motordyne M370 manifold - round 2
 

After about a week of driving the car I went back to the dyno to do some more runs. We did 4 runs with the motordyne manifold, put the stock manifold back on and did 4 runs with the stock, the last 3 of each were used for comparison since the runs were consistent (+ or - 1-2hp/tq). Each run was done with the oil temp at 160F, the AFR wasn't printed on the graphs but I had them confirm it was the low 13's at the sensor. No adjustments were made to the ecu at all.

I've attached 3 scans:
The last run from the motordyne vs the last run from the stock
3 runs with motordyne
3 runs with stock

I also gave Tony the raw formats so he can do his delta charts and post, if he so chooses.

From what I can tell, if you tune the car with standard boltons, this manifold has negligible gains and losses. In the end I opted to use my stock manifold and I am sure you can see why from the graphs. Regardless of the actual numbers (people don't seem to enjoy how this dyno reads), the delta is there, and in my case it was not good.

What does this mean? Depends on how you look at it. The manifold has proven gains for some users, all of those users however had no tuning done prior to installing the manifold. If i was not planning on tuning my car or getting test pipes etc., then this manifold would show some decent gains with no loss as others have shown, and I would use it. However in my case I will either return (if I can) or sell it to someone who isn't looking to do all the full bolt-ons/tune.

wow interesting find man... sucks but kudos for taking a risk for the rest of us.

If the diameter is the same, but the runners are longer, you won't pick up power at higher RPM's, although you should gain some in the mid range. Looks like that's exactly what happened. With tuning, you should get back what you lost up top and break about even.

You've stated this before, I don't know what makes you think you can just "tune" the power back here. Modifying timing and AFR any further than what has already been done are not going to get any more power out of this, with or without the manifold. Regardless, even if there was no top end loss, there are no gains to speak of (~5 tq for 600rpm)

Because peak torque is basically fixed by diameter, but where you make it is determined by runner length.

Head flow and design is also an issue too, but the VVEL is going to make that much more variable.

Anyway, many transient modifiers may affect what the ECU is doing now that the airflow curve has changed, so you might be able to tweak timing or fueling to get back some or all of the lost power while maintianing the bump down lower.

At least in theory.

wait so this mod has been myth busted?

maybe if he had headers there would be different gains..

no, not exactly. for cars with full bolt ons and tune, it seems its a wash, for cars without a tune it showed some decent gains with no loss.

Thank You for explaining it into simple English.

A well deserved Monster rep for your input on the manifolds performance. :tiphat:

why do people keep speaking of tuning as if it is so easy for us to do? The VHR is a falesafe for Nissan. VVEL doesn't allow us to do any real tuning. VVEL is also very annoying as most Z owners have realized the slight delay in throttle response. Not this A/F raito bs that we can do and even then, I don't think A/F ratio adjustments on a car with full bolt ons will really make a difference. Tony at FI kinda proved that when they had cleaned up the A/F ratios when the LTH's were being tested. Everytime I return to this site I always see people talking about how after a tune the gains will increase. This isn't an LS7, it's a VQ. I am supprised to see a lot of F/I set ups running for so long without any majoy issues or at least, we haven't heard of any.

thanks for taking one for the team..already rept you!

I think we have a greater chance the world will end in 2012 :ugh2:

I hope not the whole of London and the UK have just invested in the olympics!

:rofl2:

We may have to kidnap the Nissan ECU guy that did the engineering and hold him till he fixes us a good tuneable ECU.