E K

iTrader: (10)

As some of you may know, Hydrazine (Tony) has been working on a plenum spacer for the G35/350z. He offered a free spacer in exchange for dyno testing his product. I don't post much on this forum, but I go by the same username on g35driver. If any of you have seen a white G35 coupe with BMW X5 projectors in the headlights, that's me.

Saturday was the first time I had met Hydrazine in person. Whether or not the spacer gained 20 HP or lost 20 HP, I don't get anything out of it, other than a free spacer for doing the dyno testing. I'm not a business partner in his projects, and my line of work has nothing to do with cars. I'm just another car enthusiast.

Our testing was cut short due to my own personal time constraints that day and with the threads on my lower plenum starting to strip. The plenum's aluminum is fairly soft, and I have already disassembled/installed the top plenum several times. Since the car's my daily driver, I became concerned that if more threads became stripped with more disassembling/assembling, that I wouldn't even be able to get to work come Monday. I've since fixed the problem by running a bolt from the bottom of the lower plenum, through the upper plenum, and secured with a nut. So we could only do two test configurations. One with Crawford V5, and one with a stock plenum with spacer. We did 3-4 runs in every configuration.

Let me start by giving some background info on the car. It's a 5AT G35 coupe 2003.5. I've done 4 dyno sessions now.

Dyno Day #1 was on 2/7/04 at Strictly Dyno in Reseda, CA
The car only had a Z-tube at the time. In 4th gear it got:
219 WHP

Dyno Day #2 was at 6/12/04 at Strictly Dyno again
This time it had Kinetix V3 plenum, UR crank pulley, popcharger, in addition to the Z-tube. Again in 4th gear:
223 WHP

I am fully aware that you can't compare absolute numbers between different dynoes, I'm just giving this info for people who might be curious about the numbers on a dynojet.

Dyno Day #3 was on 9/4/04 at Church Automotive (this was the dyno day featured in the winter Sport Z Magazine). The results are on this page.
thread
My car was the only automatic that ran 4th gear (1:1) that day, everyone else was in 3rd. The MT's were in 4th. My mods at that time were: Crawford V5 plenum, popcharger, Z-tube, UR crank pulley, and some polish work on the lower plenum, intake manifold, and throttle body. The results are published, but just to rehash, it ran:
254 AHP (axel horsepower, since the dynapack measures the power with the wheels off)


Dyno Day #4 was 3 days ago at Church Automotive.
I had done more polishing to the lower plenum. I also changed out my rear brakes from the stock 5AT ones to the OEM 2 piston Brembo calipers with 2-piece stoptech rotors. The stoptechs weigh about 2 lbs more than the stock 5AT rotors (13 lbs vs 11 lbs respectively).
The first runs (Crawford V5) were in 4th gear, just to compare to dyno day #3's results:
259 AHP .....a gain of about 5 HP. Not bad, considering there's not much left to polish, and I'm running slightly heavier rear rotors now.

The rest of the runs that day were done in 3rd gear. I was always curious as to how my car would have compared to the others on Dyno Day #3 had my car been run in 3rd. Looks like it would have done pretty well. The reason why it was run in 4th was because I was the first g35 on the dyno that day, and I wanted the 1:1 gear ratio.



There are 6 runs here. 3 with the Crawford V5, and another 3 with the stock plenum/spacer. I put all of these runs on the same plot so that it's obvious that I'm not just choosing the best of one config vs the worse of the other. (there's actually a 4th Crawford run, which was the same as the other 3, but the plot is already busy enough). I also have the torque from the first Crawford run vs the first stock plenum/spacer run, just to give people an idea of how the torque curves look. I'm not sure what's going on at low RPMs (the funny curves), I just plotted the data, maybe the machine was picking up torque converter slip.

All of these runs were done in 3rd gear. And again, this is on a dynapack, and we expect the absolute numbers to be higher than a dynojet.

You can see the consistency in the gains above 6K RPM. These runs were done within 30-45 minutes of each other, and the car's axles were left connected to the dynapack when we switched parts.

We surmised that the spacer helps by changing where the air is directed coming from the plenum's neck. In stock form, when the air enters the plenum chamber, it hits the intake runner "hills" on the lower plenum. With a spacer, the air flows above those hills, and has a less restricted path. I'm now running the Crawford with a 1/4 spacer. There's no clearance problems on the g35coupe with this configuration. What I'd like to do is get the car back on the dynapack and a dynojet in this config, but I have to take care of some other stuff first, and get some more disposable income.

Here are some pics of my polish work.


When I say "hills" I mean the raised portions near the middle of the plenum where the air first goes when it enters the plenum space.

xswl0931

It would be great if you can get a dyno of your car with the crawford and spacer together. Of course it'll only be meaningful if you can get a run with just the spacer or crawford to get a comparison.

shinz

iTrader: (3)

nice gains with the spacer, how much are they planning to sell them for? Thanks

MY350Z.COM

iTrader: (2)

Can you post actual dyno plots seperately? Like from the dyno software.

