Jump to content
Sign in to follow this  

2010 250 Jeff Gibson test

Recommended Posts

This past week was busy the first 2 days were spent dyno testing new components i got in over 150 dyno passes with the yosh exhaust the fmf exhaust and cams @ both ends of the performance spectrum .

The best set up with the yosh exhaust got us 42 hp not any more than my best and personal carbed 250 it does make better power from the bottom to 11000 rpm and then stays the same.

Wensday i m off for Il. to our indoor test track and am meeting up with Scott Venning who is Heat Voss's personal engine builder Dave Antalak ,and Jeff Gibson Last years AMA arena cross champion .

Testing went very Well and it is amazing what a pro rider can tell you we tested 450s also and our 450 cam is definatley the way to go acording to Jeff.The 250 had the diferent cams swapped out so we could get opinions beyond the dyno what i found amazing also is Jeff described to me exactly what the dyno was showing me the only changes we made were to the lower Tposition settings in the timing and fuel curves every thing i did to the top were where they needed to be .

Jeff says he likes our tuf 250 better than the 450 its eazyer to ride and responds like a 450 He also made the statement that he did not no how it was possible but it felt like it had more torqe than a 450 we explained that it was because the engine revs so much faster than a 450.

We are confident that we have a 250 package that can take on the competition in any form or level of racing in the world and im happy because all the thoughts i had that the tb was going to be to large are dismade .

Share this post


Link to post
Share on other sites

Good stuff, so what cam did Jeff settle on?

Share this post


Link to post
Share on other sites
all the thoughts i had that the tb was going to be to large are dismade .

Same here, the large TB is turning out to work just fine.

Share this post


Link to post
Share on other sites
That is great news. What is a TB?:moon:

Throttle body, the lil 250 has the same 50mm TB as the 450. Many including myself felt it could be too large, but it's not.

Share this post


Link to post
Share on other sites

The cam is a special grind i have one in my 06 250 its nothing like the rhc 5 lift is .380"it pulls very strong from the bottom up its quiet in operation .the altenator in these efi bikes suck up some hp if there was a way to eliminate them there probally is another hp there i was gaining .4 hp on the quads by maching the lighting coils from there ignition stator reducing some of the drag from the magnents.

Share this post


Link to post
Share on other sites
He also made the statement that he did not no how it was possible but it felt like it had more torqe than a 450 we explained that it was because the engine revs so much faster than a 450.

.

If you run a couple numbers on rear wheel torque output...(what makes the bike go to everyone else...) a 22lbft 250f in first second and third puts out similar torque (at the wheel)

Combined with what you said about how fast it revs...and the weight difference between it and a 450...the feel of acceleration is about the same on a 250 as it is a 450...

Where the difference is made up is top speed! The 450 will ultimately be able to go much faster than the 250 not only due to horsepower, but because the gearing is taller spreading power more....

good stuff ron! They are gonna tear up AX this year for sure!

Share this post


Link to post
Share on other sites

Picture 003.jpg

this is a dyno run showing the actual hp being produced not corected its over 42 corected to sae this was with the fmf pipe that produced less power

Share this post


Link to post
Share on other sites
Are my calcs wrong...or are you touching 217/218 BMEP at peak torque?

Nice stuff!

It rips and thats all you need to know...........:moon:

Share this post


Link to post
Share on other sites
This past week was busy the first 2 days were spent dyno testing new components i got in over 150 dyno passes with the yosh exhaust the fmf exhaust and cams @ both ends of the performance spectrum .

The best set up with the yosh exhaust got us 42 hp not any more than my best and personal carbed 250 it does make better power from the bottom to 11000 rpm and then stays the same.

Wensday i m off for Il. to our indoor test track and am meeting up with Scott Venning who is Heat Voss's personal engine builder Dave Antalak ,and Jeff Gibson Last years AMA arena cross champion .

Testing went very Well and it is amazing what a pro rider can tell you we tested 450s also and our 450 cam is definatley the way to go acording to Jeff.The 250 had the diferent cams swapped out so we could get opinions beyond the dyno what i found amazing also is Jeff described to me exactly what the dyno was showing me the only changes we made were to the lower Tposition settings in the timing and fuel curves every thing i did to the top were where they needed to be .

Jeff says he likes our tuf 250 better than the 450 its eazyer to ride and responds like a 450 He also made the statement that he did not no how it was possible but it felt like it had more torqe than a 450 we explained that it was because the engine revs so much faster than a 450.

We are confident that we have a 250 package that can take on the competition in any form or level of racing in the world and im happy because all the thoughts i had that the tb was going to be to large are dismade .

Ron,

Are the cams just a drop-in mod? Do the valve springs need to be shimmed or any other concern? Can the stock piston stay? Are they for sale yet?

I am very interested.... Thanks!

Share this post


Link to post
Share on other sites

all of the 250 cams that we will sell will require a spring kit .Any cam that is going to make a worth while diference in power has to have faster valve motion which is going to require somthing to counter the added motion.there has been cams made for the earlyer 250s that would boost bottom end for a sacrifice in top end the torque cam that i produced for the 250 did not reduce top end and gained 2 #s of toruqe in the bottom we are testing diferent lifters for this cam @ the moment .we are very close to being able to sell the 2010 products to the public .Im compiling information for the web sight @ the moment.

Share this post


Link to post
Share on other sites
all of the 250 cams that we will sell will require a spring kit .Any cam that is going to make a worth while diference in power has to have faster valve motion which is going to require somthing to counter the added motion.there has been cams made for the earlyer 250s that would boost bottom end for a sacrifice in top end the torque cam that i produced for the 250 did not reduce top end and gained 2 #s of toruqe in the bottom we are testing diferent lifters for this cam @ the moment .we are very close to being able to sell the 2010 products to the public .Im compiling information for the web sight @ the moment.

Awesome - thank you for the quick response. Please post here again once the 2010 products are ready to purchase.

Share this post


Link to post
Share on other sites

ron are there beter springs available now , we have traveled from england to test in florida , we are staying till the end of january . we are running tunned heads , but the collets have been pushing up through the top of the valve and holed the buckets on the right hand side inlet valve . we have done three inlet valves . been running copper valve seats and they have start leaking bad . another head we have had done the valve have shown signs of detenation and had to have the seats recut , this maybe down to the pump fuel ? 19 hr done on one bike , 16 hr on another.

Share this post


Link to post
Share on other sites
Awesome - thank you for the quick response. Please post here again once the 2010 products are ready to purchase.

Looking foward to seeing the packages.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...