We have the rotary diagnostics one, it works well.

 

Looks like its my only option, the lack of a readout on the handheld is upsetting though.

Think I'll pick it up just to be safe while I am doing some diagnostics this winter.

 

I have the Rotary Diagnostics one as well...I run it on my tablet and it isn't too difficult to deal with

 

You run it in your tablet? Android tablet?

 

Surface Pro

 

Looks like the TR-01 is going on sale again for the holiday with limited supply starting next week, plus its 50 bucks cheaper then the RD one with no display.

Does the RD show RPM, and interpret the results or just display the graph in PSI, does it also distinguish rotor face?

 

The RD one is a bitch to figure out but once you figure it out its a breeze, it uses a windows based application and gives you the full scope.

Personally I'd save up some extra cheese and get the OEM mazda one its much easier to use.

 

I don't think I cant justify 2K for a tester, or 800 for a used one.

When the new handheld from twistedrotors seems to do the exact same thing for 350, there having a special black friday sale with a limited supply, I am waiting patiently for the purchase button to be activated so I can pick one up.

If I miss out for some unfortunate reason I will get the RD one, but the idea of a handheld IMO is just more practical for me.

Also anyone have anything on rear subframe removal, can't find it in any of my service docs and just want to take a look at what alignment specs I need to be concerned with.

 

If you are only using it for yourself you don't need anything flash .

Just get an ordinary compression tester and take out the check valve . When you test the compression , take a video of the gauge as you do it . play the video back in slo-mo (if you can ) and record the results of each pulse .

 

this works fine even without the video, it can easily tell you if you have a dead motor....

 

It's all about the accuracy and the hardware, when you price the pressure transducers used you will see why some are more expensive than others. I'd have to see and try the Twisted Rotors one in person before I would be sold on it because it must use a cheaper transducer.

 

Decided to go for it, purchased a TR-02 when they went on sale this morning. Stock sold out in 14 hours. Will post up a review when I get back to test it out.

 

Hoping RIWWP can chime in as I know he had the chart somewhere around here.

Got my TR-01 and the results

Front


Rear

 

I keep it in the new owner's thread:

 

Slightly unhappy considering its a brand new Pettit build with 3K on it and is only coming in at 7, which IMO is failing.

Testing done at sea level, engine was at 170 when starting and 130 when finished. Guess I will be calling Cam next week as to me that is not acceptable for a basically brand new motor.

What do you think?

 

At 3k, I'd expect the compression to still be rising slightly. I've seen a few places where the seals won't completely lap in until 6k or so. But yeah, still lower than it should be, I'd give them a call.

 

It might be where my misfire issue is coming from as well. I only misfire on rotor 2 and it is at the failing point

 

Don't you have the S2 starter? That is low compared to mine and one other S2 starter we did installed for a compression test (not that is matters as far as your results are concerned, just mentioning it). Also, this is a new tester no? I would test it on another well running 8 just to get a comparison.

 

Yeah, it is an S2 starter but my battery is shot. Sat for 3months without a charge.

Charging it tonight see what I get in the morning. If I get a nice day ill take the car in for a Mazda test see what it says.

 

Ah ok, that makes sense. Do you have any other local 8's that you could use your tester on?

 

No I don't unfortunately.

Off to get a good old piston tester to see what it says. If it stays low Ill have Mazda check it out this week. Then Call Cam.

Seems strange that both front and rear would be low at the same time at 3K so I am not sure exactly what to think about it. Nor if this is normal considering I have different seals and my rotors where machined

Also according to RB minimum compression is 75 PSI and that ported engines can range from 90-120 PSI for normal range.

 

I have seen engines fail evenly on both housings but usually it is the rear that goes first. But in this case we are talking about a fresh engine so it doesn't look good. My boosted, ported engine has 24k on it and last month when I compression tested it, it was 115psi or so across the board on both housings.

 

It is strange it usually is the rear to go first for most people. Just trying to think what could cause both to be low on a brand new engine.

Also why is compression tested on trailing vs leading plug?

 

Compression is mostly about side seal clearances and how well the apex seals are bedded to the housings

What kind of seals did you build with? Did the engine get ported? That can make a difference as well

Also what did they use for corner seals if they went to full height seals?

 

Not sure what the side and corner seals are but 3mm flex force apex seals with the rotors machined for clearance and street porting.