Grom Mods - DHM Stage 3 Review

[@vong_sak]

Loved your stage 2 video, now the stage 3 video made me REALLY want to consider go fast mod for my grom

[@CTGromer]

I really appreciate the comment and compliment, thank you! get to modding my friend!

[@filiplaskovski9993]

One good thing about Australian gas stations is that we have a separate filler hoses/bowsers for every octane :)

[@CTGromer]

California used to be like that, but at some point along the line, I think they figured they could save money by only installing one hose per fill station--not sure why they do it this way, but its a little annoying. Interesting Australia still does it that way... doing something right!

[@adamstaniforth1829]

Same pumps in England, lowest octane fuel we have is 95. I run 99. Every little helps.

[@CTGromer]

@@adamstaniforth1829 I agree, I always run the highest I can find, now I have to with the high compression. Thanks for commenting :)

[@molonlabe9602]

In my opinion, if you're not going with a big bore kit, you get the most out of the bike in a per dollar return approach by just doing an inexpensive exhaust, air box/intake mod and an ECU remap.

[@CTGromer]

I completely agree. Best bang for your buck no doubt. I'm just here reviewing things, but what you just described is the move.

[@smokinwoodz]

what about a cam? would the difference be noticeable or negligible?

[@T-revphotography]

Good review! Get that fuel can! I use a 5gal can that I fill up with every time prior to heading out for a ride. Hence the reason you never see me need to fill up.

[@CTGromer]

Hey Trevor, that's probably what I'm going to end up doing! Thanks for supporting the channel brother!

[@jean-philippehamel7026]

Welcome back on you tube

[@CTGromer]

I very much appreciate it, I'll try not to be a stranger, got some new content coming in the week couple weeks I think!

[@jtom342]

Curious to see the reliability of the stage 3 kit. Please update us in the future!

[@CTGromer]

Will do, thus far its been perfect, almost 2,000 miles later and counting!

[@CTrain]

im 3500 miles into the 186cc kit on the stock motor, you cant kill these things as long as you check/change the oil

[@Image-X]

@@CTGromer How is it holding up now?

[@samtarariverasanchez59]

@@CTrain what do u use with it power commander or aracer

[@CTrain]

@@samtarariverasanchez59 I have two of them, one is a stock ecu thats been flashed by CJR, the other is auto tuned with the af2 module and the aracer

[@Jeff-oo8gx]

My guess with loss of top speed is the switch to 91 octane with the same fuel injectors. Higher octane gas actually has less energy in the same amount of fuel and I'm sure the fuel injector is completely maxed out.

[@CTGromer]

I never thought of that! I need to research this more, and maybe just add the upgraded injector, they're relatively cheap, I know a lot of people do that when they start modding and richening the AFR on groms. I appreciate you taking the time to comment!

[@DatBoyComp]

@@CTGromer Additionally if you can find ethanol free gas it has noticeably more energy than gas with ethanol (ethanol itself only has roughly 2/3 the energy of ethanol free gas) it will also get better gas mileage.

[@Casino_life_of_justin]

Need to use 110 octane to get the full power out of the high comp piston

[@armdrop101]

The afrs were rich why it lost top speed. All he did was leans the motor up some on the top end to get the motor to pull up top.

[@lons5472]

In MD we have 93, wonder what that would do?.

[@yorkshiremanphil219]

Good review for me I will stick with my stage 2 set up the there's to many con's with the stage 3 set up and I don't think they've got it just right yet Just for interest try a run with the baffle in the exhaust I think you will get a better result due to increased back pressure All the best from Phil Yorkshire UK

[@CTGromer]

I don't blame you, for money spent, the stage 2 is the better value, that's for sure. Regarding the baffle, I may try it just for fun if nothing else to give my ears a break! DHM specifically says not to run the baffle and that his tunes are designed for no baffles in the exhaust - but hey, who knows.

[@waynep4256]

love how you poke your finger In the air with full throttle😂 good video. 👍

[@brucedunlop677]

Hey CT-2-the-MF-G :).....excellent video once again! I’ve enjoyed all your Grom content very much!! Great to have you back, and am looking forward to more. Stay safe! Cheers, Bruce (Australia).

[@CTGromer]

Hey, thanks Bruce, I appreciate the support and compliments my friend! I'll keep the content coming!

[@grominwithrob1339]

I think if I decide to do any more speed mods, I'm just going to go big bore. Love the content and information.

[@CTGromer]

BBK is best bang for your buck for more speed and power, definitely. Thanks for the compliment!

[@EstebanAGaido]

You feel flat power above 9K because you have to change your soft OEM valve springs for harder ones to prevent valve floating. You can rev the hell out above 9... 9.5K but is not effective without harder valve springs to close 100% the valves.

[@CTGromer]

I've heard of that, just haven't done the thicker springs yet, probably another mod for the future, I appreciate the explanation though!

[@mperhaps]

I think Mr. Gaido nailed it. And that would be an inexpensive way to allow the engine use all the stage 3 improvements. I'm surprised the company never mentioned it. Ya got everything you need to derive power at higher rpm except your valves aren't open.

[@Drive315]

You’re back!! Where were you?

[@CTGromer]

I'm back! Never left, but back to getting videos finished, I explained it at the end of this video, but basically, insane heat, work, insane fires here in california, then a bad map that caused 3 more weeks of down time while I waited for the new one. typical 2020 type stuff man, Murphy's law is alive and well this year!

[@Grainsauce]

Great vid, if you were going that far to replace the piston, why not go with a modest big bore kit instead? You should do another stock vs modded race video again!

[@CTGromer]

Another stock vs modded video isnt a bad idea! installing a BBK while I was in there would defeat the purpose of reviewing the hi-comp piston silly!

[@well_as_an_expert_id_say]

@@CTGromer defeats the purpose of going that invasive to go faster when you could've gone way faster for essentially the same work homie 🙏🙏just want the best for ya lol

[@well_as_an_expert_id_say]

@@CTGromer btw I subbed, pretty scientific comparison and I like that you go in depth

[@CIarkNova]

well as an expert I'd say what would you recommend, in general? DHM just released th high comp for the 22s. My goal was to stay stock bore, untill i (hipefully) went full swap. So far have the rs9T, Mtake, mini5/af2, cjr s2. Gonna prolly upgrade the throttle body next.

[@anthonybonavia2570]

Nice vidéo, I noticed you were tucked on the stage 2 run, but not on the stage 3. Does being tucked gain much?

[@CTGromer]

I was tucked, just not as low, being tucked doesn't gain much until after about 55mph.

[@Brian86992DH]

Thanks for the honest review.

[@CTGromer]

For sure man, for most, Stage 2 is enough.

[@well_as_an_expert_id_say]

Did you just cruise around the neighborhood to get your first 100 in or was there a destination in mind? Looks like fun man, didn't know they made domed pistons for these

[@CTGromer]

Yep, just did laps around the neighborhood, made sure to stay in town to hit lots of lights for lots of time through the gears, accelerating and engine breaking.

[@DoRC]

That's the engine temperature sensor not the TPS

[@CTGromer]

thanks!

[@mperhaps]

I don't buy it Dan. I would agree to your hypothesis if the piston had 2300 miles more wear than the stage two kit. But it didn't. All the significant areas where older motor and wear & tear would usually make a difference were-in this case-replaced with new. So the theory doesn't hold water. I understand the relationship you have with these companies that prevent you from being brutally honest but I think anyone else would conclude there was improper porting or lack of porting; incorrect choice of cam lobe or duration. I'm speculating here but it's a sure bet something between the exhaust, compression, port size or cam did not like each other. Finding out what it is would release another 7 or 8 mph. Conclusion-Their Stage 3 is not only NOT worth the money. There's something wrong with it.

[@jimmyk5331]

I’m pretty undecided right now about the stage 3, I have a 2018 grom and just got exhaust and intake and I pick up to speed pretty fast max out at 75mph and I just hit 14k miles, mind you I travel from city to city freeway sometimes as we’ll doing 70-74ish Fully pinned for 30-50 miles and surprisingly this thing hasn’t blown up, I do wheelies and circle burnouts a lot… I redline at 10k rpm but the bike came this way there’s gotta be something done to it because it’s been bullet proof for 3 years now not sure if I want to do anything to it till she blows… if it will.

