Jon,
I posted the uncorrected values in my first post....
Here they are again:

TR1 test, Rotor 1
RPM: 298
Face 1, 112 PSI
Face 2, 113 PSI
Face 3, 113 PSI

Rotor 2
RPM: 305
Face 1, 109 PSI
Face 2, 113 PSI
Face 3, 110 PSI

These are uncorrected.

The Mazda tool showed:

Rotor 1
RPM: 250
Face 1, 5.70 kg/cm2
Face 2, 6.10 kg/cm2
Face 3, 6.70 kg/cm2

Rotor 2
RPM: 250
Face 1, 6.80 kg/cm2
Face 2, 7.20 kg/cm2
Face 3, 7.10 kg/cm2

I will try to retest the same engine or another one, so that we get better "statistical" data.

Regards,
George

 

Oh, so you actually were cranking at exactly 250rpm for the Mazda one, that's what I missed. I thought you had corrected the mazda values to 250 as well.

Jon

 

Whats the lead time look like right now? There is a car meet on July first I'd love to have it for.

 

Payment sent!

 

dude,

straw and dixie cup for you.



beers

 

hey john received the tool last week thanx

I did a test on my TII S4 , tested from leading plugs holes, throttle wide open with raw data readings

Front 248 RPM 86 85 85

Rear 237 RPM 72 74 73


what correction do i need to do?

spec is min 85 psi on a TII right?

hybrid

 

Hey Hybrid,
I'm glad you like your tester! For correcting those numbers you'd need to multiply the readings by 1.032. That's the correction factor for a S4 TII. This is what I got:

Front 248 RPM 86 85 85 (corrected 88.7 87.7 87.7)
Rear 237 RPM 72 74 73 (corrected 74.4 76.4 75.3)

Now, that doesn't take into account for the slower RPM. For that, we need to take a look at the FSM. Mazda put a graph in each FSM that shows how to compensate for low RPMs during the test. I've got the RX8 FSM downloaded, but can't find my '87 TII FSM at this moment. I'm going to look for it, or start downloading the digital copy and I'll post when I get it.
-John

 

This is low compression, on 250 rpm it will be:
Front 89.28 88.28 88.28
Rear 78.17 80.17 79.07

Minimum is 98.6 psi.

 

You need to re-do the test. According to the FSM compression tests have to be taken from the trailing spark plug hole. It makes a big difference.

Then you have to multiply by the correction factor posted here as well as correcting for RPM.

Jon

 

That minimum is for RX-8's, it is not correct for this car. The FSM for S4's states a minimum of 85. Here's a pic from the 86-88 FSM.



As for leading vs. trailing, I would agree and recommend to re-test from the trailing hole. Personally I don't think there will be much if any difference, but I have not tested the same engine from both leading and trailing so maybe I will learn something new.
-John

 

I'd like to add to keep in mind that the minimum's are just what Mazda recommends. Now for the RX-8 guys under warranty this is a big deal because they could get a new engine installed for free. For those of us that have never owned a rotary with any kind of warranty, then this number becomes subjective. Does your car feel strong? Does it start easily? If yes, then I wouldn't let these numbers bother you that much. The readings are even across the board and that engine may have quite a bit of fun left in it. If on the other hand you've been looking for a sign to drop-in that brand new bridge-port with the giant turbo, then this may be it.
-John

 

yep will redo the test this weekend and report back......but all in all a rebuild is on order

hybrid

 

Placed my order. I can't wait to get this.

 

PM sent
Money sent

 

Payments received! Thanks guys.


And if there's anyone on the fence about getting a tester now, there's only 6 days left at the GB price!! Get 'em while they're cheap!
-John

 

What's the status on current orders?

thewird

 

Assembly in progress. Got all the parts, now I'm putting 'em together.
-John

 

Weeeeeeeeeeeeeeeeeeeeeeeeeeee

 

this seems like a must have tool!

 

It is.

-John

 

How's the next batch coming along?

 

Coming right along.
Boards are soldered, sensor modules are assembled....just have to finish machining the cases, mount the boards and screens in the case and close 'em up.
-John

 

any luck out there yet on a comparo with mazda's numbers???

 

So I figured I would show you guys what I have been working on. Anyone care to check my maths?

 

Is there time to include an order for mine as well ?