This is not an absolute rule. Many people run 15 psi with only an upgraded fuel pump and have not broken a motor. I did for over a year with no problems. Duty cycle would hit max at WOT. Of coarse that leaves little room for error but like I said it is done all the time.
Add some secondary injectors to the fuel system (with proper tuning of coarse) and there is no reason why one should be overly worried about running 15psi.
A tank of bad gas is not as common as you make it sound.

 

Dave, I agree with all of the above. I will say that popping a motor from a shitty tank of gas may not be too common, but it really sucks when it happens to you. Back in 2001 Exxon 93 cost me a motor, and I know Jodeny popped a motor not too long ago from bad gas as well. My fuel system was 100% adequate as well, I think I probably got a 93 pump giving out 87......

Rich

 

i think with a fuel; pump upgrade, an fd is ok once and awhile to run that boost, however, ive come across bad gas much more than you think. no in my rx7, but in my stealth tt, evo, and audi s4. enough so i only shop at sunoco now. maybe shell or bp if they are the only one around. but there are many places that water down gas. thats why i never run 15 lbs unless im on at least 1/2 100 octane. and my fuel system is top notch.


silver flash: with your rebuild, get some 1200-1300 cc secondaries with a 255 lph fuel pump. and re tune. just in case for next time. it seems you like boost ( who doesnt) adding some insurance will save you $ in the long run.

 

exactly, it does happen. thats why i play it safe.

 

that is that great of vac for 1200 rpms for an idle. I pull 16-17 inch of merc at idle which is 750-800 rpm. I bet you were pulling 13-14 inch of merc at IDLE!

 

yeah, i was thinking that. at 1200 rpms i probably pull 19-20 " of merc. at 950 (where i like my idle at), i pull right at 16".

however, from what i understand, low vac at idle just means maybe not sealing well, not nessesarily a blown motor... doesnt the vac bounce around at idle with being low?

 

with a cracked apex seal your vacuum will fluctuate at idle, yes.

on a stock port motor, ~20 inches is like a new motor, ~15 inches is still 'ok,' and anything below probably ~12 inches or so is very worn. These are all ballpark figures. Once you port the motor, it all goes out the window. I ported my motor very (maybe too) aggressively, with some overlap, and I see maybe 12 inches mercury at 950 rpms, but my compression checked out at 104 psi across all faces, which is healthy.

Rich

 

yeah, i have a mild port, so im pretty happy with 16 inches at 950-1000 rpms.

 

Absolutely. I had about 10 in Hg at idle on my motor, 90K original miles, still ticking

~Ramy

 

3rd motor

1st... engine fire
2nd..... thremostat stuck open
3rd..... motor ( 4/20/06)
this will be the 4th engine in this car!

I'm gonna upgrade the fuel system for sure.

People all around me,keep telling me to get rid of it
I've had the car for little over 5 years

My mechanic is very good at find problems and installing aftermarket and stock parts, he's been very helpful and saved me hundreds of dollars, he's well known rotary mechanic, just his tuning is on the weaker side.I don't have a wideband, nor a dyno around. He didn't recommend me boosting 15 lbs, he said keep it at 12. 12 lbs wasn't cutting it for me.I think my motor was getting worn out, as the vacuum wasn't great. Had about 30,000 miles on it boosting 12 lbs.I then got a Profec S and kept pushing the limit. Now i'll get ported motor, Apexi, fuel upgrades and a single. Thank god my car is paid off

 

There's a first ! ! ! ! Never heard of a thermostat sticking open and causing an engine failure. In my experiance I've always found them to fail in the "closed position" which causes the motor to overheat. Guess you were one of the lucky ones.

 

Aaaand...you realize that's why you keep blowing motors, right? I can have Mr. Felix Wankel himself build your motor for you, but if it's not TUNED properly, it's gonna pop pop pop! I'd hope you'd figure that out by now...

Now now Jack...be nice LOL. Although I was like whaaa?? The t-stat did what?!

 

I'm not a mechanic, But your right, stuck open wouldn't cause it to over heat, so i was told that my thermostat had failed, and i over heated. It was stuck closed.I said it wrong. What ever!

I'm not previlaged to have a tuner close by, so I enjoy the car, and hope for the best, and now i'm making more money, and the car paid off, i'll upgrade it. This car was a daily driver for 4 years. with no problem,Well except the first year i had it, then i got my hands on a Greddy Profec S. I messed up. Now it will sit in my garage until i can save $4000 + for engine, $3500 Single turbo, and all supporting mods need. Unless i loose my mind, and get pissed off and set on fire, or send it into the ocean. It's a love/hate relationship ....