Hawk dyno.

[Megadan]

I am entertaining the idea of doing a pre and post mod dyno run with my Hawk as I live a couple of miles away from a shop with a dyno.. Just curious if anybody has any opinions on how I should go about this. Its 55 bucks to do a baseline run with O2 readings, so obviously I don't want to do 10 runs successively. All runs will be done with corrected results since they will likely be on different days.

For baseline I had 1 of 3 ideas. Looking for opinions.
Either: 1. Straight out of the box as it comes.
Or 2. Straight out of the box, but with stock carb jetted properly, but no other mods.
Or 3. Mikuni carb jetted for an otherwise stock bike.

Modified run. I am willing to do this in 2 stages. Just trying to decide how to stage them out. Or, simply do all of the typical mods in one go and see what the difference is. I am more keen on just doing all of the mods in one shot, but a part of me is curious on what just the exhaust does on its own.

I did also pick up a new head assembly to port for down the road, and that will likely be combined with a larger carb setup. But, for now, I am interested in opinions on how to do either stage, and try to get kind of the popular opinion of starting point and finishing point. Feel free to chime in with whatever you feel. The idea is to post the results in this thread at a later time.

[pete]

start with a standard motor / pipe / carb jetted correctly & running as good as it can
as the factory intended but feel short of....

then if you can each mod on it's own then combined...


.

[Megadan]

start with a standard motor / pipe / carb jetted correctly & running as good as it can
as the factory intended but feel short of....

then if you can each mod on it's own then combined...


.

I would love to do it this way, but that could get expensive. I may have to see what the going rate is for an hour or two of dyno time. At least that way I can take advantage of the O2 readings and spend the remaining time getting the carb tuned in just right.

I would be interested to see the comparison between a stock filter with the airbox mod, and a stock airbox with a k&n panel filter though, and then obviously both. Then all of the above combined with stock vs aftermarket exhaust. However, thats where the dyno time can get expensive for me. Having to swap parts on a hot engine back and forth doesn't appeal to me a whole lot. That is why I am trying to find a logical progression of mods that most owners would do. IE, exhaust, then intake.

That said, I may be willing to do a side by side between a modded airbox with k&n vs. A pod uni filter. I think that would answer qurstions for many owners.

[Bruce's]

Sounds like you would be doing a service to the hawk owners who want more power squeezed out of their bikes ,it might be possible to have some of them pitch in for some dyno time since it will ultimately help them as well .

[Megadan]

Sounds like you would be doing a service to the hawk owners who want more power squeezed out of their bikes ,it might be possible to have some of them pitch in for some dyno time since it will ultimately help them as well .

This satisfies my own curiosity already, and I don't want or expect any sort of compensation. I am a curious kind of person, so i would be doing this anyway.

[Sir kayakalot]

At minimum, dyno results from out of the box. Then with the normal mods most of us do; carb, exhaust, air box mod, spark plug. Those two runs on the dyno would be awesome!

[JerryHawk250]

I had planned on doing the same when I got my Hawk. A friend of mines had a dyno in his shop that I had access to anytime I wanted to. He had closed down shop and sold everything the week I got my bike so it never got done. My plan was to dyno completely stock out the box then do one mod at a time. 1st mod would be stock carb with jet. 2nd remove cat and rejet. 3rd would of an adjustable CDI and finding the right timing for maximum performance. Only problem with that one was the only adjustable CDI I could find only changed when the timing advanced and couldn't adjust the actual timing itself. I would really like to see how much more HP we can get out of theses bikes. When ever I do the EFI on conversion I will be able to change timing.

[kirbo7106]

I'm with Sir Kayakalot.

An "out-of-the-box" as a base line, just so we know where we start at. Then a typical modded Hawk (air box mod, carb with jets, spark plug and exhaust).

Now, if you wanted to do one other run, between those two, how about all the mods but with a stock (gutted cat) exhaust. That will help people decide if they want to add the exhaust system.

Keep us posted!

[JerryHawk250]

Now, if you wanted to do one other run, between those two, how about all the mods but with a stock (gutted cat) exhaust. That will help people decide if they want to add the exhaust system.

Keep us posted!
Gutted Stock exhaust vs After Market and the stock carb vs Mikuni :tup:

[Megadan]

Personally, I think the aftermarket exhaust on an otherwise stock Hawk would probably give similar results to a modified exhaust. Maybe its a little better, but having seen the ebay exhaust for myself, aside from the straight through muffler on the end, I honestly don't think there would be much difference between that header pipe and a decatted stock one. If there is, it would be fractions of a horsepower.

