[Sankar]

I'd like to know whether the changed values after the resistor was put in improves performance.

I asked air870:

Originally Posted by Sankar

Does the readings translate to HP? If so how much?

Originally Posted by CPH

What is also misunderstood is that the dyno has got only limited use as we are not dealing with a real road condition situation. The dyno is for us designers only a tool to get into the right direction but does not give enough evidence on mods of this kind to prove them wrong or right.

The ultimate testing is on the road with a professional accelerometer of the likes of Vericom with about 800 reference points per run a lot of time and some fuel.

I suppose you too were talking about the resistor mods. Is the performance gains due to the resistor mod undetectable by a dyno? So the mod might or might not work?

Originally Posted by CPH

Stop being smart.

Not trying to be smart. Just asking since i want to know. See, i was of the belief that dyno should register the difference in performance.

[CPH]

Originally Posted by Sankar

Not trying to be smart. Just asking since i want to know. See, i was of the belief that dyno should register the difference in performance.

Was joking.

All rolling roads have got one problem around them, which is varying ambient conditions.

For this some people came up with the idea for a correction method and use a certain humidity, atmospheric pressure, air intake temp as the reference points.

When recently testing a K&N induction set-up on a Dyno Dynamics dyno (who pride themselves to be so good on their accuracy with correction etc) we had with increasing air intake temperatures the DIN corrected power increase over 2 minutes by 7% compared to the run made with the engine bay cooler (the engine was warm at this moment in time).

The actual output would be lower and with the temperature correction would be very close to the initial power. The air intake from K&N was running on this car for many months.

If the resistors are being taken off right now we have very little to compare if the car goes back to the rollers because we have even more to consider. The engine might be internally in a different situation (cocking up or burnt clean), the fuel batch is different, The tyres are not exactly in the same position and the angle of the car sitting slightly different, the tyres have a different wear rate, the scaling might be slightly different, the operator is in a different mood, which can affect the running up etc.

Give you another example: A guy came to have his Audi A3 TDI 150bhp mapped. Was running great. He then went to buy a pipercross carbon 'induction kit' He connected it to cold air feed. The car would go in first and second comparatively well. From third gear he lost power.

When he came to complain that the re-map was bad I told him to take the cold air feed off and drive the car. He came back and the car was much better in the higher gears.

The rr didn't show the problem.

We had cars with competitors induction kits on with and without cold air feed. The made good power on the dyno, but in reral terms were slower than standard losing top speed and acceleration.

This is why I test any of my development on the road and use the dyno only as a aid. I can read out results and directions from it, but better graphs have only limited real life value.

But I do not question the general value of a dyno. The tool has got to be used in the right way.

[headers]

Originally Posted by CPH

This is why I test any of my development on the road and use the dyno only as a aid. I can read out results and directions from it, but better graphs have only limited real life value.

But I do not question the general value of a dyno. The tool has got to be used in the right way.

Peter, I could'nt agree with you better on the above.

BTW, just a noob question. IMO fooling the ECU and getting in more fuel into the cylinder does not translate into more power. One needs to look at the intake, exhaust as well as the cylinder internals and make it breathe better to make more power.

As you had mentioned before, there are so many variables and we need to get a repeatability to ascertain the results estimated!

[CPH]

Originally Posted by headers

Peter, I couldn't agree with you better on the above.

BTW, just a noob question. IMO fooling the ECU and getting in more fuel into the cylinder does not translate into more power. One needs to look at the intake, exhaust as well as the cylinder internals and make it breathe better to make more power.

As you had mentioned before, there are so many variables and we need to get a repeatability to ascertain the results estimated!

Absolutely.

Getting more fuel in the combustion chamber might lead to over fueling. Even if it isn't to the point of being harmful it will reduce power fairly soon.

[GTO]

Originally Posted by pranavt

It is still a pity that the dyno is used as a tool to just get horsepower numbers than to actually tune cars.

Says who? One can use it for either purpose, is it not? I took my mildly modded Vtec there to know how many BHP she has at the wheels. Big deal, I can use a product or service anyway I want it as a legitimate customer. What's the pity in there?

The pricing structure does not allow you to tune a car on the dyno unless you're very rich as the payment is on the number of runs you do.

If you can spend 30 - 45 grand on a remap, I think you do have a certain level of disposable income. Fact is, most guys who tune their cars in India would fall under the "rich" category. IIRC, the first run is free, the second costs you 1,500 bucks. And if you are a regular, I'm pretty sure KS will run you a discount. Actually, I'm dead sure. I surely don't think its expensive when you're talking about remaps / other engine mods. The average modded C segment sedan has anywhere between 1.0 - 1.5 lakhs in mods & accessories (including exhausts, intakes, ICE, alloy wheels etc.). What's three grand odd to know just how your Mods are doing?

