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Old 25-10-2014, 05:27 PM   #161
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Dave Bush Racing

What has he actually done??? Raised the Rev limit!!! Added some more fuel!!! They havnt made a proper remap!!!

The biggest con is the "billet" flywheel, you'll just get your own FW back!!! That's not a billet ( that's 2kg heavier than mine) its cast stock FW!!! There Ali FW's that way about the same as my lightest one are around $2000 mine are £250!!!!

There not even solid Ali, there the stock cast one with the Middle machined out and a piece of Ali bolted to what's left!!!! Imagine if one or two of those nuts come loose!!!!

Ok so they add an air vent and move the air sensor, I use to race on flat days with a loose engine cowl and when it was rough one that sealed properly. Anyone can add an air vent!!!

Paul E the prop calculators are a guide and don't happen enough features to be fully accurate, there's to many variables as I have already pointed out!!
Have you ever seen a prop on a pitch gauge??? If a prop was 100% the same pitch all the way through then yes they would be more accurate, however a PROGRESSIVE PITCH PROP isn't!!!! So how can your calculator give a accurate reading for it??? A Repitched prop only has to have 1/3 to 1/2 of the blade area at the new pitch, what pitch is the rest of it??? How much cupping is 1" of extra pitch??? How much is 2" of extra pitch???
I have even offered to lend you props to go to Coniston with, if what I say didn't work I would hardly lend you the kit to prove me wrong would I!!!
You can argue until the cows come home why it does or doesn't work.

The only definitive way is to test it and see!!!! I fail to see how I can change the results of a test if I change the FW while the boats in the water!!! I have already offered to let the tester pick the run order on the day!!!

I have made it clear I only need to do 1 run with a lightened FW because the difference is so great and that you can spend the rest of the day trying to beat that run, I'm also happy to go last. It makes no difference, there's an absolute minimum of 3mph.
I can promise you I don't have covert scuba divers swapping props in the marina!!!!
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Old 25-10-2014, 06:12 PM   #162
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Quote:
Originally Posted by Banana Shark Dave View Post
What has he actually done??? Raised the Rev limit!!! Added some more fuel!!! They havnt made a proper remap!!!

The biggest con is the "billet" flywheel, you'll just get your own FW back!!! That's not a billet ( that's 2kg heavier than mine) its cast stock FW!!! There Ali FW's that way about the same as my lightest one are around $2000 mine are £250!!!!

There not even solid Ali, there the stock cast one with the Middle machined out and a piece of Ali bolted to what's left!!!! Imagine if one or two of those nuts come loose!!!!

Ok so they add an air vent and move the air sensor, I use to race on flat days with a loose engine cowl and when it was rough one that sealed properly. Anyone can add an air vent!!!

Paul E the prop calculators are a guide and don't happen enough features to be fully accurate, there's to many variables as I have already pointed out!!
Have you ever seen a prop on a pitch gauge??? If a prop was 100% the same pitch all the way through then yes they would be more accurate, however a PROGRESSIVE PITCH PROP isn't!!!! So how can your calculator give a accurate reading for it??? A Repitched prop only has to have 1/3 to 1/2 of the blade area at the new pitch, what pitch is the rest of it??? How much cupping is 1" of extra pitch??? How much is 2" of extra pitch???
I have even offered to lend you props to go to Coniston with, if what I say didn't work I would hardly lend you the kit to prove me wrong would I!!!
You can argue until the cows come home why it does or doesn't work.

The only definitive way is to test it and see!!!! I fail to see how I can change the results of a test if I change the FW while the boats in the water!!! I have already offered to let the tester pick the run order on the day!!!

I have made it clear I only need to do 1 run with a lightened FW because the difference is so great and that you can spend the rest of the day trying to beat that run, I'm also happy to go last. It makes no difference, there's an absolute minimum of 3mph.
I can promise you I don't have covert scuba divers swapping props in the marina!!!!
Dave, your offer of a prop for Coniston is very kind, however we've decided to stick with 3 bladers for top speed purposes and have a pretty large selection going up already. If you happen to go up and bring it with you we'd be happy to give it a run, but it's irrelevant to the flywheel discussion.

