161 rwhp
15.1 @ 98mph

That is my one time dyno run and best of three strip runs. I know my car has some issues that are still being resolved, but could a bad turbo or piping cause that much of a loss? I'm trying to get a boost gauge (tight on funds) because the Blitz one doesn't work...? I have the time slip and dyno sheet, but I don't have a scanner. At 161rwhp is when I thought my motor blew, it blew a huge cloud of black smoke through the exhaust then like a puff of white smoke. Joesphi and DavidR was there when it happened. The dyno sheet is pretty rough after that because I took it out of gear and let it coast down. Anyway, just have to wallow in my own self pity :p and that I now have another more important problem that is currently being resolved.

 

Boost is the first place to start. I would think that low or no boost could cause 161 RWHP.

I haven't had any experience with a "large" cloud of black smoke accompanied by a white puff, but I do get the regular rich exhaust...I wouldn't call that a large cloud. I don't know, but may be that was significant carbon build up letting go in the engine itself???

Depending on the boost, I would do a compression test.

 

you deff need a boost gauge,

down pipe and mid pipe, might have been letting you creep, this could be abad thing, deff need to get a boost gauge up and working

 

The guy I'd bought the car from had it for a while and all the cat's were clogged up pretty good. So, that's the reason for the straight pipe on the stock cat-back. I believe that was all the carbon blowing out with alot of pressure built behind it from the dyno run. It ran fine afterwards, not really any different. I can feel the car kick over turbo's at 3500 rpm and there was the drop on the dyno graph too, but it didn't seem like the HP jumped back up, it was pretty linear except for the loss during the switch. How much is a compression check at Mazda? I want to get exact psi numbers so I can see if I'm looking at a new engine.

 

If you are tight on funds, you could always do a poorman's boost check. there are two really; first, go to 3rd gear at roughly 35 mph. drop the throttle. your turbo's should spool and be pretty loud. But dont go wot for too long, as Bacon said, it may be boostcreep, and that is bad. You just want to go open throttle long enough to hear turbo's. That alone would confirm that the turbo's are somewhat functioning. Next:

Unattach the hoses that lead from your stock blowoff valves to the airbox. Be sure to use the larger hose that you remove to plug back into the 2 open holes in the airbox that are there when you remove both hoses.

Now, when you boost past 3500 up to 4500, abruptly let off the throttle, you should hear a psshhh sound (b.o.v.). If the sound is pretty weak, then you are having boost problems definately. If it is moderately loud, then your car should be working with a little bit of boost problems. If the sound is loud, then you might as well plug the hoses back up the way it was stock, bc the problem is much larger than just turbo's.

A mechanic friend of mine reccomended i do that before taking the car to any shop. Thats the test that i used when my primary turbo wasnt working (it wouldnt prespool when i lightly touched the throttle like it used to).

If someone knows that this test may further the problem, please post something. But from my test, there were no ill-effects.

 

wow, u must have posted like 2 mins before me. A compression check from a mazda dealer should be roughly $75. Thats how much mine was

 

I'm going to try the stock BOV test tonight, I know the turbos are at least acting like they work. When they switch over, the exhaust kind of howls instead of the sound it makes before the switchover? If the BOV test comes out good, then I guess it's to the dealer for a compression check. It should be around 110psi stock, am I correct? What should a normal motor at about 60k miles be at?

 

Post your dyno sheet... if you can get to a scanner.

 

Im not exactly sure about the psi of the motor, but everyone says that a compression number would be anywhere from 7- 9 on a good motor, with a 6 pushing it (correct me if im wrong). Good luck on the car.

 

I could fax it to someone if they could scan it for me...

I'm sure Mazda will have a reference of some sort if I can't find one anywhere else.

I couldn't get the test done last night because I had to work late and had a couple thigns come up. I'll post what I find out when I do it today, hopefully.

 

It's been a while.....

I got there after your dyno run, but I doubt that amount of smoke could be related just to build up. I would highly recommend going for a compression test. That will at least give you a starting point for troubleshooting. If your motor's not making compression, it would be a waste of time digging into the rat's nest underneath. Also, even if you've got problems with the vacuum hoses, they still wouldn't cause the excessive smoking.

I can scan your time slip & dyno if you want. Just let me know.

-Mark

 

No one's mentioned this yet but 98 mph is WAY more than 161 rwhp....more like 230. Sounds like you have an intermittent problem of some sort (probably boost).

 

Marshall, my friends volvo (granted its a piece), can break 110 mph, and it only has 125hp. The car is somewhere around 9 years old, and the turbo on it is going bad, so im sure it has less hp now, but it still gets up there.

But i do agree, go in for a compression test, thats the only real way to find out.

 

My very first run down the 1/4 mile in my 93 R1 gave a 13.945@ 99.54mph. Your 98 mph run should gave given a very low 14 instead of a 15.

Your rwhp and 1/4 speed aren't matching up.

Jeff

 

I'll get my dyno sheet and time slip tomorrow so I can have it posted, hopefully, and you can look at it for yourself. It was either 89 or 98, I'll know for sure this evening. If I can't get it posted, I'll list all my times from the slip and dyno though.

 

My speed was not 98, it was 90, read the slip wrong, my bad.

 

Fastx7, what kind of computer mod do you have? If your running a downpipe and midpipe with a stock computer, your lucky your having boost problems. If your turbo system were running properly, you'd probably running around 16-17psi of boost due to creep from the midpipe. The first thing I would do, is check your computer, to make sure you have enough fuel for the boost your car can be running. I'd bet you have bad vacuum hoses, a maybe a bad actuator or solenoid. You first have to get a boost gauge, even an autometer will do. Maybe you can find a used one for real cheap. List all of your mods, so we can better diagnose what to do next.

eric

 

Here's all the pertinent info that I can think of...
- 160k miles on the car, unknown if new set or turbos and motor and/or amount of miles
- rock hard silicone hoses, Hose Techniques kit on the way as we speak
- HKS downpipe
- Mindtrain midpipe
- stock catback, intake, computer and intercooler
Anything else that you want to know, I'll list it...