My weird dyno results

[MrDiggler]

I'm posting this here because it appears nobody visits the dyno sheet section. Scold me if you need to.

This was the first dyno pass I've ever done on my MSP. I wanted a baseline in preparation for installing my Vibrant exhaust and new SMIC. The car is bone stock and at stock boost w/ 42k miles. Still running the original plugs. It was warm and humid for this time of year. I made 3 passes, all in 4th gear, but they only got worse from here. Two things stand out:

1) It made about 10 less hp than I thought it should have. Which could be attributable to my tranny going out. It roars like hell and might be costing me some power.

2) My A/F appears way more normal than I expected. The dyno operator told me that his wideband pipe sniffer can read high by 3 or so, and that once I get the Vibrant installed he can put his sensor in the extra bung and get a more accurate reading. Too weird, I know this thing runs pig rich, especially in warm, humid weather.

Edit: The way he had the chart set up causes tq. and hp curves not to cross at 5,250 rpm. Next time I'll ask him not to print it that way.

 

[peepsalot]

Wow a wideband that is off by 3, why even bother. I'd find a new dyno shop.

Did he actually stick the probe in your tailpipe, or just somewhere near it? (boom01)

 

[MrDiggler]

From the tip of the muffler it was 6-8 inches in. And they are the only dyno in the area. When I asked whether or not it could be off, he said it could and that he's seen it happen on his own vehicles. He explained that the mixture at the end of the exhaust system that's then pumped through a bunch of tubing to the remote sensor can be a different mixture than what you get right after the turbo. Dunno.

 

[daedalus]

your numbers dont look bad for a bone stock MSP. Heat soak on those tiny IC's will drop your numbers off very quickly on back to back pulls like you did.

Swap the plugs for sure before you re-dyno (43k is WAY tooo much to keep the stockers in, and i think is a primary reason for some of your dissapointment), get that SMIC, and vibrant going and you should be VERY impressed.

Also, i would dyno in 3rd gear... less stress and load on the engine, and wont affect dyno outcome in terms of numbers.

 

[MrDiggler]

Okay, I figured as much about the plugs. I appreciate the feedback.

I wondered about pulling in 3rd vs. 4th. The tech said 4th is better because it's usually 1:1 gearing. I can't understand how gearing could not affect the dyno reading considering torque multiplication and all.

 

[terbow]

mine was like 146 stock so i say ur right on par.

 

[MrDiggler]

mine was like 146 stock so i say ur right on par.

Ahhh. Ok. I thought I was significantly low.

 

[jeffmsp]

seems about right considering how many variables there are like temperature, humidity,elevation,gas,plugs etc

 

[skrecht]

much worse results for me

I had gone to get a baseline on my 03 msp and was utterly dissapointed.
Bone stock, no upgrades the car only came up with 130 whp.
Guy told me the car was running pig rich.
2003.5 msp dynoed 2 weeks before also bone stock, and got 151whp.
You can imagine my mood after that.
Went to Mazda, explained that there is something inherently wrong with the car, and they didn't give a crap. They wasted my time and ran a "diagnostic" on the car, which i told them will not give us any answers.
I suggested we order a new computer since its under warranty, they said no nothign is wrong.
I pulled all the strings i could with people i knew at the dealer, but that's as far as anything got.
So i drove my car and decided that i'll just have to suck it up and realize that these cars were mazda's guineapigs for their mazdaspeed launch, and other people seemed to have results lower that expected, though still over 10whp higher than I got.
By the way, had colder plugs when i first ran it and it actually gave even worse results, went back to stockers and gave me a few more hp.
sorry for the long post, its fueled by aggravation.

 

[daedalus]

cold plugs on stock car = teh bad.

get the car reflashed at the dealer and it should help things out if you allready havent.

 

[jeffmsp]

ya if you are staying stock keep the stock plugs and get the flash free from the dealer.

 

[skrecht]

cold plugs on stock car = teh bad.

get the car reflashed at the dealer and it should help things out if you allready havent.

got the car 8 mnths used with the flash sticker on the door sill. can they stil reflash it with that same flash just to make sure that's not the issue?

 

[daedalus]

should be able to... the ecu will tell them what version its on... so either way its not gonna harm anything.

 

[CasopoliS]

I agree, those numbers could very well be right.
I also suggest a third gear pull..... and finding another shop.

 

[JDM Sam]

the engine is more close to 1:1 in 4th however. Theres various factors in why your car is dyno'ing low #s. I'd check for leaks and replace vacuum lines for one.

 

[BlkZoomZoom]

Just curious why on the line graph does the hp and torque not cross at 5200rpm?

 

[peepsalot]

thjey are on differerrnt scales, see left and right sides of graph.

 

[BlkZoomZoom]

gotcha.

 

[MrDiggler]

the engine is more close to 1:1 in 4th however. Theres various factors in why your car is dyno'ing low #s. I'd check for leaks and replace vacuum lines for one.

Good idea. I'm going to go do that right now.

Wait...where are my new lines? This Sam guy was gonna send them to me...

(hahaspit) (poke)

BTW, I'm getting closer on my huge project and I can't wait to get the Vibrant and SMIC in. I decided to do both at once to save an extra $65 dyno pull and some labor. I'd like to know what I got with just the exhaust, but oh well.

 

[MrDiggler]

cold plugs on stock car = teh bad.

get the car reflashed at the dealer and it should help things out if you allready havent.

I'm glad I went with the Iridium IK20's instead of the colder IK22's now. I had to gap them down a bit, but no big deal. It's definitely more responsive and a little smoother. BTW, my old plugs definitely had a reddish color to them instead of a straight brown, black or grey. I wonder what that means.

Edit- Googled and found it. The red color comes from fuel additives. I have an old-school Chevron down the road and fill up there about 2/3 of the time (a friend's dad owns it and I know the gas is good). It must be the Techron.