SamNavy Dyno Results - Miata Turbo Forum - Boost cars, acquire cats.

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Old 01-05-2007, 06:33 PM   #1
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Unhappy SamNavy Dyno Results

The smilie says it all... poop!

I'm working on scanning my sheets, but there were several problems very evident starting on the first run.

#1: My brand new properly broken in Spec Stage II clutch rated for 240ftlbs started slipping at 180ftlbs. Looks like I might be filing a claim.

#2: I've discovered that my internally wastegated T25 is going to exhibit boost overshoot to some degree no matter what I do until I go EBC.

#3: I dialed my AFPR from full rise all the way back to min rise and it had no effect on fuel pressure. I was seeing over 130psi of fuel pressure from about 10psi on up to 16psi. Turning the adjustment **** did nothing. When I bypassed the MBC and just ran off the wastegate, I made a peak of 9psi and steady 6-7psi with 95psi of fuel pressure and no amount of turning the **** did anything.

My best run was 167hp/181tq @4400rpm at 12psi when the clutch started slipping. The boost climbs steadily up to it's peak of 16psi @4100rpm and then drops off to a steady 11-12psi after that.

The A/F's on that run were:
2500: 12.0
2750: 11.0
3000: 10.8
3250: 10.8
3500: 11.0
3750: 11.5
4000: 11.8
4250: 12.0
4500: 11.8
4750: 11.2
5000: 10.8
5250: 10.6
5500: 10.2

I've decided until I get a better handle on this thing that I'm not going to run an MBC. The wastegate alone peaks at [email protected] and drops to a steady 7psi. I made 130hp/136tq @6000rpm like with an A/F curve very similar to the above one.

POOP! I'm gonna go get drunk now. See you tomorrow.
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Old 01-05-2007, 06:55 PM   #2
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no big deal sam, nobody ever gets ther results they want when going to the dyno, especially the first time. sounds like you have an issue with your afpr, is it new or used?
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Old 01-05-2007, 07:01 PM   #3
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Your a/f curve is pretty decent for an rrfpr setup. I bet leaning the top end out may yield another 10 whp. How much timing are you pulling with the bipes?
What size is that downpipe and exhaust?

Don't let it get you down. Although not what you wanted I think its a decent first session.
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Old 01-05-2007, 07:10 PM   #4
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my afpr does the same damn thing, only difference is I have a larger turbo that can use all of the fuel pressure. Sam, honestly man...an EBC isnt going to really fix your problem...port the damn wastegate man....16psi @ 4100 on a stock ecu and pump gas is not something that I reccomend.
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Old 01-05-2007, 07:11 PM   #5
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also let it be known that SPEC clutches are TEH SUCK
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Old 01-05-2007, 07:15 PM   #6
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It could be worse.. I think I dynoed like 100 rwhp my first time
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Old 01-05-2007, 07:38 PM   #7
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you need a restrictor on the FMU vacuum line. still good numbers, considering you're clutch was slipping. I bet if you fix your boost spike your clutch will hold better as you don't spike up to 16psi and shoot to 180rwtq
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Old 01-05-2007, 07:41 PM   #8
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Nice...damit why not me... :(
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Old 01-05-2007, 08:24 PM   #9
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what size exhaust piping are you using,maybee the boost gauge is f'''ed up
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Old 01-05-2007, 08:31 PM   #10
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Sucks about the clutch problems.
Did you end up using a helper spring on that WG?
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Old 01-05-2007, 08:38 PM   #11
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Well now I'm not going to use a spec clutch for sure.
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Old 01-05-2007, 09:16 PM   #12
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I had the same boost creep problem on my old rx7 until I took a dremel tool to it. Once I smoothed out the flow, it stuck solid at 8psi. Or have Cody at lovefab.com make you a manifold with an external wastegate. I almost went that route because boost you can't control ain't good boost. But my GT28 creeps less than one psi. Once you get a working FMU, you should be golden.
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Old 01-05-2007, 09:29 PM   #13
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Your 7 psi numbers sound about how my car feels with very simmilar parts, and the same boost. I have the same problem with my begi fmu, I need to play with it someday when I have more time off of work.