For the record, I've seen most places in the States charging $70 - 100 for 3 runs (KS' pricing = approx $66 for 3 runs). The cheapest was $40 for 3 runs, but they were more the exception rather than the rule.

Here's a tuner who has actually invested in a dyno and opened it up to anyone..even the regular Joe in a Santro. Lets give some credit where its due.

[pranavt]

Originally Posted by GTO

Says who? One can use it for either purpose, is it not? I took my mildly modded Vtec there to know how many BHP she has at the wheels. Big deal, I can use a product or service anyway I want it as a legitimate customer. What's the pity in there?

Each dyno will give a different reading. Even the same dyno will give variable readings on different days. A dynorun done on a summer day will not be as good as one done on a winter day. And showing off those numbers is akin to saying that mine is bigger than yours. If that's how you want it, your choice. Even your OHC wouldn't have given the same readings if it was taken for a dyno test a second time after a week or so.

If you can spend 30 - 45 grand on a remap, I think you do have a certain level of disposable income. Fact is, most guys who tune their cars in India would fall under the "rich" category. IIRC, the first run is free, the second costs you 1,500 bucks. And if you are a regular, I'm pretty sure KS will run you a discount. Actually, I'm dead sure. I surely don't think its expensive when you're talking about remaps / other engine mods. The average modded C segment sedan has anywhere between 1.0 - 1.5 lakhs in mods & accessories (including exhausts, intakes, ICE, alloy wheels etc.). What's three grand odd to know just how your Mods are doing?

For the record, I've seen most places in the States charging $70 - 100 for 3 runs (KS' pricing = approx $66 for 3 runs). The cheapest was $40 for 3 runs, but they were more the exception rather than the rule.

Here's a tuner who has actually invested in a dyno and opened it up to anyone..even the regular Joe in a Santro. Lets give some credit where its due.

If you're remapping after doing basic stuff like Intake or Exhaust, then what you say is true. For major mods like a turbocharger and especially ITBs, you require more a lot more than 3 runs to iron out all the problem areas in a fuel/ignition map, before you even get to tuning ignition timings to make more power. This is on top of the street tuning that is done for part-throttle driving and various other fuel/correction maps. Tuning ignition is a lot more critical than fuelling and it's essential that frequent runs are done on the dyno to make sure that there's no detonation. You can't just slap on 3 degrees of timing on a particular area of the map and expect it to work. By the time it's done, you've probably done 10-15 runs for a conservative tune. For serious projects, I wouldn't spend less than a few hours/days on the dyno to make sure that the map is completely perfect. Hence my proposal of leasing the dyno for X minutes/hours rather than number of runs.

If it's priced per number of runs, you just cannot use the dyno as a tuning tool unless you have deep pockets. And that's coming from a guy who has spent more than twice the value of the original car just on mods.

[viper]

Hence my proposal of leasing the dyno for X minutes/hours rather than number of runs.

If it's priced per number of runs, you just cannot use the dyno as a tuning tool unless you have deep pockets. And that's coming from a guy who has spent more than twice the value of the original car just on mods.[/quote]

Hi Pranav,

To the best of my knowledge KS offers something called a tuner special for someone who wants to tune his car on the roller. At least thats what he used to offer. IIRC he charges 10-12k for dyno tuning that was over a year ago. I'm sure his prices have reduced now going by the limited business he does on the dyno.

Speak to him you never know you might just get lucky with a good deal.

Viper

[GTO]

Originally Posted by pranavt

Each dyno will give a different reading. Even the same dyno will give variable readings on different days. A dynorun done on a summer day will not be as good as one done on a winter day.

Sure. But the difference won't be as wide as 50% right? Its not like a summer reading can be entirely disregarded. And for someone who is really concerned about numerical accuracy, go and dyno it three times for 3,000 bucks at different points in a year.

Even your OHC wouldn't have given the same readings if it was taken for a dyno test a second time after a week or so.

For all the talks of inaccuracy, fuel efficiency & 0 - 100 times also vary according to external conditions (including road, weather, driver skill etc.). Maybe we should stop calculating all parameters of a car altogether. I think we are going completely off-track. From discussing the purpose & charges of dynos, now we're discussing the accuracy! Technically sharp guys like you may care about 0.001 of the BHP rating. I don't! To a simple guy like me, it does NOT matter. It's a free market and I'm free to use a dyno in any way that I want to. Personally, I pat KS on the back for being the first Mumbai tuner (and amongst the first in the country) to invest in a dyno, and open it up to public use.

