Need Help Any and all suggestions welcomed to make my RC390 faster!!

[musti]

Hello fellow members,

Hope everyone is keeping safe during these hard times.

Reading through all the threads and forums has enlightened me a lot with technical and mechanical knowledge about my KTM RC 390. Thank you everyone!

I am posting this to see if any one can assist me on what to do next to make my RC 390 go to the next level. Here is my current setup:

2015 RC390
Front tire: MRF Radial 110 / 70 x 17
Rear tire: MRF Radial 150 / 60 x 17
Front sprocket: Stock
Rear sprocket: 42T KTM Duke 200
Competition Werkes GP Slip-On Exhaust
Racedynamics Powertronics piggy back ECU + Quick shifter
K&N air filter
Liqui Moly 10W 60 + Liqui Moly Mos2 Oil Additive
Underbelly stock fairing removed
Rear license plate stand / holder - removed replaced

I have reached 173 kmph when the bike is on top gear and does not want to go more than 8K rpm. My goal is reach 180 kmph while keeping is street legal.

Any an all suggestions are welcomed!!

Thanks to everyone in advance.

 

[ReidMcT]

A few possibilities, in ascending order of cost:

Tuck in tighter
Raise tire pressure
Switch back to the correct engine oil (15W-50)
Ceramic wheel bearings
Thinner gaskets
Larger injector and tune
Narrower chain and sprockets
Carbon fiber wheels

 

[musti]

A few possibilities, in ascending order of cost:

Tuck in tighter
Raise tire pressure
Switch back to the correct engine oil (15W-50)
Ceramic wheel bearings
Thinner gaskets
Larger injector and tune
Narrower chain and sprockets
Carbon fiber wheels

Thanks for the reply.

Tuck in tighter
I'm 5 feet 9 inches, weighing at 75 kilos, I have long legs. I tuck in hard.

Raise tire pressure
I'm doing 25 psi front and 32 psi rear

Switch back to the correct engine oil (15W-50)
How does that matter? Indian atmospheric temperature during the day is hot. I do want the viscosity of the oil to be thick in hot conditions, right?

Ceramic wheel bearings
What difference are they compared to the stock?

Thinner gaskets
Do you mean the head gasket so that I can increase the compression ratio?

Larger injector and tune
I have a powertronic unit with preinstalled maps. I dont have easy access to a dyno table. So unless anyone can provide me with a map that they use, I have no way of messing with the provided maps. :/
I am however interested in an oversized injector. I want to know the difference in the oversize vs stock and if there is any way I can mod the stock. I am located in India however. Would you be kind enough to send me a link of a supplier who would send me one if in case modifying the stock is not an option.

Narrower chain and sprockets
I have not heard of this at all, can you please share more details about this.

Carbon fiber wheels
I've seen brocks carbon fiber wheels, but at the moment I want to leave it as the last option as import and customs will kill me. But this is a legit improvement.

Looking forward to hearing from you!

 

[musti]

A few possibilities, in ascending order of cost:

Tuck in tighter
Raise tire pressure
Switch back to the correct engine oil (15W-50)
Ceramic wheel bearings
Thinner gaskets
Larger injector and tune
Narrower chain and sprockets
Carbon fiber wheels

I am thinking of installing aluminum pipes for the coolant, installing an additional radiator fan and oversize injector (I need to know more though).

 

[ReidMcT]

Vendor sponsors on this site offer injectors, ECU tunes, lighter chains and sprockets, and other go-fast parts. Have a look. Sorry I just don't have time to do all the research for you right now, but I think you'll find interesting stuff at Formula390 and Gray Area Racing.

Thicker oil is not necessarily better. It does not flow as well as a lighter oil so it may not lubricate adequately. Also, the oil pump works harder to move heavier oil, which takes power and slows you down. Racers use the lightest oil they can.

Some racers also shorten the oil pressure regulator spring to further reduce the load on the oil pump. I DO NOT recommend doing this on the RC390.

Thinner head and cylinder base gaskets = higher compression.

Ceramic bearings can use less (or no) lubrication, or lighter lubes, which reduces rolling resistance and raises potential top speed.

You could safely go to higher tire pressures.

I have no idea what you mean by aluminum pipes for the coolant. A SPAL or similar replacement fan will help with cooling while stopped or a low speeds. I do not think it will help you go faster.

Have fun.

 

[musti]

Vendor sponsors on this site offer injectors, ECU tunes, lighter chains and sprockets, and other go-fast parts. Have a look. Sorry I just don't have time to do all the research for you right now, but I think you'll find interesting stuff at Formula390 and Gray Area Racing.

Thicker oil is not necessarily better. It does not flow as well as a lighter oil so it may not lubricate adequately. Also, the oil pump works harder to move heavier oil, which takes power and slows you down. Racers use the lightest oil they can.

Some racers also shorten the oil pressure regulator spring to further reduce the load on the oil pump. I DO NOT recommend doing this on the RC390.

Thinner head and cylinder base gaskets = higher compression.

Ceramic bearings can use less (or no) lubrication, or lighter lubes, which reduces rolling resistance and raises potential top speed.

You could safely go to higher tire pressures.

I have no idea what you mean by aluminum pipes for the coolant. A SPAL or similar replacement fan will help with cooling while stopped or a low speeds. I do not think it will help you go faster.

Have fun.

Nice insight and appreciate all the assistance!

I will most certainly look into things like mentioned and get back, if not soon.

See you around!

 

[kostean]

175-180 km/h is probably the fastest you can go with stock engine and mild modifications. Have unrestricted intake/exhaust, larger injector, racing ECU, and lightened up bodywork and still clocks 178-179 km/h at longest straight on track.

 

[musti]

175-180 km/h is probably the fastest you can go with stock engine and mild modifications. Have unrestricted intake/exhaust, larger injector, racing ECU, and lightened up bodywork and still clocks 178-179 km/h at longest straight on track.

Stock engine is what I would go with for now, at least till the first 50,000 kilometers on the odometer. I am currently about 20,000 and will take more than 2 years to reach 50,000 cause I only ride the RC on Sundays and to a total of 150 km that same day on the highway.

I have a competition werkes slipon underbelly exhaust, which is loud and extremely free flowing. The airbox is however stock, with a K&N, so may be I might open up the lid and see how that goes. Unfortunately, in regards with the map, I am using a powertronics piggy back, so no other option and have to use the provided map from racedynamics. I am afraid of getting my ECU flashed here.

Larger injectors is what I am looking to import from Gray area racing. The only doubt I have in my mind is how would the oversized injectors work, if the map only allows a certain percentage / ratio... Still looking it up.

Body work has lightened up to the extend that my bike now weighs between 130 - 135 kilos wet

Thank you for your feedback and suggestions.

 

[Karfanatik]

Lots of posts regarding mods and speed.
I did all the little mods first. PCV, decat, slip-on, gray area airbox, open lid, k&n filter, big injector, quickshifter and a dyno tune on my 2019 model. Not sure what the top speed is but it definitely hit the limiter in top gear quicker after mods. I didn't do a stock dyno run but we did a baseline with mods and it was at like 42hp and 24lbft. After the dyno it was at 44.5hp and 26.5lbft. I'm sure it can hit 180kph with a different sprocket combo