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4x4 SuperFinn Snailer
Joined: 18 Jul 2008 Posts: 47 Location: UK
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Posted: Sat Oct 11, 2008 12:43 am Post subject: Exhaust tuning and timing results (or +1.5hp the easy way) |
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A while ago I mentioned I'd tested exhausts and I finally got round to finding the results:
To gain 1.5 HP fit a forced air induction like the dyane has:
Then there is my car on standard exhaust and timing 28 BHp:
and with one of the full 2 in to 1 kits as sold by ECAS, and mentioned by Geoff and Bart and a little bit of tuning 33.9 BHp and a much better torque curve.
So you if you have a lacluster engine it is possible to gain 5HP without actually taking the engine apart. A bit of timing and exhaust work can gain a lot!
So no need to get your hands really dirty, a few bolt ons, and a quick tune and you are there... |
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Kustombart Tiki burner
Joined: 25 Jun 2007 Posts: 901 Location: Arnhem, Netherlands
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Posted: Sat Oct 11, 2008 3:49 pm Post subject: |
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BY fitting that exhaust, overall torque may have improved a few percent but the shape of the torque curve is much worse. You see that at low revs, the torque value is actually lower than the standard car.
I guess that's what you get with all tuning methods. You may raise max. power or torque but you almost always lose flexibility of the engine. Remember that you only get max power at maximum rpm. Torque values are a much better indicator of an engines performance. _________________ Don't ask me what I think of you 'cause I might not give the answer that you want me to.
www.kustombart.com |
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4x4 SuperFinn Snailer
Joined: 18 Jul 2008 Posts: 47 Location: UK
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Posted: Sat Oct 11, 2008 11:46 pm Post subject: |
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Kustombart wrote: | BY fitting that exhaust, overall torque may have improved a few percent but the shape of the torque curve is much worse. You see that at low revs, the torque value is actually lower than the standard car.
I guess that's what you get with all tuning methods. You may raise max. power or torque but you almost always lose flexibility of the engine. Remember that you only get max power at maximum rpm. Torque values are a much better indicator of an engines performance. |
Yes but the torque (and power) curve is much better from 3,300 RPM onwards which is where most of the 2CV engine does its work.
And yes torque values are important, but as these are higher than original in the working range I don't see any problem.
At 3000 RPM the 2CV engine is only producing around 15HP so if you weere finding loss of power/torque then changing down a gear would perhaps help
During on road testing with the different set up the 2CV could hold 4th gear on hills where before I had to change down so it definitely makes a noticeable difference.
Each to their own tho I suppose... |
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TONY ENGLAND Lowered
Joined: 09 Aug 2007 Posts: 742 Location: MALDON, ENGLAND, UK
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Posted: Sun Oct 12, 2008 12:31 am Post subject: |
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Hey Finn, the exhaust you talk of, does it fit with the heater boxes and do you think it would be worth fitting before i haul arse to CZECH next year?
I will have four people and probably a trailer as well so need all the help i can get.
Already got the forced ram air type thing and that made quite a bit of difference.
Would fitting a lightened flywheel and 123 ignition help in any way with this exhaust?
Any help would be well received - Cheers Tony. _________________ If it works ok, "LEAVE IT THE FUCK ALONE". |
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4x4 SuperFinn Snailer
Joined: 18 Jul 2008 Posts: 47 Location: UK
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Posted: Sun Oct 12, 2008 10:00 pm Post subject: |
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Tony,
The exhaust does fit the hear exchangers so you are OK there. There is a version that was built for the 2CV racers which fits directly onto the manifold but the graphs are for the heat exchanger version.
If its worth fitting is up to you. It provides more power and torque but does cost money. Saying that tho the power/torque is noticeable and as you say every little helps. It's probably worth getting the carb jetted properly to get full benefit of the exhaust tho.
I run a sealed 123 on my 2CV and have done for years. Again get the timing set on a rolling road at the same time as the carb tune and forget it is there.
A lightened flywheel does not give you any more power. It will help the engine spin up easier so you get quicker acceleration but you may have to raise the idle speed. However the flywheel stores a fair amount of energy and this can help on hills so if you are towing to Czech then I'd stick with the standard flywheel.
I did test a racing flywheel (and engine) on the 4x4 and on road it was an effort to keep the 2CV from wheelspinning at takeoff. The 2CV had to idle at around 1200 rpm and because there was not much inertia in the flywheel revs were required to keep it going.
One thing you may want to do if you are going 4 up and towing is lower your gearbox ratio. You'll only be towing at 50-60 anyway in mainland Europe and on slight inclines you'll be forever playing with 3rd and 4th gear. Lowering the ratios will mean you can stay in 4th for longer and also have a lower 1st for loaded hill starts.