Thats disapointing about the spec clutch, I think I am leaning to a Mazdaspeed MX-5 clutch now.

What kind of dyno where you on?
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Old 01-05-2007, 09:52 PM   #14
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you know swaping to the 1.6 injectors would help keep the top lean, i would try that seems you are pretty eficient why not try smaller injectors to keep the af's more in the power range.
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Old 01-05-2007, 11:09 PM   #15
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He needs less fuel pressure!!!! Call Corky and have him send you a restrictor or use the tube form a WD-40 can.....at 170rwhp you only need like 70-80psi with 305cc injectors.

Sam not that you know where you stand, I'd suggest a few things:

Work on the boost spike...I still think you can cure it.
Cure the excessive fuel.
Buy an LC-1 and tune the fuel.
Kick SPEC in the ****. (I still think no spikw will cure some slippage)
Go back and make just three runs.

Seriuosly dont worry about it, the dyno is a great place to lay down numbers but a great tool to figure how things stand.

And yes, me and Brad drove 2-3hrs to a dyno 2 states away to find out he had nothing but problems.
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Old 01-05-2007, 11:54 PM   #16
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Does your telemetry come from the dyno's capture, or your own gauges? I may be way off base, but I seem to remember that you ran your boost/vac gauge before the turbo kit was installed, and your boost gauge wasn't calibrated. Maybe I'm nuts, I dunno...

Did you read the thread where I installed an extra check valve on the FMU to get it to bleed better? I had the same problem with my FMU's needle valve. Completely corrected with the dual check valves. With the restrictor added, I'm now getting afr's approx to what you'd get with a piggyback controller.

Oh, and what kind of dyno did you run on?
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Old 01-06-2007, 12:56 AM   #17
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Man, I don't wanna hear that the Spec II is slipping at 180 lb of torque. I dynoed at 202HP and 179HP the last time using a smaller pulley than I'm using now.

That means I'm starting to slip my clutch already. :(
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Old 01-06-2007, 08:43 AM   #18
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chuckerants
Well you have a 1.8 yours is probably a litle better.
Ben
Calibrate boost gauge WTF no such thing unless it is a digital in wich case throw it away for a analog but i geus i am biased.
Sam
Try the smaller injectors or less fp both will do the trick. In relation to the spicking issue, it helped me to move the boost vac source and mbc as far away from the turbo as possible then you have abit more head room to bleed off boost. Set the mbc a little lower than you have now and you should hit the same boost and keep it better. If not get a spring and eyebolt and dial in the tension and dial back the mbc. Good luck man with that much torque you will make some real nice power when you get it tunned.
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Old 01-06-2007, 11:55 AM   #19
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Quote:
Originally Posted by magnamx-5 View Post
Ben
Calibrate boost gauge WTF no such thing unless it is a digital in wich case throw it away for a analog but i geus i am biased.
The gauge/any gauge is calibrated from the factory. I don't mean to imply that a cheap analog gauge is recalibratable.

But I thought Sam's gauge was reading a couple psi boost back when he was NA, so he just "bent" the gauge to make it show 0 vac, instead of positive manifold pressure. So I'm wondering if he's really getting that much boost out of his set up.

But maybe I'm confusing Sam with someone else
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Old 01-06-2007, 12:15 PM   #20
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I don't know that there's anything particularly wrong with your clutch. It's rated for 240lb-ft at the flywheel. On a good day, that might be ~200lb-ft at the wheels (on an independent rear-end car like the Miata).

Okay, so, maybe you're right, though, it probably shouldn't be slipping at 20lb-ft under that. I've got a Spec Stg. II clutch also and, after having accidentally hit ~12psi once, it held just fine (much to the chagrin of my motor, which pinging like a sumbitch). I'm also running the 1.8L Spec Stg. 2, though, which is good for 275lb-ft at the flywheel, I just remembered.

Well, I don't think this is quite the damning evidence that Andy and Efini believe it is. Or maybe it is...it's hard to say.

But get that AFR curve looking a little better, stick with 8-9psi for the moment, and see what you can do. Good luck!

Oh, and what's your timing retard look like on the Bipes?
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