Dyno Results Down Pipes adds 15rwhp and 20ft-lbs!

[Guest Pete Z Racing]

Zer's

Rich at Zensport, great guy, just e-mailed me the Dyno results from a stock turbo Datsun down pipe to mine. I will try to post the Dyno sheet soon, Below is his e-mail.

8% increase!!15rwhp and 20ft-lbs! Not a bad power gain for $241.00

Have a great weekend!!!

petezracing@yahoo.com

Pete

Adrenalin is 100+M.P.H. 100 feet before a 90 degree turn!

366 H.P. 418 Torque 6cyl @ 14 P.S.I. 90 Octane

<http://www.cardomain.com/ride/2116389>

 

 

Pete,

This just in, finally we have some results. My car is running kinda

shitty, but it is at least being consistant, so it is still a suitable

test bed.

I did multiple runs with both configurations, and chose the best power

run

for each. Configuration 1 was the stock downpipe, with a 2.5" smooth

crush

bent 90* on the bottom. Configuration 2 was your downpipe. Neither

setups

had additional exhaust sections added, they simply ended under the

floorboard/tranny tunnel.

I am quite surprised by the results. The car is set at 6psi boost.

Engine

mod list is:

60mm TB

N42head/F54 block - 8.3:1CR

SDS EM-3E

440cc/min injectors

Medium NPR I/C

Stock T3 turbo

Stock cam

Gains from just the downpipe swap were 15rwhp and 20ft-lbs! Graph and

text

info attached. I will send photos of the setups later on this weekend

once

I get home to process them. I really like how the gains are over the

entire operational range, and are significant over the whole range. I

think the "stock" exhaust setup I made actually flows better than most

datsun exhausts too, but I wasn't able to get my hands on an origional

280zxt exhaust system to go with the stock downpipe.

More info to follow as time permits...

 

<http://www.zensport.ca>

[Drax240z]

Thanks for the opportunity Pete, sorry about all the delays in getting this to you.

 

Here is a shot of the dyno graph for you, I can host it no problem.

 

 

Just to reiterate, very surprised with the gains at 6psi. The gains will grow as boost increases as well, hopefully I can test those results too in the near future. Here is a quick shot of the pieces used for comparison.

 

Edited June 5, 2009 by Drax240z

[Tony D]

Heh heh heh, like Bastaad said on another pipe's dyno-proven claim:

"How do we know the pipe is responsible for that gain?"

 

(Devils Grin)

[Guest bastaad525]

Heh heh heh' date=' like Bastaad said on another pipe's dyno-proven claim:

"How do we know the pipe is responsible for that gain?"

 

(Devils Grin)[/quote']

 

 

well... there are factors that could have contributed to the increase not related to the DP swap. What was the the ambient temp during each run? What about the usual 0-5 hp variations that are commonly seen from one run to the next on just about any dyno? Not saying a good DP isn't going to be worth significant gain over the stock DP... I mean come on... LOOK at the stock DP. I never debated that.

 

I think the case I was debating was Jeff's case which didn't he get more like THIRTY HP??? Like from 150 to 180 or something like that on a stock 280zxt? All I tried to say was that people shouldn't go around saying "yeah you'll gain 30 hp from a DP alone!" when most people really dont' see anywhere near that much. What people DON'T usually talk about is that Jeff's incredible gain was NOT just a DP, but a swap from the full crap stock exhaust including small pipe, crap muffler and cat, to a full mandrel 3" system with high flow muffler and cat (and on top of that wasn't the cat easily removable and replaced with straight pipe? Like he had flanges welded on it no?). Whereas most of us with hybrid S30 turbos already are running a much better exhaust than was stock on the 280zxt, mated to the stock downpipe... so just upgrading the downpipe isn't gonna gain nearly as much. But 15 hp from a DP swap alone? Yeah I think that is COMPLETELY believable.

[Drax240z]

The dyno compensates for ambient temperature changes, barometric pressure changes, and changes in humidity.

 

First run shown was done at 46.5F, 52% humidity, 29.90inHg.

Second run shown was done at 45.7F, 51% humidity, 29.87inHg.

 

These were done back to back within less than 1 hour of each other. Same car, same tune, same building, same tires, same tire pressure, same dyno. As for the consistancy of this machine, I can do 10 runs back to back with my car and cover every graph with ~2hp variance tops. Anything greater than a 5hp deviation in my experience is well outside the realm of experimental error, and denotes a change. 15 in this case is crystal clear.

 

I've been doing laboratory experiments for the past 6 years both as part of my full-time job and education. I'm pretty well versed on how to conduct a sucessful experiment.

 

This machine costs over 3 times as much as a base dynojet and uses very high quality instrumentation as you would expect with the extra price tag.

 

Hopefully that stems any potential doubts as to the validity of the provided information.

[thehelix112]

Is that because its Australian Drax? I am most interested in your signature.

 

232rwhp on a dynojet

195rwhp (with same setup i assume) on a dyno dynamics.

