If at all possible. Ideally. Do the swap while on the dyno for the best comparison.

I already did the swap, each time I get it tuned, I clear any learned fuel settings. Weather has been 1-2 degrees difference and I'm still on the same gas tank. It should be 99% the same. After putting the stock manifold back on, I noticed more rasp and drone. The exhaust pitch is slightly higher as well. I also do not hear the headers scavange on downshfts anymore, or maybe not as clearly than with the M370.

What did you find out with the stock manifold?

Got rescheduled for Saturday evening. Shop has an anal retentive customer who needed an engine swap done in a daily driver. I can say that my gas mileage has gone up at least 15% for some reason.

May be able to sneak in tonight. I'll let you all know.

I just got back from the shop after about an hour and a half of tuning. And here is the verdict...

The M370 intake manifold made more power than the stock manifold from 2,000 rpm all the way to 7,000 rpm. After 7,000 rpm, it was neck and neck. I just sold that damn manifold too... Guess I'll be getting another one down the road.

What all this doesn't explain is how I lost 10whp and tq after a tune from 30 march till now. I'm thinking there is something else that's going on with this car. I'm not sure if it's the sensor, or spark plugs, or both. Posted below are the dyno graphs.

Keep in mind my tuned numbers are lower than my untuned numbers. It's a$$ backwards I know, I'm trying to figure out why.

1st graph is the stock manifold and the M370 (Blue is M370)
2nd graph is the same but displaying AFR's (Red is M370)

3rd graph is Stock tuned and stock untuned results (Blue is tuned, red is untuned)
4th graph is the same but showing AFR's (Blue is tuned, red is untuned)

5th graph is the M370 manifold tuned and untuned (Blue is tuned, red is untuned)
6th graph is the same but showing AFR's (Blue is tuned, red is untuned)

I'm not really feeling the M370 with my Greddy setup. If you realy want to get mine, you can once I get my stocker back from Zerolift. Or you can trade me yours with a couple bux. Let me know man!

Sent via Tapatalk 2 on my D-Team G-Slate

You should really edit this info into the first post. Many might read the first few posts and make an unfair opinion of the M370 based on it.

Thanks for the tip, reposted results.
Fixed graphs on first post, I somehow jacked it up...

great thread,lots of good data here. nice job!

i myself have the m370 and think its worth it...im not tuned,but for everyday driving you definatley feel the difference. and from what i know it seems to respond better to a more stock z..which goes for any mod,but more so this one

For clarification. All untuned dyno comparisons to the tuned ones were not taken the same day as the tuned ones. I'm only showing the difference between them and the three month difference in power.

Thanks for taking time and effort to share this data.

Well, I think maybe the m370 needs resonated test pipe or HFC to give the best result.
Just my own thoughts .

I'd say the major difference is in the temps -- < 60 F* for earlier runs and > 100* F for later ones! Even with correction (and the CF's are huge!), it will not be able to compensate. You will still see massive differences in power output.

After reviewing all dynos and taking that into consideration, I think best power is factory IM + tune.

Yes The Motordyne intake picked up a little in the midrange, but I think not enough to warrant the loss up top. The headers are probably outflowing them, and costing power up top. They might work better with factory headers.

Also, keep in mind it will take 3-4 runs for the fuel trims and such to adjust to make sure you are hitting target AFR's. Timing may also fluctuate a bit before it stabilizes.

If you want to compare and contrast more definitively, do same day, factory tune with mods, 3 runs, 15-20 min cool down, flash tune to ECU, do another three runs. Keep note of oil temps (try to keep them around 200-210* F).

If you have any more drfs, pelase feel free to send them my way -- thanks again! :tiphat:

EDIT: Nope -- I'm wrong. The tuned M370 dyno is very comparable to the tuned OEM IM dyno, and it clearly out performs it in the midrange.

Just to make sure everyone understands, I'm running PPE LTH's and Motordyne's Y pipe with a HFC. This isn't a popular setup, but it should be very comparable to a TP's and Headers, with slight variations due to different manufacturer parts.

Sig also shows NST pulley's and AEM CAI.

So i've been following this thread for a few days now, since I've been considering this mod, and with all the graphs and going back and forth between the stock manifold and the M370, I got a little confused. So what happen is that when you added the M370 you lost some top end power after the 7k rpm range? but then later down the road you ended up gaining more with it? My concern is more for the lower mid range power bieng that this is my DD and I most likely wont hit those high RPM's at least not for everyday use. Overall would you say you like it and would it work for my situation. I have stillen gen 3's and FI HFC's and CBE should be here this month.