hp gain from mods
- Thread starter blaster888
- Start date
i understand the vitos piston is not as good as a proper port job but im doing a new top end anyways and if it helps at all(witch my research says it does quite a bit at least enough to feel it in the seat of your pants) why not i just dont wanna mess around with raising the exhaust port once i decide to go that route im just gonna send the cylinder to ken i cleaned up and smoothed out the transfer ports nicely IMO and polished the exhaust thats good enough for me my blaster wasnt exactially slow before but im just hoping its a good amount faster and im not sure of the brand of pipe its quite rusty and the sticker on the scilencer is so tore up i cant recognize it but i know for a fact its aftermarket because the head pipe is shaped nothing like a stock one another question the jet in it before the rebuild was a 250 in my jet kit i got a 280 300 and a 320 what should i try first i was thinking the 300 one last question i runt klots synthetic premix oil i was running 40:1 what do you guys recommend i run as far as premix ratio on this rebuild?
my next step i planned on sending my cylinder to ken to raise the exhaust ports and maybe do a little more messaging to the transfers also im going to send him my head and have it milled id also like to get a bigger carb and brand new exhaust system as i stated before my pipe is a little beat up lol
You need to run at least 32:1 or better.
Please list all your mods so as we can give a good ballpark in jetting.
Beware of jet kits, they seldom contain genuine jets and sometimes are way off specs.
Plug chop to confirm the jetting.
Please list all your mods so as we can give a good ballpark in jetting.
Beware of jet kits, they seldom contain genuine jets and sometimes are way off specs.
Plug chop to confirm the jetting.
i have an unknown after market pipe and silencer i have vitos superstock piston .060 over i have a 3/8 inch reed spacer k and n filer i ported the transfer ports via kens videos i polished the exhaust but did not raise the port and i matched it to the exhaust donut gasket it looks pretty good if i do say so myself k and n filter no lid im going to get my head re-chambered by a local machinist im gonna show him the diy head re-chambering videos how many ccs should i run so i can run 93 the one in the video he does it at 16 cc's im gonna run 32:1 klotz synthetic what kind of power gain should i see before i had pipe 60 over no lid and k and n filter and i had the reed spacer the mods im adding are 1-ported transfers and exhaust(but not raised) 2-superstock piston 3-head re-chamber im thinking like 6-8 hp because when i called ken he said a re-chambered head with 150 psi of compression on pump fuel adds a soild 4 hp and he said a good port job will add another 4 so im thinking superstock piston adds like 2-3 my porting adds lets say 2 and the head mod adds 3 +6-7 hp probably 25-28 total i know you guys like the ass dyno but i like number my friend has a 440 ex its so fast compared to what the blaster was but it was making 36 hp so i wanna beat him in the future im thinking next step 240 sleeve have ken port my cylinder and +3 stroker and i should eat the 400ex up id say
Gee that was one heck of a long sentence.
Please break up the numerous questions, one at a time for easy reading and digestion.
Please break up the numerous questions, one at a time for easy reading and digestion.
i just wanna know how big of a difference im gonna see on the ass dyno going from.
pipe
filter
3/8 inch reed spacer
.060 over
To
ported transfer ports
port matched exhaust
superstock pistons
head rechamber
vitos 2 stage reeds
and all mods listed above?
pipe
filter
3/8 inch reed spacer
.060 over
To
ported transfer ports
port matched exhaust
superstock pistons
head rechamber
vitos 2 stage reeds
and all mods listed above?
Post up a pic of the pipe for starters, so we have a starting point, different pipes have different characteristics.
You can take the reed spacer, overbore, reeds, port polish and match, maybe the piston out of the equation as they will add little or nothing!
You can take the reed spacer, overbore, reeds, port polish and match, maybe the piston out of the equation as they will add little or nothing!
Very rarely its the fault of the parts , stock or aftermarket. The main problems I have seen between cast and forged pistons is improper piston to cylinder set-up A cast stock piston to cylinder clearance is tighter than the forged one. Getting it wrong for either one is a common mistake. Wrong angle cross hatch honing / boring and improper ring gap don't help either.
I'd be leery about porting a regularly ridden machine as your first porting job. It gets pretty easy for first-timers to go nuts with a carbide in hand and totally ruin a cylinder.
Bigger carb isn't needed until you go with a 240+ displacement engine or a high revving engine. That will give you very little up top in exchange for a lot down low.
Reed spacer will only really help with smoothing the power delivery out when coming on to the powerband.
Head mod will likely yield a good 3-5, but keep in mind that the improvements made with a head mod will be mitigated with a superstock piston because the squish band is pretty ineffective over some large portions of the piston crown. You'll likely gain a total of 3-4hp from both, even though both are supposed to bring at least 4hp each.
