063 pipe

[Jeep]

Just received my 063 ofna exhaust in the mail today

It's going on my hyper 7 with the Hobao Mach .28 engine, I installed it, but the weather prevented me from running it today. If the weather is decent tomorrow, I'll let you folks know how it did.
By the way, I saw where "nitrohouse" had a post on the Ofna forums in the "engine lounge" about this new engine and said he was checking combos for it(clutch springs, fuel, pipes) and would post results.

Jeep

 

[HeartBreak]

From what I've read, the clutch springs/shoes are best tuned for the track, and not the engine. I've been debating putting some heavier shoes on the clutch of my mugen, so it'll engage sooner.

 

[Jeep]

From what I've read, the clutch springs/shoes are best tuned for the track, and not the engine. I've been debating putting some heavier shoes on the clutch of my mugen, so it'll engage sooner.

I havn't even seen a track yet, but it makes perfect sense that you would tune the clutch springs for particular tracks, but I've also read in general that smaller engines like a tight spring setup to get more into the power band range before engagement, and larger engines can stand to run a looser spring setup due to having a bit more low-end torque.
Which engine are you running in your mugen?

Jeep

 

[HeartBreak]

the OS VZR-II Turbo. Course, it's still so pukingly rich that it is barely getting above idle with half a trigger pull. Once it gets leaned down, it'll most likely be a real snappy clutch.

 

[Jeep]

That is a .21 engine, right?

Jeep

 

[HeartBreak]

Yup, it's actually an on-road motor. The key difference between it and the counterpart VZ-B offroad motor is strictly port timing (and consequently, the power band). It has a little less torque, but a lot higher RPM band. It has more than enough snap to get the MBX5 Prospec up to speed with the stock gearing.

 

[Jeep]

Yup, it's actually an on-road motor. The key difference between it and the counterpart VZ-B offroad motor is strictly port timing (and consequently, the power band). It has a little less torque, but a lot higher RPM band. It has more than enough snap to get the MBX5 Prospec up to speed with the stock gearing.

I watched several on-road nitro racing vids online today, and the handling and speed is unreal to say the least! Almost never heard any low rpm running and even out of a turn, they were traveling so fast that the exhaust smoke almost immediately dissipated. Those engines were absolutely screaming!.

Jeep

 

[HeartBreak]

That's the key reason, coupled with an 063, the late-engaging clutch and possibly geared down a tooth. Onroad cars typically run a two speed transmission, so they can run an engine with less torque and a lot more RPM, where-as an offroad is single speed, and needs the torque to get up and go.

 

[Jeep]

That's the key reason, coupled with an 063, the late-engaging clutch and possibly geared down a tooth. Onroad cars typically run a two speed transmission, so they can run an engine with less torque and a lot more RPM, where-as an offroad is single speed, and needs the torque to get up and go.

Like I said many times,, I'm still very new to ALL of this, and what you just said about "2 speeds" reminded me of one of my first posts about 5-6 weeks ago.

I said something to the effect of deciding that I want a nitro buggy, I want it to be 4wd, and I want a 2-speed.
After reading many posts and any info I could find,,,,What an idiot I feel like now,,wanting a 2-speed buggy!
It's not only not needed, it's illegal at all racing tracks that I've read rules about,,lmao,,,hell I'm not even sure if a 1/8th buggy is available as a 2 speed ,,lmao


Jeep

 

[HeartBreak]

The older Ofna's actually had a two-speed option. I remember fitting one with a 2speed and a 4 stroke engine (when I worked for the LHS). It was slower than a 2stroke once it got going, but man, that thing was up to speed in nothing flat. Plus, it had a wicked engine note to it.

 

[Jeep]

I recently looked at alot of these engines and ran across some 4 strokes,, I can't even conceive the valve-train, and valve spings and keepers,,Geeezzz,,
I've worked on some very small 4 strokes, as in 50 cc or so, but a 3-6 cc 4 stroke to me is unreal! Especially when I think about the cam and the drive for the cam,,etc,,blows me away.
And how does the glowplug not cool down too much such that it can fire on the compression stroke, considering that it already "saw" an exhaust stroke which must have cooled it? Is it due to a very hot glowplug? or a higher nitro %? or both? how?


Jeep

 

[HeartBreak]

If memory serves right, it used a super-hot plug that was unique to the engine. I do know in aircraft 4-strokes that the engine has its' own ignition system, like the ones found on 1:1 car engines.

 

[Mr B]

The older Ofna's actually had a two-speed option.

The same is true for the Protech Ultrex Evo. Its a crappy car, but its basicly a 3 differential setup, with a gearbox upgrade. From what i can tell, the gearbox replaces the center diff, and it should be fairly easy to implement in "any" 1:8 buggy... The only real benefit i see is for those doing a truggy conversion. I dont trust plastic gears to start with.

Just thought ya might wanna know.
B!

 

[Plaidfish]

The only real benefit i see is for those doing a truggy conversion. I dont trust plastic gears to start with.

2 speed center diff is only good for road racing...they are too hard on the driveline when you land from a jump.....just an opinion here but they are way more trouble than they are worth...seen a few people do it and then go back to single speed in a few days...it's a novelty upgrade (like spinners and crome bumpers) and looses that allure very quickly......

 

[HeartBreak]

2 speed center diff is only good for road racing...they are too hard on the driveline when you land from a jump.....just an opinion here but they are way more trouble than they are worth...seen a few people do it and then go back to single speed in a few days...it's a novelty upgrade (like spinners and crome bumpers) and looses that allure very quickly......

Yup, I agree. The dude that had me install it for him (was working at the LHS at the time) wanted it just for show.

 

[Jeep]

After having learned alot more since having the buggy a little while and doing alot of studying and watching racing, I can't see at all any useful reason for a 2 speed. It seems they rarely even come close to top speed as it is, even on longer tracks, plus I don't see any acceleration problems with single speed gearing.
When I first thought that I wanted a 2-speed, I had highly underestimated the hp/pound that these things have


Jeep

 

[Plaidfish]

I think it just comes down to the clutch system used currently.....they really aren't capable of taking the ON/OFF abuse you give it constantly on a track....so it's just one more thing to break....besides the hadling characteristics go to crap......you loose the center adjustment so you have equal push as pull......sort of plows the steering and breaks loose alot easier than it should.....

 

[Jeep]

I think it just comes down to the clutch system used currently.....they really aren't capable of taking the ON/OFF abuse you give it constantly on a track....so it's just one more thing to break....besides the hadling characteristics go to crap......you loose the center adjustment so you have equal push as pull......sort of plows the steering and breaks loose alot easier than it should.....

And as little as I've run my buggy, something I REALLY like about it is it's lack of "pushing/plowing" the front end, I want it to lose a little acceleration and torque to regain front end pulling traction,,,It makes perfect sense to have a center diff now that I actually have a buggy and have operated it.

Jeep

 

[Plaidfish]

Yeah....i thought about doing it and kept getting told oone story or another from my LHS about them forgetting to order it or they were out of stock...I got the runaround for about a month until my friend just flat out told me they were not going to order it because they knew it was a waste....they were just trying to wait me out and see if I finally saw the down sides....well I didn't until actually seeing one run......I swapped buggies w/ the guy for a min and hated the steering.....I couldn't get on it since I didn't know the buggy and that stopped me from drifting it around turns.....I could see an oval racer using it but they could just put an ass stomper high gear on it and let it start slow anyway and keep the revs up highthe whole race.......point being they suck.....

Jeep are you saying you want to get more front pull than what you have now or more than a 2speed tranny will give???