I guess that’s where we see the separation from theory and practice.
Thinking about this now…. If you’re 0.2 HP down on someone in a 206, hanging in the draft is more than enough to make up for that (total guesswork here, but seems very plausible to me)
Which is probably why the on-track difference tends to be marginal.
It’s not even the draft doing the equalizing. That’s one driver having an edge on one place and the other in another.
The only real comparison is stop watch/data with the same driver, same kart, engine swap.
Love this example
By the rational in this thread, Gary Lawson (arguably the best 4 cycle driver of all time) with his hand picked engine, should have spanked the field by 10 seconds 
Sorry but I disagree, it’s all relative and that’s the point.
Ever seen the story about Tony Eury Jr stacking Budwiser stickers on the roof of Dale Jr’s car until they saw a difference with it in the wind tunnel?
Small differences, added up over the total build of a car/kart will contribute to a difference. How much of a difference and what that means? That’s a great question and part of what makes racing great. Ask 10 people you will get 10 different answers.
Would we agree that 9hp is a baseline number? You seem hard on the .3hp number, so we’ll use that. Essentially, a 3% difference. Sorry, I just don’t want to give up 3%. That’s how I approach our racing. I understand you guys built alot of winning engines and I’m not questioning you or your work, but your approach is different than mine and thus we are not people likely to business with each other. Nothing wrong with that either, it’s what makes the world go round.
I’m coming from a 2 stoke world. I promise you that there are a dozen or more teams/dads that would pay a top engine builder double or more for an engine that has .5hp more. Replacing pistons after just one day of running. Stock Honda cylinders selling for 2k a piece. Maybe I’m jaded and maybe I’m wrong, but racing is important for us and I don’t want to give away something to my competition.
I think we all agree that the drivers who placed ahead of Gary had a much better setup in their karts for that specific race.
Now you are comparing an apple and an orange.
Did I say ANYWHERE that the differences we are discussing are significant? Did I say anywhere that better engine would overcome a poorly setup chassis or bad driving?
It is my opinion that if those other factors are EQUAL, Gary would be very difficult to beat.
I think most people’s point is that those other factors aren’t and won’t ever be equal enough for that hp difference to be noticeable.
I think everyone involved in this discussion is well aware of what I’m about to point out, but I figure it couldn’t help to insert a reminder:
Dialing in chassis setup is going to have a bigger impact than the difference between a 50th percentile motor and an 80th percentile motor. ESPECIALLY in lower hp classes. (Let’s just assume driving is a constant for now)
I recently took a season off from shifter racing and did some X30 races at USPKS. I grew up racing Yamaha and Tag, yet was still astonished by the sensitivity of the chassis to small setup changes needed to find the last couple tenths. Engine builders seem to always harp on chassis setup (as opposed to the engine being the problem), and I’m now in the same camp. Provided the engine is in the ball park, you’re going to gain/lose more time via chassis setup 10 times out of 10.
Another example, years ago I had a Yamaha engine laying around, and decided to throw it on the chassis I had on hand and go club racing. This was an engine with multiple national podiums from my days running WKA Man Cup, and a chassis that won me a local class championship in Tag Senior. Long story short, that chassis was NOT a fit for this application and I couldn’t get within a half second of the leaders’ lap times.
Bolt on an engine that runs well, fix your driving, and then work work work to understand and optimize chassis setup. That’s the recipe.
Does anyone in this thread think that all tires duro within 3% of each other. Anyone willing to pay their tire retailer 150% of MSRP for “blueprinted” tires. If so, I got some ocean front property for you.
I heard plenty of stories a few years ago at my club. Pay builder X and they will do whatever you want!. I don’t think anyone is saying not to approach your racing in that way. It’s your money. I’ve just never ever once in club or regional races for 206 felt “out motored”
I have a reputable sticker on the side and he does good by me. All I really can ask for club racing
I definitely understand wanting all the odds in your favor as it is racing.
Just because people with money spend money on something to “go faster” doesn’t necessarily mean it’s actually doing anything.
Same theory on these guys who buy a new frame every weekend. It doesn’t make a difference. But if they have the money to blow, they will find a way to blow it and then gobble up the confirmation bias to justify why they are spending 5k a weekend in chassis.
Sure, go buy 10 engines and cherry pick the one that dynos .2 hp more. That isn’t going to do anything for your competitiveness in the grand scheme of things, but if you have the money and it helps you sleep at night, who is to say whether it’s worth it or not.
I have one engine and a 4 year old kart and I don’t feel I’m leaving anything on the table.
when i’m reading this, as a non-engine builder, paired with my own findings, i’m not sweating trying to find a “good” motor.
i’ve done back to back tests, same kart, just swapped motor, and my lap times were very close. when i looked at the acceleration data from my mychron5s, it was basically identical.
one motor was an old motor, black line in wire seal, straight off a refresh, where i’m guessing it didn’t dyno well, as the builder said the motor wasn’t a very good motor. he said it would do fine, as far as running and being reliable, and i thought it felt strong the season before, so i wasn’t too worried about it.
the other motor was a different builder’s motor, and it was his personal backup, so i’m sure it was damn near identical to his go to motor, cuz what engine builder is going to pick a turd as backup? it was an orange seal motor and fresh.
anyway, like i said, the data looked pretty much identical, one didn’t feel different than the other on track, and in my view, seems to validate that .3 horsepower advantage doesn’t translate into noticeably measurable gains.
i’d still love to find a freak, legal motor like what ron described about 20 posts back. something where you can actually feel a difference.
It’s always the personal engine or the personal backup. 
I recall that Scott M had rented a souped up open class WF that was making 40 hp or so for a money race.
That would be an interesting 4-stroke to try. A lot of compression.
Tangentially related. This is my first year karting.
Earlier in the year, my fellow club members saw me drive and commented that I should be going a little faster than I was and maybe something was of with the kart. Since I’m new, still learning how to be consistent, I didn’t know what to charge or what to try.
They offered to do some laps. We made no changes for them i.e. they took the kart out at is.
All three were within 0.5 seconds of their lap times in their kart. The fastest person had lap times of 35.3 that day in their kart and in my kart were at 35.7. All are really good drivers and their times were consistent.
Through this experiment we determined:
Different race - in the last race of the season, my engine felt stronger - that day was the coldest race day. Finally, it dawned on me that colder means more dense air and the air/fuel ratio must have been more favorable than
when it was warmer. Also, on this day I didn’t have the backfires that I had when it was warmer.
I suspect an engine builder could tell you how to compensate for temperature and that may keep you closer to optimum?
It would take a big swing in air temp, like 40+ degrees F. Even then they have a fairly wide a liberal window of what works well.
My carbs are the same from January to January.
What is the temperature and air density swings across that period where you live?
Out here in the PNW, it isn’t uncommon to be racing in 40-50F and extremely humid conditions in one part of the season to 100F+ and zero humidity another. I am not calling you out or anything, I am legit curious. I have heard you and a few others say they never touch their carb but I’ve never seen any of you mention the actual conditions swings you race in throughout that span of time.
The PNW is truly weird weather wise. I can confirm huge temp and humidity swings daily from my years in Bay Area. I would assume you guys have to fiddle a lot.
High 90’s and excessively humid to just above freezing and super dry.
We just did a low 50’s rain race.
We even race in the snow once a year like idiots.