I'm betting a lot of the gains came from the polished lower plenum. I always had a feeling that gains could be had there by polishing those rough castings.

Victor

E K

iTrader: (10)

I know that the software can generate dyno plots, but it gives the data in raw table form. All I did was directly plug the numbers into Excel. I only have the raw numbers at this point. I'm willing to post it, but it's 200+lines of numbers.


Butt dyno-wise, the polishing and portmatching has really helped the top end.

seanlaw

iTrader: (4)

and this cost how much to get done?

E K

iTrader: (10)

$60 + about 2-3 weeks of labor. The $60 comes from the polishing materials. All I did was clean up the casting imperfections. I didn't remove much material since that's best left to someone with a flowbench. I spent about an hour a day doing this, since I still work full time. Make sure you wear eye/nose/mouth/ear protection when doing this.

Street Visionz, Inc.

iTrader: (68)

Hmm....maybe it's time I got some headwork done to my car.

FairladyZ

I dont get what you are doing? Is that graph yours? Going by the graph the stock plenum and spacer gives you more hp. To bad you dont have just a stock plenum.

Assuming 15% drivtrain loss on dyno #2 223whp+15%= 256.45ahp

So #3 you lost 2hp but it is negligible (sp?) because that would be like 3 pulls which never are the exact same. So with the polishing and V5 you gained nothing.

#4 yet agin it could be outside factors, so you might have gained nothing.?.

nuttyprof

iTrader: (1)

his is a 5AT, so the drivetrain loss is actually higher. and also, the stock 5AT G35 has quite low numbers to begin with.

E K

iTrader: (10)

The graph is mine, it's plotted from the raw excel data, which I can email on request. Yes, it does look like the stock plenum and spacer is giving higher gains. I can't fully explain why, all I can do is to present the objective data.

My car's an automatic, so 15% drivetrain loss is probably too low. But that is why it's hard to compare absolute numbers with different dynoes, or even the same dyno but on a different day.

If it helps here is my Dyno runs in excel for the first three dyno days (1&2 at Strictly Dyno, and #3 at Church Automotive last year). I tried to correct for the absolute numbers on the dynapack run based on another member's runs at Strictly Dyno where he got 240WHP and at Church Automotive where he got 251AHP with the same mods, by creating a correction factor based on the delta at every 100 RPM increments. But I don't even focus on the raw numbers, rather I look at the difference in the shapes of the curves.



I'm not sure what you're asking with the last two points, you lost me. Can you rephrase it? Again, absolute numbers are hard to base comparisons off of, but changes in the curves can give us an idea of where changes have occured.

E K

iTrader: (10)

FairladyZ, I think I'm starting to understand what you're asking. Again, the automatic transmission has closer to a 20-22% drivetrain loss.

The dynapack is not measuring horsepower at the crank. The wheels are off, but the power still has to go through the transmission, axel, hub, etc.

No one really knows how to convert a dynapack number to a dynojet one, the machines use different methods to measure horsepower. What I've seen is that at peak HP, the dynapack is anywhere from 11-20 HP higher than the dynojet. This is greatly affected by the wheel weights/alignment.

FairladyZ

Oh, ok I get it now. thanks.

Now back to the graphs, basically you are using calculus to figure your power and torque curves? So by your results what is the best combo?

It looks to me like the stock plenum and your polishing (which looks amazing by the way) will result in the best power gains.

350tre

your comparison is completely worthless, the dyno results are confounded with the different mods you had on during every run. that is scientific talk. it means that you are trying to compare things but you keep changing the variables and trying to compare them. completely worthless beyond the gain the begining mods and the ending mods...

FairladyZ

Thats true. What are you getting out of it.

I am getting, keep the car stock.

E K

iTrader: (10)

Which comparison areyou talking about? The point of this thread isn't gains/loss from the very first dyno to now. It's the difference between a stock plenum/spacer and a Crawford V5.

We hooked the car onto the dynapack with the Crawford, did a few runs, and with the car still on the machine, swapped the plenum to the stock/spacer and did the rest of the runs. Nothing else was changed. The runs where done within 1 hour of each other. The coolant was warmed up to the same temperature with each run. Ambient temperature was basically constant at 69-70F.

JisNis

iTrader: (18)

EK,

The question has been asked a couple of times but I'll go ahead and repeat it.

HOW MUCH????

I have another question as well. When will they start selling these?

Zeromancer

makes sense to me...

E K

iTrader: (10)

You'll have to PM hydrazine for more details, but I believe he's going to sell these for about $200. I don't really know when he's going to start selling them, as again I'm not involved with the business aspect of this at all. My role was just to test the spacer on my car and dyno test it, so my job's pretty done now.

JisNis

iTrader: (18)

$200 doesnt sound to bad......How bout $150 for the first 10? I got dibs.

I'm stuck now, I dont know wether to buy a Crawford v5 or wait for the spacer?

V5 $350 (Proven) or Spacer $200 (still developing)????