This is a discussion on Stock Grom Engine 0-60 mph almost :) in 13 sec. Nothing but the bolt on mods! within the Grom Performance forums, part of the Honda Grom Garage category; And an estimated 150 lb. rider including gear. Didn't we all wish to be 6'4'' and full of muscle? Unfortunately, my physiche topped out in ...
And an estimated 150 lb. rider including gear. Didn't we all wish to be 6'4'' and full of muscle? Unfortunately, my physiche topped out in 10th grade.
On my Grom I reached 0-60 mph almost in 13 sec. The top stop light to stop light speed was 59 mph before the red light that cut the fun in 13 sec. My speedo is off due to a 36T (+2 teeth) on the rear sprocket. I've calculated a 3-5% under value indicated which is about 2 mph. That means my indicated 59 mph is more like 57 mph and my (you'll see) indicated 74mph is more like 72 mph.
The lead in:
The top speed run:
The almost zero to sixty
Last edited by Leo310; 04-05-2019 at 09:10 PM.
Koso 170 4V/34mm TB/Koso injector/ DIY intake/ aRacer Mini5 + AF1 + DG1
Koso pump & chain tensioner/ Stock clutch ring / 60% stiffer springs
Takegawa Crank Support Bearing / Takegawa Catch Can / Kitaco Clutch cover
Clear cam sprocket cover/ Egay oil Cooler
Ohlins F&R / Hindle exhaust w DB killer / Galfer brake line w EBC HH Pads
Pro Taper grips, G2 throttle tube / Gromfatherz axle spacers
Kepspeed alum. swingarm / Bar end mirror, RAM mount, USB Port
Seat Concepts / Opmid V2
I haven't run my engine over 8,000 yet. (lol)
I'll be out riding around tomorrow (Saturday)… up Fernwood, across Saddle Peak, down Stunt to Mulholland, and west to the King Gilette Ranch where my wife has a painting exhibition. For me it's just another excuse to take a ride. If you're riding, maybe I'll see you.
2018 GROM: Modified for reliability longevity gas mileage... and fun.
Use your phone to get a gps speed. I love the light to light!! Btw, I have lost 14 pounds. It does matter.
you be surprise how many cars or even other motorcycle that I beat light to light with my grom, of coarse it isn't stock but a 181-4v with all the support hardware. I came next to a 3 group rider on 600-1000c bikes near Levi's stadium and when the light turned green I went for it and the 1000 and one of the 600 passed me before the next light and the third guy pulled up to me and asked if the grom was bored out and I said no it just had loud pipes which I lied and all 3 sport bike riders talked to each other and when the light turned green I went for it again with no response from the 3 group riders.
Same thing with most cagers in Santa Clara valley and the only car that I can't beat light to light is the Tesla electric cars or a fully modified hot rod.
Like I say ride it like you stole it or until it blows up.
At 6'3 and 220lbs I'm not winning any races. I haven't ridden my grom since adding the reflashed ECU, exhaust & long tube intake but Im sure its going to add more noise than speed. I like slow bikes anyway, my other two bikes are a WR250R and an Africa Twin.
Stock rear sprocket is 34 teeth; you went up two teeth using a 36-tooth sprocket: 34/36 = .944.....so
59 MPH (displayed) x .944 = 55.7 MPH (actual).
74 MPH (displayed) x .944 = 69.9 MPH (actual).
At least that is what I think......feel free to correct me if I am wrong......
That is one way to do it for sure! No, you're not wrong your math and reason is legit. However, I've made my estimates based on my Grom's odometer inaccuracy. My commute to and from work is 34 miles to work and 34.5 miles to home. I've made the measurement several times with several vehicles. It's not exact every time with all vehicles but it is close enough for estimating which is all I'm doing. My +2T or 36T Grom shows 35.6 miles to home. Therefore, I'm using for the adjustment:
34 miles / 35.6 miles = .96
.96 * 74 = 71.0
My top speed to date (prior to the Chimera styled radiator hose mod and with side panels removed) has been 76 mph at which point the rev limiter (upped +500 rpm) kicked in. So for hauling ass on the So Cal Fwys I try not to exceed 75 mph on the speedo (or 75 mph * .96 = 72 mph est). If I hit the 76 mph mark, (76 mph *.96 is 73 mph) I bounce off the limiter just like a stocker will do at 73 mph if it can get there.
No doubt though I can tell you all that the radiator hose mod with the pod filter has made a measurable increase in how frequently and how long I can reach and maintain top speeds over 70 mph. It is so obvious. In the top speed video posted I was on my standard speed route where previously I could only reach an indicated 65 mph on 3 or 4 occasions. If you want to go faster for longer with the stock engine open that intake all the way and ditch that air box!!
I believe there are three factors involved in my last mod.
1) The increase in air volume into the throttle body at all rpm's and speeds (disregarding intake air velocity which is not a noticeable thing for a stock Grom engine I think).
2) The removal of the air box. I believe the air box acts as an air dam that produces a lot of drag. Along with the side scoops the effect is like a mini parachute that is getting pushed into the wind. Removing the air box will help you go faster with your side panels on.
3) The crank case blow by gasses are now routed to the atmosphere and only clean, filtered air is getting sucked into the throttle body for mix and combustion.
For the comment ready that shows up like clock work, to the effect of "... it's just one more thing then I'll really notice a difference..."
I've done it! I have no desire to get a 143 cc bbk anymore.
There is speedometer error above and beyond the odometer error. Just so you know.
You need to GPS your speed.