[@papad2948]

Good info, but not your best work. The grom has a 1.49 fuel tank. So you still had about 1/2 gal left when you filled up. Was a little disappointed that you didn’t run the zoom polygon exhaust. I guess because the baffle is not easily removeable. Kinda sucks because I ordered one after you were raving about it and I really like it. But at least I know the hi-comp piston is not for me. Would like to see some fuel mileage updates after a couple of tanks. Another review says fuel mileage sucks, but that was during testing. Thanks for doing these videos. This one saved me some $$$.

[@CTGromer]

Hey bud, I appreciate the comment. Yes, the grom has 1.4 gallon tank, this is true. In terms of raw power generated by an exhaust, the Yoshi makes the most power, but its SUPER loud. I liked the polygon (which they don't even make anymore so its kind of a novelty) because it was quieter but still gave more floe than stock. I can tell you that if you're pushing the throttle hard everywhere you go, there definitely a decrease in mileage. I'll try to remember to update when I can. I think on that tank I topped off in the video I was showing only traveling 85 miles from the last fill up and the light was blinking-- don't know if that helps. Glad to save you money, the intention is always to provide insight so you can decide if something is worth it!

[@papad2948]

@@CTGromer thanks for the reply, as far as the polygon, they just released it about a month ago on their site. I was waiting from the time of your review to order it. I had the zoom loop on before that but was getting tired of the noise it made on long rides. Had the polygon for about a week. So far I really like the sound. Keep making these awesome videos.

[@CTGromer]

@@papad2948 That's awesome man, I'm glad you like the polygon. The tone is waaaay better than their regular looped exhaust. I'll keep the content coming!

[@auomauom]

CT Gromer. I got the kit, but I haven't installed it. What piston ring is top and bottom? Is black ring bottom, sliver ring top? I keep getting two misleading information from DHM, and Cameron Jones racing.

[@CTGromer]

Hey bud, that's how I did mine. Top ring: Silver, bottom ring: Black. ALSO: There's a little spacer to need to make sure you install on the sparkplug - Good luck!

[@auomauom]

@@CTGromer Thanks for the reply! Looks like I'll have to get started on the install this week.

[@CTGromer]

@@auomauom Good luck :)

[@auomauom]

@@CTGromer Installed the piston during the weekend. Did some heat cycles on the stand and took my first 20 mile ride. Low - mid power is there, but top end power is lost. Did the new map really help top end?

[@CTGromer]

@@auomauom How many miles have you ridden it? It takes the ECU a while to re-dial in.

[@cnorris3513]

where did you get the mirrors I have a 2014 og and would like to get them?great vid will buying this kit

[@averageguybodybuilding]

I had my ECU flashed still running very lean I wonder if I had a bad MAP as well

[@CTGromer]

Unfortunately it could be, who flashed it? you're not the only one who I've heard complain about this after remapping.

[@averageguybodybuilding]

@@CTGromer dhm

[@operamatthew]

wind direction was the reason for the top speed difference

[@Minibikebenji]

seems that the stage 3 tune was not smooth it sounded a bit glitchy. how many kms had you run after installing it on each run?

[@CTGromer]

I don't know how man, Kms, but I did 20 mile rides until I got to 100 miles, then I sent it! Yes, the tune wasn't perfect, but it seems to be running great now.

[@dgallaher25]

Are those stock handlebars?

[@freshsheets_]

Do you know what he changed in the map?

[@__justsayno__]

How does this compare to the sucka punch kit?

[@CTGromer]

DHM kit is less involved, easier install, probably slightly less horsepower in this DHM kit.

[@__justsayno__]

@@CTGromer Your videos helped me decide to go with stage 2. Thanks man.

[@CTGromer]

@@__justsayno__ Stage 2 is by far and away the best bang for your buck and easiest install. Congrats!

[@__justsayno__]

@@CTGromer Thanks to you brotha

[@samtarariverasanchez59]

Is it worth it for stunting or the stage 2 is good

[@SemperEspi]

Where are you from? I'm from Atwater, and the area looks really familar.

[@CTGromer]

From Fresno and Clovis, filmed in Clovis!

[@varietasVeritas]

What is the difference in mpg?

[@Friedolays]

What kind of mirrors do you have?

[@brandychrisp3621]

I think you were more tucked in the stg2 vid. Also temp variations could also be a factor.

