Exhaust leak or normal?
 

So I picked up my car last night at 0200am from the shop and it sounded surprisingly different compared to what it used to sound like with the LTH and CBE. I'm not sure if it's an exhaust leak or the AEM intakes. Force Fed Racing did an awesome job getting everything installed and back together. They worked extra late last night so I can get it back sooner. George and Johnny are standup guys and showed me a lot of new things. I talked to Tony at Motordyne and we ruled out the intake manifold. We also believed the Pulleys and of course oil cooler to be a nonissue as well. The oil cooler is impressive btw. Tony showed me how to build a stethoscope out of copper tube and some flexible tubing to search out exhaust leaks, I'll post a video of that when I make it. Here are four vids that may help. The first two videos are with PPE LTH, Motordyne XYZ Y pipe w cat, and Tanabe exhaust. The second set of videos has NST pulleys, AE Performance Oil Cooler, Motordyne M370 intake manifold, and AEM CAI installed with the listed exhaust components. ALL VIDEOS ARE WITHOUT A TUNE & SES LIGHT IS ON (uprev purchased [SES light flickers a lot when accelerating]).

BEFORE

BEFORE


AFTER

AFTER

Here is a quick video I made showing how I checked for exhaust leaks. I did not find any. I'll be bringing my car to Cali this weekend and have Tony at Motordyne check it out. I'm also taking it back to the shop tonight so I can take off this heat shield that is buzzing like mad.

I'd say get it checked out. Doesn't sound right to me. Maybe someone with a similar setup will chime in.

Do get it checked out!

Thanks. The power is definitely down, I've never heard a Z sound like this one does now, and I'm sure I'm in desperate need of a tune. I'm averaging 12.2 mpg right now. I'm taking it in to get the SES read, the car dyno'd, and get AFR readings. I do know that there is an exhaust leak at the Y pipe and header on the passenger side, but very minor. I put about 70 miles on it since last night.

I'm thinking the car is throwing a LEAN code. I have seen this with certain intakes, matched with the Motordyne intake manifold. If that's the case, the car is going to be pulling so much timing and adding so much fuel to the stock tune that it will cause the car to bog and the gas mileage to go to hell. When a car is running pig rich it can change the note of the exhaust as well.

EDIT: I just read about the SES light flickering under acceleration, that would definitely be caused by a lean code being thrown.

Just got back from the shop, I'm uploading dyno information right now. The issues was with the M370 intake manifold. I'm not sure if it was installed incorrectly or something is wrong with it. I did two pulls as you can see from the graph, the powerloss was really bad. We swapped out the manifold and put the stock back one and instantly made nearly 100whp more. Doing only two pulls and no ecu learning, I gained 16whp over my previous setup.

The first dyno is a comparison between my best run and the M370 manifold run. The second dyno sheet is a comparison with the stock manifold back on with my baseline dyno. Again this is no tuning and SES on.

I thought you had it installed prior to having the intakes put on? Anyways I doubt there's anything physically wrong with the manifold, maybe just a minor installation mishap? I can snap photos of mine installed if you need something to go off of. I installed mine well over a year ago so my memory isn't the greatest but there's an added hose that extends and Tees off.

If you could, we had to purchase the T connections and hoses and didn't have very good instructions to go off of. My mechanic is familiar with Honda's, this his first 370 he's really gotten his hands dirty. He's done a great job with everything else. I've been doing a lot of research with him as well with the M370. Tony sent instructions, but there was a lot of fill in the blank. It is still beyond me an intake manifold change gone wrong had this much of an effect on performance and sound! I have the RDF files to bring to Tony on the pulls I did. Spent $140 on 4 passes and a manifold swap. I'm none too happy about getting work done I shouldn't have had to but things like this happen, and it's just part of the game.

That would be great if you could. Tony @ Motordyne met me during lunch outside six flags on his own time to help. He thinks maybe one of the throttle bodies could have been disconnected. I also am missing the metal plate that sits on top. I bought this used and he is shipping one to me free! Customer service is absolutely outstanding. After I get it reinstalled and the car tuned, ill be posting results in the M370 million page thread as well as my own that turned more into a build thread. I will also post what the issue was after I figure it out.

Will do, I'll need to get the pictures done TOMORROW as I'm going back to the stock manifold. I'm ONLY doing this because with the GTM kit, I'm using the canned tune and need to be using the stock manifold so it doesn't throw the tune off.

I will tell you this, I LOVE that damn intake manifold. It made gobs of power towards the mid-range and we all know the 37VHR isn't a torque based motor.

Awesome. Looking at my dyno graph, I get a huge jump in power after 7000 rpm. I looks like it was still making power at 7500. My AFR's were 13.5-13.8 during that run as well. I don't mind losing a bit up top (3-5hp) if it really improves my mid range. I'll reinstall after I figure out what happened. I'm not sure if I should tune pre M370 or after. I want to see the difference, but I don't wanna spend the money to do it. I was charged $80 for the M370 back to stock and a couple pulls. Lord knows what tuning costs now days.

Still troubleshooting M370 issues. I'm missing the metal top plate that Tony is sending me. I tried unplugging a throttle body, but that didn't do much besides make it quieter and limit the revs to 1500...

So the videos with the strange sounding idle, thats with the M370 without the silver plate?
Without the silver plate, the manifold cannot be torque down properly...

Glad Tony is helping, even on a used one! Hope you get some good results.

So, has the weird sound gone now as well?

Interesting about the torque down not being possible without the plate, certainly sounds like the issue.