Have you seen a DBR flywheel? Tried their kit? More air + more fuel = more power, which equals more speed! It's pretty simple. The flywheel is an additional extra for improved acceleration. I very much doubt that DBR advertises billet flywheels then just send you back your steel one! The new air vent in the cowl is in the front, to end the problem that certain rigs have with the stock cowl of water ingress through the rear intake.

I'm not doubting you see speed gains from some of your propellers, however those gains would still be seen with a standard flywheel. Flywheels and propellers are separate entities.

Aside from the variable pitch thing (which I'm not disagreeing with), what other things do you think are wrong with a prop slip calc? Again it's irrelevant to the flywheel debate but I'm interested to know
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Old 25-10-2014, 07:00 PM   #163
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Has anyone been testing with dave yet?
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Old 25-10-2014, 07:55 PM   #164
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Has anyone been testing with dave yet?
What would be the point? Speed trials would be worthless unless it was done under controlled conditions. Tearing up and down somewhere like Southampton Water is pointless checking speeds on a gps as it doesn't take tides etc into consideration. Plus its ever so easy to fudge speeds if your trying to sell something.
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Old 25-10-2014, 10:18 PM   #165
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Paul E

Paul this whole thing started with me trying to buy a lighter, lightened FW from Simonsmotorsports. I have all the emails to prove, they sent me back a stock FW with a bit more taken off it as a "Billet FW" and charged me $500 plus shipping, plus import duty ect. It ended up costing the best part of £500. I have been told that the DBR "billet" FW's are the same by several sources!!!!

The Aliuminium ones are stock FW's, they machine the Center out and keep the piece that connects to the crank and they keep the outside edge with the stock ring gear and timing marks. They then use a piece of Aliuminium and bolt the Center to the outside. I have seen one of these and several lightened stock FW's and not one of them had any evidence of being balanced!!!! The manufactuer and I do the same, drill holes to balance!!!

Know one is CNC machining FW's from a Billet of metal so you can very much doubt what you like!!!!

Regarding the props I would have to show you with a pitch gauge and then perhaps you would understand why the prop calculator is only a reference and not a bible.

Ok testing I always use two different GPS systems Racefan ( I did some testing a few weeks ago, with one and ended up ditching the data as the iPad app was inaccurate). The speed difference between a fully lightened FW and I mean one of my 4516gram or even my 5221gram ones not a 6.5-7kg one from other sources. Is so great, your talking 3mph absolute total minimum, you can see it on the GPS and the Rev counter. Both of which on my Garmin chart plotter and Smart craft gauges store max speed and max rpm and can be resetted.

They tally up, you get an extra 4 mph and an extra xxx amount of revs as well and because it usually is 4/5mph I'm not bothered 1 or 2 runs max is enough on the lightened FW. You can spend the rest of the day running up and down, you won't get close to it. Or do it in reverse I don't care, run up and down all day, I'll swap the FW on the marina with the boat in the water and go out and beat your best time on my first run!!!! I'll even fill the tank up to the brim, a full 200 litres and still go faster!!!
You can run it anyway you like, but when your going 4mph faster and accelerating like a rocket it doesn't matter, the difference is to big!!!!
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Old 26-10-2014, 07:57 AM   #166
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Quote:
Originally Posted by racefan View Post
What would be the point? Speed trials would be worthless unless it was done under controlled conditions. Tearing up and down somewhere like Southampton Water is pointless checking speeds on a gps as it doesn't take tides etc into consideration. Plus its ever so easy to fudge speeds if your trying to sell something.
Theres plenty of places in the solent you can get a slack tide and be sheltered from wind for enough time to do a few test runs. I know it wouldnt be a1 testing conditions but surley it would show if there was a change in speed. If daves not driving and a couple of different gps devices are used the how can speeds fudged as you say. There must be more point to a test then going over the same stuff for 8 pages, if my back wasnt held together with metal bolts and rods id love to test this,
Please someone go and test this out so we can see some actual real life figures.
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Old 26-10-2014, 08:50 PM   #167
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Lightened Compressor Wheels

Well said Blackbeard!!!!!!

Ok moving on I have started lightening and Balancing Compressor wheels for the Mercury Optimax Engines!!!!

Stock Steel ones are around 1kg my Special Billet (these are billet as well) Aluminium ones weigh around 250grams.

If you want to see one send me a Friend request on FB. My names David Webber and my profile pic is me on my rib!!!!

So if you want to faster, give me a Shout!!!!!!
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