Just RR'd My 182... Why so bad???

[Mike-bham]

Just Come back from a weekend down south, and my Girlfriend's uncle work's in a tuning garage down there (re worx, portsmouth) so i thought i'd get my 182 on the Rolling Road, whilst I had the chance.

The results were a little dissapointing, but to be honest I did expect it for some reason.

The only mod on it is a K&N Panel Filter, and the end result was 163bhp at the flywheel (see pic below)

Any Idea why its missing almost 20bhp???

Ive got a Vid as well (just under 5mins but 65mb if someone can host it at all)

Cheers, Mike

 

[dk]

i wouldn't worry too much as cocopops had his RR'd with mine when we had just got them and mine got 184 and his got 15X and he was well disappointed but when we went out for a blast his accelerated as fast as mine so it must have been something else.

If you are really worried then get it tested at another centre.

 

[dk]

also depends on how they calculated the power at the flywheel, they might not have added the correct losses for the car and the conditions? Would have been better if you had another 182 there to compare it to.

 

[Mike-bham]

Well its equal in a stright line to my mates 172, which came up with 178 on the rr, so somethings not right, but my car's been running a bit funny lately, with quite poor mpg, and my oil suddenly dropped....

 

[dk]

plus, did they have any fans on the engine while doing it to keep it cool?

 

[dk]

mines been using a lot of oil recently and my mpg has also dropped, but i put that down to me driving like a loon, maybe its the weather at the moment?

 

[Mike-bham]

plus, did they have any fans on the engine while doing it to keep it cool?

Yeah had all fans on etc

 

[Rcbuk]

How many miles has it done, maybe it's not properly run in yet?

 

[Mike-bham]

about 18500 miles

 

[Fred@BTM]

could be anything, rolling roads are about as accurate as George Bush

 

[BenR]

because?

 

[Fred@BTM]

loads of ways to cheat, you never get the same reading twice (from one to another)

they should only be used IMO for before and after testing, then you know you have a certain %age gain

 

[BenR]

so the users honesty affects the accuracy of a measurement instrument?

 

[Ali]

who cares what bhp you run, it's the torque that counts!

 

[Andy GDI]

we saw a 182 at the last RR day with low power... drove perfectly..... tested it twice to be sure..... made about 160 bhp...... dont think the owner ever got the bottom of it either......

 

[BenR]

who cares what bhp you run, it's the torque that counts!

torques directly related to bhp, so i care.

 

[Bagus]

Before a few days we went to rr a friends 182 with 14500 km at the odometer....

He has only dropped a K&N panel filter at the induction and after the first rr he had his ecu remapped...

Here is the results...

Before 171,4 bhp 20,4 kg

After the remmap 181,5 bhp and 21,5 kg...

Nice curves though....

 

[GordonD]

Any rolling road that quotes horsepower figures that are the same as the manufacturer's figure for the car, and torque figures that look anything like the manufacturer's figures, is simply lying. They are not quoting what they're actually measuring ... they are massaging the numbers to massage the egos of their customers.

Dynos measure wheel horsepower. How much power the car puts to the road. That will necessarily be substantially less, probably by about a third, than the flywheel horsepower figure the manufacturer quotes.

You can use any rolling road to compare two different cars, or to compare before and after something was done to a particular car. But only dynos that are calibrated and that are quoting real figures can tell you what real horsepower you're getting.

 

[Ali]

torques directly related to bhp, so i care.

Granted...Tho engines can be tuned for grunt rather than straight line pace...As an engine builder i'm sure you'll be aware of this. Hence my comment for High Torque rather that high Bhp.

 

[BenR]

As an engine builder i understand that all we ever do is tune for torque with it being the actual forcable output of an engine. Just so happens that the more torque you build, the more bhp you naturally end up with. Thats my point, anybody who is tuning (proper) is always trying to build torque.

GordonD is quite correct, wheel bhp is wheel bhp. I'm not one for corrections and taking into account the smallest details. If it make 150bhp ATW's on a certain day, then thats the power it has, i wont quote for power on a sunny tuesday in florida. And he correct about calibration, if you have a direct crank output measuring device and can compare your RR against the dyno with the same engine but in a vehicle, then your pretty much straight on the way to knowing exactly what losses occur between a chassis and engine dyno.

