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Old 08-07-2003, 05:45 AM   #1
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Default Would the OS turbo have enough HP for a heavy car(like the hpi r40?)

exactly how fast is the os turbo?...

faster than a Std(3 port) Nova based engine?.Want to try one in the R40..but its a heavy car...think its got enough grunt?..
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Old 08-07-2003, 08:51 AM   #2
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Why don't you try the Mugen MT-12? It has a lot of torque and it will be enough to pull the car. You can also try some lighter gearing. Hope that helps
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Old 08-07-2003, 08:55 AM   #3
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I believe the Os turbo makes 1.3hp, but you know you can never trust these ratings. I found Os engines to be very torqy and it should be able to move the R40 pretty quickly if geared right. Don't get me wrong thought, a Nova would probably be a better choice for speed and raw power but the OS is alright if you have your heart set of getting it. I would choose the new NS12 if you can afford it, or even HPI new Nova motor which amkes 1.3hp.
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Old 08-07-2003, 09:17 AM   #4
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Well, my ReflexNT is a pretty heavy car with the 4mm chassis and all, but the standard OS .12TR has enough grunt to snap it off the line, or onto the straight, with no problems at all. So I figure the turbo should be plenty strong enough.
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Old 08-07-2003, 01:14 PM   #5
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Ummm, granted cars like Reflex NT has a relatively high internal drive ratio equivalent to MTX-3 and V1RR, I am not too surprised that any decent engine would be able to snap it off the line

I would think the R40 having somewhat high internal drive ratio (I think it's 2.421 ) somewhat compensates the car being heavy and all. The OS engine being torquey and all helps in this case.

Strictly NOT for large open tracks with the OS on the R40... Short technical tracks will work fine on this car. The gearing on the R40 is not permitting for large tracks.
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Old 08-07-2003, 02:18 PM   #6
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There are already plans for several extra 1st and 2nd gear threaded clutchbells and spur gears, so gearing for different tracks should be pretty easy. I'm not sure that a certain type of engine or a particular horsepower rating is required to handle a little extra weight. Considering that other cars have 4mm chassis or extra aluminum parts, etc. the R40 is probably less heavier than most people may think, especially when weighed by hand and not a proper scale.
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Old 08-07-2003, 04:05 PM   #7
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Frank how much does this car weigh dry?? Ie ready to run minus fuel?
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Old 08-07-2003, 05:06 PM   #8
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I really don't know the exact numbers but honestly it is about a couple hundred grams heavier than an MTX-3. You can add Ti screws and graphite shock towers to drop some weight, but if you add aluminum shocks it might go up a little. I suppose using the one-way instead of the front diff would lighten the weight a little too.

Personally I believe that only an expert-level racer would be able to truly feel the extra weight on the track. Those racers with enough experience and a realistic outlook know that most racers that buy kits like the R40 don't NEED to lose gobs of weight to keep up. It's the same thing as sportsman drivers buying $250 engines to keep up with other sportsman drivers.

Still, I know most of the folks here will comment on the weight. To that I would respond that even a certain top-level AE driver (former world champ) pulled off the track during practice so he wouldn't be passed by Thad and his R40 (a common practice to salvage one's ego on the driver stand ). He's a good guy so I won't bust his chops without him here to defend himself. So it goes to show that the weight doesn't make much of a difference, even among top-level pro drivers.
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Old 08-07-2003, 05:11 PM   #9
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Frank I agree totally. Thats why I was asking. My brand new Kyosho V1RR Evolution comes in at 1806 grams dry and my old kyosho was heavy compared with cars like the tc3 and mtx3 and it still ran well against these cars. Nitro cars are hideously overpowered on most tracks in any event.
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Old 08-07-2003, 05:14 PM   #10
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Quote:
Originally posted by opeldragon
I believe the Os turbo makes 1.3hp, but you know you can never trust these ratings. I found Os engines to be very torqy and it should be able to move the R40 pretty quickly if geared right. Don't get me wrong thought, a Nova would probably be a better choice for speed and raw power but the OS is alright if you have your heart set of getting it. I would choose the new NS12 if you can afford it, or even HPI new Nova motor which amkes 1.3hp.
the new HPI RE motor is not NOVA based..
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Old 08-07-2003, 05:24 PM   #11
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Guys,thanks for al your replys..


My intention was not to imply that the r40 is a heavy car..(It is heaiver by 25 grams over a Serpent 705)...so it IS a heavier car..

That doesn't bother me...

hers why I question the motor choice...

When I race on tues nites,on a 125 x 100 road course,the STD TR(RE) OS in my tc3 is plenty against the serpent cars with 5 port RB's..

but in Edison NJ,where the course is 250 x 200 ft,with a 190 ft straight,the car is giving up on the long back stretch to teh belt cars with NOVA based motors...not by much mind you(and I still nail them in the corners with the car),but enough to make me want a touch more motor(of course,while they are flaming out,and the OS is still runng,thats a big part also)...

so I'm wondering,on the same track,would the os TURBO in the belt HPI(and heavier then the tc3) be enough?...I'm niot looking for absolutes here,just some good thoughts...


again,I'm more concerned about the turbos power in a NON tc3 belted situation,then how the r40 compares in weight to other pro cars..

as Frank said,a few grams makes little difference..
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Old 08-07-2003, 05:25 PM   #12
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Quote:
Originally posted by AMGRacer
Frank I agree totally. Thats why I was asking. My brand new Kyosho V1RR Evolution comes in at 1806 grams dry and my old kyosho was heavy compared with cars like the tc3 and mtx3 and it still ran well against these cars. Nitro cars are hideously overpowered on most tracks in any event.

Hi AMG....this HPI looks sweet...

what motor was in your Kyosho?...
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Old 08-07-2003, 05:39 PM   #13
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I have three motors that I have decided upon for my three different circuits.

120x60 foot concrete track, very windy. I used an OS TR for a long time here, but decided on the MT12 in the end. Brilliant motor for this track, but the OS is nice too.

150x60 foot asphalt track windy with long straights. I also use the MT12 here for great corner rip. Goes nicely. My JP RS12 and Rody 3 port also are very nice here.

210x90 foot asphalt grass bordered circuit very flowing and wide. OS TR is no go, too low RPM. MT12 is no good stock but my MT12 RTU with shims works great. Rossi Pixy Black is also excellent here, this motor really rocks hard on longer tracks and my Rody 5 port and RS12 5 port also are good choices.

Frankly (frank ) I never had problems with flameouts so motor choice for me is based on powerband. My car is within 80 grams of minimum legal weight and is belt driven and it is as fast as any car (yes including NTC3) out there with a properly tuned clutch and 2 speed unit.
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Old 08-07-2003, 06:14 PM   #14
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ya know,I've had such problems wit RB's,I hate them...I own 2 3 ports,AND a 5 port turbo....always tuning them etc..


And its not just me..every one of my freinds has the same problems..includig the owner of my LHS,who swears by them...

My pit man (in edison) pits for the world champion(whenn he goes to CA)..he hates them also..

Maybe I should try a different NOVA based engine..or a genuine Nova rossi motor...

anyway,AMG,you agree the TR turbo won't have enough grunt on that big race course of mine?...
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Old 08-07-2003, 07:22 PM   #15
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On a 250 x 200 track you are gonna struggle to be at the pointy end against Novas (especially the new NS12) since they have way more top end and RPM and on a track that big you spend a lot of time up in those RPMs. So yeah OS would not be my first choice. Will it work, with the right gearing sure it will, but dont expect to blow by Novas.

As for the RBs dunno what the probs you are having man. I know you are running the NTC3 and a mod X12 + NTC3 took Pavadis to a good win so the combo works well. You run a centax? Tuning novas without a stiff clutch is a PITA. Is it hot there? Running some extra head shims loses you some power but makes them idle a little easier. Similarly use a hot plug, a #5 or even an OS #8 (yeah I know they are short) to keep em idling.

I run a Rody 3 port with a #7 plug and .2mm extra head shim on our large track sometimes in 30+ degree heat with the centax cranked fully down and they rock.
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