The octane is higher more like 100, 111 is most likely 4 grams of lead which would raise the 93 to 96-98 and then average to 100-102. The first gram of lead would raise it 5-6 octane and then 1 octane for each other gram. I am glad to see its still at certain pumps. With the new G5 oils zdp is making a come back too, to help older cars.

 

Today is a sad day. Put in a straight tank of 111 leaded. Increased boost to 14 psi. Experienced 3 pulls of INCREDIBLE thrust, pulls that likely will not be felt in an l15 fit again for years. Then on my 4th pull.... psshhh, rattle rattle, tap tap tap clank clank clank. Rod knock. Got the fit home luckily. Leason learned, previously I survived up to 16 psi briefly thanks to detonation. The ecu would pick up the detonation and retard me down to 14 degrees BTDC - 0.75 per psi = 2 degrees btdc, this was survivable. However, with the 111 octane leaded fuel there was no detonation, Thus 24 degrees btdc - 0.75 per psi = 12 degrees btdc, this was not survivable. The sheer force was too great (effectively runnin 20.8:1 compression, insane) Now for the fun of tearing down this engine, seeing if the head is intact, and if it is, swapping it to my original short block. Otherwise I'm going to have 2 extra engines in my garage!

DO NOT EXCEED 10 PSI WITH STOCK COMPRESSION UNLESS YOU PLAN ON RUNNING 0 TIMING (and thus making no power gain over lower boost levels). This is the limit of our stock longblock. I'm glad I was the one to find it

 

Ouch! I guess you have to pay to play tho.

What was your a/f ratio at 16psi?

 

12.0 ish. Injectors maxed out. I'm Suprised they didn't fail.

I'm starting to have impure thoughts about moving on to another platform. It's been a great platform to cut my teeth on but the magic is gone. I know exactly how far I can push the envelope now. I could start upping internals but at that point I'm falling outside my cost to value constraints. I'm probably going to complete my rebuild and go back to NA. I'm confident I could boost anything with wheels now and it may just be time to boost something that's going to make some incredible power, not to mention a platform with a community of more than 10
people that actually have know how. And displacement! That would be awesome. I'm thinking foxbody again.

 

I can relate to the way you feel... It wasn't uncommon for me rotate air cooled VW engines in and out weekly 40 years ago... There is something very gratifying about lifting and carrying the front wheels, hitting 2nd gear and pulling away from a slicked out emission control laden Corvette of that period... I have an old Volvo 244 that I would love to put the engine and drivetrain ( minus the A/T ) out of an intercooled 760 Turbo or even a tweaked SBC with boost... Everyone that has followed you through your endeavor has information that you have provided that will be beneficial to those that quest for more power in their little station wagons... I think that 14PSI has wrecked a few GD3s that were boosted.. I believe one had a bucket of hundred dollar bills thrown at the internals... I can't think of a car that I would prefer to drive over a Fit with boost but since I can't wrench like I used to or wrap my head around all of what I need to in order to tune, there isn't any way I will be increasing boost... I hope that other things that are bouncing off of my inner cranium will result in better performance without having everything coming unglued.

 

Lyon sorry to hear that, watched a show that explained the connecting rod bolts in a factory car are not make to withstand that much more HP than it was made from the factory. Now's your chance to build a K20 with 14 pounds boost.

 

makes me sad man, with my plans in the works, makes me have second thoughts but do you think maybe meth could have saved it??? i noticed in your video you just posted that you have 55k on her so with your previous running with nitrous and then extreme boost, would the nitrious have weakened the motor? when you get it apart let us know what happened! she will be back and running soon enought. im sorry it happened

 

Ouch. Well that'll ruin your weekend! I just want to point out a couple things though, first being that this is one data point on a second hand motor...

Even on the 110 Leaded you should, IMHO have been running richer than 12.0:1.

You don't need a ton of timing to make power.

Again, this is one data point.

Lyon, you should blow up a couple more L15's before moving on. Especially if you plan on a bigger motor and more power. You should take my word on this one. I wouldn't send you a-stray would I?

Can I take apart the motor with you or at least see the aftermath? I really want to see what actually happened.

I just find it hard to believe that this failure was from such low boost (yes 14psi is low boost guys) with only 16* peak timing with 111 leaded on only 10.4:1CR. Especially considering the abuse the last motor took with the nitrous backfires.

 

Back in the early eighties 1.5 liter Formula 1 motors were making close to 1500 hp. There's more in it!

Turbo motors are real sensitive to a lot of things. I've thrown rods from having the wrong distributer rotor and cracked a few pistons in the Omni from not enough fuel under boost.

Now she runs 20 psi on stock cast pistons and is as smooth as butta. Its all in the tuning.

You should figure out what went wrong. Turbos are fun aren't they?

 

Well, then there is the issue of the water in the pan that I just dismissed when I bought this engine. Bearings could already have been crap, but at the same time 14 psi is low boost but at this CR? I'll be better able to diagnose this once I start tearing it apart. For all I know a 'real' gremlin could be in there hitting the block with a wrench everytime the crank turns over because it scares him.

I'm just a little frazzled from getting raped from all directions. My escort decided now would be a good time to have the terribly degined steel valve seat fall out of the alluminum head and destroy cyl 4. Not worth rebuilding.

And then the silverado decided to do this:



Funny fact: 2009 L15a7 engine - $500 1992 k1500 axle assembly w/190,000 miles - $400.

 

AHH WTF! Just to screw with me even more my t28 showed up today while I was at work...

Now, that I'm out of shock, It does seem likely that something besides shear force is at play here. I see rdx injectors, methanol, and a richness that borders on cylinder wash in my future. Just further out in the future because I am going to need a decent amount of time to replenish my $ reserves from all this rape. I'm staying NA until I have money to replace the next engine I will blow up. I'm almost thinking I will just buy the 4th engine and have it sitting on a stand before I boost my 3rd engine. It's somewhat entertaining to try to explain what I do to a layman, they just look at me like I'm retarded, rightfully so.

 

Revised hypothesis: 14 psi is the point at which the consequences of knock become so severe in the l15a7 that failure will occur before the ecu can pull timing. The ecu's excellent knock detection is only effective up to 10 psi. After 10 psi tuning must be taken to conservative levels. Rich as you can safely get it, cool as you can get it, little timing, chemical intercooling, etc. will all prove to be essential at this point.


Pulled the head today, it is perfect. I will just bolt it to my old bottom end, total cost of this failure is looking to be less than $100. Can't wait to get my bent rod out and make it into a trophy.

 

Pics please.

 

Thanks for the offer, I'll post some pictures up once I get my engine lift back and pull the rest out. My oil pan is holding up the engine right now so I cant remove it to extract my bent rod. I can't believe how fast I can tear this motor apart now.

 

Heres some info on turbo cooling for your next adventure. http://www.iiis.org/CDs2010/CD2010IM...df/FB075TI.pdf