 

[Ali]

As an engine builder i understand that all we ever do is tune for torque with it being the actual forcable output of an engine. Just so happens that the more torque you build, the more bhp you naturally end up with. Thats my point, anybody who is tuning (proper) is always trying to build torque.

GordonD is quite correct, wheel bhp is wheel bhp. I'm not one for corrections and taking into account the smallest details. If it make 150bhp ATW's on a certain day, then thats the power it has, i wont quote for power on a sunny tuesday in florida. And he correct about calibration, if you have a direct crank output measuring device and can compare your RR against the dyno with the same engine but in a vehicle, then your pretty much straight on the way to knowing exactly what losses occur between a chassis and engine dyno.

ok.

AWT figure on RR is useless too imo...We did a test on mine on the rollers and the AWT BHP in one gr was miles off the what it produced in another gr.

Crank output is the only reliable measure imo..Then again i'm not an engine builder, i'm only the driver.

 

[BenR]

ATW, not AWT

Depending on the type of dyno you were using, i would be more inclined to look at the setup and operator if two cars were miles off yet compared quite equally on the road.

And engine dynos have to be calibraed in exactly the same way as an eddy current (load hold), you measure the output of a torque moment on a load sensor, you dont actually measure any of the 'spinning'. You can make 20bhp just by sitting on the load sensor. And because both chassis and engine dynos use load sensors with set inputs for bhp conversions, you have a mathmatically set and perfect calculation to the amount of load which the torque arm should transfer onto the sensor.

You'd be surprised at the amount of tuners who couldnt give you any lessons on engine building/tuning.

 

[MarkM]

Ben as an engine builder your business is to provide your customers with a power increase for the work they are having done. To prove this I assume most of the time a rolling road will be used.

Without before and after on the same road on the same day are you saying the power increases can not be trusted.

I am not questioning your honesty or anybody elses but how can a customer be satisfied they get what they have paid for I assume they are in the hands of the person who has done the work?

 

[BenR]

certainly.

Justification of the VFM or the effectiveness of the modification/s is ultimately down to the owner.

My point is that changes in output between different days is only ever in the percentile range even if one is sunny and one is hailing. What we care about is air density, and even if ambient local pressure is down, you will have an lower air temp, which keeps offsets within a tiny percentage range. So as long as your on the same roller, your fine. I tend to trust the older rollers better. New rollers which rely on computers to calculate with a multitude of inputs and rolling losses etc etc invariably have alot more chance for 'mucking around' or accidental/mistaken altering of input factors. Old skool dynos measure wheel torque, apply one simple calculation and give you a bhp reading, thats it. Its like a scale it will always give the same value for the same item, your weight might change from one day to the next, but its only minute.

Trust is another issue, you know how fast your car was before and after. In some cases a before and after is impossible if people want all the work done in one day. In some cases a RR check before is pretty pointless as most of the cars do make the same power within a 10% range and 90% of that is within a 4-5% range.

And yes, the customer is in the hands of the tuner. So it is the customers work to do their homework and to feel comfotable with the tuner. Ask questions, and ask more questions, ask until your beyond satisfied. A good tuner will be happy to answer and explain any question, and if they cant, then you can be start to queery why they cant or wont. Vaugeness hides poor knowledge. And IMO, a good tuner will tell you where his abilities stop, why he doesnt do somethinge or why he cant do it, or isnt setup for it or just isnt his area of specialisation. And more importantly, will point you in the direction of someone who can help with that aspect of your queery.

 

[Ali]

ATW, not AWT

Depending on the type of dyno you were using, i would be more inclined to look at the setup and operator if two cars were miles off yet compared quite equally on the road.

And engine dynos have to be calibraed in exactly the same way as an eddy current (load hold), you measure the output of a torque moment on a load sensor, you dont actually measure any of the 'spinning'. You can make 20bhp just by sitting on the load sensor. And because both chassis and engine dynos use load sensors with set inputs for bhp conversions, you have a mathmatically set and perfect calculation to the amount of load which the torque arm should transfer onto the sensor.

