Went to Englishtown Wednesday night to get some runs in and see if I could improve upon my lousy 12.5 @ 115. First run out it blew at the top of 3rd gear, not sure why. I did the standard burnout. Got an ok launch and took 1st to redline, hard shift to 2nd. Spun the tires for a second then hooked. I hit the rev limiter by accident but then got a good shift to 3rd. At around 7k rpm it detonated badly multiple times, brown smoke out the back, and major power loss. I backed off and exited the track. Car didn't want to idle at first and stalled a few times. Runs really rough but rpm is consistant. Pulls about 10" vacuum, as opposed to the 16" it pulled before. I checked all the obvious stuff like map sensor, plug wires, etc. Ito from JR's Rotary listened to it and confirmed it sounded blown. I was going to tow it home for fear of damaging it further but AAA said it would be an hour and a half wait and they would only tow 15 miles cause they were busy. I was 50 from home. Tried to find a a private tow but had no luck. Pissed off and tired, I said **** it and drove it home. Made it fine. Drove carefully. Its a dog off the line but once it gets over 3k it pulls. So its rebuild time, again. Selling the car hasn't even crossed my mind. I've been trying to contact KDR with no luck. I might have JR's do it, more convenient and I can actually do alot of the work myself here and learn alot. I also want to go with a monster streetport, and JR is know for his porting ability. Basically I'll go with whatever is faster. The only reason I'm upset is down time, not a big deal though. Relevant mods are mild street port, upgraded twins running sequential, power fc, 1200cc secondaries, intake box, large stock mount intercooler, full exhaust with no cats, mazdacomp rad, no ast, 99 front end probably lets more air in, stock ignition with ngk 10.5's leading and 9's trailing 300 miles ago. Car was dyno tuned at KDR for 16 psi. Air fuel ratios were conservative low 11's. So the question is why did it blow? It was a hot day, probably in the mid to upper 80's when I ran. My coolant temperature was in the low 90's. Air intake temperature was in th high 60's to low 70's I believe. Does that seam too hot with an M2 large intercooler? I didn't overboost either, according to the peak hold on the power fd I only hit like .96 bar on that run. The engine bay seamed kinda hot before I ran though. Somone even commented on this. I even had a little ice on ther intercooler for a few min before the run but didn't seam to help much. What puzzles me is that I've been driving the car hard regularly. In the winter I've seen boost spikes to 17 or 18psi at the track before I realized and was able to correct it. Why would it blow now? I think the heat did it. Dunno what else it could be.

 

Was runnnin 93 octane Mobil. I never really thought about it, but shoulda run race gas.

 

That sucks. Sorry to hear it blew on ya. As for why it blew I have no idea. Any coolant leaking at all? I guess what I mean is did you notice it running hot on the temp gauge or anything either?

 

I dunno, but 80s isn't hot. I call upper 90s and low 100s hot. 80s is normal I think, with 60s-70s being mild, 50s and below being cold I guess.

 

Coolant temps were in the low to mid 90's Celcius as I recal. No leaking. It didn't overheat.

 

One time Cam at Pettit told me that apon inspection a huge percentage of blown motors have dirty fuel filters. Have you changed yours in the last 15K???

If those are your actuall intake temps they are too high. There is a theory that the temp sensor gets heat soaked from the hot manifold. The Power FC has air temp correction for the timing and adjusts your timing thinking that your air temp is 80C when its actually 40C (or what ever) and.

I'm going to try and relocate my sensor to the elbow. If its to much crap to relocate it I'm going to change the temp correction values in the PFC.

Good Luck,
STEPHEN

 

I think he's talking about 80 Celcius as he's using the Power FC and thats how it reads.

I'f your running high boost especially on the stock twins I like to keep it below 50C when racing.

Silver 93TT - Where you talking about C for you air temps??? I assumed so.

80C = 176F !!! Thats around 100F over ambient

STEPHEN

 

I posted about the PFC and larger secondaries in the PFC forum. I speculated that its not the PFC, but the reliability -mechanically- of the injectors suffers from the enlarging process. They might flow the rate stated, but can't do it long mechanically something breaks and you run lean for a brief tim e, long enough for you to lose your engine. Your like the 6th car with the PFC and enlarged secondaries that was tuned rich enough by most standards....mid 11's range, to blow the engine for no aparent reason. Every time I hear that combination of mods and a blown engine, I cringe at the thought of actually installing the 1300's I got.

Tim Benton

 

how many miles did you have on the motor?

 

well you guys scare the hell out of me.

Im sorry to hear about your motor...that totally sucks. I blew mine in similar fashion last year.

just did another motor....full rebuild with ceramics...added the fuel pump...1300 cc inj....etc...

just broke in the motor...put on boost controller again...went out for first mild tuning and under full throttle at about 6k experienced a fuel loss and detonation...no blown motor thankfully....only experienced the cut in fuel/power when it was under hard throttle....led me to believe that either I have a bad fuel pressure regulator or a bad leaky 1300cc injector...either way I have a horrible fuel smell coming from under the plenum....the car sits back at the shop til monday when we pull it apart and try it again.

I cannot blow my motor again or Im out and on to the dodge omni forums.

I definitely feel for ya...your mod list was very nice and it seems that all should have been ok...except for the race gas issue....

Im starting to worry myself about the larger injectors and the fuel issues brought up in the other thread of the 1300cc set not ionizing the fuel correctly or other probs....hopefully someone will get this figured out.

good luck

j

 

Ahh celcius, nevermind

 

Were you running stock seals on the engine.

 

Yea the intake and water temps were celcius. Motor had less than 15k on it. The turbos are SR Motorsports upgrades, supposed to be more efficient at higher boost. They have larger compressors, clipped exhaust wheels, and ported wastegate. What gets me is that I didn't even hit 15 psi on that run.

 

hey ihor why were u running pump gas.
even on my litlle almost nothin mods i use sunoco ultra ONLY.
and in track u should u cam2 they sell it cheaper a couple of blocks from my house.nut damn sucks on motor blow-up oh well bigger port time.

 

Damm, sorry to heard that ihor, one love

OneEvilRx7,

Ito, should do a good job on it, he knows what his doing......

One

 

did you have compression test done while at JR's??

im sort of having same troubles except that i have 1600cc injectors and haltech dialed in very consevatively (read: VERY rich), but started experiencing symptoms of a blown motor before i got the chance to hit the dyno to see where my a/f ratio is at.

not sure if i heard detonation or not cause ive never heard it in person before - just read descriptions. what did it sound like? and what is your idle like right now?

 

You mentioned that you have 1300's but you didn't say anything about having a higher volume fuel pump. What fuel pump are you running?

 

i think that the M2 intercooler that he was running was really heat soaked that day. i saw ihor at the track when he first arrived, and i told him he was running hot. i felt his intercooler, and it felt like a grill.

i guess we will find out when the motor is dissassembled.

 

I'm running a cosmo pump. At 16 psi my injectors will hit about 84% duty cycle if I rev it out.

 

I've been tossing the idea around of going with a front mount. I'm just having a really hard time letting myself put something infront of the radiator.

 

Gordon, air intake temps were in the mid to upper 60's C. The water temps where in the 90's C. Too many numbers, I'm confusing people

 

I guess my time is coming.
I have every bolt on mod possible w/stock/eng/ turbos/injectors/upgraded ecu and run 13.5-14lbs.at the track only 12.3@116 when I can hook up w/drag radials.
I always at the least run ultra 94 or an unleaded race gas (high flow cat) for insurance.
You may never find out the cause of the failure but hopefully it wasn't an electronics/ecu issue.
Always sorry to hear when someones motor goes south this early in the season,or any time.