7AT w/ I-H-C-E Dyno'd
 

Max Hp: 305.3, Max Torque: 241.2. Current mods are Stillen Gen3 Intake, Stillen Headers, Berk HFCs, Stillen Cat-back. This was a DynoJet at Carboy in Houston, 3 pulls, very humid day. They used 4th gear on the 7AT for the pulls.

Video of all 3 pulls shot on my mini-DV:

[YOUTUBEHQ]gj6MetAjrCY[/YOUTUBEHQ]

I don't have graphs to post yet, but I have the raw data attached here in a zipfile. Unfortunately DynoJet's free software to interpret the data and make graphs is Windows-only, and I only have Macs here. Could someone grab the attached data and make some pretty graphs for me? Preferably include the A/F data too (it's in there).

As I said in the other thread.. These numbers sound a little low to me for full intake/exhaust compared to what else we've been seeing (given that its a DynoJet), but on the other hand (a) This is a 7AT, the rest have all been 6MT so far, (b) It was extremely humid in Houston today, and (c) Every dyno and every car is different. I'm planning to hit a Dyno Dynamics place on Monday if I can, which will provide another good data point.

This is the link to the DynoJet windows software (click "Trying to View Your Run"): Dynojet Research Inc. - Software - Downloads, and the raw data from my DynoJet runs in 4th gear is attached, if anyone wants to process it for alternative graph views.

UPDATE: Attempted 5th gear run on same DynoJet, doesn't fly because with the 7AT's rear-end ratio, you can't top out the revs in 5th due to the stock ECU's speed limiter tripping at 160 mph. Also did a Dyno Dynamics run at EngineLogics (these guys were great btw, highly recommend going there to other Houston-ites), which clocked in at 300 hp and 243 tq.

At this point, I'm kinda suspicious of the DynoJet results, the machine may be mis-calibrated or something. It doesn't jive with my Dyno Dynamics results given what we know about how they typically read versus each other. Attached are various related graphs:

Dyno Dynamics HP+TQ vs RPM (all 3 runs):
http://www.the370z.com/members/wstar...-tq-vs-rpm.jpg

Dyno Dynamics HP+AFR vs RPM (all 3 runs):
http://www.the370z.com/members/wstar...afr-vs-rpm.jpg

DynoJet HP+TQ vs RPM in 4th (best run):
http://www.the370z.com/members/wstar...m-4th-gear.jpg

DynoJet HP+TQ vs Speed in 5th (only run, incomplete):
http://www.the370z.com/members/wstar...d-5th-gear.jpg

I know the dyno is adding to the sound, but damn your Z sounds great! :tup:

dyno report/video = rep points

Why wasn't it dynod in 5th gear?

I don't know, why would it be? 4th tops out somewhere around 120-ish mph IIRC.

5th gear on the auto is 1.0. Most cars are dynod in the gearing that is 1.0.

Interesting, does it make a significant difference? Seems weird to me that there would be a universal standard on what ratio to use on the transmission, considering the differential's ratio differs between cars as well, but then again I know nothing about the subject at hand.

It doesn't make a enough difference which gear they dyno it in. 4th and 5th reveal results within 5hp on cars making over 500HP. HP is a calculation of torque (from what I understand).

Sounds mean as hell. And most cars are dyno'd in their 1:1 gear,but as stated earlier it probably wouldn't make too much of a difference. Either way... nice numbers for an auto although I was expecting more on the torque end.

I respectfully disagree with Crash on the gearing not making much of a difference, at least for the 370Z. I say this because when I took mine to a DynoJet, the guy did pulls in both 4th and 5th. (2 pulls in each gear.) The 4th gear pulls came in around 10-15hp less than those in 5th for my car, if I recall correctly. In fact, it may have been even more, because I seem to remember that on his first pull (which was in 4th), the hp came in lower than my DynoDynamics number, and when I saw the number on the screen my immediate thought was 'WTF are you doing wrong, dude? There's no way I'm making less hp on a DynoJet than I'm making on a DynoDynamics'. (The 4th gear numbers were so bad that I had those pulls tossed from the graph, so I can't go back and look at them to verify the delta, unfortunately.) I suggest you tell them they need to re-do it in 5th gear. I mean, think about it -- you're getting less on a DynoJet than I got on a Dyno Dynamics (306.4). And I don't even have the headers on yet! I know I've got a 6MT while you've got a 7AT, but there's no way the delta between the transmissions is THAT big. There's just no way. Regarding Crash's statement that 4th and 5th reveal results within 5hp on cars making over 500HP, perhaps gearing makes less of a difference in dyno results the higher the hp a car has? I don't know. I have no reason to disbelieve Crash's statement. But I'm just telling you what I personally saw with my Z when it got dyno'd in both gears.

Edit: Check out this thread: http://www.the370z.com/engine-drivet...gear-dyno.html DannyGT got a baseline done today on a DynoJet. 282whp. 5th gear. So the delta between his baseline and your number is 23hp. I know these are different cars, but still, with the full intake & exhaust setup you've got, you have to be making more than 23whp over stock. The cat-back and HFCs alone yield way more than that.

How's your AFR? Also, did you gain or lose response. I'm wondering if headers + HFC + exhaust would have any adverse effects with torque and throttle response.

I may do the same setup, but leave the intakes stock.

Hmm, maybe I'll go back and get a 5th gear run on the DynoJet too then.

The AFR on the graph he gave me was right on 14.0 at 4k RPM (first time it's stable, I think that's where he punched the throttle at honestly), and gently glides down to what looks like about 12.5 at 7.5k RPM.

By response did you mean throttle response? It revs unloaded a lot quicker than it did before, but I think that's pretty much a given. I don't think I've lost any torque at useful RPMs, although I think I've dropped some torque in the very low RPMs (3k and under -ish), just based on feel when driving.

ya dude, 5th gear is where you wanna be.

Well, I do agree that 1:1 is always best for dynos, but it's just been my experience that you're still getting a ballpark and sometimes even very close to accurate result in 4th. It's anything less than 4th that things start going way off course.

Well, there's enough doubt on the issue now that I may as well do this back to back and settle the issue for our cars anyways :)

Yea, throttle response. I spend more time driving under 3k than anything else, and will go all out once in awhile. There's no surprise with the Z hauling a$$ to redline after a brief late start. HAHA!

The mods are probably overkill for my everyday driving, but it's all in good fun. I wonder how much torque we can recover from having a tune.

This is definitely something to work on this July during my 2-week company shutdown. :tup:

I can't wait for my car to sound like that.

Also either the humidity is robbing you of a good bit of HP or the dynojet is reading a little low. I expected a little more power from those mods on a dyno jet....
We will see what I get :)

I agree with RCZ, I would expect a little more power with all of the mods done so far, but man does that sound sooo sweet! I was planning on this exact set-up. nice work!

:drool: Makes me wish the meet hadn't fallen through.

Well as I said, the numbers look low to me too. We've got 4 possible excuses now, and it's probably a combination of all of them: (1) Dyno/Car variations, (2) Being in 4th instead of 5th, (3) the humidity, and (4) 7AT vs 6MT. Monday looks to be better on humidity, so I'm going to try and get 5th gear runs at the same DynoJet and/or a Dyno Dynamics place then, pending the scheduling working out.

God your car sounds so awesome.

I also hear that rasp you were talking about in your other thread. Fix that and it would be near perfect.

I don't know if rasp is the right word for it (seems to have some fixed connotations to some people), but there's definitely a vibrational noise at certain RPMs. I hear it pretty distinctly inside the car when driving, but I couldn't hear it much at all from outside when I was videotaping the dyno run. I think from the outside the actual exhaust sound drowns it out.

Being the paranoid worrier that I can sometimes be, my main concern is it could be a small leak that only opens up under the pressure of a loaded run (never hear it revving the engine in neutral), but the rational part of my brain says I've rechecked those bolts plenty of times now, and there's no leak. Most likely it's something else vibrating: perhaps something in the lower engine bay is rattling against the piping near the headers/cats, or perhaps one of those flimsy, thin undercar heatshields is vibrating in response to the exhaust, or something of that nature.

Anyways, I just got two more dyno runs scheduled today, one at the Dyno Dynamics place (Engine Logics), and a second run at the same DynoJet I used at the start of this thread (but will do it in 5th gear), so hopefully this evening we'll get some clarity on the numbers.

Yeah, I was talking about that tinny noise characteristic of metal on metal contact. The note wasn't raspy at all, and sounded excellent. Sorry for the poor choice in wording.

I see others with the Stillen catback are having similar issues. Hopefully Josh will find a solution quick.

At this point I doubt my vibration noise is anything specific to the Stillen catback. I know the catback part isn't touching anything but its own rubber hangers and has good clearance.