As far as stock carb vs. the VM26 Mikuni. Personally, given the similar specs and layout of the two carbs, I don't think there is any performance gain between the two. The main advantage of the VM26 is that it is far easier to setup thanks to the availability of jets. That said, A comparison between the traditional VM26 and a 30mm flat slide PWK/KOSO or Mikuni would be interesting. I just don't happen to have one of those on hand.

As far as the baseline. My only problem with out of the box with zero carb tuning is that it's essentially not as it should be. That is why I like Pete's idea for an otherwise stock bike with the carb jetted properly. I think that is a fair baseline to start with. It won't take much for me to toss a 105 main into the stock carb.

Just keep in mind guys, while I would love to spend the time to do every little bit, this isn't a free endeavor for me. $55 each set of runs out of my own pocket here. While doing 2 or 3 runs is reasonable, 10 of them will cost half the price of the bike. That is why I think a properly jetted stock bike vs. a completely modified bike comparison would be a great comparison. With maybe an exhaust only run tossed in, and only because I believe the stock exhaust is the most restrictive part of the bike.

[JerryHawk250]

Just keep in mind guys, while I would love to spend the time to do every little bit, this isn't a free endeavor for me. $55 each set of runs out of my own pocket here. While doing 2 or 3 runs is reasonable, 10 of them will cost half the price of the bike. That is why I think a properly jetted stock bike vs. a completely modified bike comparison would be a great comparison. With maybe an exhaust only run tossed in, and only because I believe the stock exhaust is the most restrictive part of the bike.
Yeah, when you put it that way that would be the best thing to do. lol All my runs would of been free and I could of made as many changes as possible. I was really disappointed when the guy told me he was shutting down the shop. I have to rely on the old butt dyno now. The local Harley shops has a dyno but I think they start at $120.

[RogerWFarrier]

I would love to do it this way, but that could get expensive. I may have to see what the going rate is for an hour or two of dyno time. At least that way I can take advantage of the O2 readings and spend the remaining time getting the carb tuned in just right.

I would be interested to see the comparison between a stock filter with the airbox mod, and a stock airbox with a k&n panel filter though, and then obviously both. Then all of the above combined with stock vs aftermarket exhaust. However, thats where the dyno time can get expensive for me. Having to swap parts on a hot engine back and forth doesn't appeal to me a whole lot. That is why I am trying to find a logical progression of mods that most owners would do. IE, exhaust, then intake.

That said, I may be willing to do a side by side between a modded airbox with k&n vs. A pod uni filter. I think that would answer qurstions for many owners.

I don't know about on the Hawk but I did the K&N on my TT 250 and the end result was sluggish performance, struggling to run 55 mph and 7 mph less top speed. I put the factory filter back in normal performance was restored and it was like a completely different bike. It's not a total loss though because the K&N is the one that my lawn mower takes....lol.

[Megadan]

I don't know about on the Hawk but I did the K&N on my TT 250 and the end result was sluggish performance, struggling to run 55 mph and 7 mph less top speed. I put the factory filter back in normal performance was restored and it was like a completely different bike. It's not a total loss though because the K&N is the one that my lawn mower takes....lol.

Thats interesting to hear. From the few threads I have found on people doing the k&n, aside from having to bump up a jet size, much like people that have done the uni pod filter, there were no reports of sluggish performance.

[hertz9753]

I will only say that the K&N filter should be dry and not sprayed. You also need to seal it under the retaining bracket. Roger also didn't talk about carb adjustments.

[2LZ]

If it gives the same dyno results as the Qlink XF/XP 200, expect about 5 hp increase.

It started at 15 hp and after jetting and a different muffler, it dyno'd at 20 hp. That's a substantial increase percentage-wise.

I can't find the original post but here's the vid for proof.

http://chinariders.net/showthread.php?t=10306&highlight=dyno

I have not seen anyone do this with a Hondoid. It will be cool, megadan.

[Megadan]

I will only say that the K&N filter should be dry and not sprayed. You also need to seal it under the retaining bracket. Roger also didn't talk about carb adjustments.

Not sure who's post I read about it to be honest. I will find out for sure in either case if the K&N has any effect, good or bad, or requires any carb adjustments. I almost wonder if the airbox needs a larger opening than even a modded snorkel to really see any benefit.

