1/5th newb with a few questions...

[xjedix]

This probably belongs in the introduction section but I figured it would get a better discussion here.


I'm looking to get into the 1/5th scale stuff... been running 1/10th and 1/8th scale Redcats for awhile now, love em'. A buddy of mine that I bash/race with just took the plunge with an HPI Baja 5b 2.0 and the thing is an absolute blast. I used to work for a Go-Ped shop (Engine Trix) and these little motors really bring back memories.


Anyway I'm here looking for advice on building up an Redcat into a Baja killer. The track that we have been running is a baseball field with nice short grass, the track is a fast one with a long 75yd~ straightaway and some high speed turns. I know the Redcats are already at a disadvantage for this style racing with the weight and being 4wd but I'm a better driver than he is and I'm sure a little motor tinkering couldn't hurt.


With this track/ driving style in mind what model would you recommend, the Rampage TT or the Dune Runner?? I can't seem to find the info but does anyone know that actual weight difference between the TT and Dune Runner?? The HSP website shows them as being the same but I find that hard to believe with the Dune Runner having a 4" longer chassis. I much prefer the Dune Runner but if there is enough of a weight difference I would go with the TT.


Looking forward to your thoughts,


-Derek


Edit: since it's my first post and everyone likes pictures.... Here is one of my buddies 5b and my Backdraft 8E that I've currently been kickin his butt with.

 

[Obeast44]

Either model will be well suited for a little Baja-beatdown as long as its 4wd


I have personally never seen a dunerunner, all my experience is with a Rampage. Your are right about the track favoring the Baja, but you should be able to make up the difference with a little skill. Just get a good pipe and maybe a clutch spring to help the performance.

 

[hamster huey]

I have had 5bSS, 5t, Ramp MT, Ramp TT, and Dunerunner all started RTR and ended up hopped up. Its possible to keep 4wd AND be almost the same weight as a 2wd 5b/t:


http://www.redcatrampageforum.com/showthread.php?t=3857


You can make a apples to apples comparison if you remove the front wheel drive on the Ramp which will get them pretty close to the same weight or lighter if you do a P2W build. Its nice to have the option for either which HPI does not have.


In my opionion: the 4wd Ramp corners best, the 5b is harder to drive fast than the 5t even when they are both equipped with axle extenders, anything in 2wd has to be toned down a bit to make spinouts less, and the dunerunner is heavier than the TT and mine seems slightly slower than a similar equipped TT- all my opinion. If you havent heard there is an ultra lightweight Redcat 1/5 coming out that makes P2W look heavy.

 

[xjedix]

I've narrowed it down to two choices...


1. I could keep it on a somewhat even playing field and go with the Dune Runner since the size and chassis layout is so similar to the 5B. I'd run it with a HPI rear exit pipe and possibly run it as a RWD just for added throttle response and less drag on the motor on the top end. Or....


2. Go with the smaller TT chassis and run it 4wd with a side dominator pipe. See how it runs and convert to 2wd if the extra power is needed.


I'd really like to know the weight difference between the TT and Dune Runner. I can't seem to find the actual bone stock out of box weight for either of those. If the TT is considerably lighter then that's what I'll go with.


Anyone help out with some accurate weights??


D.

 

[racetruck]

If it was me i would go 4x4 all the way! do some reading on the forum i have a stock MT 23cc engine with a sprint modifed pipe and rob64n has a MT with a 28.5cc engine and with a jetpro pipe i can stay with his big bore! most of the power can be gained just by putting on a good pipe. as for the clutch spring i wouldn't go any more than 5000 stal i run the stock spring and it does great

 

[krashkrieg]

If it was me i would go 4x4 all the way! do some reading on the forum i have a stock MT 23cc engine with a sprint modifed pipe and rob64n has a MT with a 28.5cc engine and with a jetpro pipe i can stay with his big bore! most of the power can be gained just by putting on a good pipe. as for the clutch spring i wouldn't go any more than 5000 stal i run the stock spring and it does great

on a big bore 30.5 what is best spring to run? isn't stock 6000?

 

[racetruck]

I think most of them are 3000! tmr has a race spring that is a 5400 rpm and a 6000 plus a super high stall spring of 9500 i can't find the specs on the stock spring rob64n is running a 6000 from tmr it works ok I think the high stall is hard on the drive train and most cy engines top out at 10000 or 12000 rpm so your engine is toped out to fast. if your on a race track like large scale rc you can't use the low end and it is hard on the engines it makes the car hard to handle

 

[RampageHopUps]

The stock spring is 6,000.

