The Naked Scientists

The Naked Scientists Forum

Author Topic: What does "more torque" do to a car's performance?  (Read 73955 times)

Offline Nizzle

  • Hero Member
  • *****
  • Posts: 964
  • Thanked: 1 times
  • Extropian by choice!
    • View Profile
    • Carnivorous Plants
Re: What does "more torque" do to a car's performance?
« Reply #25 on: 05/04/2012 06:44:59 »
They can't alter pressures or combustion chamber design without mechanically altering the combustion chambers. They might be able to do something with valve timing, but only if the engine has a mechanism to do that, so I think they can only be modifying the fuel/air ratio “map”.

You must be correct cause it seems you know what you're talking about :D
But I'm sure they can alter some pressures.. It must be the Turbo pressure then..
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #26 on: 05/04/2012 08:16:03 »
They can't alter pressures or combustion chamber design without mechanically altering the combustion chambers. They might be able to do something with valve timing, but only if the engine has a mechanism to do that, so I think they can only be modifying the fuel/air ratio “map”.

You must be correct cause it seems you know what you're talking about :D
But I'm sure they can alter some pressures.. It must be the Turbo pressure then..

I don't think they can control the pressure boost produced by the turbocharger directly. The boost pressure depends on the mass flow and temperature of the engine's exhaust gas which ultimately comes back to how much air is passing through the throttle that's controlled by your right foot   :D 
 

Offline peppercorn

  • Neilep Level Member
  • ******
  • Posts: 1466
    • View Profile
    • solar
Re: What does "more torque" do to a car's performance?
« Reply #27 on: 05/04/2012 13:17:51 »
ECUs on spark-ignition engines may be able to control some or all of:
- ignition timing
- fuel injection dose (air/fuel ratio) and timing of squirt(s)
- valve timing (CVVT)
- Throttle butterfly position (fly-by-wire, where ECU 'translates' pedal position)
- Exhaust gas recirculation (becoming more widespread on S.I. engines) ratio.
- Variable exhaust tract (usually high-performance only)
- Cooling (obviously!); thermostat, radiator-fan and occasionally water-pump speed.
- .... probably some others...

Many manufactures may 'lock-out' after-market changes to all but the most basic of these, but subtle adjustments to the maps for just the first three could make a major difference to economy and feel of the car.
 

Offline Nizzle

  • Hero Member
  • *****
  • Posts: 964
  • Thanked: 1 times
  • Extropian by choice!
    • View Profile
    • Carnivorous Plants
Re: What does "more torque" do to a car's performance?
« Reply #28 on: 10/04/2012 12:23:26 »
Many manufactures may 'lock-out' after-market changes to all but the most basic of these, but subtle adjustments to the maps for just the first three could make a major difference to economy and feel of the car.

Don't know if the 'lock-out' worked though, cause they did take out my ECU and used a soldering iron on it. Maybe they did that to bypass the lock-out to be able to change more parameters.
 

Offline peppercorn

  • Neilep Level Member
  • ******
  • Posts: 1466
    • View Profile
    • solar
Re: What does "more torque" do to a car's performance?
« Reply #29 on: 11/04/2012 00:14:32 »
Don't know if the 'lock-out' worked though, cause they did take out my ECU and used a soldering iron on it.
Wow! That future we dreamt of - we really are finally living in that future?! ;)

How's the post-mod mileage testing going BTW?
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #30 on: 11/04/2012 18:41:00 »
Don't know if the 'lock-out' worked though, cause they did take out my ECU and used a soldering iron on it. Maybe they did that to bypass the lock-out to be able to change more parameters.

Hope they didn't "dead bug" it.
 
(A dead bug is a chip that's glued on to the PCB upside down and hand soldered into the circuit with jumper wires.)
 

Offline syhprum

  • Neilep Level Member
  • ******
  • Posts: 3825
  • Thanked: 19 times
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #31 on: 11/04/2012 20:16:56 »
"Dead bug" what a wonderful idea with my shaky hands it is beyond my skills to fit some of the surface mounting chips in the proper way but I might just be able to manage this bodge up.
PS what happened to the forum this morning ?
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #32 on: 11/04/2012 20:24:10 »
PS what happened to the forum this morning ?

Dunno - maybe we overloaded the server with too many deep thoughts.
 

Offline syhprum

  • Neilep Level Member
  • ******
  • Posts: 3825
  • Thanked: 19 times
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #33 on: 11/04/2012 20:32:35 »
I have had my BMW for 10 years and did not realise until today how the variable valve timing worked! of course variable valve timing is not a new idea some 19th centaury cars used it.
« Last Edit: 12/04/2012 15:03:13 by syhprum »
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #34 on: 11/04/2012 20:50:09 »
I had a five banger Volvo that had variable timing, a turbo, and just about everything you can think of. After I spent an afternoon changing the plugs, I decided to get rid of it before it started to go wrong. (I traded it for a diesel tractor!)
 

Offline SeanB

  • Neilep Level Member
  • ******
  • Posts: 1118
  • Thanked: 3 times
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #35 on: 11/04/2012 20:53:46 »
Just be thankful you never had anything Italian then, or worse French. Lovely vehicles, but to service them.............

The Frogs seem to have a love of the following item - "Tool, Special".

 

Offline imatfaal

  • Neilep Level Member
  • ******
  • Posts: 2787
  • rouge moderator
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #36 on: 12/04/2012 09:12:07 »
Just be thankful you never had anything Italian then, or worse French. Lovely vehicles, but to service them.............

The Frogs seem to have a love of the following item - "Tool, Special".

And for the variant "Tool, Special (no longer in production)"
 

Offline SeanB

  • Neilep Level Member
  • ******
  • Posts: 1118
  • Thanked: 3 times
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #37 on: 12/04/2012 18:49:45 »
Friend of mine inherited an inventory of 100 odd pages, almost all "Tool, Special". He did eventually manage to figure out what they were and reduced it down to 15 pages of stuff he actually did use. Stores was not happy with the return of nearly 20 tons of assorted steel and such, they had to look after it then, so they scrapped the lot.
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #38 on: 12/04/2012 19:04:12 »
And sometimes "sans tool especial".
 
The big ends on my fabbby Citroen Ami were making a bit of a racket, so I went to the local dealer to buy new bearings.
 
Gzr: "How much for a set of bigend shells for my 602cc?"
 
Parts johnny: "Sorry - no can do."
 
Gzr: "What do you mean! Are you sying I won't be able to instal them myself?"
 
Parts johnny: "Yup. The bearings are one piece cylinders that are put on the crank before it is cryogenically assembled. I can sell you a complete crankshaft/conrod assembly for 350 quid."
 

Offline SeanB

  • Neilep Level Member
  • ******
  • Posts: 1118
  • Thanked: 3 times
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #39 on: 12/04/2012 21:10:30 »
Did they actualy have it in stock? Here it is almost always - Ex Factory ( 6 weeks).
 

Offline SeanB

  • Neilep Level Member
  • ******
  • Posts: 1118
  • Thanked: 3 times
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #40 on: 12/04/2012 21:14:21 »
And to add, "Tool, Special" often was a standard tool, just modified. A standard box spanner, with a ground down face, so as to fit a reduced thickness locknut as an example. Another, a standard flat blade screwdriver with a thinned down blade, to fit in a hole to turn a screw head recessed deeply in a machine.
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #41 on: 13/04/2012 00:20:36 »
Did they actualy have it in stock? Here it is almost always - Ex Factory ( 6 weeks).

I never really got that far because that was about as much as I paid for the car! (It was 35 years ago).
 

Offline Nizzle

  • Hero Member
  • *****
  • Posts: 964
  • Thanked: 1 times
  • Extropian by choice!
    • View Profile
    • Carnivorous Plants
Re: What does "more torque" do to a car's performance?
« Reply #42 on: 13/04/2012 13:29:45 »
How's the post-mod mileage testing going BTW?

First empty gas tank increased my range with 85Km until the "Go fill up light" came on, but I had considerably more traffic jam on my commute due to road works.
The tank I'm doing now might be more comparable due to more comparable traffic situation, and I have high hopes of getting more than 110Km extra range, which would be 10% of the total pre-chipping range.
 

Offline peppercorn

  • Neilep Level Member
  • ******
  • Posts: 1466
    • View Profile
    • solar
Re: What does "more torque" do to a car's performance?
« Reply #43 on: 14/04/2012 23:08:49 »
I have high hopes of getting more than 110Km extra range, which would be 10% of the total pre-chipping range

Thanks for the feedback.
I hope you're enjoying those extra torques that were promised!