[Megadan]

If it gives the same dyno results as the Qlink XF/XP 200, expect about 5 hp increase.

It started at 15 hp and after jetting and a different muffler, it dyno'd at 20 hp. That's a substantial increase percentage-wise.

I can't find the original post but here's the vid for proof.

http://chinariders.net/showthread.php?t=10306&highlight=dyno

I have not seen anyone do this with a Hondoid. It will be cool, megadan.

That would awesome to pick up about 5hp. Being rated at 14.1hp with a too lean carb and restrictive exhaust, I honestly wouldn't be surprised if there were a hp or two picked up from a properly tuned carb alone.

I would wager, with the stock carb tuned properly, 14 wheel hp. With mods, if your numbers are any sort of indicator, then 18whp isn't unrealistic. I am using conservative numbers obviously, but I think realistic.

I should be getting my Hawk friday, hopefully. If so, I will get it setup, do the stock carb, and put a couple hundred miles on it before it's date with the dyno. Believe me, I can do a couple hundred miles in a day or two lol.

[GeneralTso]

Just keep in mind guys, while I would love to spend the time to do every little bit, this isn't a free endeavor for me. $55 each set of runs out of my own pocket here. While doing 2 or 3 runs is reasonable, 10 of them will cost half the price of the bike. That is why I think a properly jetted stock bike vs. a completely modified bike comparison would be a great comparison. With maybe an exhaust only run tossed in, and only because I believe the stock exhaust is the most restrictive part of the bike.

IMO if you don't establish the baseline you are wasting your money which is why what you say about getting it dialed in totally stock and then making upgrades makes the most sense to me. Keep it stock, get the carb dialed in as best you can and see what it makes, then figure out how you want to stage the subsequent runs with which upgrades.

It's a cool project, don't get me wrong, but based on the mods being discussed not sure how much improvement you'll actually be making because like was pointed out already the mods are mainly making it more tune able and are like for like. I'm thinking any increase you do see will be more a result of being able to dial the bike in tighter to it's existing capability as opposed to actual HP increasing modifications beyond the stock configuration.

That said though any more HP you can squeeze from it that you don't have now is a good thing!

:hmm:Now if we did some head work or maybe a carb upgrade, something along those lines.............

[Megadan]

Intake and exhaust upgrades will be where most of the power would be gained. The carb change is mainly for tuning ease and simplicity. That is the only like for like upgrade being made. The VM26/PZ30 is more than enough carb to support up to about 18-20hp in the limited rev range of these motors.

In my first post you will read that I did just buy a new head assembly to do a port job on, which will be installed later on with, most likely, a 32 or 34mm flat slide carburetor.

The point of this is to mainly show that, if a person gets a Hawk or any GC250 powered bike, what they can realistically expect if they do all of the bolt on upgrades. I have only seen guesses on the power of these bikes, besides the factory rating, when it comes to their power. Everything from 16hp to 20+hp with the basic mods. It would be nice to have some hard figures to toss up as a reference. That is why all figures and dyno charts I want to post will be corrected. The numbers themselves aren't the goal, just the differences.

Then, later on, what can be gained from a basic port job and a proper performance carb setup. Which, at this point, I would guess 20-22whp. The reason I want to do that separately from the bolt on mods, is that most people are generally happy with the bolt ons, or may not want to invest the time and money in head work etc. I will say that my goal with the head work is to not alter the powerband of the bike itself. It's not going to be overly aggressive, just a simple radius smoothing, and port matching to whatever intake I choose to run to make the larger carb manifold work correctly.

[GeneralTso]

In my first post you will read that I did just buy a new head assembly to do a port job on, which will be installed later on with, most likely, a 32 or 34mm flat slide carburetor.

Well there you go, I got the names crossed up and thought you were talking to the OP, didn't go back and look. Well that will be interesting then to see what that gives you compared to the baseline stock.

[Megadan]

Well there you go, I got the names crossed up and thought you were talking to the OP, didn't go back and look. Well that will be interesting then to see what that gives you compared to the baseline stock.

I often talk to myself, so it's a fair mistake lol

[hertz9753]

Stock filter on the left K&N on the right. I would think that if the flow less limited it would make better use of the air that it could get. I have pictures of pretty much that I did with my Hawk 1, because it's not the 2 or 3...