You'd be surprised at the amount of tuners who couldnt give you any lessons on engine building/tuning.

Tomato, Tomato!! lol...Old man!

Sod all this engine stuff...Mine developed 171 as std...You choose any race track in the UK, regardless of what engine/chassis set-up your running and i'll be rite with ya....(Or in the distance) You have to be able to drive ist to utilise the performance.

What Ben's sayin is spot on tho, any drivers who's had him bum in the seat on various racetracks will be able to feel the difference. Paper means sweet FA to me, it's just assurance.

 

[MarkM]

certainly.

Justification of the VFM or the effectiveness of the modification/s is ultimately down to the owner.

My point is that changes in output between different days is only ever in the percentile range even if one is sunny and one is hailing. What we care about is air density, and even if ambient local pressure is down, you will have an lower air temp, which keeps offsets within a tiny percentage range. So as long as your on the same roller, your fine. I tend to trust the older rollers better. New rollers which rely on computers to calculate with a multitude of inputs and rolling losses etc etc invariably have alot more chance for 'mucking around' or accidental/mistaken altering of input factors. Old skool dynos measure wheel torque, apply one simple calculation and give you a bhp reading, thats it. Its like a scale it will always give the same value for the same item, your weight might change from one day to the next, but its only minute.

Trust is another issue, you know how fast your car was befo tuner. So it is the customers work to do their homework and to feel comfotable with the tuner. Ask questions, and ask more questions, ask until your beyond satisfied. A good tuner will be happy to answer and explain any question, and if they cant, then you can be start to queery why they cant or wont. Vaugeness hides poor knowledge. And IMO, a good tuner will tell you where his abilities stop, why he doesnt do somethinge or why he cant do it, or isnt setup for it or just isnt his area of specialisation. And more importantly, will point you in the direction of someone who can help with that aspect of your queery.

OK

PS why are you wasting time writing these essay length replies?
Shouldnt you be developing exhausts or new inlet manifolds or something

 

[Andy GDI]

yeah.... get on with it ben... i am watching

 

[Dash]

OK

PS why are you wasting time writing these essay length replies?
Shouldnt you be developing exhausts or new inlet manifolds or something

Yeah good paying customers waiting and all that.

Get your little honer out and get on with it .

 

[Mike-bham]

Just thought i'd add, here's the figures from the rolling road that my mate went on, its on a differant one, so as you lot said earlier, its difficult to compare.....

His came up with 179 at the fly, and mine with 163, but when we compared a while ago, there was absolutely nothing in it.

But since then, in the last few weeks, its been feeling slower, and he caught up with me no problem..... Looks like its a trip down to the stealers again for me! :dapprove:

Could it be anything to do with valve seals, or piston rings, as my oil level has dropped alot lately???

Mike

 

[izibizi]

how come the torque curve looks the same than afr curve between 4k-5.5k rpm? how would it change if afr gets corrected?

and howcome your car cuts out at 6.5k, is it cold!!!

 

[Mike-bham]

That one there is the one my mate had on his 172, and I didnt think the graph looked right either... but this is the first time ive ever been on a RR anyway, so i dont really know much!

 

[BenR]

OK

PS why are you wasting time writing these essay length replies?
Shouldnt you be developing exhausts or new inlet manifolds or something

Was waiting for my overalls to dry.

I peed in them.

 

[BenR]

yeah.... get on with it ben... i am watching

nothing new there then.

 

[Fred@BTM]

nothing new there then.

chuckle!!!

 

[Andy GDI]

oh soooo funny....

dont twist my own joke...

 

[JayGTT]

Rolling roads are a can of worms IMO i had my 172 tested when i first got it, it produced 175 bhp but more importantly 170 ft lb of torque theres no way that this is right, car only had a cat back on it.

 

[skinner]

Looking at the graph, it makes good Torque at 3000rpm, and about book at 5200rpm, but dies a bit after that.
So I'm not sure where that puts the fudge factor arguement - can the various "compensation factors" have more % effect at one rpm than another?

If not then I think there are 3 scenarios

The measurements are low and your car actually makes more torque than std.
The measurements are about right and your car is not performing at higher rpm.
The measurements are high and your car is running on 3 cylinders.