No Straight Away Speed in Spec Class

flattop1

Dawg 89
First thing is finding if they are equal size . If so that's not a problem .
If they are that's a problem that needs corrected .
Yes multiple people could instruct you how .
I'm not fast enough .
I'm sure that's not the problem .
Is the wrong approach .
 

alvin l nunley

Premium User
There are so many things that could be happening. When we were having trouble the first thing we checked was the compression pressure. It's such a simple easy thing to do. I've heard all the stories, but when you're low on compression, you're low on HP. It's just a place to start your search. Eliminate any possibility of a problem. I'm pretty sure books could be written on this one single problem.

One jet size, let's say .039" to .038", is a 5% change in mixture. That's a lot. Your gear ratios the same as others, you say, what about your timing? What about your spark plug? The list is endless! Have you ever had the engine on a dyno? Have you ever been able to compare your dyno curve to others? Does this happened with just one engine, what about other engines you might have? Have you tried subtracting one tooth from the axle? If you did that, and didn't lose any RPM, that would indicate something. What fuel do you run, is it a speck fuel for the class? I can go on and on. Not knowing what you've done, or if what you've done has helped or hurt, leaves me wondering.
 

BrendanFitz#73

Mohawk Dawg
What engine. I can tell from the pic that it looks like a world formula or a 206. If tjats what it is the engine most likely isnt the issue and everything is spec'd and you cant do much of any tuning.
 

95 shaw

Premium User
https://www.amazon.com/Beginners-Complete-Karting-Guide/dp/0936834404
https://www.amazon.com/Chassis-Setup-Technology-Steve-Smith/dp/0936834870
https://www.amazon.com/Karting-Manu...AV08T9JXGZX&psc=1&refRID=8A7VQZN58AV08T9JXGZX
Here are some beginners guides to help get you started for not much money.
These will be more oriented to sprint racing, but maintenance, tire care and measurement, and basics are mostly the same.

Do not get discouraged or allow yourself to be overwhelmed. work the problem, don't let the problem work you.

We all started somewhere.
 

alvin l nunley

Premium User
But what am I going for. I can measure things all day but have no idea how to adjust accordingly.
My
Pretty simple, if they're not the same circumference, find 2 that are! I know you knew that! Going fast is not easy, it takes work, even a lot of measuring for instance.

Years ago, when I built a lot of McCullough's, I always measure the rod for straightness, just something you had to do. I wouldn't put the engine back together until I got the rod straight.
 

flattop1

Dawg 89
What engine. I can tell from the pic that it looks like a world formula or a 206. If tjats what it is the engine most likely isnt the issue and everything is spec'd and you cant do much of any tuning.
Post #1 . He stated series organizer builds and seals . Which doesn't eliminate the engine .
 

paulkish

old fart
How could anyone possibly argue if you have more speed on corner exit it would not translate to more straight speed. Your 1/2 hr starts Now lol !!

I watch it happen each and every weekend.
One racer down low gets around the shorter corner with the outside racer starting their straight at the same time behind where the short distance petal to the metal racer started their straight.
The end result is the racer who started their longer straight at the same time or sooner, soon fly's by on the outside.
 
This was something overlooked because everyone in my series runs a .038 or .039 sized and I was doing the same. We threw a .035 in there and instantly gained .5 second lap time and 400RPM and could actually keep up on straights. Even though every ones carb is the same especially with clone parts made in china there is so much inconsistency with them. The issue was so obvious because my motor was always the dirtiest due to all the carbon buildup from running too rich and I never really paid attention. Very surprising considering no one is running that small size of jet but it made a huge difference. Bought a bunch of sizes too.... it is a really nice and easy adjustment to do and can make a huge difference depending on weather. Thank you for all the comments and suggestions given it helped a lot.
 
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Brianf60

Member
How do you know that nobody is running that jet? You will find that everyone is very helpful and willing to give you info but when you are faster than them or within striking distance it's a different game. All you can do it try a change and see if it made an improvement or not and go from there. That's what practice days and a notepad s for...
 

MAG17

Member
SOOO.. a ratio is not always a ratio! Unless you need it to do something. Like get you down the straight better>>>Just saying
 
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J par

Member
This was something overlooked because everyone in my series runs a .038 or .039 sized and I was doing the same. We threw a .035 in there and instantly gained .5 second lap time and 400RPM and could actually keep up on straights. Even though every ones carb is the same especially with clone parts made in china there is so much inconsistency with them. The issue was so obvious because my motor was always the dirtiest due to all the carbon buildup from running too rich and I never really paid attention. Very surprising considering no one is running that small size of jet but it made a huge difference. Bought a bunch of sizes too.... it is a really nice and easy adjustment to do and can make a huge difference depending on weather. Thank you for all the comments and suggestions given it helped a lot.
Nice read and good lesson...
Like to see more progress reports...
Came and went in two weeks... Likely won't...
 

paulkish

old fart
"We threw a .035 in there and instantly gained .5 second lap time and 400RPM and could actually keep up on straights."

I sure hope they next put a .034 in the thing and beat them down the straights.
Keepin up just ain't good nuff. ... :)
 

MAG17

Member
My issue when running the same gear as other guys I pull them in corners and passed corner exit, then they're gone on the straights after a few seconds of acceleration. Its like I am severely under powered. Other guys with same gear are about a max of 300-400 RPM higher than mine. I think I might be running to rich. I always hit a wall at a certain point usually around 5900 RPM.
You have too much gear on.. and your corner roll is not as good as your competitors. You beat the competitor out of the corner because you have more teeth on the rear. Once you get on the straight they pass you because they are still accelerating.
 

alvin l nunley

Premium User
Mass produced engines can vary significantly. I know with the KT100 there are average ones, there are poor ones and there are special ones. Average ones make up the bulk of the available ones. Your engine could be one of the poor ones.

My first suggestion would be a new engine. Why do you suppose they are turning more RPM than you? Got to be a reason!

If you think they're cheating, can you claim their motor?
 
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