If that sounds like too much work then you can always invest in a new set of rims and fit Smart front tyres as they are 15 inch but lower profile. (Bear in mind that the speedo will read incorrectly)
Hope this helps
SuperFinn... |
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TONY ENGLAND Lowered
Joined: 09 Aug 2007 Posts: 742 Location: MALDON, ENGLAND, UK
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Posted: Sun Oct 12, 2008 10:07 pm Post subject: |
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Thanks Finn for your words of help. I think i will leave the flywheel then but look at fitting ther bigger jets and 123ign. I'm going over in my fairly standard 2cv, (more head room than SCAR lol) which is a sweet runner but a little extra get up and go wont go a miss.
Thanks again - Tony . _________________ If it works ok, "LEAVE IT THE FUCK ALONE". |
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JoZeF Grave Digger
Joined: 25 May 2007 Posts: 1734
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Posted: Sun Oct 12, 2008 10:24 pm Post subject: |
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Pimslet has achieved very good results on his original 425cc AZ, with nothing other than fine adjustments and use of original parts.
I hope he will join in this thread.
Obviously the secret of good performance is a healthy engine adjusted to it's optimum settings.
Thanks for the dyno curves inputs on the mods you've tried, it's good to have real input, not "Joe Bloggs told me that..." kinda bullshit.
Much appreciated ! _________________ "That bumper fits there like sunglasses on pig" O.E.
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4x4 SuperFinn Snailer
Joined: 18 Jul 2008 Posts: 47 Location: UK
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Posted: Sun Oct 12, 2008 11:16 pm Post subject: |
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I quite agree, a healthy engine is always the starting point but what you want to achieve also affects what you do.
I drive a 4x4 2CV and so speed is of no great concern to me. What I wanted was torque as when going thru mud or on steep uphills the last thing I wanted to do was have to drop a gear or stop. A torquey engine was my aim and as a by product I also got a more powerful engine so I can't complain.
Sounds like Pimslet has a good 425cc AZ engine. Whatever you start with you can make a bit better but some just gave that edge.
Glad you like the dyno curves. It shows what worked for me. Obviously if you want speed or power in a certain rev range you would adjust your timing and a carb settings to suit but it at least shows that the exhaust does provide more power in the usable driving range. |
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4x4 SuperFinn Snailer
Joined: 18 Jul 2008 Posts: 47 Location: UK
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Posted: Sun Oct 12, 2008 11:25 pm Post subject: |
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TONY ENGLAND wrote: | Thanks Finn for your words of help. I think i will leave the flywheel then but look at fitting ther bigger jets and 123ign. I'm going over in my fairly standard 2cv, (more head room than SCAR lol) which is a sweet runner but a little extra get up and go wont go a miss.
Thanks again - Tony . |
Oh while I think of it a Harley coil is a good investment. None of this hot starting problem of coil overheating. On the way to a European meeting this year it was 30C and we were traveling 2 adults 2 children, trailer, roofrack 4 bikes, etc etc and no starting issues... |
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Harley Dropped
Joined: 26 Nov 2007 Posts: 394 Location: Braidwood - Australia
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Posted: Mon Oct 13, 2008 5:58 am Post subject: |
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4x4 SuperFinn wrote: |
Oh while I think of it a Harley coil is a good investment. |
Hey Superfin,
Could you post a pic or a link to the Harley coil... Is it this type Harley Coil?... They need to be 3 ohms correct? Do you know if they work with the early black 123ignition?
Cheers
Harley _________________ Check out my Dinosaur www.youtube.com/watch?v=RPF_uU61als
Spot my 2cv www.youtube.com/watch?v=Zoq68CPLq4M |
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4x4 SuperFinn Snailer
Joined: 18 Jul 2008 Posts: 47 Location: UK
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stefan Dropped
Joined: 25 Aug 2007 Posts: 257 Location: holland
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Posted: Mon Oct 13, 2008 10:43 pm Post subject: |
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whaha i heard stories that harley riders used 2cv coils becouse of there reliability, now i'm reading 2cv owners use harley coils that's funny _________________
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4x4 SuperFinn Snailer
Joined: 18 Jul 2008 Posts: 47 Location: UK
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Posted: Mon Oct 13, 2008 11:07 pm Post subject: |
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From experience I can only say that in Italy when it was 40+ the 2CV ran OK and the year after in Finland -25 the engine still ran.
Perhaps we 2CV drivers ask a lot more from our coils!! |
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Malte Lowered
Joined: 11 Dec 2007 Posts: 534 Location: Germany
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Posted: Tue Oct 14, 2008 9:11 am Post subject: |
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would be interesting to hear something about reliability of those coils and if it's useful.
don't want to blow off my money. :) _________________ in rust we trust... |
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Jasu Dropped
Joined: 30 Sep 2007 Posts: 211 Location: Finland
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Posted: Tue Oct 14, 2008 10:30 am Post subject: |
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I haven't any problems in my Harley's, with coils. Only problems what I have heard are with Taiwan-made parts... _________________ Make it today, tomorrow it's probably illegal... |
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