Judge

What is the purpose of the red hose? Other than creating a tug of war between the intakes during high load conditions? I've disconnected it and plugged the ports it was connected to (with the bank 2 PCV port still connected to bank 2 intake) and driven the car for a couple of miles to test. Idle, part throttle, WOT all seem to be ok.

Thanks.

For anyone interested, these are made from 201 stainless steel, the resonator has no additional sound absorption material and is primarily intended to reduce drone rather than rasp, expected power gains are minimal.

I'm currently considering one of these but am having trouble finding much information other than a few Youtube clips. Has anyone got any experience with them? They're clearly a copy of the Motordyne XYZ but how do they compare (power gains, sound, quality, fitment, etc)? Cost is about £390 (including shipping, duty and VAT) which is considerably cheaper than the XYZ...

Thanks.

On 06/02/2019 at 12:59, Mark@Abbey m/s said:

did they do a run before the tuning?

Paul said the dashed line is the pre-tuning run...

44 minutes ago, Mark@Abbey m/s said:

All our dyno work is carried out in 4th gear.

 

dyno is a tuning tool , before and after on the day is what counts.  But I am afraid every one wants to say they have the most BHP so  dyno plots get waved around then people says this cant be true.

 

 

 

Hi Mark

Seeing as TDI North offers UpRev remapping in association with you, what's your opinion on the figures?

14 hours ago, VRRacing said:

4th is generally the preferred gear for power runs, usually the most direct ratio 1:1. Also the figures on the sheet are BHP, N/A cars are never going to yield fantastic gains, but making good your AFR is never going to be a bad thing, although it would have been nice and safe at the top end with that AFR. It’s also not beyond the realms of possibility that an inefficient hand built Power Flow exhaust could loose you power especially in the Y pipe. When i used to run a dyno we always had a “special” BMW M3 Mode because the average person would have been a little upset if a car left after a map only making “stock” power, the fact is they consistently made significantly less than BMW claimed as their figures were engine out of the car with a different intake and exhaust. BHP is basically a best guess and there are a few ways of calculating it. WHP is where it’s at, just not as good for the old pub talk. 

For the 6 speed manual 5th gear is the 1:1 ratio.

I agree the Powerflow is possibly not the best CBE on the planet, but I doubt it has lost me the power and torque that the ART pipes gained me. So the results are either over-reading WHP or under-reading BHP. But either way they're probably not very accurate.

17 minutes ago, davey_83 said:

Pretty sure 5th is a better 1:1 ratio for the transmission. I'm not entirely sure what effect gear choice has on dyno pulls lb-ft figures

You're right. I guess he didn't fancy doing ~160mph. If that was the case he should have asked me to drive it!

10 hours ago, davey_83 said:

Reads as a 4th gear pull also, irrc 5th is the preferred gear for Dyno runs?....

I asked about that as well and he said he didn't like doing runs in 5th because of the speed... 

On 28/01/2019 at 22:07, evilscorp said:

18mins to tune... wow... don't think I've ever been in and out that quick. DE's must suck as when mine was N/A I was lucky to get just above 290BHP, surprised HR's make that in WHP.

18 minutes between runs 3 and 4, not 1 and 4. But it was still only about 1 1/2 hours total and I got charged for 3 hours which I'm not especially happy about.

46 minutes ago, Dave6188 said:

Works out at around 357bhp at the flywheel then, I'm going to guess it's a Dynojet going by those numbers 

I don't know much about dynos so I'll take your word for it. 

42 minutes ago, RobPhoboS said:

Manufacturers quote engine power, not engine power plus drive train losses.

So 308 or whatever is the engine, not the power at the wheels.

9 minutes ago, Kryptek49 said:

HR is 313BHP if I remember correctly.

Per the Dyno sheet for my HR done at Abbey Motorsports with an UpRev & DeCats it was running at 297.2 WHP - around 337 at the fly according to Mark who works there.

 

311BHP is pretty high compared to stock, but wouldn't surprise me as being correct - all Dyno's vary slightly ayway

It's 313 PS, which is 308 bhp. But I used the figures 306 bhp and 268 lbft as they're the ones most often used on various websites. 