Just got back from EngineLogics where I did the Dyno Dynamics run. They put me at 300rwhp and 242rwtq. Graphs came out very consistent, it's a really nice machine. I'll scan them at a copy place in a few hours when I go out for the DynoJet retake. This is still lower than semtex's numbers, but it's a lot closer, within the margin of error for differences in car, dyno, weather, and 7AT/6MT.

^ Except I don't even have the headers installed yet and I'm making 306.4whp. My guess is that the difference in drivetrain loss between 6MT and 7AT is coming into play here more than anything. Still some good numbers though. 300whp on a DynoDynamics is nothing to sneeze at. Congrats!

Hmm... it was my understanding that the noise was coming from clearance issues with the catback?

A few of us have had clearance issues, which does make a vibration noise. However, on my car that problem is solved. I'm talking about some other noise.

Yeah I'm happy with it. 6hp isn't much, and there are a lot of variables in play here between your situation and mine.

Re: the headers, the guy at the dynojet shop (carboy) said he didn't think headers were going to do much on this car. Who knows if he has any idea what he's talking about. Apparently he has a long history with recent Nissan engines though, and he (and everyone else in the shop apparently) are all Japanese immigrants if that makes any difference. On the other hand, this is the same guy who ran my car in 4th gear, so take whatever you want from that :) I'm leaving in 20 minutes or so to go try the 5th gear run there.

Ok I just got back from the DynoJet shop. Learned a few things:

A dyno run on 7AT in 5th gear isn't really possible with our current stock ECUs, they hit the 160 mph speed limiter at around 7K rpm. We actually tried it, and the ECU basically holds the gas pedal dead on 160 mph when you reach it, it won't let you accelerate any further. The 7AT has a different gear ratio in the diff than the 6MT (7AT = 3.357, 6MT = 3.692), which is why you 6MT guys are able to make 7.5k (just barely) in 5th.

In any case, the lines looked about the same, if anything roughly 5-10hp lower throughout the rpm range versus the 4th gear pull. The graphs he showed me afterwards, the data seems to die off even earlier than what I observed during the pull (more like 155mph) and topped out at 288hp, so I don't really know what's going on there.

So I think 7AT pulls on DynoJets will need to be in 4th for now, at least until we can raise the speed limiter. I also suspect this particular DynoJet is need of some maintenance and/or calibration.

The Dyno Dynamics guys claim gearing doesn't matter on their machines, due to a different theory of operation.

Very interesting... Thanks for the update.

Very cool thanks for the update!

I scanned in the printed-out graphs at a Fedex/Kinko's place, they're added to the original post at the top of the thread.

I would tend to agree. You're DynoDynamics plots look good but the DynoJet should be reading a lot higher.

The exhaust sounds great BTW.

wstar,

I live in Houston, and I've dyno'd multiple cars at both shops you mention, as well as organized/particpated at dyno days at both shops. No Z's though, this is my first Z, but my experiences should still relate I think. There is no way the DynoDynamics dyno at EngineLogics should be spitting out the same results as a Dynojet. Chris (the owner of EngineLogics) prides himself in calling his dyno the "heartbreak dyno", because all of the Houston dyno queens that put up big numbers on Dynojets in Houston see about a 12-15% reduction at EngineLogics. The Supra guys hate going to EngineLogics for this reason. Nothing against Carboy, I've had good customer service there as well, but I would lay my money on EngineLogics as being the correct reading. Something seems amiss with the Carboy results.

Next time you go, drop me a pm, I'd like to join you if possible. Not necessarily in the Z (it's stock), but I have an Evo I'd like to get back on the dyno for tuning reasons. I'm off Wednesday :-)

Well this has been my first experience with both shops. They have very different natures :), but I really liked both shops actually. My money's on the EngineLogics dyno results being more accurate than the Carboy ones for sure. But I also had a lot of fun at Carboy, they've clearly got some import connections, and it was great hanging out and talking to them there, and looking at other project cars they're working on.

Sure thing. Probably won't be until late next week that I go again, after a few more changes that are in the works. By then I should be able to install the underdrive pulley at least, and then next on the list after that is switching to a good synthetic and installing a ground strap kit, and then finally putting some heat-shielding stuff on the headers and the intakes (I don't want that stuff in the way while I'm still looking for vibrations near the exhaust stuff though).

I've decided to skip the oil cooler for now, at least until I see how things go as the weather heats up over the next month or two. For now, it's doing better than I initially expected. Some of that could be temps going down as the engine breaks in, and some of it could be that I added Water Wetter to the coolant too. I still haven't managed to make it past the 240 mark on the street.