willahlborn

...fed a stock d15b7?

I have a Subaru rbh5 turbo on mine... stock internal wg... up till a week ago I was hitting a solid 7psi on my boost guage, then when I installed my intercooler, I was only getting 5-6 psi... So, I completely closed my ghetto fab boost controller.

2 x (the boost you're used to) = fun

The boost guage went past 13 psi before I got scared, and got off it. Did this a few times, no ill effects. It should be noted that I have a wideband and made sure my afrs were okay during this ordeal. When I looked at my wb log, I noticed that the voltage from my map sensor climed steadily to 4.8v, then leveled off; indicating I had reached the limits of my map sensor. I can assume the boost kept climbing to an unknown level past that, until I let off the throttle.

How close to the breaking point of this engine am I?

Semnos

Depends...not all engines are the same...I ran 15 psi daily on my D15B2 with the Hack. The engine is still running great...A gurl a sold the car to is riding around with it.
If the voltage of the map is falling off...it probably could be that you might begin to run a bit lean on top...so be carefull..if it gets enough fuel you're ok.
Some engines break at 10 psi some brake at 15-16...There is a lot of variables that can cause that..weather...engine care, load, etc etc...also some engines may have come out of the factory stronger then the other.

Bizzar

Oh how true that really is. I work at a Saturn dealership and during our pre-delivery inspections you can tell just by the sound which engines are tighter than others. Even on a road test one car will just rip harder than another straight off the truck. No two engines are ever the same even brand spankin new. I was boosting my D15B7 at 8psi non-intercooled supercharged psi for well over a year and took it to 256,000 miles without a hitch.

sohcrxsi

I ran mine d15 w/ DPFI, non-intercooled with a fmu pretty high. First it was 6psi, then that got old so I turned it up to 9psi, and then 12psi. Once I had a problem with my wastegate and the boost probably got to about 17psi before I let off. I looked at the guage after letting off and it was coming back past 15psi

robs99si

i hit 18psi on my b16 once or twice while in 4th gear cause my MBC vacuume hose broke. no detonation noises at all. i would'nt go past 11psi on a d15 though, i run 11-12psi on my b16, but b15 rods are weaker then the b16s'. you should be ok with 11psi and good fuel management.

djfob

Like everyone else said engines are hit and miss, the d15 has pencil thin rods even compared to other D rods. I wouldn't push it much over 180whp. I know a guy with a D15 w/ihi rhb5 pushing 10 psi at 160/146 whp/wtrq for over a year.

robs99si

realy good tunning makes a world of difference in how long the engine will last. running a little richer on weaker rodded engines will keep them alive too like running 12/1 afr throughout the rev range.

willahlborn

Yeah, i'm solid around 12.0/12.2 in boost (uberdata, 450cc injectors, Zeitronix wbo2)

robs99si

that's some good fuel management you gots der. :P

Bizzar

Thats they key to a happy engine. Proper tuning! my high mileage jrsc b7 was tuned with Uberdata, 450's and a techedge wideband.