New Fuel - Engine Re-tune?

[2000delux]

Hi Guys,

Just after reading about matty's tuning problems - stoked he's almost there - I'm wondering (I'm pretty sure I will) if I will have to completely retune the engine if I am using different fuel with same nitro percentage, I realise I'll have to tinker a little due to oils used etc but should I take back to factory and start again or is this overkill??.
Also does anybody know anything about nitrowitch fuel?? Was pretty much all they had at LHS...

Cheers,
Delux.

 

[Rolex]

You might not have to change anything, as long as you're still using the same % of nitro.
It might just need a HSN tweak. No reason to start from scratch.

 

[2000delux]

Exactly what i wanted to hear - Thanks Rolex!!

 

[CharliesTheMan]

If it was me I would try to start it just like it is and see how it does and go from there. And then if I can't find a tune or its way off I might start from scratch, but not unless I had to. But I'm not all-knowing like Ralph is, not yet anyway

 

[2000delux]

Well it was pretty much good to go I had to richen it juuuust slightly to get her cranking but that could have been temps etc, got it going real well and started doing a couple of laps... Started actually getting around the track without hitting any walls (hahaha) and my cables slipped the zip tie and my rx battery wire got pulled so I had a F*&KING RUN AWAY, bent chassis like a banana (I'll try get a pic up) but only other thing damaged was the front bulkheads and even they are re-usable, everything else OK thankfully (not bad considering it went about 80K/ph into a concrete gutter)- either of you or anybody else that stops into this thread have a better way of securing wires?? I have already rebuilt it with a new chassis (should have held out for the 4mm but that means waiting) but am a little more than scared to run it now..

 

[joneser4u]

a failsafe and throttle return spring work wonders.

 

[2000delux]

Hmm it has throttle return spring but it didn't do much, it seems to push the servo out rather than close throttle if there is no power at all in the car (the idle screw etc is set correctly when power is on and the servo is at neutral but if no power carb opens about 1/3 - 1/2) does failsafe work even when there's no power to anything?? I know if your tx looses power (mine has alarms etc for voltage levels) they kick in but what if rx does?

 

[rckid91]

i believe when voltage gets low a failsfae returns all servos to nuetral or if you want i think you can program it to apply break dont quote me on this thou

 

[Rolex]

If you lose the signal, or the battery in either the Tx or Rx gets too low, the failsafe returns one servo to your programmed position. That would be throttle off, with brakes applied.
NEVER run without a failsafe.

 

[2000delux]

I won't be doing it again trust me I have one on order but would it have helped?? if my rx looses all power the brakes would still be applied?? Like I said the carb pushes the servo out (and opens throttle) unless there is power to the servo - it's like there is a spring in the slide which is stronger than an unpowered servo, as soon as servo has power it pushes this back in to the idle / 1mm opening... I have decent servo's (KO 2413 low pro for weight / low CG) but at a guess it wouldn't matter if they were the best there was as when there is no power..... there's no power.
Is there a way to either loosen or remove the spring (didn't even know there was one) in the slide?? It's not linkage etc it pushes it out with nothing attached

***Oh and Rolex (or anyone else with 'the knowledge') which failsafe would you recommend?? Price isn't an issue as this could have would up costing me hundreds...

 

[SublimeRevo]

I can tell you that Rolex recommended the dynamite failsafe when I asked about this a couple of months ago.

 

[Rolex]

I've always used the Dynamite but the Venom is equally dependable.
By the way, if you lose ALL battery power, such as the wire being pulled out, nothing will stop it other than the throttle return spring....or a wall.

 

[2000delux]

Heheee wall it was
I'll see if anybody in lil ol NZ carries either Dynamite or Venom - thanks guys. Also got told a cheap n nasty trick for the total power loss (which although is NEVER happening again I'm going to put in place) - just sling a rubber band around the carb onto the slide so it pulls throttle closed when no power is going to servo's - why didn't I think of that..? Will look tragic but I jus don't care if it saves my baby. :yes: