very nice how does the pocket doweling work im about to build one soon and think that looks way more efficient than traditional doweling

 

It seems much less invasive than traditional dowel pinning. It's also using a skinnier pin.

 

is there a way to tell if ur trigger harness is being effected by noise?
does it creat a magnetic field around the wires?

 

the EMI is usually from the alternator, the coil packs, and the plug wires.

think of a radio antenna. you have to position it so that its not close to any speakers or anything. anything that produces a large ammount of current such as coilpacks or the alternator or an electric motor will create noise.

 

and of course our alternators are right there lol

 

So this thing has to have some miles on it by now, any updates?

 

Yep, got it running. Has about 300 miles on it or so. Been boosting it little bits here and there. I went back to an older map from the last setup prior to going real heavy on the alcohol. Went back to a ~75/25 ratio and thinned the alcohol way down. Trying to still get it dialed in to mid 10's:1 at 15psi. Even still, at 1bar, the IAT's in today's temps shot down to the low 70's at 1bar which is about 6-8* below ambient. Pretty neat. Got it up to 20psi once. Ran like a roaring lion. Will do more later because I've still got a few things to tweak. Driving real nice, though.

B

 

Oh, and almost forgot. Saw EGT's hit mid 1600's around 7krpm on one of those 1bar boost runs but only on the rear rotor. I have the alarm set for 1620*F and it illuminates with this ridiculously bright blue LED. It went off a few times. Looks like the rear rotor is running around 70*-100* hotter. Really need to park it on a dyno and run the rear secondary injector a bit heavier to see if I can get them closer to levelling out.

Makes me wonder how many other Rx7's run hotter on the back.

B

 

probably the fast majority since compression almost always seems to drop on the rear rotor first.

Do you think its more of a fuel delivery issue or a heat issue caused by inefficient coolant circulation to the rear ?

 

Does the coolant flow from the front to the rear of the keg? Maybe in higher powered applications, the coolant heats up quicker and less effectively cools the rear.

 

It goes drivers' (spark plug) side to the back then to the passenger side (exhaust/intake ports) forward. If you have a spare front iron laying around, you can trace it and see.

I think it mainly has to do with turbo placement (wherein what part of the lower intake manifold is getting hotter relative to turbine housing placement), intake runner and manifold design (length/diameter differences in runners in particular the LIM), fuel starvation in the standard sequential fuel system layout (rear secondary is at the tail end so if there's a backend fuelling problem it gets the first pressure drop), and perhaps a few other things. That's just my guesses but ultimately I don't know.

Hit 23psi today running right at 9.8:1-10 flat:1- low 10's:1 to mid 7krpm. Runs like a damn rocket ship and no hint of any knock or rattle canning like last setup. Might be I may've stumbled across a fix for whatever it was that was breaking up. Today was about 90* and the IAT's at 23psi IIRC were around mid 90's. Didn't get any datalogs. Had buddy of mine with me.

Need to do some tweak s on the alcohol system to get it to prime and turnon better. I think the alcohol in the lines in the engine bay is boiling and causing a priming problem. Considering use of check valves just aft of both nozzles. Also went back to a 75/25 ratio of gasoline to alcohol at 15+psi. At 15psi AFR's are around mid 10's.

Runs solid so far. Need to not get greedy and get it on a dyno and really work it all out.

Oh, and hit 1710* on the rear rotor and mid 1600's on the front. Going to stagger the rear secondary injector a bit and see if I can cool that side off a bit more.

B

 

rear rotor getting that hot huh. how can u stagger it b?

 

Injector Trims under Options.

B

 

learn something new everyday ha

 

Got an update.

Getting the car ready for a few hours on the dyno. Just got a pair of 10psi check valves to add to the inlets on both nozzles to combat an engine bay heat and alcohol lag problem. Also swapped one of the nozzles back from an M15 to an M10. It's back to a pair of M10's.

Running about 10 flat to 10.5:1 at 23psi of boost and it runs terrific. Anxious to get it to 25 and then try and shoot for 30. Hope to be able to do this on the dyno while it's still hot outside prior to the Fall season cool down coming. I really want to see progressive intake air temps in this hot summer weather.

My years old EGT probe finally died. Need to replace it so I can do comparative data between front/rear chamber to setup secondary injector staggering.

With cars, if it ain't one thing, it's somethin' else.

B

 

EGT imbalance will be mostly due to the log mani.

I always had 150F (hotter in the rear) difference on the log style manifold no matter what I trimmed + or - to the rear rotor.

 

everyone i have asked said its simply due to the hotter temps it sees due to coolant being hotter in that general area.

also bdc, i forgot the specifics of the setup but could you just go over what the setup is and where you get your fuel?



also, i have been toying around the very same idea, but en lu of jets, im going to be using a fuel injector. preferably a stock s4na fuel injector, a fuel pump, and a fpr to handle everything.

 

The last (and thereby hottest) exhaust sleeve in the flow is the front rotor, so if that were the case the front rotor would be the hottest of the two.

 

Got up to 25psi of boost tonight. Ambient air temps 90*. Can't seem to get a datalog to save my life for some reason. IAT's were hanging in the 120's to low 130's at that boost according to my co-pilot Derrick. AFR's parked around 10 flat to mid 10's from 1bar of boost up to 25. Thing runs spectacular. Really need to hit it on a dyno and see what she does. Want to push it up to 30 and see if she'll do it.

B

 

Great stuff!

 

Crazy fast!!!! Aaaaaaaahhhhhhhhhhhhhhh!!!!!!!!!!!!!!!!

 

As the post title says, I hit 27lbs of boost today. I installed a pair of 10psi one-way check valves just aft of both M10 nozzles to help with system delay. They work very very well! They work so well that I had to pull fuel out of the earlier boost ranges (ranges 14-16; about 4-7psi) to adjust for the "harder" transition of alcohol. From what I can tell, boost now starts in the mid 12's and steadily nosedives into the low-mid 10's by 15psi which is my target. From there and above, it seems to hold a steady low 10's as boost rises.

I hope to hit 30psi (2bar) if at all possible before the thing grenades itself into a million pieces leaving several quarts of oil all over the shop floor.

I managed to get pieces of a datalog to show a few things. I was eyeballing mainly the air temps relative to boost. What I got were this:

20psi 110*F
23.9psi 113*F
24.6psi 115*F
25.5psi 118*F
26.4psi 121*F

At this boost with this ambient temp range air temps seem to be sitting sub 130*'s. Not bad for no intercooler on a post-Summer day.

Ambient today is about 85-90* or so. The temperature has been dropping a bit I'm assuming because of what looks like to be some isolated thunderstorms coming. Cruising air temps were between 130-137*F which follows the rule of cruising IAT's being 45* above ambient on this car's setup that I've found to be true.

2nd gear is worthless. By about 50mph, it'll fishtail the car.

In 3rd gear the car now gets loose a bit on the highway at around 80mph.

I haven't heard any breakup, noise, rattling, or anything else odd like what I experienced on the last version of this. Everything seems to work really well!

It's ready for the dyno. I'm not fooling with it anymore until it's strapped down.

Will post a couple recent engine bay shots shortly.

B

 

forgot to ask, but did coolant temps do anything?

 

Here's a few pictures taken today. If you look closely, you can see the two check valves I added at the end of both alcohol lines.


Can't recall. Think they're still hot in the high 190's.

At 27psi of boost I see 122-123*F. All air intake temps in boost are remaining flat and linear, kind of like dialing in an air temp vs. boost. The ambient temp today being about 18-20* hotter than the test days last year pretty much corresponds exactly. If I run say 25psi and have air temps at 120*F, and run it the next day with an ambient temperature drop of 10*, then the air temp will be about 10* cooler, too. Nifty.

Curious to see what air temps will be at 30psi. I wonder if they'll hit 130*F.

B

 

damn brian im gonna have to come take a ride in this rocket!! nice work!