Author Topic: New member here with my slightly modified Continental GT 535  (Read 10648 times)

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derottone

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Reply #30 on: December 26, 2020, 08:52:27 am
Taurim, what seat is it you used for your project? It looks great.  :)

I'm also looking into half fairings, can't decide still if I like the looks of one or not but want one for the functionality. Kind of impossible decision to make.
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Taurim

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Reply #31 on: December 26, 2020, 11:34:01 am
It's a cheap no name eBay item you can easily find by searching for "Cafe Racer seat".
I think it suits really well the continental GT. It is larger and thicker than the stock seat and way more confortable.
It is not perfect as the base is not flat, il goes upward on the rear and does not follow the line of the bike. I will have to find another one with a flat base.

A French shop "Tendance Roadster" used to sell a nice retro looking half fairing but it looks like it's not available anymore : https://www.tendance-roadster.com/shop/index.php?id_product=41&controller=product&id_lang=1








oldphart

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Reply #32 on: December 26, 2020, 12:25:55 pm
Gee, that's a corker looking GT.
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derottone

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Reply #33 on: December 26, 2020, 01:06:25 pm
Gee, that's a corker looking GT.

Would ya prefer this fairing?  ???
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oldphart

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Reply #34 on: December 26, 2020, 01:37:26 pm
I've got a scooter besotted mate who would love it.
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ace.cafe

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Reply #35 on: December 26, 2020, 02:53:12 pm
Thanks gizzo  ;)

I did not talked about that because I forgot to take some pictures but I did some work on the exhaust header also.
As you saw it the exhaust port is enlarged at 35 mm. Then I machined a ring to receive the 41 mm header tube with 35 mm ID matching the port and 28 mm long (If I remember correctly).
Then I inserted a OD 38/ID 35 tube inside the header. All of this makes a constant matched 35 mm diameter from the head to approximately the position of the original lambda sensor (I reduces the bung protrusion inside the tube as much as possible).

Once again it probably adds almost nothing performance wise but it's nice to know it is looking clean inside ;D

I read the discussion here about sleeves and anti-reversion ;)

Did your AT work well ? What target AFR did you choose ? For me this map goes now from 14 for little openings/revs to 12.8 when WOT and high RPM.
I have yet to test it but you know, it's the winter this side of the globe  :'(

My observations:
That 35mm exhaust sleeve is helping more than you may recognize. It is a good mod.

The cam timing figures you quote are very different than any UCE cams we have seen in the US. They look like timing fron Iron Barrel model cams. Perhaps they changed cam timing on the newer GT than the ones we have seen. Also, the ideal stack length is definitely related to inlet cam timing, as Derottone indicated. I can't comment on which is right because I have not seen cam timing like you reported on a UCE up until this time.

Your 150 psi compression reading comes from the retarding of your inlet cam. With a squish chamber you can run as high as 185-190 psi cranking compression. I always use a higher compression piston when retarding the cam. You have plenty of room to boost compression there.

I have some concerns about reducing the overlap too much when retarding the inlet cam so far. Vizard talks about this, so since you read his stuff maybe you are familiar with the importance of the effects from exhaust extraction providing the most pull on the inlet mixture at any time during the inlet stroke, and the losses coming from losing it. However, if your cam retarded timing actually is as you report, the overlap should be fine in your case.

I think that since you are so concerned about trying to optimize a possible 3% potential stack inlet flow improvement, you might want to look at the other things that I mention above.

I think your bike looks very good, and that is the look that I wanted for my GT until it was stolen and not recovered.
 

« Last Edit: December 26, 2020, 03:06:02 pm by ace.cafe »
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Taurim

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Reply #36 on: December 26, 2020, 05:38:27 pm
Today the weather was not too bad with 5°C and almost no rain. So I did a little 60 Km ride to test everything...

There is absolutely no doubt about the fact that the ACE Airbox brings much wanted power.
There is not so much torque around 3500/4000 but from 4500 to 5500 the engine now flies when before it was totally dead  :)
I tried to push up to 6K RPM in 3rd and 4th but it useless. The engine loses all steam past 5.5K.
But it's so much better than before to feel the little engine galloping from 4500 RPM :D

And the speed ?... 150 kph at the GPS, almost 160 kph on the clock (almost !) at close to 5.5K RPM  ;D

A tourist photo  :) (and a pause to heat up my hands !)



