Disappointing dyno results 370z 7at
 

Recently had the car uprev'ed

Mods are as follows

Z1 intake hoses
K&N drop ins
Invidia cat back

Before figures were 299.7hp , 250ft lbs , after remap 309.4hp and 265ft lbs at the flywheel.

Dyno was a dyno dynamics

Tuner thinks the stock cats are holding it back and agrees it's lower than we expected but has little experience of the auto version .

Is this about right ? Or any other ideas

Put it on a Mustang Dyno (heartbreak dyno) and you would cry. The figures for my stock 370 was around 261/218

I baseline only 265 on dyno dynamics before re map :/

You don't have that many mods... What did you expect to get?

Also, I assume you mean at the wheels?

How did you determine crank horsepower from the dyno dynamics WHP figures? Or is this a dyno that calculates flywheel horsepower from its own wheel hp measurements?

How much did the car actually make at the wheels?

Different dynos read lower or higher. They can all be messed with. Some tuners make their dynos read really high because that way it makes the customer feel good about the extra performance they didn't really get. ;)

Anyway, if you don't know what a 370Z usually makes on that dyno (using the same settings, same ambient temp, etc.) I wouldn't be too concerned, but maybe take it somewhere else to double-check this dyno doesn't read low. Those chp numbers are far below stock - if they were whp numbers, I'd say you did pretty good. :)

Those numbers are fine. Put it on a dynojet to get more easily comparable values -- the OEM cats are indeed holding you back. Get resonated HFC's or TP's and retune.

Search for my username and proven power dyno thread to see lots and lots of details on what to expect in terms of output on a dynojet for that and similar set ups.

EDIT: Wait, in Europe I don't know if there is access to dynojet. Seems like Euro dynamometers are usually rolling road... I would see if you can find data for other Z's (MT or AT) at that particular shop to compare and contrast.

That said, I'm sure your results are in line with everyone else's -- no reason to be disappointed.

When testing a car with my ported parts the customer had cats too. Just an example of what can happen he was 4-5 degrees less timing then mine, and 2 other friends who are catless. and he even had berk HFCs. Conclusion was the cats heat up and hold a ton of heat. That heat creeps back to the motor starting knock which is why we pull so much timing.

I never researched it but I'd be curious if it's the heat more or the flow restriction that kills HP with cats. If it's heat I wonder what a cat does back further like in a mid pipe or muffler. Is it even an effective cat back so far with less temps?

HP is just a number and dynos always vary. Take their results with more than a few grains of salt.

Your butt dyno (how the car makes you feel when you're actually driving) is much more important.;)

yah, it's a good way to get a baseline and post-mod measurement to see the increase.

for a street machine, unless you go forced induction the difference is almost undetectable...hot/cool day could have nearly the same results.
but at least you get better sound.

sound is important.

http://images.tapatalk-cdn.com/15/05...8828662ac7.jpg 2011,base,automatic-speed limiter kicked in @ 156mph...drop in K&N's only


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Before figures sound just about right. I have the same mods(except my exhaust is an ARK) and got almost identical numbers (301whp, tq i cant remember) without a tune and on a mustang dyno. Like some have said: butt dyno is more important than any numbers a machine will tell you :tup:

I also agree with getting hfc or TPs and retune in case you want mo' powa :tup:

Your in the UK and using UpRev?

You should have your tuner get EcuTek and retune using that.

I can also help if you want

John

Not very many mods man. You basically have an exhaust and tune. I know people like k&n's and post maf tubes. I had them and now have Gen3's. Get some HFC's or TP's.

Get a true CAI, MD plenum, LTH and call it a day.
you're only having a catback btw :) so don't expect more ..
before the mods i would say your car was putting down ~285 whp ? with the mods u put down 299 whp ( and that's from the catback ), then after tuning you got 309 whp only and that's because your tuner didn't have enough room to play with so he probably advanced the timimg just a lil bit and maybe smoothed out the a/f ratio.. thats all.