 

So thats around 15% difference between the two?

 

Dave

[Tony D]

"What people DON'T usually talk about is that Jeff's incredible gain was NOT just a DP, but a swap from the full crap stock exhaust including small pipe, crap muffler and cat, to a full mandrel 3" system with high flow muffler and cat (and on top of that wasn't the cat easily removable and replaced with straight pipe?"

 

The statement was that he gained 20HP on a stock ZXT by bolting on his exhaust system (including cat). At least to my recollection, it may have been just the pipe, but I believe it was the whole system because all the experts said "you loose torque when you use a 3" system on a STOCK ZXT"---which Jeff proved incorrect, IN SPADES. Just another example of internet experts blather and bluster.

 

So Jeff's claim of 20HP GAIN form his _system_ really is a valid claim. And it went in the face of what people were TELING prospective customers at the time, as well.

 

Then consider that Jeff's goal was to size it for people to add on to their systems at a later time, and NOT have to continually upgrade the exhaust every time something was changed.

He is up to what? Near 500HP with that same system? So his engineering rationale was sound, "Buy my system, and you won't have to replace it till you reach "X" horsepower." What "X" is still remains to be determined, but given his last testing at 7000rpms having the same backpressure in the manifold as the intake, the exhaust downstream of the turbine STILL isn't a restriction to the horsepower he's running.

 

Which is the reason Jeff is asking for the tests (and for Pete to do a whole system) so he can see where the 2.5" system all mandrel bent will peter out horsepower wise. Until someone does the test, there will be no concrete number to point to saying "at 350HP, you need to go to 3" piping and system"... He went to 3" because of his calculations, but you always want to know "could I have gone smaller and met my goals?"---I mean, packaging a 3" exhaust in a ZX Chassis....well, lets say the 2.5" would be easier to do, for SURE!

 

I just find it interesting you can see 15HP from a downpipe as "believable" (yet you chose to contest the facts as presented by Jeff when he gave a number of 20hp bump for his _system_) without claiming that this pipe also might have had something else responsible for the bump in HP...

 

Mind you, I'm not doubting EITHER claim, I just find it funny that one was called into doubt, yet the other is "totally believable"---I can see why Jeff gets frustrated when talking about his developmental work.

 

I mean, with the cross-posting of the identical thread, with the cost included, it really looks like a thinly veiled classified ad, but that is beside the point I suppose...

[Cjarloz]

wohooooo thats great i cant wait what it will do for me at 16 lbs.

[Guest Pete Z Racing]

Zer's,

Once again, of course, if the rest of your exhaust is restrictive the DP WILL NOT HELP.

ONE POINT today:

1. Anyone can see the DP is better than stock.

 

Have a great day.

Pete

[EZ-E]

I think I would have to agree with all that Tony D has said. I have seen Jeffp's set up, his exhaust is finely made piece. It is something you would expect to pay 1200+ for in any venue.

 

I have also seen his dyno sheets for his "complete system change," from a stock 280ZX turbo exhaust, to his 3 inch system.

 

In his own web page it clearly states that he made the swap on a standard 280ZX turbo and swapped the complete exhaust, not just the down pipe.

 

He netted 20hp and 20ft lb of torque, or something close to that, I would have to source his page for the exact numbers.

 

I do think that there is no way that anyone could contest the validity of his claim, it is for all to see in black and white.

 

Also as stated by Drax himself, all he used was the stock down pipe and a 90* bend that ended in the transmission tunnel, then did the same thing with Petes down pipe, ending the exhaust in the trasmission tunnel.

 

He also posted his gains.

 

I dont see where he could be contested either as both were done, Pete's and Jeff's system, on the same car, at the same boost, tune levels.

 

I think that both products are well made and something anyone would like to have on they're vehicle.

 

I seriously don't see though, where there is a problem with the validity of either product.

[Drax240z]

Is that because its Australian Drax? I am most interested in your signature.

 

232rwhp on a dynojet

195rwhp (with same setup i assume) on a dyno dynamics.

 

So thats around 15% difference between the two?

 

Dave

 

Actually we run a +17% on all our numbers now right out of the machine. Sadly our explainations as to why dynojets read too high were falling on deaf ears among a large portion of our customers, who do most of their racing by comparing numbers over the internet. Normally I wouldn't concede to doing something like this, and it was not an easy decision for me, but business is what it is, and having an expensive machine to pay for left us little other option but to maximize our customer base.

 

The 195rwhp was with the stock downpipe and my car in a crappy state of tune (relatively), with fairly old gas, etc. 232rwhp in my sig was also at 6psi, but in a much better state of tune... though it was a bit peaky for my tastes. Shortly after that I tuned it for better power delivery, and lost some peak power. All these numbers are with +17% from the RAW Dyno Dynamics numbers. That's all we deal with now, due to the reasons above.

[thehelix112]

Thats fair enough. I didn't mean to bitch'n'moan, but I get the feeling everyone is going to laugh when I post my raw dyno dynamics figure in a little while. ``what? only xxxhp? somethings wrong with it?''

