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Go Back   Madabout Kitcars Forum > Mad Build Area > Tribute Automotive Builds

Tribute Automotive Builds Discuss your Tribute kit build

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  #41  
Old 5th April 2016, 11:42
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  #42  
Old 5th April 2016, 11:51
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Quote:
Originally Posted by smash View Post
I can't believe Jaguartvr is talking total bollocks!

Stripes just introduce additional turbulence - everyone knows it's down to paint colour and black cars are always fastest!

Black is faster by keeping the air near the surface warmer, it reduces the viscosity of the air in the boundary layer. This reduces drag, like shaving your legs (oh come on - we all do it - don't we?).

This was confirmed to me by professor Pat Pending of the ACME Black Paint Company (the bit about air viscosity not leg shaving)
Don't talk crap....we don't all shave our legs (thats an Essex thing!) Just our heads and chest. Thats good for 2MPH
And another thing I told you not to reveal my real name
Pat
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  #43  
Old 5th April 2016, 12:02
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Default Dimples

Dimples are the future, nothing but a round-headed hammer, plenty of time and precision strikes to your body work needed for less drag and an added 11% fuel efficiency

Video here: https://www.youtube.com/watch?v=eR5SlwNf4K0

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  #44  
Old 5th April 2016, 12:28
WorldClassAccident WorldClassAccident is offline
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Forget speed stripes and dimples, it is the engine cover colour that matters



That red adds at least 15bhp of bragging maybe 20bmp when spotted through the engine vent
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  #45  
Old 5th April 2016, 19:19
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Quote:
Originally Posted by smash View Post
I can't believe Jaguartvr is talking total bollocks!

Stripes just introduce additional turbulence - everyone knows it's down to paint colour and black cars are always fastest!

Black is faster by keeping the air near the surface warmer, it reduces the viscosity of the air in the boundary layer. This reduces drag, like shaving your legs (oh come on - we all do it - don't we?).

This was confirmed to me by professor Pat Pending of the ACME Black Paint Company (the bit about air viscosity not leg shaving)
How come F1 Redbull have black cars but matt - I thought Black Gloss be best
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  #46  
Old 5th April 2016, 22:02
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My VW 1.4 TSi is black - when washed. And it is a beast !

(I'm going to keep saying it until I believe it at least)

I do have terrible wheel arches though. The wheels look silly - on the beast

Dave
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  #47  
Old 9th May 2016, 20:39
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Quote:
Originally Posted by Nubodi Automotive View Post
Sarcasm is definitely the lowest form of wit. As I stated my car went from 231 BHP to 259 BHP. When I went to school that made 28 BHP. Most remappers will GUARANTEE (or your money back) 10-15%. Perhaps you went to a different school?
28BHP is in the middle of this range. And not a throttle body or cam in the equation. I was fairly happy with this although not ecstatic.
In an earlier post, Richard claims that a gain of 30-40bhp in peak power is possible by remapping an otherwise standard, naturally aspirated BMW Z3. From personal experience he claims his 3 litre Z3 gained 28bhp rising from 231 to 259bhp. I don’t know why his car falls outside the full increase he reckons is available.

In my humble experience, this is not achievable and I stated this here at the time. For N/A motors I place it in the same camp as raiki, acupuncture, fortune telling and so on. It seems that many people put their belief in the fact that because a remap can achieve significant gains on supercharged motors (whether supercharged or turbine supercharged (ie turbo)) then a similar gain, naively, must be possible on naturally aspirated motors.

A number of reputable remap tuners state that a potential gain of 10-15bhp is possible on this motor. The very experienced Superchips claim a 14bhp gain, and it is worth noting that this is in the less useful rev range beyond maximum power - not an increase in maximum power as Richard’s tuner claims can be achieved. Up until maximum power, the Superchips increase is between 5 and 10bhp (my interpolation from a Superchips power plot).
I’ll use the term power throughout, as that’s what we’re discussing. In reality, we’re increasing engine torque – which is measurable, whereas power is a simple calculation.