Reeds will only put a bit of emphasis on power delivery.
Pics of your pipe is extremely important.
I like hp numbers as well but keep in mind that, just because so and so made 40hp on a setup, it doesn't mean that you'll be able to make the most out of it. It may be the other way around and you're limited by it. 50hp doesn't mean sh*t if the torque curve looks like a church steeple. 30hp with a flat curve is much more desirable.
Hell, I'm gathering the parts for a +75hp trail Banshee build, but I've got years of research into narrowing my choices down to exactly what it is. That build is going to have a monstrous curve (for a 2-stroke anyway) to go with that 75hp. But I didn't set my goal at 75hp, I set my goals based off of what I needed my quad to do and I'm going to build to that. I estimated that I'd need the acceleration equal to or greater than a CR500, and with a wide curve because I ride everywhere. I set my goals there. The 75hp range is just where that happened to fall.
Shooting for a number very often leads to disappointment.
Bigger carb isn't needed until you go with a 240+ displacement engine or a high revving engine. That will give you very little up top in exchange for a lot down low.
Reed spacer will only really help with smoothing the power delivery out when coming on to the powerband.
Head mod will likely yield a good 3-5, but keep in mind that the improvements made with a head mod will be mitigated with a superstock piston because the squish band is pretty ineffective over some large portions of the piston crown. You'll likely gain a total of 3-4hp from both, even though both are supposed to bring at least 4hp each.
Reeds will only put a bit of emphasis on power delivery.
Pics of your pipe is extremely important.
I like hp numbers as well but keep in mind that, just because so and so made 40hp on a setup, it doesn't mean that you'll be able to make the most out of it. It may be the other way around and you're limited by it. 50hp doesn't mean sh*t if the torque curve looks like a church steeple. 30hp with a flat curve is much more desirable.
Hell, I'm gathering the parts for a +75hp trail Banshee build, but I've got years of research into narrowing my choices down to exactly what it is. That build is going to have a monstrous curve (for a 2-stroke anyway) to go with that 75hp. But I didn't set my goal at 75hp, I set my goals based off of what I needed my quad to do and I'm going to build to that. I estimated that I'd need the acceleration equal to or greater than a CR500, and with a wide curve because I ride everywhere. I set my goals there. The 75hp range is just where that happened to fall.
Shooting for a number very often leads to disappointment.
I've been wrenching and modifying 2 strokes for 38 years.
I have a Auto Mechanic training, Machinist certification, Millwright certification and am currently a maintenance supervisor in a 1200 person factory. I have one of JoeAK47's cylinder and head and I gotta tell you he knows what he is talking about. His machine work is impeccable. His porting works HARD! Joe is the real thing kids. He can be harsh but knows his stuff. But enough about Joe...
I had a DT200 which supposedly makes 32hp stock.
I also have a KTM 125, 250 and 300 which supposedly make about 40, 48 and 50 hp.
I also rode a 35 hp Raptor and my son has a Banshee which is what, 37hp?
So we (my son and I) have a DT200 engine in a Blaster and KTM 250 engine in a Blaster so we can do some interpolation of hp values. The values below are rough guesses based on the DT200 and KTM as bench marks:
17 hp stock
21 hp Air lid off, head planed slightly, timing advanced, FMF pipe and timing advance.
27 hp All the above plus a rechambered head with the timing back to stock.
- also 1mm squish, leak tested and careful attention to jetting
32 hp All the above plus exhaust raised 2mm (1mm recommended) like the DT200
35 hp All above, 1mm exhaust port raise and squared, intake opened and smoothed
37?hp All above plus epoxy filled intake and careful porting on intake side
38?hp Extra 6mmx19mm window cut in piston at center boost port
We are pretty much at the limit of what you can get out of a stock carb and FMF pipe.
The good news is that if you bought your pipe used, you have less than $200 in mods and gained over double the hp.
Just opinions based on doing these mods.
Steve Best
Lid off aircleaner mod. Seat becomes top of aircleaner box. Has foam gasket around edges. Draws air between seat and tank for water protection:
Modified cylinder head, ~18-23cc chamber, 1mm squish. Hemi or torroidal.
Epoxy filled intake:
Boost port cut piston:
I have a Auto Mechanic training, Machinist certification, Millwright certification and am currently a maintenance supervisor in a 1200 person factory. I have one of JoeAK47's cylinder and head and I gotta tell you he knows what he is talking about. His machine work is impeccable. His porting works HARD! Joe is the real thing kids. He can be harsh but knows his stuff. But enough about Joe...
I had a DT200 which supposedly makes 32hp stock.
I also have a KTM 125, 250 and 300 which supposedly make about 40, 48 and 50 hp.
I also rode a 35 hp Raptor and my son has a Banshee which is what, 37hp?
So we (my son and I) have a DT200 engine in a Blaster and KTM 250 engine in a Blaster so we can do some interpolation of hp values. The values below are rough guesses based on the DT200 and KTM as bench marks:
17 hp stock
21 hp Air lid off, head planed slightly, timing advanced, FMF pipe and timing advance.
27 hp All the above plus a rechambered head with the timing back to stock.
- also 1mm squish, leak tested and careful attention to jetting
32 hp All the above plus exhaust raised 2mm (1mm recommended) like the DT200
35 hp All above, 1mm exhaust port raise and squared, intake opened and smoothed
37?hp All above plus epoxy filled intake and careful porting on intake side
38?hp Extra 6mmx19mm window cut in piston at center boost port
We are pretty much at the limit of what you can get out of a stock carb and FMF pipe.
The good news is that if you bought your pipe used, you have less than $200 in mods and gained over double the hp.
Just opinions based on doing these mods.
Steve Best
Lid off aircleaner mod. Seat becomes top of aircleaner box. Has foam gasket around edges. Draws air between seat and tank for water protection:
Modified cylinder head, ~18-23cc chamber, 1mm squish. Hemi or torroidal.
Epoxy filled intake:
Boost port cut piston:
why would you do that to the pistonI've been wrenching and modifying 2 strokes for 38 years.
I have a Auto Mechanic training, Machinist certification, Millwright certification and am currently a maintenance supervisor in a 1200 person factory. I have one of JoeAK47's cylinder and head and I gotta tell you he knows what he is talking about. His machine work is impeccable. His porting works HARD! Joe is the real thing kids. He can be harsh but knows his stuff. But enough about Joe...
I had a DT200 which supposedly makes 32hp stock.
I also have a KTM 125, 250 and 300 which supposedly make about 40, 48 and 50 hp.
I also rode a 35 hp Raptor and my son has a Banshee which is what, 37hp?
So we (my son and I) have a DT200 engine in a Blaster and KTM 250 engine in a Blaster so we can do some interpolation of hp values. The values below are rough guesses based on the DT200 and KTM as bench marks:
17 hp stock
21 hp Air lid off, head planed slightly, timing advanced, FMF pipe and timing advance.
27 hp All the above plus a rechambered head with the timing back to stock.
- also 1mm squish, leak tested and careful attention to jetting
32 hp All the above plus exhaust raised 2mm (1mm recommended) like the DT200
35 hp All above, 1mm exhaust port raise and squared, intake opened and smoothed
37?hp All above plus epoxy filled intake and careful porting on intake side
38?hp Extra 6mmx19mm window cut in piston at center boost port
We are pretty much at the limit of what you can get out of a stock carb and FMF pipe.
The good news is that if you bought your pipe used, you have less than $200 in mods and gained over double the hp.
Just opinions based on doing these mods.
Steve Best
Lid off aircleaner mod. Seat becomes top of aircleaner box. Has foam gasket around edges. Draws air between seat and tank for water protection:
Modified cylinder head, ~18-23cc chamber, 1mm squish. Hemi or torroidal.
Epoxy filled intake:
Boost port cut piston:
Early entry of the fuel and air charge into the crankcase, also assist in cooling the underside of the piston crown and wrist pin bearing.
Excellent and exactly correct answer Blaaster. The small 6x19mm slot did increase power but larger did not work any better. Did not run it long enough to see if it increased longevity.
Steve
Seeing that pic brought back memories of many moons ago, when I was experimenting with drilling boost holes in the piston for extra charge transfer.
poking the old thread back to life, anyone get anywhere with this? I'm also interested in real or close to real potential numbers before i start spending money on machining and this and that and time pulling the quad apart in the cold garage.
well i already have a fmf header and pipe, vforce4 reeds KN intake and ram air mod to the airbox, and jetting but that according to this post doesn't really add power, but i just picked up a head to be rechambered into the hemi head style but before i ship it out and go through with it I'm interested in numerical gains and if they're worth the already $100+ i have to put into it. AS well as the eventual porting of the cylinder that i want to do. i just wanna see numbers to justify the $ i have to spend.
Numbers don't win races, my mods do. I had a customer post dyno numbers from a KOR head mod and some home porting he did by following my You Tube vids. He was hitting around 25 HP. That's a 60% gain. The porting I do here is nothing like what I show on You Tube. Expect much more.