[@Casino_life_of_justin]

Try the koso cam it has all around power in every rpm

[@Epiphalactic]

Just a little thought, if you download a screen recorder app or already have one, as well as a GPS app, you could start the GPS speed test while recording put it in your pocket make the speed run and stop when you're done, and then you would have footage of GPS mile-per-hour that you could cut and paste into the video. You should also take into effect things like wind direction and speed. Maybe start doing your speed tests going One direction and then coming back the other. on my Samsung I have the ability to do split apps so I could do real-time wind speed and stuff like that and direction of speed as well as a GPS app that shows direction of travel and miles per hour. Recording the whole thing would give you some stock video that you could cut miles per hour the direction stuff like that and kind of simulate a heads up display on your video Just an idea.

[@CTGromer]

This is a really thought through and good idea. Next speed run video I think I'm going to do it this way, I honestly never thought of it. I already do my speedtest in one direction on the same road to keep them consistent, I also try to always do them on the same day at the same time to avoid differences in things like wind and even air temp, which will also affect performance. Never thought about GPS though--thank you.

[@Epiphalactic]

@@CTGromer sweet, glad to give you a good idea! I think it would just be cool to be able to see on the screen the speeds you're going as well period and the only reason I say going both ways for each speed run is just in case the wind is blowing One direction and helps or hurts you and you have an average between the two like they do with other top speed runs. Love the channel. You got me wanting a grom so bad

[@mperhaps]

There's something missing here under proportionality when your talking about the ounce or two of lower octane in the hose. You would notice a more significant improvement to top speed if you were to clean the bugs off your head light, helmet and fender. You're putting way way too much stock in a couple of octane numbers. In a ten gallon tank 92 octane is noticeably better than Mexico's Pemex at 85 octane. But in the chemistry of oil refineries there is reason to believe that a tank of half 87 and half 91octane would give you an octane rating of no less than 91 and in some cases higher.

[@kodogg2437]

What mirrors are those

[@Grainsauce]

Finally got a grom what would you say is the best bang for your buck the 2nd stage dhm or 3rd or none of those? Assuming I already have an intake an exhaust.

[@CTGromer]

Definitely stage 2 is the better bang for your buck.

[@Grainsauce]

@@CTGromer How do you feel the cam impacts reliability, especially since it is missing the lobe for decompression on startup. that is the one thing holding me back, I wonder if it's harder on the engine or not, maybe only on the battery?

[@nickb9563]

@@Grainsauce it would just be harder on the battery/starter, but with a mild cam it's not a huge deal. If anything it's easier on the engine as it's slightly less rotating mass

[@thewheeltroll1833]

Decided on their 186 kit and just going to send it lol. Also anyone who knows racing a second in acceleration is a lot.

[@CTGromer]

A second is a huge difference, I agree, but not everyone agrees, you know? Let me know how the 186 bbk works for you!

[@bryankellis9384]

What’s the difference in the stage 3 vs the bbk ?? Obvi the bbk is bigger bore, but as far as performance… what’s the difference?

[@viciousviolet3783]

What mods can be done to raise the top speed?

[@CTGromer]

You're watching the right video for that, keep the stocking gearing, get intake, quality exhaust, DHM CAM and reflash ECU. That's all you need to get it significantly faster.

[@dabmanbatman2935]

Do you need to go up sequentially. From stage one then two then three?

[@sambravo67]

No

[@CIarkNova]

I just added the hcp and a ported head to my 22 a few months ago, during winter. Did the cam a month or so before, and it ran fine. Sat all winter after piston and head, just tried to ride the other day: I’m getting a kinda violent sounding valve noise (doesn’t sound like the normal, slightly loose rocker noise), or knock, from what sounds like the left side of the head. Only does it when coasting to a stop with clutch in- Also I havnt gone faster than 15, in first. It doesn’t do it under normal load, or accel. I hand cranked everything before start up. It idled fine, I noticed it first when stopping at the end of my driveway. I’m at my damn wits end. : /

[@christophercoffin6126]

Do you have any videos of your 22 I’ve been searching for someone that has done bigger mods than just I/E on these with the upgrade trans

[@CIarkNova]

@@christophercoffin6126 i do not yet, but will be glad to try and get some! im currently re running autotune to map for all the mods i installed over the winter. and being somewhat gentle while seating the hcp piston. im currently at just under 1k. i think i also sorted out my other issue too, i think the noise was becase i adjusted my clutch cable at the pearch wayy too much.