And showing off those numbers is akin to saying that mine is bigger than yours. If that's how you want it, your choice.

I'd appreciate your not putting words in my mouth, and certainly NOT assuming my intentions behind using a dyno. Why does it have to get competitive? My humble Vtec with barely an exhaust & intake is hardly "tuner" material. In fact, it is NOT capable of "mine is bigger than yours" discussions at all (I'll be the first to admit). I have repeated stated that its got "minimal modifications" and was more excited about the fact that she's retained her horses at 73,000 kms. My simple Vtec is puff cake compared to the many (way better) modified cars on the forum. Now, and again, where does this "mine is bigger than yours" syndrome come in? I can use the dyno, calculate my 0 - 100 times, my fuel efficiency or any other automotive parameter for my own personal benefit, can I not? Since you brought it up, the primary reasons behind Rehaan's Dyno thread were:

1. Education. An overwhelming majority of this forum didn't know exactly how a dyno works (including myself). The thread talks more about how a dyno works, rather than the Vtecs rating.

2. For fun.

3. To know just the state of a Honda engine after 73,000 kms of hard-driving. The compression tests and other methods of gauging its health were already performed. I just wanted to know the BHP rating for the kick of it! Its that simple.

4. To show my support for the first dyno in Mumbai.

If you're remapping after doing basic stuff like Intake or Exhaust, then what you say is true.

Like it or not, that's 90% of the modified cars out there!

For major mods like a turbocharger and especially ITBs, you require more a lot more than 3 runs to iron out all the problem areas in a fuel/ignition map, before you even get to tuning ignition timings to make more power. This is on top of the street tuning that is done for part-throttle driving and various other fuel/correction maps.

By the time it's done, you've probably done 10-15 runs for a conservative tune.

Major Mods = 3.0 lakh rupees? Cost of 10 runs = Rs. 10,000 (presuming discounts). You are entitled to your own views and how you want to spend your money. But personally, I don't agree with them. You spend 2 - 3 lakh rupees on major mods, and then whine about spending 10 grand on a dyno? That's like going for a bypass surgery at Asian Heart Institute and crying about shelling out for angiography!

Hence my proposal of leasing the dyno for X minutes/hours rather than number of runs. If it's priced per number of runs, you just cannot use the dyno as a tuning tool unless you have deep pockets. And that's coming from a guy who has spent more than twice the value of the original car just on mods.

Did you try asking KS Motorsports for the same? Or is this a presumption? Because, Vipers post clarifies that the KS dyno indeed offers custom packages for those (like yourself) looking at advanced solutions.

Originally Posted by viper

To the best of my knowledge KS offers something called a tuner special for someone who wants to tune his car on the roller. At least thats what he used to offer. IIRC he charges 10-12k for dyno tuning that was over a year ago. I'm sure his prices have reduced now going by the limited business he does on the dyno.

Thanks for the insight, Viper.

[pranavt]

Originally Posted by GTO

Sure. But the difference won't be as wide as 50% right? Its not like a summer reading can be entirely disregarded. And for someone who is really concerned about numerical accuracy, go and dyno it three times for 3,000 bucks at different points in a year.

The difference can be as much as 10-15%. The dyno he uses is a Land & Sea Dynomite. There are various other manufacturers that have other types of dynos. People have gone directly from one dyno to another one 2 blocks away and got a difference of 35-50 bhp on a car making around 400 bhp. That is why I was not concerned about the numbers. They're variable, and the only reliable dyno is the one that is run in a clean room directly off the engine. Numbers can be enhanced if the dyno operator wishes. The point about inaccuracy was to tell you that if there was a second dyno across the street, you would've got different numbers; and that they're inconclusive. I do not care about numbers anyways.

But if you did have a car that was extensively modified and you were remapping while on the dyno, a simple fuelling/ignition timing change would reflect immediately, if the variables were kept constant. That is all that matters to me.

Major Mods = 3.0 lakh rupees? Cost of 10 runs = Rs. 10,000 (presuming discounts). You are entitled to your own views and how you want to spend your money. But personally, I don't agree with them. You spend 2 - 3 lakh rupees on major mods, and then whine about spending 10 grand on a dyno? That's like going for a bypass surgery at Asian Heart Institute and crying about shelling out for angiography!

If 10 runs cost 10,000 Rupees, I will be heading there as soon as my car is done. It is nothing compared to what one gains when on the dyno. Rs. 3000 per run puts it at Rs. 45,000 for 15 runs which is prohibitively expensive. I understand the value of it, but I cannot afford it at that point.

