Lateral Performance Hybrid Turbos
29 April 2003, 10:35 PM
#123
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John,
"What do you reckon I could get from my UK spec then?"
I guess that would depend on what you're using to measure the power with
Mark.
"What do you reckon I could get from my UK spec then?"
I guess that would depend on what you're using to measure the power with
Mark.
29 April 2003, 10:37 PM
#124
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I hope to be in the position where the engine is no longer the limiting factor.I hear that the Road Dyno seems to agree to PE within +-2% in tests.
However, it won't really be a UK car any more other than what it started as
[Edited by john banks - 4/29/2003 10:47:30 PM]
30 April 2003, 12:47 AM
#125
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"I hear that the Road Dyno seems to agree to PE within +-2% in tests."
Which means it could be up to 10% out with Well Lane, and up to XX% out depending on how good the info is, that's put into it.
It was very interesting at Elvington on Sunday. Cars were getting up to a second differences in their 1/4 mile times, and terminals were varying by up to 6mph through the day, I suspect due to ambient/track temps/weather conditions, and due to inconsistant driver technique.
Mark.
Which means it could be up to 10% out with Well Lane, and up to XX% out depending on how good the info is, that's put into it.
It was very interesting at Elvington on Sunday. Cars were getting up to a second differences in their 1/4 mile times, and terminals were varying by up to 6mph through the day, I suspect due to ambient/track temps/weather conditions, and due to inconsistant driver technique.
Mark.
30 April 2003, 01:42 AM
#126
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its getting a bit boring all the crap, claims about power output etc etc. The only real measure of engine power is on an engine dyno or next best a rototest hub drive rolling road, no slipping, there are one or two in the uk and one 4 wheel in Dublin. The wheels are removed and the hubs are bolted directly to the machine.
http://www.rototest.com/products/index.htm
you input the gear ratio it will give u at the flywheel figure u can also get at the wheels figure if u put in the wheel size.
http://www.rototest.com/products/index.htm
you input the gear ratio it will give u at the flywheel figure u can also get at the wheels figure if u put in the wheel size.
30 April 2003, 09:54 AM
#128
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There seem to be plenty of biases with engine dyno results too? Like fuel system, dyno exhausts, putting the intercooler in a real air stream in a real bumper, with real world loads?
If an engine dyno was that realistic why do you have to finish off the mapping of the car on the road?
Are you not just swapping one set of confounding variables for another?
If an engine dyno was that realistic why do you have to finish off the mapping of the car on the road?
Are you not just swapping one set of confounding variables for another?
30 April 2003, 10:37 AM
#129
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sorry john but I am not convinced by that logic.
the power meters estaimte/calculate power at a specific point in time, they don't emphatically tell you a car has xbhp all the time, they only indicate what it did when it was tested.
The same goes for a dyno, the only difference being that the figure you get is far more accurate. You dont have to use the road set up, infact it is often impractical since the exhaust system doesn't fit in the dyno room.
The power reading you get is reading as tested, no one is saying that the dyno readong is the same as what it gets on the road, only it shows what the engine has produced to an acceptable accuracy. No other measurement can give a reading to an acceptable accuracy because they arent calibrated against known measurable quantities.
The dyno isnt about power outputs, its about mapping. The map needs tweaking but there is no question it can be more accurately done on the dyno, and tweaking is far easier once you have a base map.
You question the difference made by the intercooler air flow, but equally, fans on a rolling road are never going to give the airflow that you get at 100mph on the road. Despite this, your figures are within 2% of PEs. The same logic you use to discount the dyno therefore discounts your own figures.
Personally I wish people paid less attention to figures, and were just happy with how they "feel" about the car. The numbers game seems to be purely about competition and one upman ship.
Look at rallying and formula one or even drag racing. How much glory goes to the most powerful cars. None. In those circles its success that counts.
I am not even convinced of the use of power output to confirm the improvement from a mod due to a lack of controlled conditions. But then a dyno can help there.
the power meters estaimte/calculate power at a specific point in time, they don't emphatically tell you a car has xbhp all the time, they only indicate what it did when it was tested.
The same goes for a dyno, the only difference being that the figure you get is far more accurate. You dont have to use the road set up, infact it is often impractical since the exhaust system doesn't fit in the dyno room.
