Cars had been running strong @ 1200 rpms i had vacuum of 16
I was boosting 13lbs on first turbo and 15lbs on the secondary
Drove it for about 1/2 hour and only got on it a few times to where i was boosting 15 lbs.

got only oil changed,I have a oil leak, looks to be a small leak from primary turbo, had my mechanic take it for a ride cause the tranny is sounding loud. I think it's my short shifter, but i watch him go down the street, he didn't get on it, Trying to listen for noise in the tranny, comes back and i lost a corner seal.

He said it's from me running 15lbs of boost! that i need 3mm seals !

Blowing a corner seal is to much boost, or could it be a bad Air/fuel ratio?

 

Guess maybe you should have listened to us in your previous posts about modifying. 15 psi on an F-Con and stock fuel system....what did you expect?

Still, sorry to hear you blew your motor.

 

LOL, yea 3mm apex seals with fix your poorly engineered set up!
Get a new mechanic.

 

So you think it's fuel related, not boost pressure?

Just weird i ran it hard a few times a month, i'd figure it would have popped then when i was adjusting the fuel. It ran good for a while, no signs, what sucks i wasn't driving my car when it popped..

 

So a blown coner seal is due to improper Air/fuel mix?
I guess it takes a while to blow , i ran it for a while.

 

420, how ironic.

 

Yup, It blew some smoke that day

 

Exactly! Did the mechanic even do a compression check? It's very hard to determine that it's a corner seal without the compression check.

 

15psi on the stock fuel system is what did it. your stock injectors must have been running well over 100% duty (very bad). basically, a stock fuel pump on top of that isnt able to flow enough fuel to keep up the fuel pressures needed to run that boost (also very bad). 11 maybe, MAYBE 12 psi is very tops that the stock fuel system can take. it doesnt matter if you have the fcon, even though you can turn up some fuel, your hardware is way lacking and unable to keep up to take 15psi. its amazing it lasted that long... your not even supposed to run 15 psi on 93 pump gas with a highly modded fuel system because there is ALOT of bad gas at many pumps that could be lacking the actual RON grade, or be watered down. i have a supra pump, 1600cc secondary injectors, fpr, 5 bar map, professionally tuned apexi power fc. and i dont even run 15psi on pump gas.

so basically, to answer your question, yes to both... yes, your fuel system is very much inadequate for that much boost, yes, running 15psi on stock fuel system eventually blew the motor.

 

Oh no compression test needed. Not my first blown motor. Has all the signs. Turn the key now, it is very slow to start. Vacuum is at 10 now and the whole car rocks alittle, exhaust note sounds like a sick engine. 1st gear is alot slower,trying to get some rpms. What's weird it still boost 15 lbs and runs strong. But my mechanic says it's like say have a 6 cylinder engine, but only running on 5 cyclinders. I could do a compression, but would cost $75 ,and i feel it would be trowing money away, since 99.9 % it's blowm. He took out 2 spark plugs and put in the RX8 plug, says it's a better plug, not sure what plugs he did, since i didn't ask, i was shocked about my engine was good , when i came to the shop, but now i go home with a blown motor.

Thanks rt turbo, for your thoughts, make since, i've read on this forum people saying the stock fuel system is good up to 400 hp, i had the fcon, i wasn't even on the highest setting, i could dump alot more fuel, i was definately running rich, but injector duty i pushing for sure, seemed that some peeps have been running 14- 15 lbs boost on stock fuel setups,

How much boost can 2mm seals take ?

 

I thought the stock fuel system could only support low 300 hp range without maxing it out?

 

2mm seals can take 30 psi, with the proper fuel injectors, fuel pump, ecu, and tuning. 3mm seals are not the answer here.

So your FD ran and drove fine, your mechanic drove it (yet didnt boost it) and then he gets out of your car and tells you it's blown? sounds like bullshit to me......something is fishy. Who is this mechanic?

 

yeah, definatly not 400 hp. your fuel pump is also more than maxing out. most people like the 2mm, they can handle as much if the proper provisions are made... 3mm seals would have broken with 15 psi on the stock fuel system.

 

Oh he boosted it, but not as hard as he usally does,I bossted and redlined it to the shop which is a hour away, the mechanic went 2 blocks and i saw him go one way, but did see him return. he's been my mechanic for 5 years, turned the auto into manual, very knowlegeable guy, I don't have a wideband, i thought i was running rich, i've had many signs of running rich, but i guess i did. I driven first 1-4 gears to redline for a few months on the same setting on the FCON with no changes, and blew when my mechanic was trying to listen to my tranny noise.

 

Mechanic said there's was a large black cloud that came out, then the crappy idle!

 

double post

 

Hmmmm I run the stock fuel system and was told that 14 to 14.5 is no problem on racing fuel. Said as long as i didn't run 15 or higher I'd be fine (Pettit ECU) 12.5 was the max i could run on 93 octane pump fuel without issues.

 

Well alot people are running higer boost with 93 octane, i don't know ! but found a post full of people boosting 20Lbs on 92-93 octane. https://www.rx7club.com/showthread.p...x+boost+octane

 

boosting 20 psi on 93 octane (without water/methanol injection) is asking for a blown motor. not to mention, those people sure as hell arent doing it with a stock fuel system

Rich

 

Silver,

what are you going to do now? You will be on your 3rd motor correct? Are you finally going to listen to the good advice here or continue down the path that you did before.

I would also wonder about your mechanic, espicially if he thinks just adding 3mm seals with your current setup is all that you will need

 

You can be a great mechanic and still not know **** about the proper engine management for these cars.

 

Wake up, man. You're on you're 3rd motor and think this guy is a great mechanic! Stock injector's maxed out at 13 psi has been well known in the FD community since the mid-1990's.

Jack

 

How I-Chronic

 

racing fuel does not cure duty cycle/ you may have cured bad gas and knock from pre-ignition. but your still victim to injector misspraying becuase they are stuck open at 104% duty cycle. go ahead, run that, have fun, il stay safe and still be much faster with much higher capabilities.

 

I was trying to figure out why no one else had pointed that out. 3 motors? And I thought I was dense...

Oh and I can attest to the stock fuel system. W/ a WOT tune, I was seeing 93% and 96% duty cycle on a stock pump and injectors at 13psi at the top of 3rd and 4th gears respectively. I was also seeing 100% duty cycle at 15psi on cold nights

~Ramy