Maxthe7man

ah well, **** happens..
S4 T2 streetport
t04e 60-1 1.15 a/r p trim
11.7:1 a/f
12 degree advance'
17 psi of boost..
First run went ok, second run it popped.....Max

jhammerrx7

iTrader: (5)

Nice run. Too bad about the motor though. Build it up again and shoot for some higher numbers.

Astro

max, nice numbers.
Shitty about the motor. I thought you were running a wideband.
I honestly dont think im ever gonna slap my car on the dyno.
I've just heard too many horror stories!
I'll probably tune on the street and then maybe just take it to davenport to see what it makes.
what kinda gas were you running?
run out of injector?
man...that really sucks.

Manolis_D

iTrader: (2)

Any ideas on why it popped? It seems like everything was pretty much in line.

Hmm... That's a bit disconcerting,because that's real close to what my setup is / will be (To4B 60-1, Haltech, planned low 11AFR, 15psi, etc.)

What were the intake temps? What kind of plugs? What octane fuel?

Sorry to hear about it,
Manolis

Maxthe7man

The fuel was premium(as far as we can tell?), the intake temps were in the 80's everything looked right...Injector, not sure, but it was good on the first run, I made the mistake of not datalogging the run...back to the drawing board...Max

Maxthe7man

Astro: Yeah, I have a feeling dyno's do tend to load the car beyond what it would be loaded on the street, which greatly increases the chance of knock, I actually said the same thing to Erik afterwards, next motor will not go on the dyno, in street driving it was fine...Max

Astro

what split were you running?
how about plugs?

I agree with the loading issue...i think a wideband and a nice flat straight road is the way to go

Maxthe7man

At that boost the split was around 6 degrees or so, I was running 7's in the leadings..
I am thinking about getting an HKS twin power to go with the new motor, ignition is a difficult thing to deal with, its sort of trial and error, no one has a definitive answer on what works and what doesn't.... Max

Judge Ito

Max, at such low boost? Im scraching my head here trying to help you. Max for next time I would double check your timing advance. Gives us more info. Did you hear a pin before you broke? something like a detonation. I mean your a/f were not bad it had to be timing related. Maybe to much timing advance.

Manolis_D

iTrader: (2)

I'm certainly not an expert, but don't people usually run much colder (?) plugs than that? I hear of people running 10.5's at that power level, and you had 7's. Might that have done something?

Lots to learn! (me I mean )
Manolis

jeff48

The intake temps were in the 80's ???
How was that measured (at the intake which would be essentially ambient air temp) or at the TB or UIM?

I always wonder about dynotesting because there is little or no "cold" air running over the intake and effectively no cooling to the IC. With those conditions, isn't detonation much more likely than at lower temps.

JScott

Hmmm, what wideband were you using. I alway's use the one at my dyno shop(MC Racing O.P. Kansas). I know it's very accurate. 11.7 afr doesn't leave much room for error and I agree that 7 plugs are a tad hot. 9's or even 10's would be safer for sure. I'm betting your afr had a spot that peaked higher along with the 7 plugs and I could see it popping.

Also, did they put a MONSTER fan in front of the IC/radiator?

My air temps, observed at the Haltech, were pretty high on back to back runs. I was seeing 180 deg plus. I'm pulling a lot of timing though at those temps.

Sorry to hear the bad news but I still believe in dyno tuning. I really think it's a more controlled environment for WOT tuning.

Scott

SPOautos

I also agree about 7's being way to hot. I started running 9's all the way around at around 12psi of boost and went to 10's (B10egv) at around 14psi.

Also as far as getting a HKS twins, I'd save about $350 and get one MSD 6a for leading or get a MSD digital 6 and still save $250. You dont need a ignition amp on your trailing unless your running no split. Your leading combusts most of the mixture and your stock trailing should be plenty for the remaining.

STEPHEN

Maxthe7man

Thanks for the help guys, this was my first jump into the world of high horsepower turbo rotaries, so I am not upset by the engine going...
The gas was 91 octane premium as far as I can tell, you can only trust what the pump says right..
Yeah I have been thinking about the plugs, although I have been at this boost level for awhile now..
The intake temps were measured at the TB inlet via the haltech...
I have an MSD 6a already...
I like the dyno for tuning, although for ***** out hp number getting, next time I will give it a pass, I now know what I am capable of getting for HP..
Now, next question, what do I build next...
I have a2 series 4 n.a motor's, I have a set of S5 TII endplates, but I really am intrigued by the comso 13b-re and its larger port than the FC motor... I would like an REW however the Flyhweel tranny setup could be a major pain in the ***...
Next years goal is 500 rwhp and 330 ft/lbs, that should make my TII a nice docile street car for spirited jaunts to the ice cream shop....Max

1FastT2

iTrader: (1)

91 octane gas is pretty low IMO. May I ask what apex seals you were running?

rx7tt95

What dyno unit were you using? I believe the Dynojet 248 series uses 2500lb. cylinders which would load your car less than being on the street (assuming you're heavier than 2500lbs)?

Hope you get her rebuilt and up and running soon! It's not fun having your baby down for the count.
Michel

Maxthe7man

they were 3mm one peicer's...
The dyno was a mustang dyno... we are discussing dyno loading in the Canadian forum in another thread about my catastrophe if you want to have a gander at it..
I want to acheive better chamber sealing this time around, my motor only made 70 psi on each face previous to the blow up, if I could run tighter chambers the boost could probably be pulled back a bit as well as the advance...Max

1FastT2

iTrader: (1)

What particular brand seals I was wondering.

Maxthe7man

That I could not tell you, the engine was in the car when I got it, so I have no idea what make they were, however I will be running stock mazda 2mm's in my new motor..Max

1FastT2

iTrader: (1)

Sounds like more the condition of the engine than the tuning. You'll get good numbers with the new engine, and im sure you'll be fine with some stock seals. I use them and they have been working great so far.

Chronos

I hope you're getting a new engine, you can't switch back to 2mm from 3mm can you?

Maxthe7man

I am gonna build a totally new motor most likely, this one sounded like a blender when it went so there is probably not to much left...
I just have decide how extreme I want to go, and what parts to start with, I am considering :
1: buying a j-spec and tearing it down to port
2:mazda reman and tearing it down to port
3: just buying the parts and assembling from there..Max

setzep

Sorry to hear about the engine but hey, this only means more power down the road right?
I'd take your bad engine apart and take it from there. If everything is infact junk then you can't go wrong with a j-spec. I got my 13B-RE from fc3s.org and I can't be happier with the service. Dave there is a damn good guy to deal with. I ordered a cosmo engine from him and upon receiving it had water/ice in the rear chamber (most likely from when they pressure washed it with no spark plugs ) so I ran a compresson test and the rear came up at a peak of 40psi I e-mailed him this and he had another engine on it's way the same week! This one I have now has 120psi front and rear. Mike-p-28 bought one from him also and his car is running like a raped ape.

good luck with whatever you decide to do.

-Cam