The power reading you get is reading as tested, no one is saying that the dyno readong is the same as what it gets on the road, only it shows what the engine has produced to an acceptable accuracy. No other measurement can give a reading to an acceptable accuracy because they arent calibrated against known measurable quantities.
The dyno isnt about power outputs, its about mapping. The map needs tweaking but there is no question it can be more accurately done on the dyno, and tweaking is far easier once you have a base map.
You question the difference made by the intercooler air flow, but equally, fans on a rolling road are never going to give the airflow that you get at 100mph on the road. Despite this, your figures are within 2% of PEs. The same logic you use to discount the dyno therefore discounts your own figures.
Personally I wish people paid less attention to figures, and were just happy with how they "feel" about the car. The numbers game seems to be purely about competition and one upman ship.
Look at rallying and formula one or even drag racing. How much glory goes to the most powerful cars. None. In those circles its success that counts.
I am not even convinced of the use of power output to confirm the improvement from a mod due to a lack of controlled conditions. But then a dyno can help there.
30 April 2003, 11:13 AM
#130
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Just like different RRs give different results for the same car, the same applies to engine dynos.
When I was in Australia, I took my newly rebuilt modified Ford V8 engine to two different engine dynos. One was at Sam's Performance and the other was at Bakers. Sam's dyno showed 640hp and Bakers showed 560hp. This was with nothing changed on the engine. All engines that went to Sam's dyno always showed more power than Bakers. Both dynos were in controlled rooms with the same temps, barometric pressure, humidity etc.
Cars that had 500hp at Sam's were getting beaten by cars that had 420hp at Bakers down the quarter mile. I am talking of similar cars here, with similar weight, gearing, etc.
Bakers produced engine dynos and sold them to work shops. Sam had a brand name one.
It depends how they are calibrated I suppose. Also what is the correct formula used to measure horsepower? All these dynos give different results. Do all the dyno builders follow one standard, or do they all use their own recipe?
Cheers,
Wrexy.
[Edited by WREXY - 4/30/2003 11:16:47 AM]
When I was in Australia, I took my newly rebuilt modified Ford V8 engine to two different engine dynos. One was at Sam's Performance and the other was at Bakers. Sam's dyno showed 640hp and Bakers showed 560hp. This was with nothing changed on the engine. All engines that went to Sam's dyno always showed more power than Bakers. Both dynos were in controlled rooms with the same temps, barometric pressure, humidity etc.
Cars that had 500hp at Sam's were getting beaten by cars that had 420hp at Bakers down the quarter mile. I am talking of similar cars here, with similar weight, gearing, etc.
Bakers produced engine dynos and sold them to work shops. Sam had a brand name one.
It depends how they are calibrated I suppose. Also what is the correct formula used to measure horsepower? All these dynos give different results. Do all the dyno builders follow one standard, or do they all use their own recipe?
Cheers,
Wrexy.
[Edited by WREXY - 4/30/2003 11:16:47 AM]
30 April 2003, 11:55 AM
#131
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What's basically missing is a way for us to show who's got the biggest ***** 
F1/Rallying et all does this via the TV. We can't, so we use calculated figures which will always have an error.....and generate masses of forum traffic
Even if it's not accurate, I applaud something like DeltaDyno - at least it's as innacurate for all cars and gives a chance for comparison (given 'correct' input settings [what's 'correct' though]).
Interestingly, DeltaDyno and my AP22 have never been more than 4% apart on back to back testing. Given they use different technology to arrive at these figures, I was impressed.
Can't comment on rolling roads, my car doesn't go near them
Richard
F1/Rallying et all does this via the TV. We can't, so we use calculated figures which will always have an error.....and generate masses of forum traffic
Even if it's not accurate, I applaud something like DeltaDyno - at least it's as innacurate for all cars and gives a chance for comparison (given 'correct' input settings [what's 'correct' though]).
Interestingly, DeltaDyno and my AP22 have never been more than 4% apart on back to back testing. Given they use different technology to arrive at these figures, I was impressed.
Can't comment on rolling roads, my car doesn't go near them
Richard
30 April 2003, 11:58 AM
#132
Engine dynos are great, dyno time is cheaper than track time for a start. Can you imagine trying to test 3 different cams in an engine on the road? On a dyno you could change them in situ with relative ease, time them, adjust fuelling etc. On an inline 4 engine a rolling road would suffice in that situation
Abbey's chassis dyno is, I think, the best compromise, it's effectively an engine dyno that relies on the transmission. But in terms of taking the tyres and roller pitch out of the equation, it's very good.
Anyone that thinks that an engine dyno isn't prefferable probably hasn't used one.
Paul
Abbey's chassis dyno is, I think, the best compromise, it's effectively an engine dyno that relies on the transmission. But in terms of taking the tyres and roller pitch out of the equation, it's very good.
Anyone that thinks that an engine dyno isn't prefferable probably hasn't used one.
Paul
30 April 2003, 12:06 PM
#133
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I would have thought a 3d acceleromter would be quite accurate at measuring 0-60 times. If you input a viald number for the mass of the car, dont see why you couldnt get an accurate power figure.
Not so convinced when you have to start integrating once to get 0-100s and twice to get quarter mile times.
Not so convinced when you have to start integrating once to get 0-100s and twice to get quarter mile times.
30 April 2003, 12:12 PM
#134
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I agree with you all
No one is saying engine dynos are worthless, but neither are they irrefutable for power figures as George has so clearly exampled.
I like Dowser's summary about what's basically missing
I don't have the biggest *****, can't pi$$ the furthest, and I don't have an icecream in hell's chance of winning the power contest
No one is saying engine dynos are worthless, but neither are they irrefutable for power figures as George has so clearly exampled.
I like Dowser's summary about what's basically missing
I don't have the biggest *****, can't pi$$ the furthest, and I don't have an icecream in hell's chance of winning the power contest
30 April 2003, 12:45 PM
#136
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Agree with Pavlo,
Engine dynos are great. They are definately not worthless. They are great for tuning and to see what power you started with on the dyno and to see what gains or losses you have made with changes. They also give you the opportunity to change things quickly, ie easy access, by having the engine out of the car.
In my last post I was not suggesting they are worthless, as John picked up, just saying that you can't be certain you have the real horsepower thay claim you to have.
Cheers,
George.
Engine dynos are great. They are definately not worthless. They are great for tuning and to see what power you started with on the dyno and to see what gains or losses you have made with changes. They also give you the opportunity to change things quickly, ie easy access, by having the engine out of the car.
In my last post I was not suggesting they are worthless, as John picked up,
just saying that you can't be certain you have the real horsepower thay claim you to have. Cheers,
George.
30 April 2003, 01:39 PM
#138
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<Blush>
Engine dyno's can also give some odd results.
I've seen this, with my engine. We actually saw figures some 40ftlb more than we recorded, but the opperator explained that it was a spike, so we ignored it
An engine dyno is also able to hold the RPM, and boost, at a specific point for long enough to get a stable reading.
My engine has been run on two different dyno's, and the torque varied by 2 ftlbs, BHP by 2.2bhp.
Accurate, I've no idea, but bloody consistant !
As for tweeking the map back in the car, well, you can't really do the idle on the dyno, and yes, it may need tweeking for the whole exhaust, and boost control, depending on set up.
Mark.
Engine dyno's can also give some odd results.
I've seen this, with my engine. We actually saw figures some 40ftlb more than we recorded, but the opperator explained that it was a spike, so we ignored it
An engine dyno is also able to hold the RPM, and boost, at a specific point for long enough to get a stable reading.
My engine has been run on two different dyno's, and the torque varied by 2 ftlbs, BHP by 2.2bhp.
Accurate, I've no idea, but bloody consistant !
As for tweeking the map back in the car, well, you can't really do the idle on the dyno, and yes, it may need tweeking for the whole exhaust, and boost control, depending on set up.
Mark.
30 April 2003, 06:34 PM
#139
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Mark,
But doesn't holding load long enough to get a stable result render it innacurate for any given load point around max torque on the road?
I whizz through these load points in the real world, and would be scared about holding any single one above 1 bar and WOT for too long. Isn't this why cars OK on the road, det on the rollers; the run up time is long (along with the crap cooling, of course)?
