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Oh, just got 2 new wheels and some tires for them. Great day! I decided to give bassets a try, they have larger holes compared to my aero wheels. The air stem is behind the face, that seems weird.
Made it to the top of the Mount Washington Auto Road. Elevation 6,288. What little torque my street port had at the base was gone by the top. It was just a friendly cruise but I spent most of the climb at 4,000 RPM in 2nd gear to keep it from bogging. Total trip was about 300 miles of driving. The motor seems to be burning an excessive amount of oil. I changed it and topped it off before the trip, and it was half way down the dip stick when I got back. No visible leaks.
Yeah, it's the stock 3.90. If I can figure out a speedo gear for the 4.77, I think I'll upgrade this winter. I still drive the car regularly and I don't want the speedometer off.
I got some good data logs for the drive up to the mountain. Plenty of climbs to just run flat out to redline in 2nd and 3rd in a real world scenario (not a dyno). Average trim values for cells below 7,000 RPM were for the most part within +/- 2%, some of which is air temp and coolant temp correction, and the rise in elevation had fuel getting cut a bit across the board. At 7,000 RPM and above my map needs some work, I knew the cells were rich because I finally put a filter on and the air horns didn't fit under it. Those restrictions mean it doesn't need quite as much fuel. I saw trim levels at -5 to -8% but even then it was running at 11.5AFR instead of my target of 12.5AFR. I don't think i was losing power with those numbers, but it meant the data below WOT was a bit wonky since the trim level was so far off when I lifted off the throttle. I ordered a larger K&N filter that should fit the horns underneath but it hasn't come in yet. I also need to do something about getting more cold air to the intake. A custom box or at least a duct from the headlight area is in order.
A friend behind me had a supercharged 97 Miata. When I floored it up one of the hills he said he couldn't keep up. I'm not sure I believe him since he should be making way more power with his setup. Perhaps he was in 4th gear when I was in 3rd. My car still feels slow, slower than stock below 4,000 RPM for sure. I need to get it back on a dyno to see what it's making.
I spent the afternoon working on my Edelbrock carb tuning, driving the hell out the car until 2am. At 2am, on a 55mph local road,.. after spending 40 miles between 80 & 100 on the PA Turnpike,...
I threw a belt, which DESTROYED my distributor cap and rotor and left my car on the side of the road.
Thank the Rotary Gods for Uber. First thing in the morning I'll tow it home. If I had an extra dizzy cap-n-rotor I could drive it home. I'm buying two of each right now, plus some more belts.
Man, my Subaru smokes Audis and BMW's every day,... but it doesnt make me feel like a teenager like a broken down RX7 can!
Well that sucks at 2am. I get why you were doing that at that hour. I do the same to put myself out of step with traffic,nobody on the road but you and the police...REALLY sucks having to leave car on side of the road and worry it's still there when you go back for it.
Not to mention all the other benefits of running DFI,if there was ever a reason to do so this is it. You would have been able to drive that car home. Experience has taught me on a maintenance belt change,to put the removed belt(s) in spare tire well on top of spare in all my vehicles and under the seat in my truck.
I have had new v and serpentine belts fail for either no reason or like the time a squirrel decided to hang out overnight in engine compartment of my truck and go to work with me in the morning...
If you had DFI AND a spare belt with you,you could roll a "new" belt on,disconnect trailing coil wire from cap and plug wires from trailing plugs. Remove remains of rotor and metal shield and throw that stuff in the back. Take the trailing coil wire and tuck it somewhere down on frame so it can unload harmlessly and drive home. Had to do this once from a failure similar to yours. DFI !!!
Yes, I've been contemplating what kind of intake to put on the 13B I have in the garage. My brother in law is a drag racer and keeps telling me to go with
ProJay stuff like he uses, but it's $$$ and his car is a dedicated racer (can you say 96mm turbo and billet plates?). The guy I got the motor from says to use litre bike TB's on a custom intake, which my bro also says is popular. These guys don't know how to find or fix classic parts like this forum does, but they can build 7-second 12A's.
Anyway, I don't know if the belt (dual pulley) hit the wires and pulled the dizzy loose, or the dizzy rotor just exploded independently of the belt. There aren't any Mark's on the spark plug wires or ignitor, nothing looks like a belt hit it. IDK. Why ya gonna make a rev happy motor with slo-mo accessories?
So here it sits, resting in peace, at the Graveyard where it came to rest last night. Yes, a Graveyard. Lol.
I got some used belts from the garage and bro has a dizzy cap. If he can find a rotor I'll drive it home. If not we'll pull it to his house until my new parts come in.
It Lives! HaHa! Yeah, the new rotor looks much better than the old one.
The tin piece under the rotor got all pitted from arcing and the broken pieces going around in the blender...
I'm going to the parts store to get some New belts, and I'm back in business. Typical rotary weekend.
Good deal on cap and rotor!
As far as figuring out what happened,if there's a belt,or both missing from pulleys-that's your culprit,witness marks or not. Likely you had the engine twisted pretty good in all your testing,maybe not at that point.
I have never seen a rotor implode and damage a cap like that,and i've twisted more than one rotary a good bit past the buzzer. I have had similar damage that was my own fault,in a hurry and didn't get metal shield oriented correctly and one of cap latches didn't slide all the way home,popped off and rotor chewed cap and grabbed one of the terminals that broke cap. Turns car into a glider quick...right?
