I noticed an oil leak coming from under my oil filter pedastal on my 550 RWHP HBP, S5 irons.
Turns out it was a small crack and I am going to need to pull the motor and replace the back iron.
I heard it crack when I was getting in to it. It happened right whne my meth injection kicked on at about 1.4 bar.
I noticed my AFR's (gas) were in the low 10's also. I am running E85.
So my question is, can you crack plates because of a misfire from too much fuel?

 

The s5 dowel area on the rear plate has less material than the new REW plates. They are prone to crack....

 

yes. I have cracked one the exact same way you are talking about. I know I did it from too rich and ignition couldn't fully ignite it causing a misfire. I was coming out of a turn on the track. I was all over it and I had forgot to set the rev limiter as I was working on raising the rev limiter the day before. Because of this I went into a part of the map that had tons of fuel that I had not fully tuned AFR's were 10.0 or lower when it happened.

You are running E85 + meth correct? I have not used E85 yet but from my understanding you should be good w/o meth at 20 PSI. I know of several guys running around 23 to 24 PSI on E85 only.

What is your ignition set up?

 

Yeah...I'm going to ditch the meth injection.
I am jsut running a Crane HI-6 box to the leading coils.
Stock TII coils which have worked great so far.

 

Sounds like a great set up.

I would recommend ditching the meth w/ E85 as well. I am not a fan of using 2 fuels. We have enough problems tuning one fuel why complicate it more? I am a fan of water injection as I have seen great results with it and have seen it save a motor on the track when the fuel pump sucked air.


Keep you head up and get her going again. Keep us updated how it turns out.

 

Frickin finicky engines!
Too little fuel....blows them up!
Too much fuel .....blows them up!
Can you use a REW rear iron on a S5 block?
I just happened to have a spare S5 rear iron I purchased from Japan2LA last year figuring I would need it someday. Maybe after I crack this one I could slap on a REW iron?
Getting sick of trying to bullet-proof my engine. Thought I was pretty close with ALS seals and E85.

 

12.7mm Full Stud time..

 

Why is it everytime somebody cracked an iron you suggest them going full stud when they can just use 2 extra dowel or stud? Also doing the oil mods would help too. We use only 2 stud on our 8's and hopefully high 7's cars 1/4 miles.

 

Because it works...

If you have had success doing something else, then good for you..

I recommend what I have used, and has worked for me...

 

These are all theories. Everybody needs to find their own and apply it. But it is through peoples ideas that we can push these engines a lil further. I know people who have made 800+HP without studs, pins, etc... My advice is RXTSY57 should just buy a thicker JDM rear iron and call it a day.

 

Bruce, if you can source a newly produced rear iron (whether it be S4 or S5) they come with the newer, REW-size dowel land. I bought a new S4 iron from Redtail-Racing.com out of BC, and it had the larger size w/ triangular rib. Are there any differences between S4 and S5 rear irons? If not, check them out, they're dirt cheap.

-Taylor

P.S. That isn't that rich for E85. Remember, the fuel is 85% alcohol, and even ethanol likes richer A/F ratios then gas. If you're still on the standard stock leading coil, I would definitely look into an amp at that kind of power.

 

Brian, I would love to do the stud kit, but I just don't have $1500 to spend right now.
Here is a picture of the iron I am planning on using. Can you get one that has any more material on it than this?

 

Why are you running methanol injection with e85 as your primary fuel source?

Don't bother with the dowells or studs, just get a new iron with the meatier dowel area, much easier, cheaper, and faster.

fwiw, S5's have the meatier dowell area except the very early '89 engines. All the S4's had the smaller dowell areas. I have not heard about newly sourced S4 irons having the larger dowel area as I have never bought a new S4 rear iron. That is cool if they do offer them that way now though. Also, new rear irons are dirt cheap as already mentioned.

Who tuned your car?

 

i had broke my rear plate in the same location it was like they say it just isnt as meaty in that area mines just broke dew to boost pressure pushing out just find a plate with a thicker dowel area

 

I had my meth injection coming on at about 21 PSI, but as I already said, I am going to ditch it. Already had it when I did the E85 conversion and figured what the heck.
I tuned the car myself. Have quite a bit experience tuning the E6K.
Did anybody see the picture I posted above?
Taylor, I have an amp on the leading coil.
http://www.youtube.com/watch?v=oHlm_1aWcc8

 

I can attest, new rear irons be it S4 or S5 have the meatier dowel area. $250 from redtail, I was pretty stoked.

 

Thats the thick one.. nothing better than that...

 

I think I will start building a race engine.
ALS seals, pinned and doweled, new housings, balanced and clearenced with external lubrication. Large Streetport.

 

I don't have alot of experience with this, and I know the price is WAY up there... but will the aluminum housings from racing beat not really have this issue? From what there reviews on it say, is sounds as if it's a great part and will be withable to stand alot of power.

http://www.racingbeat.com/FRmazda2.htm

Just curious if anyone has actually used them or knows if they really hold up as well as they?

 

i was also curious at to the experiences of peoples with the racing beat units, mainly on decent boost level drag cars though ?

 

if you buy new irons from mazdaspeed they have updated casting around the dowel area and they are as big as rew and re's

 

Here is a picture of the old cracked iron in comparison to the new one.
Both of these irons are S5, but as you can see the new iron is much thicker in the dowel area.
I think the cracked iron was caused by a misfire from my E6K.
E6K is going away and am replacing with a Platinum 1000.