It's a geniune question, I don't know the answer I just assume that a single power run on the road (lasting 10 or 15 seconds) introduces less thermal stress than doing the same on, at least, a rolling road lasting a lot longer.
Richard
But doesn't holding load long enough to get a stable result render it innacurate for any given load point around max torque on the road?
I whizz through these load points in the real world, and would be scared about holding any single one above 1 bar and WOT for too long. Isn't this why cars OK on the road, det on the rollers; the run up time is long (along with the crap cooling, of course)?
It's a geniune question, I don't know the answer
I just assume that a single power run on the road (lasting 10 or 15 seconds) introduces less thermal stress than doing the same on, at least, a rolling road lasting a lot longer.Richard
30 April 2003, 07:18 PM
#140
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Marks engine would be more likely to survive towing a caravan up a hill on a hot summers day on boost. This is part of the reason that OE maps occasionally seem to be conservative... they are mapped to survive some serious abuse.
01 May 2003, 04:56 PM
#142
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The optimum conditions for the engine to operate at during steady state rpm WOT on an engine dyno will be different from the settings used for say 1/4 mile use. A similar car tuned on the road for 1/4 mile will be quicker over this distance than any car tuned on a dyno.
As someone said earlier, do you want big numbers or a fast car ?
As someone said earlier, do you want big numbers or a fast car ?
02 May 2003, 02:37 AM
#147
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Andy,
Can you explain why a car tuned to get the maximum power out of each map zone, would be slower, than a car that isn't mapped to give maximum power in each zone ?
Mark.
Can you explain why a car tuned to get the maximum power out of each map zone, would be slower, than a car that isn't mapped to give maximum power in each zone ?
Mark.
02 May 2003, 12:14 PM
#148
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must admit I was confused by this too.
if you have the engine on the dyno and can make sure it is producing as much torque as possible at any given point for the conditions, then why would mapping it on the road make it quicker?
When mapping on the 1/4 mile and testing against the clock, there are far more inconsistencies, whereas on the dyno, the variables are far less, well, variable.
You may not get the same temps, and air flow, but if you optimise it for the conditions you do provide it, then why would for example providing warmer air, or moving quicker through a zone make the map less optimal.
if you have the engine on the dyno and can make sure it is producing as much torque as possible at any given point for the conditions, then why would mapping it on the road make it quicker?
When mapping on the 1/4 mile and testing against the clock, there are far more inconsistencies, whereas on the dyno, the variables are far less, well, variable.
You may not get the same temps, and air flow, but if you optimise it for the conditions you do provide it, then why would for example providing warmer air, or moving quicker through a zone make the map less optimal.
02 May 2003, 12:55 PM
#149
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Less likelihood of detonation (so more timing) if you quickly traverse a zone rather than hold it there (with artificially inflated load) and wait to see what torque you are going to get and then tweak it for MBT?
02 May 2003, 01:05 PM
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I'd suggest internal temps will be higher on the static mapped load zone, no? That's what I was (very badly) trying to explain above - I don't hold my peak torque load zone for very long, so I can run more advanced timing through it.
If I was holding the engine at that exact load point, I would expect the localised temps to (very) quickly rise; the timing would need to be adapted to suit.
Again, I'm happy to be told differently - but similar to Moray's "towing a caravan up a hill" analogy, I had a well used road map I took on a new track; there was one very long drifting RH corner which I quickly learned to nail in the 3rd gear with 'large' slip angles
It was great fun, so I drifted the corner for as long as I could - at one point it started detting. Returning to driving the corner rather than drifting (faster, but doesn't look so good!) fixed the issue. I figured the slipping was causing load points to be held for too long, allowing things to overheat....
Richard
If I was holding the engine at that exact load point, I would expect the localised temps to (very) quickly rise; the timing would need to be adapted to suit.
Again, I'm happy to be told differently - but similar to Moray's "towing a caravan up a hill" analogy, I had a well used road map I took on a new track; there was one very long drifting RH corner which I quickly learned to nail in the 3rd gear with 'large' slip angles
It was great fun, so I drifted the corner for as long as I could - at one point it started detting. Returning to driving the corner rather than drifting (faster, but doesn't look so good!) fixed the issue. I figured the slipping was causing load points to be held for too long, allowing things to overheat....
Richard