Hard to believe you haven't,with all your go fast mods,done a proper DFI system,not terribly expensive and no need for expensive ignition boxes like MSD stuff.I've done several both ways and DFI is much more cost effective and MSD didn't add anymore to the equation . It is worth your time,as is going to a streetport exhaust system, the exhaust will help your engine to breathe to its full potential. I know you have a RB single system now. Those two items wake up a rotary and are biggest bang for your buck mods that'll last the life of the car you can do. Once those are in place with the work you have already done you will feel the difference. Being that you're going to a 13B,wait til then to do streetport exhaust as header for 12A and13B are different.
I've had many flavors of rotary,carbed,Holley,Carter,nitrous,carbed with turbo, FI. For a street driven car,reliability,not fussy or high strung powerplants appeal to me as i've gotten older. I had my streetracer beasts but you can't say that and reliability in same sentence. You can have a modded rotary that is reliable and fun to drive. Add a turbo and engine lifespan goes down(unless BIG $$$ is spent on race parts and even then...) as does drivetrain parts. IMO a lot of people,like i did,these days go too far with these cars and the fun to drive reliability factor in a car you can jump in and rip around or take on extended drive or a road trip somewhere goes away. One of reasons i dislike 2nd,3rd gen cars,they are less reliable than 1st gens in stock trim,more so when power building mods are done.
You(not you personally) have to decide what you want the car to be and proceed down that path.
Thanks GSL-SEforme. Yes I want to put a good reliable FI (DFI is digital fuel injection, right?) On the new motor. Carbs are classic and cool looking, but I'm getting sick of playing with them I just want it to start up, rain or shine, cold or hot, and GO! I really don't know where to start though.
I was looking at simple DIY throttle body conversions for V8's, like the ones made by FITech. But my bro in law said it wont work right and keeps trying to get me to go with racing stuff. I don't need all that, so I need to find something simple, reasonably affordable, and use friendly so I can do it myself. On my Subaru I do all the wrenching but then I have to pay a guy to tune the computer $$$.
The software that comes with those DIY throttle body conversions is unrelatable to rotary engine needs. Several,some on this site have tried it with poor results. If you could get your hands on a throttle body,Holley,Fast or Fitech,even used for a good price, you could build and install a megasquirt standalone ecu and convert your fuel system using an intank hi pressure pump and new lines with an adjustable hi pressure fuel regulator and tune it yourself or have someone do it for you.
If i was looking to modify a 1st gen for reliable horsepower,this is the direction i would go. Aggressive streetported 13B with this setup and DFI,RB streetport as supporting mods would have you in 200+hp territory easily. 200 hp in a 1st gen is just about right for fun factor/reliability and for an amount of $1500-$1600 hp is realistic and should still be able to use whatever air cleaner you're using now for that time period look. An upgraded alternator to feed the components that didn't come on car originally also necessary.
Look thru chuyler1's build thread for how he modified his existing fuel tank using a Holley pump and Hydramat to feed his aftermarket Jenvy setup.
If you had DFI AND a spare belt with you,you could roll a "new" belt on,disconnect trailing coil wire from cap and plug wires from trailing plugs. Remove remains of rotor and metal shield and throw that stuff in the back. Take the trailing coil wire and tuck it somewhere down on frame so it can unload harmlessly and drive home. Had to do this once from a failure similar to yours. DFI !!!
You can connect your leading coil ingnitionkabel with the leading spark kabel L1 front and your trailing coil ingnitionkabel with the leading spark kabel L2 rear rotor directly. Your engine will start and you will be able for drive home without the ingniton rotor and rotor cap. Some tape will help fix both end of the ignitionkabel. Sparktime will not be perfect but it will work for emergency aid.
Last edited by Rx7fb spirit r; 08-11-19 at 12:56 PM.
I think,.... that I might have an idea how I caused this. The double belts were new and adjusted properly. The cap and rotor were new and installed properly. But, as I said I was tuning my carb all night (8pm till 2am).
Most of my pit stops were at well lit convenience stores parking lots, but my last stop was not. It was in a dark church lot, and I didnt use my flashlight because I was just changing throttle springs, and could do it by feel. Well today I cannot find the biggest spring anywhere in the car with my other tuning parts.
I'm wondering if I left it under the hood somewhere and it fell into the belts, prying it off at the pulley. 😯
The last pic is how I found the belts when I opened the hood. One was off and the second was "inside out" and out of the groove. Weird.
I don't know. I had been running it hard (7000+) for hours, and when this happened I was driving easy coming back into town around 3500 rpm. WHACK ching ching ching ching dink dink ching ching ching. Turned into a glider as GSL-SEforme put it.
Those Jenvy side drafts look nice. I was looking at PAC's site at their IDA FI conversion....
They are about $1300 USD for the kit, plus fuel pump and line, etc. Pricey, but I've gone through that already in carbs.
I am aware of the company but have no 1st hand knowledge of the products. Suggest you read thru chuylers' build thread regarding his complications with his Jenvy conversion,horsepower,driveability issues. At this point i think he is considering a rear gear change to help performance.
07-16-19, 07:58 PM