 

[racetruck]

hey rob is that also the 23cc engines

 

[RampageHopUps]

As far as I know, all CY and HY come with a 6,000 as stock.

 

[krashkrieg]

As far as I know, all CY and HY come with a 6,000 as stock.

This is what I had heard when researching the HPI 8000 spring....


I will be installing a Big Bore ported stuffed 30.5...should I stick with the 8K spring I have in it or is it better to use the stock one (will I still hole shot with the 6K?) I heard DDM also has a 7500?


Also Racetruck I have heard that the stock CY engine can go to 14K RPM and a Ported one can even go higher....someone please jump in....

 

[racetruck]

the specs for the zenoah g230rc peaks out at 14,000 rpm and the torque peaks at 10,000

 

[xjedix]

Quick question about the TT vs Dune Runner....


I notice that the Dune Runner center dog bones coming off the center diff are put in at some odd angles. Is the TT chassis setup the same way or are they lined up with the front and rear diff?? Any issues with the Dune Runner because of this??


PS Poll added to first post.


D.

 

[Obeast44]

The Rampages driveline is straight as an arrow, and lined up with the F/R diffs. I havent heard any issues with them causing problems but I also don't read alot of the Dunerunner posts. Im pretty sure they are angled like that because they offset the motor to help bring the gearplate closer to the centerline.

 

[rob64n]

Ok first answer tt has straight driveline 4x4 dunerunner has 3 driveshafts that are in crazy angles so i think there would be an issue there. second if you keep wondering what to buy any longer the new xt will be out and it would be a no brainer to buy one of those if your stressing the weight issue. third issue concering engine clutch spring take your wife or moms car out hold it to the floor now drop it in gear, now you have a race car, but car didn't like that very much did it?

 

[rob64n]

So to clear things up, i am running a 7,000 rpm clutch spring and no it's not tmr the tmr springs are only for tmr's aluminum clutch shoes that is why they have such odd rpm numbers. so if you need more punch run a 7,000 rpm only or go to the eclon 4 shoe clutch and adjust you own rpm setting other than that i think your thinking to much and you should remember it's just a hobbie enjoy it,lol.

 

[krashkrieg]

So to clear things up, i am running a 7,000 rpm clutch spring and no it's not tmr the tmr springs are only for tmr's aluminum clutch shoes that is why they have such odd rpm numbers. so if you need more punch run a 7,000 rpm only or go to the eclon 4 shoe clutch and adjust you own rpm setting other than that i think your thinking to much and you should remember it's just a hobbie enjoy it,lol.

Yea, a hobby that some get enjoyment from obsession...


I am seeking too much knowledge?...I'm just looking for the right take off with a new engine coming without ripping apart my drive-train...I heard some things about using too high an RPM spring and wanted to try and clear it up...


I don't think you can compare a "Neutral drop" on a Corrolla or hundai to a race car ever...

 

[lightning73]

Am I the only one wondering why everyone shoots down the 8k spring for being overkill, but yet everytime in the same sentance recommends the 7500k spring or 7000k spring, I mean is there really that much of a difference in 500rpm there cant be, 1000rpm yeah maybe, it cant be such a huge difference that a 7000k is safe to use and an 8000k is gonna be all wrong right?

 

[lightning73]

Erased this message cause it was double posted!

 

[Obeast44]

Let me try and clear everything up


The stock 6k spring is just fine for everyday use and is generally alot easier on the driveline. No you wont get the power off the line, but its a more user friendly powerband. The DDM 7500 and HPI 8k springs will give you a lot better off the line punch and wheelspin, but is generally harder on the driveline. That I am sure everyone here knows.


But what Rob64n is trying to explain, I think, is its not really needed. Especially for what he needs, on track performance. The lower engagement point of the clutch will give a smoother pregression through the powerand in the corners. Which makes the chassis more predictable. A more predictable chassis means you can push the limits even farther, thus decreasing lap times. The 7500 and 8k springs make the lowend extremely snappy, because the motor is making more power at 8k rpms than the 6k rpm the other spring uses. If you do alot of braking and on/off throttle turning the 8k spring can making the car "jerky" feeling. I hope that helps, I tried explaining it the best I can (with a few beers in me )