[@CIarkNova]

@@christophercoffin6126 regardless, if youre on the fence about mods, just do it. even if you stick with the i/e, no you dont need a tune, but i feel like it will unock whats left on the table. even from there, just stopping at a cam would put you a bit above most. but the hcp, and head combo, is just ::chefs kiss::

[@leopoldtyo]

Was this test done on the 2nd gen DHM piston? I’m getting 75 tucked on a monkey. I weigh 135-140 with full gear

[@CTGromer]

Not sure what gen it was, but I got the piston last year. Thats insanely fast. I wasn't able to get anywhere near that.

[@adrianvillarreal1810]

Great Video

[@CTGromer]

Thanks Adrian, I appreciate you taking the time to watch!

[@taylorgray6223]

What did the ring gaps need to be

[@CTGromer]

top ring: approx 0.0092 2nd ring: approx 0.0113

[@treeLiter]

Bro im cookin that jawn with my clone. Had it for a week. Just a new carb. No pipe.

[@shadespiker4742]

Try racing gas 110 octane no alcohol

[@18Chriss88]

Thats the good thing in Germany, every sort of fuel has it own nuzzle/fuel line. Every sort of Diesel and every sort of gas (95 98 100 and 102 oktan) our 95 would be a 93 at you.

[@CTGromer]

Didn't know that! you see many groms in Germany?

[@18Chriss88]

@@CTGromer not so many. They arent that famous here.

[@hugoparox]

Actually 98 is 93, 95 is 91.

[@joherickburgos5645]

My boy ran cjr I ran dhm and to be honest they both run the same tune

[@CTGromer]

I'll have to reach out to CJR and see if he's interested in me reviewing some of his product(s). I'm sure the tune is the same or similar, if their both dynoing with a grom and similar mods the map will most likely be the same. Thanks for the comment!

[@joherickburgos5645]

@@CTGromer I found the acceleration on dhm setup better imop

[@thewheeltroll1833]

I run CJR on my grom as well and heard they pretty much work together on the tunes

[@Shmack_]

You should look at how fast it gets to top speed not top speed. People with big bore kits still capping out at 68mph so top speed limited.

[@TwistedThrottleyt]

First

[@CTGromer]

Hell Yeah!!! If you're not first your last! Thanks for watching and commenting!

[@Patrick.Henry1776]

Find a place that has 91 octane ethanol free. Ethanol free is supposed to give more power, but it doesn't share the hose with other grades.

[@taatoken]

Second. Notification gang

[@CTGromer]

oooooh you almost had it, you gotta be quicker than that! Thanks so much for watching!

[@jodynichols1510]

Change your front sprocket to a 17t

[@CTGromer]

Lol no way! thats waaay too tall gearing for front sprocket.

[@daisbestDA9]

Find a gas station that each octane of fuel has its own nozzle

[@CTGromer]

I haven't seen one like that in years here in California, I don't know why they do it this way, but they do.

[@Miwiz1]

67???????? tf? all that work to get 67 top speed? not worth it, then. My stock piston hit 74 top. I get in the freeway all the time here in LA with my Grom. I dont find it any use to get faster from light to light.

[@CTGromer]

67, that's it man. I have no idea why. I was actually faster on my stock piston and just the CAM too. Weird.

[@Miwiz1]

CT Gromer i think it’s the ECU. I have the Aracer & the AF1 and i increased fuel and air percentages all across the fuel table. I increased The throttle response from 100% to 112% and it takes off way faster. Also i have 2 maps set ups for the grom; summer and winter time. The auto tuner takes care of it. I have the koso cam and the chimena air filter with zoom exhaust. One thing i noticed is the oil makes it faster too. I use motul full synthetic. I switched back to regular oil and it dropped my top end speed. Went back to motul and gained back the top end, from 68 to 74 mph. I do oil change every 2000 miles with motu. With regular oil, i was burning it really bad at 1000 miles. Also, keep your chain tensioned in the sweet spot. It helps maintain top speed. I had it loose a little bit and i was doing 67 the most.

