using a 13b,13bt,13bre,13brew,20b or the like. 3rd cost in drivablity; goes way down. 4th the time investment would be very high 5th the ablity to use that power goes way down. and agin I got to ask why would you when the cost are considered. 400 rwhp or 400fwhp in a street 12a I do not think so. save your self the money and time go 13b or above and try to reach 400hp. 12a 400hp is a pipe dream for most. ajc13b had a hard anuff time getting to it with his 13b and that was well documented. I understand he still crusies this board why don't you ask him or someone else that has gotten to the magic 400 number on a rotary engine? I hope to be at 350hp on my 13bt

 

i could be done with well done port and good sized turbo IMO

but life wouldnt be all that long

 

AJC ended up with around 470rwhp on a dyno dynamics dyno. This is well over 500 on a dyno jet. So how did he struggle to make 400?

400 hp is quite achievable from a 12a. My old set up made 301rwhp on a dyno dynamics dyno. That is close to 350 on a dyno jet. This was with a very similar set up to what barnsey has described above. It was still very streetable too. I drove it to the track, put the slicks on, ran 11.9 and then changed the tyres back and drove home.

It doesnt mateer whether it is a 12a or a 13b. A decent sized turbo will get you 400hp, fullstop.

I am hoping for 500+ from my new set up.