These are not whp figures as I said in my first post this is the calculated flywheel output

This is a dyno dynamics dyno so (I think) the flywheel figure is based on the mode selected the run was done in shoot 6 mode

The measured Wheels figures were (estimated as the graph as hard to read accurately)

245hp before uprev and 255hp after uprev

I don't have a chart showing wheels torque

The tuner knows his stuff and I'm sure the problem doesn't lie with him

Dyno dynamics dyno's are the most common here in the UK , dynojets are rarer and usually more often used by motorcycle tuners

Ok to try and make it clearer

This is the WHEEL horsepower from my car before and after uprev
http://i80.photobucket.com/albums/j1...pszgov1rmk.jpg


I am realistic and wasn't expecting massive figures, this is my first N/A car after owning a couple of Skylines R33/R34 and an Evo 6 which were all highly modified but I thought it should make 20-30hp more , hell even stock I thought it would be 260hp at the wheels

If you compare my chart with a manual 370z with similar mods PLUS Berks high flow cats on the same dyno (These are flywheel calculations of course)

http://i80.photobucket.com/albums/j1...psypgkyszk.jpg



I do have a set of test pipes I can fit , but will i really pick up 27hp and 20 ft lbs by fitting them ? Are the stock cats really that bad ?

Flywheel (flexplate?) numbers -- not quite that much, but in that ball park. Expect (dynojet estimated) 12 -15 whp gain.

Also, note that I have never seen any evidence of greater drivetrain losses on the AT as compared to the MT for this car. Full lock up, well designed trans, and CFRP driveshaft must help quite a lot!

Seriously, I highly doubt you are seeing values that are wildly different from anyone else's.

Go through this thread for excruciatingly detailed discussions plus dynos with various mods -- bear in mind that load holding dynos are always highly variable from shop to shop depending on calibration values whereas dynojets tend to be very stable from unit to unit, shop to shop.

http://www.the370z.com/south-east-re...se-thread.html

It starts getting very detailed by about p. 5.

Go by proportionate (i.w., % change) changes to make estimates -- these measured values are all to the tire; no estimated flywheel numbers from coast down.

I'm used to my cars exceeding the factory claims , it seems by spending around $2000 I'm still 20hp down on where Nissan claimed :(

Take it to someone with a dynojet before you get all worked up about the number. I seriously doubt you're making less power than stock.

Guys these cars have about 15% drive train loss. You need a dynojet, SAE, 5th gear to be most accurate as all manufactures use SAE for the motor tests. 5th is our 1:1. If you're not doing that you cannot compare.

I don't know of any dynojet dynometers unfortunately as I said in the UK dyno dynamics are the most common, there are a few sun dyno's , dastek and dyna packs around

I understand but I'm saying don't then compare to the factory.

I'm not a big fan of chasing around dyno's to get the figures you want , I'm not convinced that a dynojet dyno will give more accurate figures than a DD one but I've found one about 65 miles away so I'll get a print out from them to compare

Don't then. If the dyno said you gained hp after parts and a tune and the before was zero hp and the after was 15hp you know what you gained. You may only have a 15 hp car but so what. I'm sure it still feels fast (as fast as any Z with same bolt on's and tune). Just don't worry about comparing to others or oem output.

Disappointing dyno results 370z 7at
 

Intakes don't usually help too much on the dyno (hood open breaths pretty well)

HFCs or test pipes will help way more. However once you drop the hood gen3s are great as they drop your heat rise 10-20 degrees.

First, you were almost definitely dynoed in 4th, which is fine, but that will affect final torque values by a few lb/ft (I actually have data on this in my dyno thread). You have to have the speed limiter removed to dyno in 5th on the AT.

2nd, because the "flywheel" values are estimates derived from measured wheel power (and on a load holding dyno at that), its hard to evaluate how close they are to actual values, which could only be calculated by unbolting the motor from the car.

Then there's however it applied correction due to temperature and air pressure.

But, yes, assume you will be in the ball park as that other dyno given the same mods, a good tune, dynoed in same gear, and in similar conditions.

If you aren't, it might be that different calibration values were entered for your vehicle vs. another.

I can honestly say I don't know what my whp will be but I'm very optimistic about it (though I shouldn't be). With only a stillen intake (gen 3), injen CBE, and Berk HFC, it probably won't produce that much. The real production of power is when you drop a SC or TT in her (which I wish I could do)....

I had my car tuned at Uprev in Austin TX. The top end gain was 4hp from 282 baseline to 286. In the middle of the power band, I picked up 10hp. To be honest, I was super disappointed with the results as I was expecting an improvement of up to 20hp.

The tuner told me that about 5hp on the top end was normal for the AT and that a 20hp gain was impossible for these cars.

In my experience, the tune was not worth the expense. I needed it to clear the codes created by my 4.08 gear upgrade.