[@salsalvador2]

Hrmm maybe time for aracer management review in near future 🤔🤔🤔

[@CTGromer]

@@salsalvador2 Might have to, the ECU seems to be a means to an end, like a band-aid on the AFR, but not perfectly tuned like an Aracer or PCV would be.

[@Chappo19901]

99 in the uk

[@reynaldorivera7641]

Doesn’t seem worth the upgrade to me.

[@CTGromer]

Depends on who you talk to I guess, the Cons are significant, no doubt--thanks for commenting :)

[@Image-X]

You have the weirdest throttle grip. Why do you have your pointer finger sticking out?

[@CTGromer]

Always ready to apply front and rear brake if need be, thats why... I do it with both pointers, always ready for clutch or front brake.

[@Image-X]

@@CTGromer That’s really not the correct way to do it. You should know when you will need to brake and clutch. It’s not as if something is going to come out of thin air and make you panic brake. I guess the Grom is your first motorcycle? You should have your hand fully on the grip at all times…. except when you are actually braking. You will find the front brake in .003 seconds. There is no need to have brake or clutch fingers sticking out like that. If it’s your first bike, you really should break that bad habit before you can’t. I’ve never seen anybody ride like that in my 36 years of riding. Street or racetrack. You need to fix that and ride with proper grip. I’m not trying to give a hard time or anything but it’s really a bad habit that you need to correct. There is no need to always be ready for the clutch or brake like that. They will be there when you need them and you’ll grab them faster than you can even think about it. All fingers on grip until you are actually going to use the levers.

[@DWBmotorsports]

@@Image-X actually everything you said leads me to believe you’ve been riding with bad practices for 36 years. Always keep a finger on brake and clutch. Any motorcycle school out there will tell you the same

[@Image-X]

@@DWBmotorsports I’ve been riding for 36 years… including holding a road racing license. You are 100% wrong and don’t know what you are even saying. Why would you have your finger ready for the clutch? Are you expecting a surprise need to shift? Do you not know when you will need to shift? Really? You show me one single article where any motorcycle school says to ride around with your fingers not on the grip….. as if unexpected shifts and braking is needed. The ONLY time this would even remotely be a consideration is if in tight traffic. You just don’t ride around like that. Not even close to proper technique. You don’t see racers doing that even at insane speeds. They know exactly when they need to use a lever and only then will they reach for it. They don’t ride around with fingers off the grips, do they? If you see a picture of a racer with fingers off the grip, it’s because they are reaching for the lever. Then it’s back to full grip. They don’t use some extremely poor and rookie technique.

[@DWBmotorsports]

@@Image-X again, no one has asked for your riding career resume’. It is proven that covering the brake decreases reaction time and stopping distance. Some of us more experienced riders will actually trail brake through a hard corner. But go on. Tell me more about your 36 years of “road racing”

[@theboogieman401]

Try CJR you’ll never go back to David again lol 😂 these runs were good but Deff give it a try !!!!!!!

[@CTGromer]

I'll reach out to him, there's a lot of comments on here telling me to hit him up, so I will! Thanks bud!

[@theboogieman401]

Np thanks for helping me in the past !!

[@theboogieman401]

Subscribe if u can or give me shout out when you get it !!

[@theboogieman401]

Cjr I find is better

[@CTGromer]

I've actually never purchased anything from his shop before, CJR is better than what?

[@theboogieman401]

Camron Jones has some nice stuff . A lot better then David’s . I ran all Dhm Then I just switched to cjr performance but there pulling better numbers a lot better .

[@CTGromer]

@@theboogieman401 I can't believe how many people here in the comments have specifically mentioned CJR, I'm going to hit him up for sure.

[@SKITTLELA]

@@CTGromer Only two I'm aware of who tune and sell reflashed ECUs are CJR and DHM. Anyone know of others?

[@arag1574]

Third

[@CTGromer]

Hope you didn't hurt yourself trying to get over here so quick to watch! lol. Hey for real though, thanks for watching and commenting!

[@tjjohnston7920]

Wrist pin.

[@CTGromer]

Yes. A wrist pin, that's the word I was looking for! Kinda scary I installed the the kit by myself huh lol. Thanks for commenting!

[@iMotoTactic00L]

4th

[@CTGromer]

Hell yeah, thanks for getting over here so quick to watch!