That's like saying I went 8.90...... once. The other guy went 9.0...... all day. Who's the better tuner? The problem here is comparing two very different cars. As a basher, there are better choices than either. Since they wouldn't race in the same class, you'd need to decide which class you'd rather race in. Should you intend to race.

Im gonna say it comes down to personal preferance. Doesnt matter what rc he chooses hell be happy and have loads of fun. But Mayhem Maniac you are wrong about the jato i was reading the traxxas forum and they speak often of their jatos in the late 50's its a straight line bullet. Its a bit iffy how you post your information based on rc videos. How ever dont get me wrong im not bashing on you like many others around here im just saying you can be a little wrong at times.

To be honest 300 is not really that bad on a small mill like the Jatos. Though Traxxas may be wild with their estimates, I believe they would have to prove it to print it on the box, Americans would just sue if it was a blatent lie, the trading standards in the UK would be all over them here, so I would say after having my XB8 lose in a 200m drag race against a Jato that 55Mph is possible, But nowhere do Traxxas say how the car was setup on these speed runs, was it overgeared, overlean or even catching a lift on the delivery truck?

Anyway MM your arguement may have a point here but both sides have vindicated their veiws in this one, so I say why don't you go and buy one, get it running (ROFL) and speed check it yourself. Then we will all be able to sleep in the knowledge that a grand master of rc has blown apart the myth of 55 Mph.

Here is another thought. How well was the engine run in on these cars that were reviewed in these magazines that the jato only hit 50. I have found that with my limited experience with nitro, that my motors tend to get faster and faster for about a the first gallon or two. Also what fuel where these mags using of the shelf 20% oil or a race blend with 12% or less fuel.

My thiughts are that the jatos that where reviewed in these mags were only doing 50 ild also think that you'ld quite easily get a 10% or more increase in top speed by running the motor and car in for longer then the mags do using different fuels and fine tunning those needles a bit more.

As for increased power by running lean, i recently had a bad experience with a dodgy fuel tank lid, my buggy was just lighting the wheels up comming out of corners at a bout 1/10th throttle and went passed some highend engines done the straight like they were standing still. i only did 2 laps before pulling it in the pits but that was enough to stretch the rod and ild be guessing that would have got me almost an extra 10 000rpm (i know it sure felt like it).

Yep, that could be the case Jeff and the most common sign of a dieing engine is a sudden jump in performance (but uncontrolable), so I wonder if they had the little 18 running on 30%? Well anyway the stretched rod would have increased your compression, advancing your timing and maybe this actually put your motor into it's optimum timing for the fuel you have ??? But if that is the case then I suggest removing a 0.1mm shim from the head, fit a new rod and see how it likes that.

it ran way quicker for those two laps and that motor has always been quick, when i say it ran lean i mean really lean i thought that the motor was a through away when i pulled of the track it just rev way hard then i've heard anything rev before that the straight also has too bumps in it which it doubled. My thoughts were that it stretched the rod when it over reved as opposed to it reving harder 'cause the rod was stretched, but either way i raced four other races that day and another race meet on that motor expecting it to stop any old second. It cooked the rear bearing at the same time so it was sounding real bad. I decided 'cause it was still running real good though sounding awful that i'ld replace the rod and the bearings and go from there (same piston and sleeve and it runns as good as new)

as for taking out a shim i'm thinking about it, but i'm running 30% in it and it still has lots of compression (when the motor is at temp and when cold) and i'm not looking for any more power out of it, so unless i'm advised that its not good for the motor i'll probably leave it as it is for now.

[8D]

Personally if your happy with it as it is, then stick with it, But with 30% I'd be tempted to actually FIT another 0.1mm shim, but as you haven't said which engine it is, I don't know the spec's for it and cant really say if it's needed for that mill/fuel combo.

But hey, maybe you just got a minor air leak, which is actually working in your favour atm. Over time though the engine could start to rev even higher, if so I would start to be worried about leaks. If it remains constant now then there is the chance that you've got it spot on and just routine maintenance is required to keep it going (ARO and cleaning of dirt).

Still enjoy it while it lasts and slap some Jatos.

its a vspec and it has the extra shim installed that came with the motor. It is running like a dream now and was also running like a dream before the mis hap with the fuel tank. Basically the lip decided that it didn't won't to close properly some of the time. And no adjusting of the "O" ring would fix it. Replaced the lid and it was all good. But in reality our back straight is actually one of the tricker parts of the track, due to the fact its not straight and has bumps that actually aim off the track, so even if i was only going 5 or 10% faster (which i'll say might just well have been the case) it sure felt insanley fast

..but this is way off topic and sort of missed the point of what i was trying to say, so i leave it at that

[8D]

Ah the same engine as me, so to me it sounds like you have the fabled front bearing leak. The rest is OK. Finished.

OK I hve just been out and seen a mate that owns a Jato, we measured out a 200m run up and then a 100m timing zone. We ran his Jato at WOT till it would go no faster, timed it between 100ms and guess what, 57Mph on the nose. So to me I believe Traxxas' estimate as I HAVE SEEN IT. But I forgot the Vid cam (as it's packed for CA) but next time we'll catch it on tape for you (Motopro, I'll also get in the pic so you can see the difference between me and Showtime).

I forgot to mention that this was done on a runway, uphill at a gradient of 2 degrees (NO GARDENING WAS INVOLVED).

I'd do the test on a larger space. 400-500 yards

If the timing was done with exact electronic equipment, then there is no need for a longer straight. But if it was taken by hand, then a longer straight would have minimized the influence from timing errors. And when considering that at 57 mph the vehicle travels 25 meters per second, the chance of error is rather big.

If it has reached terminal velocity, then it matters not how far the test distance is. We chose 100m for timing as we could easily see the 2 marks on the floor for clicking the stop watch. 400-500 yds (approx 1/4 mile) though your eyes may be binocular, to me it sounds too far. Remember you still have to CONTROL the Jato, and running it at WOT for that distance is not recommended.

But we did the run again last night, WITH A RADAR GUN. Finally we have some conclusive proof. 58.3Mph on the dial. The convinces me that Traxxas' claims are well founded. This was a totally stock Jato, engine is 3 Imp Galls old (approx 2 months), Tornado 20% and A3 plug.

So MM do you believe now?

Well done Grahama