tt40 or st46 with a Jett stream?

tt40 or st46 with a Jett stream?
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tt40 or st46 with a Jett stream? - 6/14/2007 3:32:42 PM

Capn America

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From: Holiday City, OH, USA
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Bob,

We are getting ready for our first club pylon event here. rules are base on 424 with the options to run a different muffler and up to a .46.

I have a viper set up with a tt40 and a super tiger .46 lying around. It was apperent after practice last night I need more power to keep from getting lapped.

I need to order up a Jett stream today and wante to know what you thought of the 2 motor possibilities, stay with the tt40 or go to the st46, dont really see myself ordering one for each at this point...

The rules outlawed my Jett 46 already with the retail price limit so Im looking for suggestions.

Also do you know what sealant is used in the jett tanks? Im repairing one and silicone does not seem to be very fuel proof.

Thanks

Post #: 1

RE: tt40 or st46 with a Jett stream? - 6/14/2007 4:32:46 PM

bob27s

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From: Cleveland, OH, USA
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quote:

ORIGINAL: Capn America

Bob,

We are getting ready for our first club pylon event here. rules are base on 424 with the options to run a different muffler and up to a .46.

I have a viper set up with a tt40 and a super tiger .46 lying around. It was apperent after practice last night I need more power to keep from getting lapped.

I need to order up a Jett stream today and wante to know what you thought of the 2 motor possibilities, stay with the tt40 or go to the st46, dont really see myself ordering one for each at this point...

The rules outlawed my Jett 46 already with the retail price limit so Im looking for suggestions.

Also do you know what sealant is used in the jett tanks? Im repairing one and silicone does not seem to be very fuel proof.

Thanks

You must have some tough competition. What are other guys flying ?

Usually a Q-500 with a TT40 is pretty quick (110 mph range) when set up for 424. stock muffler and a 9x6 prop. Set up this way, the TT40 should turn between 16,300 and 16,500 on the ground.

If you are not seeing at least 16K from your TT40.... you are at a loss. Can sometimes be fixed with some bench running with a clipped 9x6 prop or an 8" prop .... let the engine scream up around 17,500 for a tank or two... then go back to the full 9x6.

You may want to check with Dub on the muffler..... he has been running about a week on parts deliveries.

If you are allowed to used the tuned muffler......

I would go with the TT40 ---- the TT40 and 46 love the Jett-stream. Instant 1200 rpm increase from what ever the engine is turning now. You would want to us a 9x6, 9x7 or maybe a 8.75x8 prop.

You want to keep the rpm pretty much as I noted above --- ground peak just under 17,000 rpm... down no lower than 16,000 rpm. Find peak (what ever it ends up being), back off on the needle 500 rpm --- fly it.

Set up like this, you should see 110-120 mph on the race course easily.

As for the fuel tank..... I do not recall there being sealant in there, other than a very thin film of adheasive around where the stopper is pressed in. Dub may be putting a tiny bit of GOOP or RTV silicone on the vent/pressure tube. The tanks are generally not repairable if the bladder breaks or the stopper area is damaged. If the vent tube is the issue, that one is easy... just stuff it back into the hole... it is a tight fit, and there will be no fuel to leak out anyway.

Parting thought....

Racing is not always won by the fastest airplane. You have to fly smooth, stay on the course, not make any sudden control inputs. Every time you hit the elevator or ailerons it is like putting on the brakes. Practice is the main key. A reliable and consistant aircraft/engine is the other key. You will see many folks ruin their chances trying to get an extra 100rpm and end up with a lean flight...... others will set up the plane way too sensitive and it will be all over the sky... stay consistant, stay smooth... and practice.

Bob Brassell

< Message edited by bob27s -- 6/14/2007 4:37:38 PM >

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RE: tt40 or st46 with a Jett stream? - 6/14/2007 4:37:10 PM

bob27s

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One thing I forgot.......

if you have the ST46.......... you can get in the air a bit quicker.

you can use the Jett muffler you already have on that. The muffler bolt pattern should be the same. Just that the bolts will be too big --------- (you would have to drill the case for the 6/32 bolts)

But I dont think its going to turn up quite like the TT40 pro - might ----- only way to know is to try.
Same prop ----- 9x6 or 9x7

Bob

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RE: tt40 or st46 with a Jett stream? - 6/14/2007 5:49:44 PM

Capn America

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From: Holiday City, OH, USA
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the fastest thing there is an evolution 46 on an ultrathrust, lapped most 3-4 times in 10 laps and seriously pulling away in the straights...

Forgot my tach last nite, but the tt was running well, only took 15 feet to get in the air off the grass.

I'll try to give Dub a call today, thanks

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RE: tt40 or st46 with a Jett stream? - 6/22/2007 4:56:12 PM

Capn America

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From: Holiday City, OH, USA
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Got it sorted out, the tt with the racing muffler is turning 17600 with an 8.75 x 7 and the st with the same prop is turning 18900 peak, looks like ill use the st and bump up to a 9x7 maybe.

Thanks for the info on the st using the same muffler as the jett, that made all the differance in the way the ST runs.

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RE: tt40 or st46 with a Jett stream? - 6/22/2007 5:42:46 PM

bob27s

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Wow.....

yeah, the ST engines are usually pretty good....... but that one is kicking some but

Which ST engine is it ? They made a few different versions of the 45/46 engines.

Bob

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RE: tt40 or st46 with a Jett stream? - 6/22/2007 6:10:38 PM

Capn America

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Im not really sure, its an older ST I got on a profile plane I bought. I use it for Open C combat once in a great while... I milled the spray bar last nite to thin it up and get a little more air to it, seemed to help. First club race is Sunday, we shall see how it goes.

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RE: tt40 or st46 with a Jett stream? - 6/22/2007 6:13:57 PM

bob27s

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good luck ! go fast... turn left

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RE: tt40 or st46 with a Jett stream? - 6/22/2007 6:36:02 PM

Capn America

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Looked at the case when I loaded it in the truck, it has a big "G" on the case with an "S" inside it.

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RE: tt40 or st46 with a Jett stream? - 7/6/2007 2:41:42 PM

bob27s

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Just wondering ....... how did the event go ? Did you end up running the ST ?

Bob

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RE: tt40 or st46 with a Jett stream? - 7/8/2007 3:49:35 PM

Capn America

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I did run the st in the end, it pulled the 8.75 X 7 prop much better than theTT. Ended up loaning the tt to another racer that day who lost his tt to a bearing failure. I finished 3rd, the evolution 46 was still faster down the straights and ended up 2nd another ST took first using a sport 9x7 apc and about the same rpm, better turns and a bunch more speed, the tt was about the 4th-5th fastest thing there but did not finish that high.

We are getting ready for RC combat at Nats this week, then we will do some more tuning and get ready for a late summer pylon event back home. It was a good time and one plane lasted me all day, unlike combat

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RE: tt40 or st46 with a Jett stream? - 10/5/2007 2:47:12 PM

Capn America

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Trying pylon a second time this saturday, the ST lost a rod during tuning wed nite so I swapped to the old jett45 I had lying around, WOW!

It definatly needs more prop, 8.75X 7 N apc seemed to be turning to easy, thinking maybe a 9x7 sport or even 9x8. What prop in a 9" variety do most run on a sport jett 45 with the red pipe? recomended rpm range?

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RE: tt40 or st46 with a Jett stream? - 10/5/2007 5:42:39 PM

bob27s

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Prop it to run over 17,000 on the ground. Back off 800 for the flight. RPM is a good thing. Don't think its over-revving.

APC 9x7 is good, perhaps a 9x8 if it gets over 16,500 at ground peak.

If you can find a 8.75x8W use that.

the 7N is probably turning up nicely..... might be worth staying with that if the engine likes it.... at least to start with.

If its on a Q-500, any of the above are fair game.

Is this a SJ-46? Dub only made a .40 and a .46

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RE: tt40 or st46 with a Jett stream? - 10/9/2007 12:29:42 PM

Capn America

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the 8.75x7N was really turning but it would blow the plug A8 with that on it. Its a cast case jett, I thought it was stamped 45 but i will look again tonight. turns out it needs rebuilt, I picked it up on the net and the crank and bearings are rusty and noisy, probably why it was blowing the plug.

thanks for the info bob

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