Now some checks. The spark plug still looks OK ?



The velocity stack is still in place.



The look of the top of the piston (the picture quality is very bad). Intake up, exhaust down, spark plug on the right.



Now I check the map computed from the previous trims and today's trims. No adjust over the -/+20 limit I set so it is correct.



For gizzo, here is my Target AFR map and my ignition map :




(I forgot some values in the 20% column !)

Next steps will be the test of otto's velocity stack and next, hopefully, the installation of Hitchcocks performance cams !
Maybe I will try to have a dyno session before installing the cams...


derottone

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Reply #37 on: December 26, 2020, 07:01:51 pm
I can't stress enough how nice your bike looks.

I'm still very happy that I got the Euro 3 and not the 4. Air temperature sensor in the intake tract. That must be the cleanest bike on the surface of the planet earth. A whole lot more wires in total too as I can seen on your top down view building picture.
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Taurim

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Reply #38 on: December 26, 2020, 07:16:55 pm
Thank you  :)

I removed a lot of Euro 4 hardware and spent a lot of time reorganizing almost everything on the bike ;D

A photo taken at the end of today's ride. Please notice the ACE logo on the side panel  ;)



As a reminder here is the same bike when I bought it  ;)

« Last Edit: December 26, 2020, 07:22:40 pm by Taurim »


gizzo

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Reply #39 on: December 26, 2020, 09:53:29 pm
Thanks fit for the update. Love the tourist Pic! The GT with it's stock pipe sure looks frumpy compared with the after photo..

No way will mine do 160. Maybe 150 with a tailwind. When it was new it'd do 145. But took a lot longer to get there. Now it romps up to the same speed and hits a brick wall. That's ok, I got faster bikes too.

I used the same ebay seat on a build a few years ago. It's a good item, especially for the price.
« Last Edit: December 26, 2020, 09:56:09 pm by gizzo »
simon from south Australia
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Taurim

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Reply #40 on: December 26, 2020, 10:14:57 pm
With the Euro 4 emission limits the CGT hardly reach 130 to 135 kph on the clock ! Its so under powered they had to replace the Euro 3 18x36 final drive with a 17x36 ! Mine is back at 18x36 with a lighter chain (non O-Ring 5/8'' X 1/4' sold by H in place of the stock O-Ring 5/8'' X 3/8'').


derottone

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Reply #41 on: December 27, 2020, 09:23:03 am
As far as I remember the Euro 3 bikes didn't go any faster when stock, maybe only after replacement of the lead filled stove pipe which they call exhaust it could reach around 140kmh.
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Taurim

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Reply #42 on: December 27, 2020, 12:34:35 pm
The GPS speed for my stock Euro 4 was closer to 120 to 125 kph with a lot of vibration and a totally muted noise.
I only kept it in this configuration for... 2 days  ;D


derottone

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Reply #43 on: December 28, 2020, 05:45:34 pm
You may need the longer duration cam from H to rev the engine more than 5500rpm. I don't get to rev mine out to 6500rpm with the stock gearing. It doesn't go above 5800-6000 in 5th. So to take advantage of the last 500rpm it would take the fairing I think, but they all look fugly somehow.

And if the conditions are not ideal it gets stuck around 5500 too. Maybe a little shorter gearing could help as well.
« Last Edit: December 28, 2020, 06:05:17 pm by derottone »
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Taurim

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Reply #44 on: December 28, 2020, 06:25:27 pm
5800 to 6000 RPM is 163 to 168 kph (102 to 105 mph), this is more than my target  ;D
If it's not too difficult/long to reach the ton I will be more than happy with that level of performance  ;)
I'm also asking myself if installing a 34T rear sprocket may help to gain some kph...
Not sure if the available torque will permit it. With that ratio 5.5K RPM will be 164 kph. 42 Nm will be needed to reach that speed if my calculations are correct. That's a lot for the little engine at this high rpm...
(I will have to share my computations  ;) )

What is your engine tune derottone ?

If everything goes well I should receive a used (but never installed) Hitchcock's performance cam kit in the next few days  :)
(new cam kits are not available at the moment at Hitchcock's shop)