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Interesting Dyno results 2530 / setting up the tiing with a dial gauge


menthol369
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Interesting Dyno results 2530 / setting up the tiing with a dial gauge

Had the car on the dyno the other day and seemed to run into some strange issues.
Ill start by explaining the setup:
Stock bottom end
Stock head with internal VCT mod ( expect has upgraded cam springs

Gt35 front wheel on a holset HX35 ( 12cm, 60mm inducer, 70mm exducer)
supporting mods for 350+rwkw


So the dyno sheet attached was the absolute peak the car made on 20 pound, it was a hot day with the ambient temp in the shed 40-50deg
however back to back runs showed the car lacking power each pull dropping to 280rwkw, and then even when letting the car cool it would not make the 300 again.
After mucking around with a few different ideas and finding that the VCT was not working we called it.

After doing ssome research on here its possible that the cam timing is out ( even though the marks are all pretty well lined up) its possible that due to tensioner placement, decked head and block etc that it could be quite out.

So my questions are:
does the dyno graph shape indicate the cam timing? ( what 2530 continues making power to 6800 with no drop off?)
and what degree to set the cams up using a dial gauge?

Any other suggestions?

Cheers
 

317.jpg

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I wish people would not put kph on their dynos instead of rev/min!!!!

My power output is very similar to yours. I thought it was because of the .63 rear on the GT3540 but others with the same turbo make 350kw at 18psi so I suspect cam timing. My mechanic is very keen to change the cam and springs which may be a good idea but 350kw should be possible without that. Others have said that cam timing is the key but they haven't spelled out what they did to fix it...

 

2013.11.21 Power & Torque 001.jpg

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50 minutes ago, KiwiRS4T said:

I wish people would not put kph on their dynos instead of rev/min!!!!

I know this is off topic, but!

 

I just asked this question in a tuners group, as it has always bugged and confused me too. I have seen tuners one car will be rpm and the other speed.

Here is a great explanation.

" Mph is usually only used when a good rpm signal can't be acquired. Using a fixed ratio based off of mph is not the best way either to get rpm, due to tire deflection, vehicle movement forward during a pull and potential small amounts of tire slip. And setting the ratio requires that an absolutely perfect mph and rpm be inputted or you get wrong tq numbers as the rpm gets away from your set point. "

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1 hour ago, Trex said:

" Mph is usually only used when a good rpm signal can't be acquired. Using a fixed ratio based off of mph is not the best way either to get rpm, due to tire deflection, vehicle movement forward during a pull and potential small amounts of tire slip. And setting the ratio requires that an absolutely perfect mph and rpm be inputted or you get wrong tq numbers as the rpm gets away from your set point. "

That explanation doesn't make sense to me. Saying that  the printed mph/kph figure is too  unreliable to convert to rpm means you have given up on getting accurate data. . Given that for many purposes the ecu requires an accurate rpm signal it would seem that the tuner hasn't gone to enough trouble to make the necessary connections to get a proper rpm reading. 

Seeing videos of people sitting in the boot of cars trying to stop tyre slip on dynos is another reason why i think hub dynos are by far preferable.

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Hi guys,

I'm on the way to Tassie so don't have time for a proper post. For the record, I was the tuner for this. This particular mainline doesn't have an rpm pickup and I didn't bother to set the rpm conversion as I had tuned 3 other cars on the same day in the dyno shed where it was ~47 degrees (yes we measured it). 100kmh on this car is 3100rpm or near enough.

Between timing and fuel sweeps and dropping the exhaust this just would not make any more power. At this point I'm suspect on cam timing and would like to see it degreed back to OEM RB25 specs as a starting point and I can dial it in on the dyno from there.

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20 hours ago, XR Pilot said:

At this point I'm suspect on cam timing and would like to see it degreed back to OEM RB25 specs as a starting point and I can dial it in on the dyno from there.

^^ this is the best approach.

I'd be suspicious that the "internal" VCT oil feed mod isn't functioning as intended either.

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  • 4 weeks later...

If they spent 3 days on just your car then it needed more than just a tune.  A tune does not take 3 days of solid work.

Identifying and then resolving issues and further scope for improvements that are found during the tuning process are what takes the time.  If a tuner takes 3 days to tune a vehicle I have to question his ability.

Also, just because the car is at the tuner for 3 days doesn't mean it's on the dyno for the whole time! 

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8 hours ago, Shoota_77 said:

If they spent 3 days on just your car then it needed more than just a tune.  A tune does not take 3 days of solid work.

Identifying and then resolving issues and further scope for improvements that are found during the tuning process are what takes the time.  If a tuner takes 3 days to tune a vehicle I have to question his ability.

Also, just because the car is at the tuner for 3 days doesn't mean it's on the dyno for the whole time! 

That's exactly right only a fool would believe it was on the dyno the whole time.

However I know that my tuner spent at least a day just on low rpm/cruise. My car runs as smooth as a factory car.

Do you think these car manufacturers only spend a few hours tuning before they release a new model? No they spend a ridiculous amount of time getting it perfect before they do.

 

Don't expect an amazing tune for a few hours on the dyno. And if you are a cheapskate go to Chequered because you will get what you pay for...

 

 

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Have you had a bad experience with Chequered? I've only heard good things in the past!

Very keen to hear some facts as I was planning to and most likely still will tune my car there unless you've got some pretty solid evidence as to why I shouldn't. 

We're all entitled to an opinion I guess, hence why I personally wouldn't set foot inside Melbournes most discussed workshop (again) due to the fact that they really only like customers that have no idea about their cars and rely on pushing their own financially rewarding opinions on said customers.

Sorry for the thread bomb Daniel! I hope you get to the bottom of the problem. 

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  • 2 weeks later...

Noone would ever spend 6 hours of a 8 hour working day doing a cruise tune.

You can do the entire off boost area in about 2 hours loading up all pointed and all rpm points within reason.

Then another 1 to 2 hours doing power runs provided there are no changes need to cam timing etc.

If your tuner is saying he or she spent 3 entire days tuning then I call bullshit.

I can understand 2 full entire days if that involved parameter settings, scaling of all tables, setting up all inputs and outputs, scaling sensors, setting up the duty cycle vs rpm vs load vs ethanol concentration.

I suggest you secretly install a dash cam in your car and prove me wrong, because I tune cars and I consider myself slow and take my time and even so I would never spend 3 entire days.

These aren't F1 high strung high comp motors and even so, 90% of tuning shops don't even have the appropriate data acquisition tools/sensors 

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On 13/02/2017 at 8:13 PM, Daz said:

Do you think these car manufacturers only spend a few hours tuning before they release a new model? No they spend a ridiculous amount of time getting it perfect before they do.

No, because they have more variables to combat such as emissions, noise, heat, longevity, baro, air density, air temperature, gearing, list goes on.

Also they go into every single cell and tune it, RPM vs. Load, then repeat for different conditions and the motor is attached directly to a dyno in a controlled test environment.

Tuners of modified cars are merely 10% of what those Engineers are. Don't be fooled by what shops will say/do... if they were to "tune" your car like a proper car manufacturer it would cost in the 10s of thousands -> 100s of thousands.

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Yes I know from first hand experience what Chequered tunes are like and never again. Comparing the tune I have now is like night and day (no lean spots, no cold start problems - just smooth).

Fact - my current tuner put in the time

In most things you get a better return the more you put in until it hits diminishing returns.

 

goodluck 

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On 2/13/2017 at 6:53 AM, Daz said:

Wow three cars in one day. 

 

My tuner spent three days on just my car.

 

you pay for what you get...

Normally I don't respond to stuff like this but since it's a direct attack on me I'll reply.

As an FYI - this was a full 10 hour day from 8AM to 6PM without lunch breaks. As soon as one car was off the dyno the next one was loaded straight up, I didn't take a break. In addition to this I had spent about a day to a day and a half on each car prior to the dyno checking for problems (boost leaks, setting up boost control ignition timing set correctly etc) as well as doing a road tune on each car with a wideband - I had a pretty good idea of what to expect for each car when they went on the dyno and also meant that dyno time was maximized - this was a straight out tuning session, not setup or troubleshooting.

Car #1 was an SR20 S15 Silvia on Nistune. The ignition map from the road tune was very close from the get go, however the car wasn't making the expected power. Dropping the exhaust with no other changes brought power straight up from 220rwkw to mid-240kw so I sent the owner home early, advised him to fix the exhaust along with a few small other problems and cut the price down accordingly. Yes, cruise mixtures were checked and adjusted.There were a couple of small problems with the tune after the fact, these were fixed with a further road tune after the dyno the following day at no charge.

Car #2 was an RB25-swapped S13 running a Megasquirt 3 ecu. This had a fair bit of time spent prior to the dyno setting up the base maps. In addition they have a very good autotune so I made use of this to help correct the cruise maps inbetween power runs and while adjusting ignition timing and setting up boost control. Should I mention this car was setup for flex at the same time and we tuned both P98 and E85 maps or does that not seem possible? Both fuel, spark and boost control was setup with full ethanol blending. I also did a follow up the next morning to check cold start on E85. This tune will need more work in the future as tuning was cut short as the car has a >4psi pressure drop across the cooler and IAT's were heading past 80 degrees. Current feedback from the owner is he is very happy, cold start and driveability is much better than the ecu it replaced.