So, let’s think of this logically. Returning to first principles, an internal combustion engine is a pump. Air is sucked in, mixed with the correct volume of fuel and exploded at the right moment, and gas is exhausted. Extra power can be gained by increasing the gas flow through the engine, increasing the amount of fuel being burned, or exploding it more effectively, or at a more optimum time. To burn more fuel, the volume of air will also need to be increased and this returns us to the fact that to increase power substantially we will need to increase gas flow. If we increased the volume of fuel and air into the engine then we should produce more power. It’s easy to increase the amount of fuel – a remap can do that, but to explode it to achieve maximise power we need a volume of air about 14 times larger – and that’s hard to suck into the engine without removing physical obstructions to air flow. A gain of 40bhp is an increase of around 17% - to achieve a similar increase we would need an engine size increase to around 3500cc. That’s a high expectation for a remap and realistically unobtainable. Next, we’ll discuss why.
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  #48  
Old 9th May 2016, 20:41
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Dealing with these things in order: first, gas flow. Maximum power is available at wide open throttle (WOT), because then the largest volume of air is allowed to enter the engine. There will be losses due to obstructions in the inlet or exhaust tracts, and because on a standard Z3 the cam train won't be engineered to flow air effectively if we increase the rev limit (which is why performance declines as we near the rev limit) but software changes in a remap won't alter these, so there's no gain here. At high revs and WOT the variable valve timing will be enhanced to its maximum so there's nothing to be gained here either. The only way to increase gas flow is to make a physical change(s) such as better flowing air filters and plenums, throttle bodies, intake or exhaust manifolds, ported heads, larger valves, high lift, different profile cams, etc. World Class Accident has made good progress here by swapping the inlet manifold, fitting a free-flow air filter with cold air feed (good use of a flowerpot), and fitted a straight through, free flow exhaust. A good next step would be to fit an M3 exhaust manifold. In other words, Nick is working to increase gas flow through his engine. His final step before spending huge sums of money would be to remap his ECU so fuel and ignition parameters exploited this additional gas flow.
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  #49  
Old 9th May 2016, 20:43
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What about fuelling? At WOT whilst the engine is under load, fuel will be injected perhaps 20% above stoichiometric to provide a level of cooling for protection and to stop detonation. This amount of richness will not liberate more power by being increased further. We'll return to this later when considering timing. Weakening the mixture risks detonation and serious damage so cannot be contemplated.
At lower engine speeds (at maximum torque or less) there will be the potential for torque gains by richening fuelling as the OEM setup will air towards economy. Looking at dyno plots by Superchips this can typically be up to 5%, but remember this is <4K revs, and therefore equate to around 5bhp on the Z3.
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  #50  
Old 9th May 2016, 20:45
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Ignition Timing:
The Z3 3litre has active detonation control – a knock sensor. The trick with these is to run the engine close to this limit without triggering the knock sensor, as doing so will retard the ignition. Hitting the trigger repeatedly increases the amount of retardation by increasing amounts so is to be avoided. Without running higher RON fuel or changing the combustion chamber design the trigger level will be the same. No gains here either, other than the combined effort that may be possible on some engines after peak power, already covered above.
Again, it may be possible to find 5% at lower revs. Let’s be generous and offer a potential 10% increase at 4k revs, or therebouts. That could provide up to the 15bhp bandied about by most remappers as being achievable on the Z3.

Excuses 1:
What about ‘other markets’ having shite fuel, often used as justification for gain. No gain here, as manufacturers map cars for their target market and whatever RON fuel is generally available. So a UK car will be mapped for 95RON. A custom remap should provide 2 or 3 bhp if you run on 99/100RON fuel and the car has active detonation control. But we’re not discussing that here.

Excuses 2:
If you read adverts by tuners, they use subjective terms like ‘lively’ and ‘spirited’, which mean little. A common way of achieving this is to over-fuel when you quickly mash the accelerator pedal to the floorboards. Power won’t be increased (it may actually decrease) but there will be an effect like an accelerator pump on a carburettor’d motor. If you’ve driven a car with correctly set up multi choke carbs (such as Weber, Dell’orto or Solex) you’ll have experienced that feeling of sharp throttle response that’s difficult to achieve with fuel injected motors. Only two manufacturers come to mind that have done this properly: Peugeot did it very well on the 1900 205gti and more recently, Alfa Romeo did it superbly on the wonderful Busso v6. It feels great, but no power gain though.

So we can gain a couple of bhp (though maximum gain probably won’t occur at peak revs) and make the car feel more spirited to drive. Only you can decide whether that’s worth hundreds of pounds.

For another discussion, is whether you should believe that an ordinary bloke with a laptop and a map altered by someone else in Italy (there’s a well-known Italian website selling maps for most cars for not many Euros) can really introduce benefits compared with a manufacturer with highly skilled and highly resourced staff.

I’ve not visited the forum much in the last weeks due to the same reasons expressed by others. I’m told that Richard has defended his claims, and I may address this later once and if I read all the posts.

But, you’re not going to gain 30-40 bhp on a Z3 by just a remap.
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  #51  
Old 9th May 2016, 21:41
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Over the years, I've had a number of people tell me that their car achieves a certain quarter-mile time or has shown a particular power output on a dyno.

When I have expressed mild scepticism, they have become aggressive and said things like "I bet you $100 it does".

My simple rejoinder has always been- "Show me the drag strip ticket (or before/after dyno readout) for which I don't need to pay you $100".

No-one has ever produced one...

As ever, I would be happy to be proved wrong on such a point and celebrate the performance with the owner.

Last edited by IanA; 9th May 2016 at 21:46..
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  #52  
Old 9th May 2016, 22:02
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Quote:
Originally Posted by y cymro View Post
Ignition Timing:
The Z3 3litre has active detonation control – a knock sensor. The trick with these is to run the engine close to this limit without triggering the knock sensor, as doing so will retard the ignition. Hitting the trigger repeatedly increases the amount of retardation by increasing amounts so is to be avoided. Without running higher RON fuel or changing the combustion chamber design the trigger level will be the same. No gains here either, other than the combined effort that may be possible on some engines after peak power, already covered above.
Again, it may be possible to find 5% at lower revs. Let’s be generous and offer a potential 10% increase at 4k revs, or therebouts. That could provide up to the 15bhp bandied about by most remappers as being achievable on the Z3.

Excuses 1:
What about ‘other markets’ having shite fuel, often used as justification for gain. No gain here, as manufacturers map cars for their target market and whatever RON fuel is generally available. So a UK car will be mapped for 95RON. A custom remap should provide 2 or 3 bhp if you run on 99/100RON fuel and the car has active detonation control. But we’re not discussing that here.

Excuses 2:
If you read adverts by tuners, they use subjective terms like ‘lively’ and ‘spirited’, which mean little. A common way of achieving this is to over-fuel when you quickly mash the accelerator pedal to the floorboards. Power won’t be increased (it may actually decrease) but there will be an effect like an accelerator pump on a carburettor’d motor. If you’ve driven a car with correctly set up multi choke carbs (such as Weber, Dell’orto or Solex) you’ll have experienced that feeling of sharp throttle response that’s difficult to achieve with fuel injected motors. Only two manufacturers come to mind that have done this properly: Peugeot did it very well on the 1900 205gti and more recently, Alfa Romeo did it superbly on the wonderful Busso v6. It feels great, but no power gain though.

So we can gain a couple of bhp (though maximum gain probably won’t occur at peak revs) and make the car feel more spirited to drive. Only you can decide whether that’s worth hundreds of pounds.

For another discussion, is whether you should believe that an ordinary bloke with a laptop and a map altered by someone else in Italy (there’s a well-known Italian website selling maps for most cars for not many Euros) can really introduce benefits compared with a manufacturer with highly skilled and highly resourced staff.

I’ve not visited the forum much in the last weeks due to the same reasons expressed by others. I’m told that Richard has defended his claims, and I may address this later once and if I read all the posts.

But, you’re not going to gain 30-40 bhp on a Z3 by just a remap.
There is a flaw in your argument, IMHO, you state a number of very logical reasons why remaps on naturally aspirated engines don't benefit from a remap.
But then you say 15bhp is achievable.

So if 15bhp is achievable, why isn't 28bhp?

Surely, either a remap gives nothing or "some" increase. The factors that determine "some" will depend on how the manufacturer set the engine up from the factory.

On a separate note, my 1925 Citroen only makes 11hp. Is there a chip that will mean I can go up hills without resorting to first gear?
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  #53  
Old 10th May 2016, 07:56
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Quote:
Originally Posted by landmannnn View Post
There is a flaw in your argument, IMHO, you state a number of very logical reasons why remaps on naturally aspirated engines don't benefit from a remap.
But then you say 15bhp is achievable.
No, if you read the posts again you'll see I explained why a tuner's claims of 15bhp could be achievable.

Quote:
Originally Posted by landmannnn View Post
So if 15bhp is achievable, why isn't 28bhp?
Surely, either a remap gives nothing or "some" increase. The factors that determine "some" will depend on how the manufacturer set the engine up from the factory.
Re-read the posts

Quote:
Originally Posted by landmannnn View Post
On a separate note, my 1925 Citroen only makes 11hp. Is there a chip that will mean I can go up hills without resorting to first gear?
Why not fit a Citroen v8 flat head from a wartime vehicle. Available with a gearbox for around £1k.
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  #54  
Old 10th May 2016, 20:12
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Quote:
Originally Posted by landmannnn View Post

On a separate note, my 1925 Citroen only makes 11hp. Is there a chip that will mean I can go up hills without resorting to first gear?
Yes Chip Foose

http://www.chipfoose.com/ws_display.asp?filter=Home
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