If you still have a stock cat back exhaust then those figures sound about right to me. But as you say, all dynos vary.

On 27/01/2019 at 15:47, Dave6188 said:

Not sure if I am reading this wrong, says BHP on the graph which is measured at the flywheel not the wheels ! Why does the top end of the power and torque band peak and trough so much ? 

The HR has 306 bhp and 268 lbft stock. So assuming that dyno is accurate, those can't be flywheel figures because it would mean the modifications gained me 5 bhp and LOST 18 lbft. I've test driven several HRs with similar mileage and maintenance and mine is considerably quicker. So I'd say those are wheel figures but might be a bit optimistic.

I have no idea about the weird peaks and troughs at the top end. It certainly doesn't drive like that! I just assumed it was a glitch with the dyno system so didn't ask the tuner. What I did ask was why the tuned peak figures were only 3 bhp and 4 lbft higher than pre-tuned. He said the gains were “subtle”. For £450 I'd say “disappointing” is a better description. But I did get some bottom end and mid range gains, the removal of the throttle response delay in the first three gears, and the slightly rich AFR was corrected.

EDIT - Looking at this again, what also doesn't make sense is the speed shown at peak power. If it was 4th gear, how could it be 117mph at those revs? I have a stock final drive so the speed should have been ~127mph. Maybe it was a typo...

2008 350Z VQ35HR (34500 miles, FSH)

Motordyne ART Pipes, Powerflow CBE, HKS Super Hybrid Panel Filters, UpRev

Unknown Dyno @ TDI North

311 whp

250 ftlb

Looking at various exhaust manufacturer's websites, the part number is the same for the 350Z and 370Z Y-pipe (ISR is an exception because it uses 2.75” primaries for the 370Z). Does anyone know if the Motordyne XYZ with resonator module is also interchangeable between the 350Z and 370Z? I've looked on the Motordyne website but it's not clear. I've also looked on various trader's websites and on some the part numbers are the same, on others they're different.

Does anyone have any information regarding power / torque gains, preferably with dyno charts? I can't find any information on the Motordyne website and the only other information I've been able to find is shown below. There are other threads on various forums but they're so old the images of the dyno charts are no longer there.

XYZ Gains 1

XYZ Gains 2

Thanks.

I've got a really irritating tinny resonance coming from my exhaust (back of the car, not underneath). It starts at around 2500 rpm WOT and continues all the way to the red line. It's not really noticeable part throttle and does it briefly when revving WOT in neutral as the revs pass through 2500 - 3000 rpm. Initially it sounds like there's an angry rattlesnake in my back box, but at higher revs it almost sounds like there's a circular saw strapped to the back of the car. Here's a link to a short clip of it. https://youtu.be/jDQ4JZ3nyG0

My car is a 2008 350Z and current exhaust setup is stock headers, Motordyne ART pipes, Powerflow Y-pipe (leftover from CBE fitted by previous owner), Fujitsubo Legalis R mid section and back box.

This all started after installing the ART pipes. I'm assuming they're not what's making the noise, but are a contributing factor because of the increased exhaust gas flow and decreased muffling compared to stock cats.

I don't think it's the Fujitsubo (even though the tailpipes are a bit tinny sounding if you flick them) because the previous Powerflow mid section and back box made the same noise. And I don't think it's the rear heat shield as they tend to produce a lower pitched buzz (I had a cat heat shield issue when I installed the ART pipes so am assuming the noise would be similar).

As the headers are stock, that only leaves the Powerflow Y-pipe. Their current Y-pipe has been redesigned slightly, but the one on my car is similar to the Scorpion. There's a slight bore mismatch as the ART pipes outlets are 2.5” ID and the Y-pipe inlets are slightly less than that (2.5” OD, haven't been able to measure the ID). There's also a mismatch between the Y-pipe outlet (2.5" OD) and the Fujitsubo inlet (3" ID) which might not be helping the harmonics.

So would replacing the Powerflow Y-pipe with a better designed Y-pipe (that also matches the bore of the ART pipes and mid section) solve the problem? Or am I barking up the wrong tree?!

Thanks.