Car #3 is Dan's HR and I am very familiar with the setup - their is over 80 power runs for this car logged on the dyno with various setups. I ended up spending a good 4-5 hours on the dyno the following day trying to troubleshoot problems. Yes, cruise fueling was checked.


For the record, both car #1 and #3 were tuned by a 'reputable' tuner and both owners complained of very poor driveability and economy and I was asked to retune - they are much happier with the current tune. It doesn't take 3 days to setup cruise mixtures - it takes about 20-30 minutes to get it 95% of the way there and then a bit of fine tuning to get it spot on. A tuner might need a car for 3 days to setup an aftermarket ecu from scratch for a comprehensive setup (for example, individual cylinder trims, flex, cold start, modern infinitely variable VCT and electronic throttle) but this is absolutely not the norm.


So yet another SAU thread that has been derailed. At the risk of putting it back on topic I'll post up some updates.

- Cam timing has been checked and the exhaust cam timing was about 7 degrees off (Dan may correct me as I am working from memory). Inlet was 1 deg off. Has been fixed.
- The rear housing was found to be far too small as it is a 12cm twin scroll. Back pressure was very high, a 16cm TS housing has been swapped on. Car now makes 20PSI on the road by 4K in lower gears vs past 5K on the dyno loaded up in 4th.
- Internal VCT feed wasn't supplying enough oil. The 30DET has been converted to external oil feed and VCT now makes a noticeable difference - I have pulled my own 30DET down to convert to external VCT for this reason.

We're aiming to get the car back on the dyno in early-mid March for a retune.

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Wow daz still acting like a fking legend putting shit on people yet never actually contributing any good information to the forum. Nice one champion.

On my 25/30 Neo I set the cam timing as per RB25 timing cover marks and i am almost certain that cam timing is out. It makes power super early but still doesn't drop off at 7krpm. I have been meaning to get my tuner to play with the cam timing but never got around to it and now I am selling the car.

FWIW. maybe some people are happy paying ~$1000 for a tune Daz and getting 90% of the 'factory driveablitly' that you like tugging your dick over without not having their car for 3 days.

Please elaborate more on Trent at chequered tuning please. He is one of the nicest and most knowledgeable people I have ever met. If you want to bash him you may as well put it out in the open and tell us what he did to hurt your feelings.

OP. Was your timing advanced or retarded? For info my car made 370kw on 20psi (25/30 Neo with standard RB30E bottom end and standard RB25 NEO head with standard cams and external VCT with Hypergear SS2 on E85)

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Im not going to bother responding to the shit talkers in this thread, clearly they have no idea and i could probably gain more information about my issue playing Need for speed than reading that garbage.

And yeah the Dyno day was savage, so it made it hard to get enthusiastic and start trouble shooting everything when we were both dehydrated and exhausted.

The Cam timing was as follows
Intake= 121  Factory =120 : Advanced by 1 deg.

Exhaust= 119 Factory = 117 :  advanced by 2 deg
So it was pretty well spot on, i didnt bother adjusting the intake as a little advance wont hurt it, exhaust i have now marked the 117 spot on the came and we can adjust from there.

I swapped out the turbine housing as stated above which has given gains at all RPM ranges ( yet to put it on the dyno to see how much)
And the VCT now activates with the external line fitted.

 

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8 hours ago, iruvyouskyrine said:

Wow daz still acting like a fking legend putting shit on people yet never actually contributing any good information to the forum. Nice one champion.

On my 25/30 Neo I set the cam timing as per RB25 timing cover marks and i am almost certain that cam timing is out. It makes power super early but still doesn't drop off at 7krpm. I have been meaning to get my tuner to play with the cam timing but never got around to it and now I am selling the car.

FWIW. maybe some people are happy paying ~$1000 for a tune Daz and getting 90% of the 'factory driveablitly' that you like tugging your dick over without not having their car for 3 days.

Please elaborate more on Trent at chequered tuning please. He is one of the nicest and most knowledgeable people I have ever met. If you want to bash him you may as well put it out in the open and tell us what he did to hurt your feelings.

OP. Was your timing advanced or retarded? For info my car made 370kw on 20psi (25/30 Neo with standard RB30E bottom end and standard RB25 NEO head with standard cams and external VCT with Hypergear SS2 on E85)

You are selling your car because it is a pos? :)

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