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Discussion Starter · #1 ·
Okay so I took my car in for my dyno session today to get a before and after with the res exhaust header which will be a catless 4-2-1 very similar to the stock manifold in. Here is the before dyno. I have an injen short ram, corksport cold air box, BBR GTI camshafts and corksport catback exhaust (60.5mm) and OVT tune He did warn me that his dyno reads like a Mustang dyno it's called a dynocom I believe. 90hp and 105 lbs ft. Seems a bit low given all the mods and tune but who knows lol. I will be getting the headers installed next week hopefully and tuned and I will post the after. This is a 2.0l and was done in 4th gear.
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Wow, there is something very wrong there......A stock 2.0 should make about 132 - 135 at the wheels, your results show 90? With an axleback and an intake it should look something like this -


First, find a different shop to corroborate those numbers. If you get the same results, whatever you did to your motor was done wrong. With just an axleback, SRI w/enclosure and a good 93 octane tune a 2.0 should be making 160 - 170 at the wheels.

 

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Discussion Starter · #4 ·
Thank you for posting. I remember what the car felt like stock and it is most certainly making more power now, I think I will see a different shop and see what numbers I get from there. My 3 doesn't feel like it is underpowered at all, I think I would notice a loss of 60hp or atleast I hope I would...
 

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Discussion Starter · #5 ·
Wow, there is something very wrong there......A stock 2.0 should make about 132 - 135 at the wheels, your results show 90? With an axleback and an intake it should look something like this -


First, find a different shop to corroborate those numbers. If you get the same results, whatever you did to your motor was done wrong. With just an axleback, SRI w/enclosure and a good 93 octane tune a 2.0 should be making 160 - 170 at the wheels.

Was that in 4th gear as well?
 

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I've only done v-dynos, but the dyno should be able to take into account gear ratios, temperature and other factors to get an accurate reading.

As long as it can, getting to full WOT after starting from a low RPM from your set gear is the main thing.
CK
 

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Was that in 4th gear as well?
2nd gear pulls from just above idle to 7k rpm.

Auto shouldn't really matter on the dyno as long as you get the full rpm range in a single gear at wide open throttle right to the cut off. There is no way you'd lose nearly half your hp through the AT....either the dyno is broken or the car is. I'd go with either the dyno being crap or the operator not doing his part. Get a second opinion from another dyno before doing anything else.
 

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Discussion Starter · #12 ·
Update:

I have had the RES exhaust headers on for about 2 months, I have been getting Raf to retune the car for the headers but it has been taking him a long time to respond. Raf saw some knock occurring above 4500 rpm in my logs. He is first trying to play with the AFR to try and stop the knocking. I did some logs after that tune and sent them back, so I do not know if the knock is still there. I have also put in octane booster and will send him some logs with that, to see if the higher octane fuel (around 97-98) will stop the knocking. If neither of these two things works, I think the header will have to come off. Could it be possible that a leak in the exhaust or the extra vibration caused by this header is causing false knock? The butt dyno says that the headers have made a noticeable difference, but these are likely not worth the hassle of trying to get them to work and I may have to go the custom route for headers. Let me know what you think!
 

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Is the ECU pulling timing to reduce the knock?
Could be the headers are not as good as you think. Any real before and after dyno comparisons, other than the erroneous numbers already posted?
Less efficient headersless scavenging higher cylinder temperatures less resistance to knock. Put the OEM headers back on, they are probably better anyhow.
 

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From what i have read about Mustang dynos is that they usually read about 18% less than dynojet which most manufacturers numbers are from.

132 whp which should be around 108 on a mustang dyno and about where you are now .
With a higher flow exhaust (no cats on the header) you should be bit more than oem.

Are you sure the OVT tune got mapped ?
 

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Discussion Starter · #16 ·
Hey all, ya he was seeing knock in the data logs I sent in. When doing my WOT logs I am not feeling the engine pull anything but I am not saying it's not happening. I'm tuned to 94 right now but he said 95-98 octane might solve the issue so with the booster he might be able to get it to stop knocking. I haven't taken it back to the dyno because I wanted it to be fully retuned first. Would you recommend going back before I decide to take them off? And yes I'm sure the files got mapped lol
 

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Discussion Starter · #17 ·
I know these aren't real dynos, but I have kept all conditions the same between the two dyno charts, and this is in the same locations. The first vdyno is before the headers with my full tune. The second is after the latest revision from Raf with these headers installed, this is the best I have for data.
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With a higher flow exhaust (no cats on the header) you should be bit more than oem.
Assuming the header does flow better.....
Chances are even though the header looks like the OEM part, its more restrictive, even without the cat. There is more to it than making it look like the OEM part.


I know these aren't real dynos, but I have kept all conditions the same between the two dyno charts, and this is in the same locations. The first vdyno is before the headers with my full tune. The second is after the latest revision from Raf with these headers installed, this is the best I have for data.

So if the first graph is before the headers were installed, and the second one is after, you've lost 23 hp and 27 ft/lbs.....😩
You sure thats right?
 

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Assuming the header does flow better.....
Chances are even though the header looks like the OEM part, its more restrictive, even without the cat. There is more to it than making it look like the OEM part.



So if the first graph is before the headers were installed, and the second one is after, you've lost 23 hp and 27 ft/lbs.....😩
You sure thats right?
Hey @arathol could it be possible you have too less restiction / too much flow / exhaust is too big on the heads and hits the rest of the and its like it slam a wall at the mid and end as it tries to funnel the exhaust out
 
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