 

Oh well. Good luck with it and I hope it works well for you. Dyno dynamics is all we have here in Australia. I was trying to find a dyno tuning shop once and walked into the dyno dynamics factory here in Melbourne. Who'd've thought the dyno shop would be 2 doors from a tuner. :S They look like a good bit of kit.

 

Dave

[Drax240z]

The best in the world in my opinion... I'd certainly buy one again!

[Guest bastaad525]

Tony - you misunderstand me. I DON'T doubt in the slightest that Jeff gained the amount of power he did from upgrading the 100% bone stock 280zxt exhaust up to his very well designed full 3" mandrel bent system.

 

Again, what I WAS debating (in that old post/thread that you referenced in your first reply in this thread), were the people who somehow got the notion from Jeff's results that simply swapping from a stock DP to a DP like the one shown in this thread would be good for the same kinds of hp gains as Jeff saw from upgrading the whole system (I did find Jeff's 280zxt webpage and you're right it was actually more like 20 hp, from ~150hp to ~170hp).

 

This is all such ancient history that my memory of whatever the argument was and whatever post triggered it is pretty foggy to me now, but I seem to remember it as such... someone claiming that a DP swap alone was worth the kind of HP that Jeff saw when he upgraded to his full 3" system... which just didn't make sense.

 

Again.. I feel 10-15 hp from just upgrading the DP is completely believable, and 20-30 hp from upgrading a 100% stock exhaust to Jeff's beautiful and very well designed system is also completely believable.

 

And Drax, I'm not debating the validity of your dyno results either, I just threw that out there in jest in response to Tony's joke... I do feel and have seen for myself that dynojet dynos are typically pretty consistent from run to run and if you are doing back to back testing on the same day would give a very accurate picture of how much difference any given changes do make. I did assume you probably dynoed before and after the DP back to back on the same day, but I do believe had you NOT tested back to back like this that at least a few hp could have easily been attributed to varying test conditions. Still not enough to say "oh well the DP CAN'T be worth that much increase".

 

I guess in the end the numbers are close enough that it's kind of a moot issue... which is interesting to me... that a DP alone is worth 15 and a full 3" mandrel system over the stock system 'only' worth 20. The whole thing about getting a good number from someone on just exactly how much a DP upgrade really is worth has been something I've really wanted to see for quite some time now... too bad it comes after my own turbo Z is already gone. I still feel it's inaccurate and misleading for people to go around telling others "upgrade the DP you'll get 20hp!" but I guess now these results are close enough that there's no point debating it anymore

[twoeightythreez]

I want to get a 3" downpipe for my '78 after I do the turbo swap because the rest of the exhaust is already 3" (installed 3 years ago but with a turbo swap in mind)

[Scottie-GNZ]

172rwhp and you need a 3" DP?

[Guest JSutter85]

^i think he means after his turbo swap

[Guest Cronic]

Haha, 30hp is hard to believe? I have several, not one or two, but more like 5-6 friends with 7M motors who upgraded to a 3" downpipe with an o2 eliminator who gained upwards of 50-90whp. On stock boost. Talk about hard to believe....

[jeffp]

I guess in the end the numbers are close enough that it's kind of a moot issue... which is interesting to me... that a DP alone is worth 15 and a full 3" mandrel system over the stock system 'only' worth 20. The whole thing about getting a good number from someone on just exactly how much a DP upgrade really is worth has been something I've really wanted to see for quite some time now... too bad it comes after my own turbo Z is already gone. I still feel it's inaccurate and misleading for people to go around telling others "upgrade the DP you'll get 20hp!" but I guess now these results are close enough that there's no point debating it anymore

 

I could not see doing simply the downpipe. I was going fo the complete setup for the car and be done with it, however you wanted to configure it.

 

The other thing is that pete was running 16psi of boost and got his numbers, not exactly a factory boost setting. I ran stock boost levels and got a little more performance. I am not sure if that difference between the two would be a linear increase from idle to max rpm levels. Seems like the dyno chart I looked at showed a peeky power band, but that could easily be the cam causing that response curve.

So who knows, I am happy with my results, the car likes the system so I run it.

[Tony D]

The other thing is that pete was running 16psi of boost and got his numbers, not exactly a factory boost setting. I ran stock boost levels and got a little more performance.

 

Then again, the last time I saw your car on a dyno, Jeff, it was making what, 278 HP and 319 Ft-Lbs @ 4875rpm?

 

 

 

 

On 8 pounds of boost.

 

 

I love mixy matchy claims. Given the above facts would it be an untruthful claim to say JeffP has close to 300HP @ 8#, on his Nissan-ECU'd (meets SCCA Rules for STOCK COMPUTER), downpipe and exhaust system equipped 83 280ZXT?

 

Not at all. A bit misleading, but not untruthful in the least bit.

 

Claims are not much unless the testing is comparative, which is what JP is poking at I guess. Amongst other things.