If you have added standard upgrades like intake, TP and exhaust, you don't need a tune. The ECU will adjust properly to accommodate the improved air flow.

http://images.tapatalk-cdn.com/15/05...af24f2ad59.jpg my first run was in fourth & Dyno guy let off gas @7200- because shift light came on, 2nd run was in 5th 1:1 & numbers increased,but speed limiter kicked in @7k 156mph.


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Disappointing dyno results 370z 7at
 

I respectfully disagree a bit with the tune not being required for small mods. Half the fun of a tune is getting the most out of your mods, but also you correct for rich or lean which can be a bit dangerous for the motor. (Well lean anyway).

Also and perhaps more fun, our EDC can hold 5 tune "maps" (accessed using the Cruz control buttons)

Mine are
1 91 octane high alt map for denver
2 94 octane Cali map
3 2800 rpm valet map
4 kill switch (no fuel map)
5. Stock.

I use all these maps occasionally and they are worth the price of admission for a tune I would say. I'm up about 60 whp from stock using the z1 400 hp kit and Berk catback (that's based on increase from baselines before and after mods on a dyno jet). The stock tune did not keep up with my mods and I worry if I'd gone that route I'd be very lean driving around. (And would have to avoid wide open throttle)

Still not sure why you're not happy with the gain with just a catback. Like everyone else has said don't get cought up in numbers . I make 287 WHP on what I'm being told now is a inconsistent machine ( mustang) Al tho it's the lowest machine around and I sont mine that.
Just for you're arguments sake I went to another shop to get some pulls done becaue the place I use was booked and I made a WHOPPINH 252 WHP ! So did I really go backwards from stock ( 265 ish) no the machine was differnt and actually found out later was set up wrong. Numbers are number that's it dyno's are a tunning tool and not bragging rights. Yes it would have been great to see a higher numbers but the numbers you got are just that numbers . Be happy and keep modding . You can use the same dyno just compare the gains and not the end WHP .

OP (and everybody else):

Provided you use the same dyno, whatever kind it is, and use the same correction factor, and dyno in the same gear (again, 4th is fine -- less stress on the motor), you can always determine magnitude of gains or losses by the percent of change from your baseline (of course, that means you need a baseline...).

In other words, absolute values are less meaningful than the delta (i.e., a gain of "5 whp" isn't as clear as a gain of "3% from baseline"). Likewise, don't dismiss gains under the curve over peak gains.

A good way to evaluate overall change is to look at the % change where hp and tq cross (i.e., 5252 RPM).

Peak values are only critical for drag racing time and and top speed, but for daily driving and your "butt dyno", you will be more aware of changes much lower in the powerband, and off the line most of all.

Thought I would update the thread just so you know I took advice:icon17::icon18:

I mentioned earlier than I had Z1 intake tubes , I actually had some Mishimoto ones which arent as good quality as the Z1 ones and since my tuner reckoned the MAF readings were a little screwy I ordered some HPS ones (incidentally there is very little difference between the two) to be sure.

Also bought some Berks test/decat pipes and fitted those

So before was 309.4 flywheel HP

After just fitting the above parts it produced 328 flywheel HP but it had leaned out .....a lot !

After an Uprev remap and smoothing it made 345.9hp. +36.5hp increase

http://i80.photobucket.com/albums/j1...psm4fnvce8.jpg

The car drives a lot better especially at the top end and ultimately that's what's really important , I will however get a run done on a dynojet dyno to compare at some point

So thanks all

Thats better like 285 WHP , nice man

Haven't seen a Dyno read flywheel HP. You'd have to subtract 17% for an automatic & 15% for a manual @ the wheels.


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Alternatively you can just read the print out prior to the set correction factor the DD dynos adds on to give estimated fwhp ;)

I only posted the flywheel figures to give an accurate comparison

I have never bought the idea of transmission losses being a set percentage , if you double the horsepower of an engine do you really double the transmission losses?

That be a Yep!
A baseline average that is calculated is 15% loss of power at the wheels due to friction,etc...through all moving parts.
An automatic seems to lose about 17%
This number will vary from type of vehicle....but ultimately averages out to 15%.
So if you're putting down 500hp @ the wheels...you're close to 600@ the crank.
:)

Mine is right at 17% pending 332 crank hp. Not sure if drop in K&N filters helped any....here's video in 5th gear 1:1 speed limiter tripped in at 156, 1st run was in 4th gear & spooked the Dyno guy when the shift light flashed just over 7k & he backed out.https://vimeo.com/140489018


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