Did you try asking KS Motorsports for the same? Or is this a presumption? Because, Vipers post clarifies that the KS dyno indeed offers custom packages for those (like yourself) looking at advanced solutions.

It is based on what he has/had put up on his website. There is no mention of custom packages on it.

[CPH]

Both of you have got their point.

But I think we have got a bit of a misunderstanding here.

To start with, I would like to say that KS has taken a big gamble for installing the Land and Sea.

I have worked most likely more hours on a Land and Sea than KS so far and know the problems of using it quite well. Unfortunately I have seen KS operating their dyno and must say the way it is operated leaves room for a lot of error.

For us as developers/designers it is important to make sure that the variables are as little as possible, which requires a lot of experience and skill. You can learn how to operate a dyno in a day, but won't necessarily get any credible results.

What seems to be the most misunderstood point when it comes to dynos is that the bhp figures give you any clue of the tuning state of the engine. BHP figures can't be measured and peak bhp figures are just meaningless.

What propels the car is the torque delivery throughout the rpm range.

Just to give an example: On an equivalent European model to the Palio 1.2 I designed an AIR (or CAI), which had barely a peak power increase of 5%, but the acceleration time was cut down by 14% (best run out of ten before and best out of 10 after. Average was about 12%).

This is not possible with just 5% more peak power. The gain came from torque delivery and even more so from the bottom end delivery.

To measure the bottom end torque correctly you need to be very precise in the setting up and need to run up the engine in a very constant fashion as other wise the rollers interprete the the signals wrongly. This is where practise differs from theory.

But even the suggested torque graph differences did not explain 14% reduction in acceleration.

Also setting up a car after major mods would mean to spend on average about 2 days on the dyno using the eddie current to the full. On many cars an added problem is the fact that the ECUs can't be live mapped.

This is where Pranav's point of view is coming in. The dyno is just a tool and it can't be read too much into dyno readings.

But nowhere it is being claimed that it is useless.

[kutlee]

As far as my experience goes, the Dyno ( I did hub dyno - dynometer) figures are bit clinical. The clinical since it doesn't operate on the road. But as i compared stock vtecs done on the same dyno, my figures were good. But Dyno offered a good chance to get know what is what. Again worthless for a comparison. Almost all dyno shops offer custom packages if you have extensive tuning sessions.

[CPH]

Originally Posted by kutlee

As far as my experience goes, the Dyno ( I did hub dyno - dynometer) figures are bit clinical. The clinical since it doesn't operate on the road. But as i compared stock vtecs done on the same dyno, my figures were good. But Dyno offered a good chance to get know what is what. Again worthless for a comparison. Almost all dyno shops offer custom packages if you have extensive tuning sessions.

Very good post in general. Just wouldn't go as far as claiming they are useless for comparison. You have to take everything with a pinch of salt

[kutlee]

why i said worthless since the difference is figures is meaningless. The way the car feels and responds is (as a matter of fact) is huge. I gave the car to the person who did the dyno and came back with shaking hands. for really experience hands figures might be meaningful and might be able to guess the car's performance.

[GTO]

Originally Posted by pranavt

The point about inaccuracy was to tell you that if there was a second dyno across the street, you would've got different numbers; and that they're inconclusive. I do not care about numbers anyways.

Well, we will just have to wait for another tuner to take the initiative in Mumbai then, right? Until proven otherwise, I'll give KS Motorsports the benefit of doubt.

But if you did have a car that was extensively modified and you were remapping while on the dyno, a simple fuelling/ignition timing change would reflect immediately, if the variables were kept constant. That is all that matters to me.

Good news is, the opportunity is there and waiting for ya!

If 10 runs cost 10,000 Rupees, I will be heading there as soon as my car is done. It is nothing compared to what one gains when on the dyno. Rs. 3000 per run puts it at Rs. 45,000 for 15 runs which is prohibitively expensive. I understand the value of it, but I cannot afford it at that point.

From his website, 10 runs will cost you 13,500. A 25 - 30% discount for so many runs should be easy peasy. Look forward to your dyno report

[air870]

The reason I went asross to KS was for the Torque spread ,[ref CHP s post] , but was distracted by the BHP numbers as my other car is a GTX and was conditioned to concentrate on only the BHP.I however dont feel alone in this respect as a few replies also focused on the 140BHP figure. The TQ quitely went unnoticed. With ref to the Thead, has anyone tried duplicating my Mod and felt the difference [ or are you not convinced by the ease and afforadbility of installing and uninstalling this mod ] {This is specific to the 1.9Tdi }. I would sure like to know if people other than me feel that ' IT WORKS'. A testamonial will swing it either way.