Interesting. For the most part the 2 step and clutch valve just makes it a lot easier and consistent, but you still have to try different things like rpm and amount of time and boost on the 2 step to get good resultst and traction. I could still do 1.5s without all that when I had stock turbos and 411 rwhp. 1.6s should be easy with the right technique and at least half decent traction.

 

Any updates ?

 

I pretty much blew the engine Saturday on the first run of the season, in 4th gear after the 1000 ft mark it started cutting out and recorded unusual very high knock readings. Still ran a 10.46 @ 122 with a 1.45 60ft. It did the same thing during a 3rd gear pull on the way to the track. Everything looks normal and good on the datalogs except the knock when it happened, so I don't really know what exactly happened or exactly why. Before this the last recent compression check did show lower compression around 75-80, and it lost a small amount of power on the dyno.

was able to drive it home after bump starting it. compression is now 60 on the piston compression gauge on both rotors, uneven bounces on the rear rotor. It still runs but very hard to start and had to turn up the idle to keep it running, low vacuum at idle.

 

Dang man. Sorry to hear. But you are using stock apex seals and a small street port? Sounds great if you are. I hope to mine is this fast when its done. Did you ever try the different sized housing out? I was thinking of ordering the 1.15 divided.

 

It ALS apex seals and a mild streetport to the intake ports. I did put on a 1.32 divided turbine housing over the winter, it made the power curve better, the power doesn't drop off at high rpms like it did before and spool up is quicker, peak power was about the same, 532HP. I'm gonna rebuild the engine with a large streetport. I hope to tear it apart soon.

 

^ i had the same exact issue but it was after street pulls. either the egt's got up too high or maybe a fuel pressure drop off so check into that. in my case i was running too high of an egt for the ALS seals. nice to have bending seals rather then breaking and ruining all the internals.

 

I do not log egt, egt shouldn't have been any higher than usual. I do log fuel pressure, when it happened it did show a drop in fuel pressure for only 1 datapoint, I don't know if that is possible to have a drop in pressure for that short of time, there was no other drops in fuel pressure throughout the run and there was no drop in fuel pressure when it cut out during a pull on the highway on the way to the track.

 

a vacuum cap did pop off of the upper intake manifold during the beginning of the run and that caused the air fuel ratios to be a little leaner (that happened once last year too and the knock readings stayed low/normal) so I am not sure if that contributed to what happened to the engine in 4th gear.

I pulled the engine and took everything off the block yesterday. from what I can see through the exhaust ports the apex seals and the rotors look fine, and the turbo exhaust wheel looks good. I'll tear it apart soon. thanks

 

a missing vacuum cap would have virtually no effect under boost as it would vent little of the charge air (probably near 1000 CFM in your case) nor would it effect AFR. it would effect idle in vacuum.

hc

 

I wanna see the carnage.

 

Pics here - http://czfitnessproducts.com/tom94RX-7/Blown-engine/

 

wow that is a detonation hit. good dent on the rotor. one question i have is how are the rotor housing surfaces? they look cat scratched a bit. is that true or it is just the pics? i think you have one of the first als seal motors apart so i am wonder how they treat the housings. also how many miles were on it?

 

For more info and discussion see here https://www.rx7club.com/auxiliary-injection-173/pre-turbo-wi-vs-post-ic-wi-dyno-test-results-987107/page3/

the rear rotor housing is scratched up a lot and the front is a little too. it looks like the rear rotor face was hitting the housing, and the rear rotor has a textured surface so I'm sure it would really dig into it. the front rotor has a smooth surfaced, it is different. The front rotor ALS seals feel pretty smooth, the rear ones are just a little less smooth, not bad like the housings are. I don't know how many miles, the display stopped working, it was a little over 2 years old, lots of highway pulls, some drag racing and dyno pulls, not much regular street driving.

 

nice pass good numbers

 

Wow thats really unfortunate . Great times though! hopefully you'll get to the 9's sometime int he future.

 

thats impresive

 

Hey, this is super late.. but what tires are you running??

 

Thanks guys.

26x10.5x16 Mickey Thompson ET Streets, these tires are great, stock rims. and 500/525-16 Excelsior Blackwall 26" bias ply tires and spare fd riims for the front when drag racing.

 

nice time love the wheels off the ground.

 

Thanks. I got the rotor housings resurfaced and the engine rebuilt with a good set set of rotors and ALS seals, just got the car back on the road and breaking it in. Also put in a new RE-medy high flow water pump from Mazmart.

 

Built by DJSeven again?

 

Yeah.

 

Nice!

 

VERY impressive -- killer 60'! Did you ever determine root cause of the engine failure?

 

Thanks. Detonation, my AFR's were too lean, they went up to 12.4 in 2nd and 3rd gear in the high rpms, then the motor started knocking and losing power 1 second after hitting full throttle in 4th gear. I was only running about 500cc of water injection with pump gas. So the AFR's went too lean after a vacuum cap popped off and I wasn't running enough water injection on this day.