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Old 01-28-2006, 09:30 AM   #181
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Quote:
Originally Posted by asar
The GPX-4 is more comparable to the MTX-4 as far as the fuel tank and battery lay-out, but the GPX-4 has lower CG.

The MTX-4 has beter balance, smoother drivetrain and a fast free-wheel even off-throtle. However, it is also more difficult to get a good set-up and has a tendency to oversteer (loose rear end) after 12 to 15 mins of run during race finals.

GPX-4 may be a fraction of a second slower on the inside but more consistent even on 30-45 runs. It's also easier to set-up. Runs at par when drive train belt loosening fixes are made. Cheaper parts is just a bonus.
Good explaination in the differnce between both cars.
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Old 01-28-2006, 12:56 PM   #182
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Hi all, would like to know what wt rating of diff oil you guys are using for the GPX4? Thanks in advanced.
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Old 01-28-2006, 08:15 PM   #183
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Asar, this is an awesome practical explanation on the difference between the two. Now I know exactly on what merits to compare the two against when I make my decision.

Thanks so much!


Quote:
Originally Posted by asar
The GPX-4 is more comparable to the MTX-4 as far as the fuel tank and battery lay-out, but the GPX-4 has lower CG.

The MTX-4 has beter balance, smoother drivetrain and a fast free-wheel even off-throtle. However, it is also more difficult to get a good set-up and has a tendency to oversteer (loose rear end) after 12 to 15 mins of run during race finals.

GPX-4 may be a fraction of a second slower on the inside but more consistent even on 30-45 runs. It's also easier to set-up. Runs at par when drive train belt loosening fixes are made. Cheaper parts is just a bonus.
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Old 01-28-2006, 08:20 PM   #184
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Quote:
Originally Posted by NoobRC
Hi all, would like to know what wt rating of diff oil you guys are using for the GPX4? Thanks in advanced.
Start with 30,000.
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Old 01-28-2006, 08:42 PM   #185
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How about actual experience on the durability of this car? I heard the MTX4 is a veritable tank...definitely a big plus. Is the HoBao far behind?

How about weight?

Cheers to all!
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Old 01-29-2006, 02:07 AM   #186
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hey all,i like the look of this car alot would this car with os tz12 be competitive in the nitro touring class with a half decent driver how often do you guys go through tires.when i raced i could use a pair of GQ foams for like 2+ race meets and practice.how much do tire truers go for?does anyone know where i can get a review on this car i like it alot?
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Old 01-29-2006, 04:58 AM   #187
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Actually, one big advantage of the GPX-4 is durability. It is THE TANK.

MTX-4 has two weak points:
1. The carbon fiber rear shock and body mount breaks.
2. The chasis bends on hard impact due to a weak point on the chasis middle area where the battery hole and two screw holes on both sides are located.

But I am sure Mugen Seiki will address these weak points with hop-ups or upcoming Prospec version.

Quote:
Originally Posted by Hammer0412
How about actual experience on the durability of this car? I heard the MTX4 is a veritable tank...definitely a big plus. Is the HoBao far behind?

How about weight?

Cheers to all!
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Old 01-29-2006, 05:08 AM   #188
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weak point of chasis is where the 2 battery cover screws are located with 2 other screw holes.
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Old 01-29-2006, 05:17 AM   #189
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Default Rear mounts

When bumped hard from behind or hard impact flip over the rear carbon fiber shock and body mounts breaks.
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Old 01-29-2006, 05:26 AM   #190
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Asar, you have been a wealth of input! I no longer have any apprehensions of saving a few coins and purchasing the GPX4 Pro.

I'm sure a lot of people interested in this car are also learning a lot from you and the other veritable fountains of information on this thread.

Kudos to you and regards to all!
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Old 01-29-2006, 06:55 AM   #191
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Quote:
Originally Posted by NoobRC
Hi all, would like to know what wt rating of diff oil you guys are using for the GPX4? Thanks in advanced.
hi im using 30,000WT for the rear diff anf 100,000 for the front. im going to rebuld my rear diff in a few days and will put 10,000WT in it.
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Old 01-29-2006, 08:59 AM   #192
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Quote:
Originally Posted by mykel chua
hi im using 30,000WT for the rear diff anf 100,000 for the front. im going to rebuld my rear diff in a few days and will put 10,000WT in it.
Hi, i'm still new to nitro r/c. I was told to use 30,000 wt in front and 10,000wt in the rear by one of the hobbyst. When i asked my lhs he gave me a funny look. He then told me that 30,000 was too thick!. I'm puzzled to this as now i find out that even 100,000 wt oil is used.

Can u gurus advise me on what factors that will determine the wt of oil to be used?

On a different question about the GPX4, before running the car on the track (when it is cool), i noticed that when i spin one of the rear wheel, the other side will spin opposite direction. I understand this is the action of the diff right? But after running a few laps on the track, when i spin one of the rear wheel, both the rear wheel will rotate the same direction. Is this normal? Hope u guys can enlighten me...
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Old 01-29-2006, 07:50 PM   #193
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Quote:
Originally Posted by NoobRC
Hi, i'm still new to nitro r/c. I was told to use 30,000 wt in front and 10,000wt in the rear by one of the hobbyst. When i asked my lhs he gave me a funny look. He then told me that 30,000 was too thick!. I'm puzzled to this as now i find out that even 100,000 wt oil is used.

Can u gurus advise me on what factors that will determine the wt of oil to be used?

On a different question about the GPX4, before running the car on the track (when it is cool), i noticed that when i spin one of the rear wheel, the other side will spin opposite direction. I understand this is the action of the diff right? But after running a few laps on the track, when i spin one of the rear wheel, both the rear wheel will rotate the same direction. Is this normal? Hope u guys can enlighten me...
well for the front diff, i was adviced to use 100,000WT since it would make the diff work as a spool and slow down the car. This setup is in tune to the tracks layout since its small and pretty much the technical track(less high sppeds). Im switching to 10,000WT as what was adviced by a fellow racer. With the wheels, my wheels spin to opposite directions. Better check your diffs on whats going on.
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Old 02-01-2006, 07:11 PM   #194
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I've been very happy with the combination of 100k front diff and 30k rear diff. My times at my track are getting more consistent every week. I shimmed the transmission on the front pulley of the car and it rolls a whole lot smoother. Other changes that I made are side belt = Mugen, front belt = kawahara low friction belt, and the rear belt = Kyosho Sp belt. The brando belts are less then desired. Hope to have a successful outing. Thanks for all the information posted so far, this is a great reference tool.
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Old 02-03-2006, 09:54 PM   #195
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My GPX4..
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Hobao GPX4 Pro-dsc01838.jpg  
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