Have you got as far as doing a rough calculation on what the payback period is for the cost of the 'chipping'? Not that it's all about the dosh necessarily, but it's nice to know.
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #44 on: 15/04/2012 05:44:19 »
I await the results with bated baited baytied
 
The results should be interesting.
 

Offline syhprum

  • Neilep Level Member
  • ******
  • Posts: 3825
  • Thanked: 19 times
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #45 on: 15/04/2012 11:55:03 »
Modifying the engine mapping sounds to me like a very dangerous procedure (financially) professional programmers are known to leave the occasional bug in programs let alone amateurs who do not have all the debugging facilities that the original engine mappers had.
 

Offline Nizzle

  • Hero Member
  • *****
  • Posts: 964
  • Thanked: 1 times
  • Extropian by choice!
    • View Profile
    • Carnivorous Plants
Re: What does "more torque" do to a car's performance?
« Reply #46 on: 16/04/2012 05:58:15 »
I have high hopes of getting more than 110Km extra range, which would be 10% of the total pre-chipping range

Thanks for the feedback.


I hope you're enjoying those extra torques that were promised!

Have you got as far as doing a rough calculation on what the payback period is for the cost of the 'chipping'? Not that it's all about the dosh necessarily, but it's nice to know.

Yes, the extra torques does provide extra driving pleasure :)
If, for the sake of easy calculations I assume a gain of 10% (which it's likely to become I've noticed), then let's see what the payback period is at current fuel prices:

Before chipping, I spent 85€ to fill up and drove ~1100Km pump to pump (~985 until "low fuel" light turns on, but then I still have 10L)
After chipping with an assumed 10% increase I will spend 85€ to drive ~1210Km pump to pump.
I annually drive ~44.000Km, so I save (44000/1100)-(44000/1210)= 40 - 36.36 (let's stay conservative and take 36.5) = 3.5 trips to the fuel station per year, or 297.5€
Chipping set me back 500€, so payback period is about 1.7 years under fixed fuel prices.

Modifying the engine mapping sounds to me like a very dangerous procedure (financially) professional programmers are known to leave the occasional bug in programs let alone amateurs who do not have all the debugging facilities that the original engine mappers had.

I've been given 3 years warranty on the engine, and 1 year on the gearbox. I'm thinking that if nothing goes wrong in that period, it won't go wrong after that period either? And I can always have it "rechipped" after 3 years just to get an extended warranty and still make profit :)
« Last Edit: 16/04/2012 07:53:55 by Nizzle »
 

Offline Nizzle

  • Hero Member
  • *****
  • Posts: 964
  • Thanked: 1 times
  • Extropian by choice!
    • View Profile
    • Carnivorous Plants
Re: What does "more torque" do to a car's performance?
« Reply #47 on: 08/05/2012 07:48:01 »
Hi guys,

I did another test with some very good results. I expected some fuel economy improvement, but not this much..
In Belgium, motorway speed limit is 120Km/h. Now I did a full tank with maximum speed 110Km/h on the meter (which is about 102Km/h in reality). This increased my range from pump to pump from ~1100Km to ~1450Km (!!)
I also noticed that it impacted my work-home commute time with less than 5 minutes, and I must admit, I'm driving with a lot less stress caused by "slow cars, get out of my way!" situations :)

I think I'll stick to my new max. speed from now on...
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
Re: What does "more torque" do to a car's performance?
« Reply #48 on: 08/05/2012 15:23:31 »
Are you saying you reduced your cruising speed? If so, that will have a large impact on fuel consumption because most of the power produced by the engine goes into overcoming drag, and drag is proportional to the air velocity cubed. Reducing your cruising speed by 20 km/h will save a lot of fuel.

On freeways, I tend to drive a few MPH less than the limit. It makes little difference to the journey time, and it's a lot less aggravating (for me anyway). I think I might invest in a trilby.
 

Offline peppercorn

  • Neilep Level Member
  • ******
  • Posts: 1466
    • View Profile
    • solar
Re: What does "more torque" do to a car's performance?
« Reply #49 on: 08/05/2012 21:11:18 »
Yes. Not wanting to lessen your good efforts, but it may be at least in part a little of improvement by placebo - ie. taking more care with your driving because you want good results...  trying to replicate how you drove before is the best test you can hope for but even then it's probably still going to be skewed subconsciously.
 

The Naked Scientists Forum

Re: What does "more torque" do to a car's performance?
« Reply #49 on: 08/05/2012 21:11:18 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums