Phil's 8

iTrader: (3)

No not now. I would consider a compression test as a normal tuning procedure now that I see what can happen. My fuel trims are know by Jeff (Mazda Maniac) and not really by me. He does my tuning. My problem was that it happened so slowly and so evenly you would have also blamed it on tuning or something else closely related. My compression loss is almost flat across the combustion range 50psi.

olddragger

iTrader: (3)

now if I can just remember how i got those pics to cross over

Glad yall liked that
I am not through with it yet and yep it is labor intensive. The vdi area looks one heck of a lot better than oem AND yall havent seen what I have done to the other sides of it --hehe. When I swap out I will also have a heat barrier gasket going on. Remember a bunch of little things carefully done can result in a pretty good result. keep in mind that total cross sectional area on a intake runner is very important and the shape of the runner leading to the intake port is very important. Also --you would not believe how thick the aluminum is on this baby.
Not ready yet to do anyone elses. Maybe at some point. Stay tuned.

Moon that is really good work man, Grassroot stuff yet advanced. Something about making it yourself isnt it?

Phil do the decarb (very heavily 1st) x fingers for ya friend. There are some things that can help with cooling this baby but you have probably read them all. jeff is very much aware.
OD

olddragger

iTrader: (3)

the lost of compression is either carbon buildup or just flat wore out. end of story. and since it is across the board it is probably not carbon---but you never know.
with leaky seals i dont think i would have the s/c belt on?
OD

MazdaManiac

iTrader: (3)

Well, not exactly. "Wore out" would indicate a condition where parts that normally wear did so at an accelerated rate.
In Phils case, its likely that he distorted something by overheating it - maybe repeatedly. Not really "wear".

No. In Phil's case, it was a gradual degradation of his idle as the thing got hot and a general lack of power.

That depends on what you mean by "bad seals".

With seals that are just "leaking" - or in Phil's case, warped/bent or riding in deformed housings or against scored irons - boost will just make up for the lost compression. Can't hurt the motor. It will just keep it from being sluggish.

olddragger

iTrader: (3)

Yea I do have a tendency to over generalized, i define wore out as just not working right. Sort of like me sometimes
I certainly can see how the boost would help with the output. I thought at this point the less demand on the engine the better. He has a rebuildable engine now, hope it doesnt turn into a non rebuildable one.
OD

Moon Assad

In any case when something isnt rite you shouldnt keep driving it, If you havent taken it apart to see what the problem is for sure. Dont make any estimates because you never now. It could meen the difference between needing new housings, rotors, even needing machining of the rotor or not. Thats why they say tow your car if you nitice a problem.

MazdaManiac

iTrader: (3)

Nah. His car developed this problem gradually. The likelihood of a catastrophic failure at this point is low.
Furthermore, we have such an abundance of parts at our disposal right now that we can take care of whatever might arise.
If there is any scoring (which there might be), it isn't going to be made and "worse" by driving it - those parts are already toast.

Phil's 8

iTrader: (3)

Thank you for your concern Moon. I don't think it could get worse than it is now. They have new everything ready for the rebuild. We even have a contingency for a thrashed engine (I hope it does not come to that).

Rote8

I just can't stop building huge long term fuel trims. and the car dies if you let off too fast when you are on it. (say HARD 9K burst, let off, immediately clutch in and let engine idle)
This only started when I got rid of my Cat.
I just had to go with a 3 inch exhaust all the way back from the exhaust manifold......

It's also NOT changing, it is worse after pulling the ROOM fuse.

My thoughts:
exhaust just too large???
bad MAF sensor?
intake leak?

Then there is always:
Bad compression?

That is why I ask if the car can make over 300RWHP with a "bad" engine.

I plan on a compression check soon to settle my mind on this last issue.

If it is bad, I plan on buying a second engine to rebuild, or buying housings, rotors and E-shaft.

I wanna build a cermet one, one day....

Norm

MazdaManiac

iTrader: (3)

Is dumping the CAT the only thing you did?

Rote8

What made the change; Mazsport midpipe and Racing Beat REV8.

Yeah, I have since added methanol, but without any drivability changes.
The sudden let off killing it, after a hard run, it's been there ever since the exhaust change.

It feels almost like a lightened fly wheel.

Don't get me wrong, the car is perfectly drivable, you just need to remember to let off slow if you get on it very hard.

I would be shocked if it did have low compression, but with all the current talk of tuning problems becoming bad motors.....
Paranoia maybe.

Still, a simple compression check can tell the facts, regardless of my paranoia....

PS: Maybe I should have used Mazda sand to clean it, not Honda sand.
(I loved that story)

olddragger

iTrader: (3)

anything from a vacuum leak to a potato in your exhaust pipe.
would not happen to have the a/c on do ya? just a thought.
time to do the check sheet?
olddragger

Rote8

<Eddie Murphy voice>
I'm not gonna fall for the potato in the tail pipe.



A/C off helps some, when the IAT goes down it is the most help.
With the methanol, I can run IATs below ambient temps.

I have searched, tested, sprayed and everything else I can think of to test for an intake leak.

MazdaManiac

iTrader: (3)

OT - This has nothing to do with anything:

Rote8: do you know who this Rote8 is?:
https://www.rx8club.com/showpost.php...&postcount=182

I'm trying to figure out how there could be two people on the forum with the same screen name.
The above-quoted "Rote8" is, apparently, banned since they have no info.

Rote8

Banned?
I thought the forum was just slow sometimes.

Phil's 8

iTrader: (3)

There are some nice people that have been banned on occasion - don't hold that against them.

Rote8

<nervous>
Hello?
Anyone?

MazdaManiac

iTrader: (3)

What's wrong?

Rote8

Didn't hear anything from anyone in a while.....

Phil's 8

iTrader: (3)

They are all saving it up for the "big bang" that's sure to come.......

zenrx8

iTrader: (4)

Phil, sorry to hear about your problems; you've had your fair share with the INT-X.
Ironic it should show up after you get the flash. The best I can tell you is htat now's the time for you and Jeff to start new - good luck.

Charles R. Hill

iTrader: (7)

Where are your injections points for the alky?

MazdaManiac

iTrader: (3)

Well, once all the other impediments were out of the way, it was easier to see what the base behavior was.

zenrx8

iTrader: (4)

Now if we could just accomplish the same thing with you. Maybe dock a ScanTool up your ***.

Rote8

I have one 175ml nozzle about an inch past the inter-cooler, spraying down vertically.
(I know, it should be spraying up, but it wets the I/C this way...)
Still too lazy to install the other nozzle on the intake side.....

I do have the dual nozzle kit and a 60 ml nozzle.
At this point I have quite a nozzle assortment:
60, 100, 175, 275. (The 175 is installed)