I'm very excited to see the numbers in comparison once you get them. I have a question I've been meaning to ask, but have been neglecting.
In your opinion how will this modification to the exhaust system, and or the J-pipe replacement effect the car's Air Fuel ratio?
I only ask because once I installed my Full Length / Long Tube headers on my Eclipse the gains I dyno'ed from bolt-up were dwarfed in comparison to the gains after installing a SAFC-II with tuning.
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The AFR as near as I can tell is not going to change at all. These pigs run rich, no two ways about it. A reflash or tuning would help significantly, but we need a proof of concept before we can get Hondata to budge even a little I am sure.
I see, you are taking your time...
I still live in Integra days, 6 headers back to back, ear muffs, 1 day and only regret was not having couple of more headers to try out
Great stuff though, thanks for the numbers. I hope you post the chart once you do J pipe. ( SAE corrected of course)...
I do have to make a comment on 207 WHP, sort of funny to think that we were getting that ages ago from 1.8L B18c1/5 normally aspirated. 188 ft-lbs is nice, but again nothing that K24 with flashpro and couple of things can't do.
You probably got most of that TQ at 2K or so?
These numbers are low for 3.7L (probably hurt by restrictive intake, pre cats, pretzl j pipe and that pre cat friendly head casting), engine must be chocked up something fierce. I wouldn't be surprised you see 30WHP or something, unless that dinky panel air filter puts the hurt on it...
Anyway, thank you for sharing and looking forward to J pipe numbers.
Yea this this new age stuff we won't get a good after number until we run it 15-20 times and I don't have the cash for that to budget here
The computer will be adjusting and adjusting and then we will go back once it is all settled in.
Remember, this is a chassis dyno with rollers. Our number at Church on the Dynapacks was quite a bit higher as well. From what I figure a 25-30% drivetrain loss in this test is pretty understandable and acceptable.
The number is LOW for sure. But remember this is also working to spin up four heavy wheels through a relatively complex AWD system. A K-series or B-series in a Civic pumping through two 12 lb wheels is a very different scenario. We have closer to 15% drivetrain loss on am FF setup.
Of course at the end of the day the RELATIVE number is what counts. We did a back to back dyno on an SH-AWD TL with a cat-back, and while the number was under 200 whp on the Mustang dyno at that shop, the 5-7 hp and torque gain was rock solid and consistent.
Peak tq at 2k rpm? Well, I guess a pic is worth a thousand words....
Here are some dyno since I can tell you two guys will really appriciate them
And forgive me, right before submitting this post I see I have these numbers against SPEED not RPM, so...sorry, will get that right before I post the 'after.'
First, here is the dyno on the Dynapack:
The power is more because we've removed the wheels. But, this dyno we think had a lot more funkiness because the rear wheels were connected to separate dynos, and the VSA was freaking out. It couldn't get it straight which wheel to give more power to, we think. Anyway, consistency led us to believe this number is relatively true, but still low for a 300 hp engine we think. The newer J-series is a fiend for pulling timing, and we think this might have been going on as well.
Here is the Dynojet curve:
Power and torque are proportionately lower than the Dynapack run. Clouding the issue is the fact that the Dynapack numbers are with stock mufflers while the Dynojet is with the ATLPs. How much power the mufflers add is a mystery. I am not sure I could claim much more than 6-10 hp, and won't even try to advertise it, but overall the curves are not so different, again giving me faith that we have good tests running. I like the resolution on the Dynojet graph but the Dynapacks really are better for tuning because of the whole parasitic loss of the wheels.
Speed. I misspoke before on the speed differential between front and rear but you can clearly see the difference is rather significant! The higher line is the front wheels, the lower line is the rear wheels. One concern we had was that the computer would start freaking out and pull timing because of the speed differential. Maybe to a certain degree it was, but I think we got clean runs. We had two back to back that were essentially identical. This one is more for informative purposes than anything else. Interesting that the front speed increases faster with higher torque but the rear is a linear change.
Lastly here is the torque versus AFR. This you can compare with the Dynapack before and after the mufflers. She's rich for sure, but the mufflers made this no worse and the j-pipe won't either.
Just for grins, the MDX on the Dynapack:
And a shameless plug: