My latest project

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Yes hole drilled and motor is ready to instal. 34mm bore with 30mm stroke 27.2 CC. DDM had the head shell and cylinders on sale for less then $70 for both. I am a gear head and like having and trying many different motors. I have 4 ready to instal 2 have not been fired one is in my 5b started breaking in. One has been run and one I am building. All so have another set of 4 bolt cases but not sure what I am going to build in it.
 
Nice looking looker2756. Not into all the billet aluminum as it adds too much weight. My HPI 5b is too heavy now at 25 pounds.
 
46u said:
Nice looking looker2756. Not into all the billet aluminum as it adds too much weight. My HPI 5b is too heavy now at 25 pounds.
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Thank you ! Mine is just a 26cc, without the +2mm stroke.

I have always been the same way about weight, until I seen a few of the heavier cars run, that were set-up correctly. In the racing world, depending on what type of racing your doing, the weight can actuall be an advantage. The HPI 5b design has always been a bit tough to get really good at driving, because of it's known traction issues. The additional weight helps plant the car a bit better & gives it More dig into the surfaces.

I'm not totally sure what I will do with this car, as for right now it will just be a show piece, but eventually it just might become a racer. I have my current racer to to a complete rebuild on here soon, an it will be the opposite of this build, with lots of carbon fiber stuff to save on weight.
 
I have some carbon fiber on mine to help cut the weight down. I still need to put her on a diet and get a couple more pounds off her. LOL
 
rager33 said:
seems like allot of trouble for no performance gain.
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Weight is HP. Something is lighter less HP lose. A 25 pound 5b will go faster then a 30 pound 5b both with the same engine! Then we could talk about rotating weight which is even MORE of a HP lose.
 
46u said:
Weight is HP. Something is lighter less HP lose. A 25 pound 5b will go faster then a 30 pound 5b both with the same engine! Then we could talk about rotating weight which is even MORE of a HP lose.
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I understand your point, but here is something to consider.

Racing is not about who has the fastest car, and with that I mean, no track I have ever seen will allow top speed for any of these cars.
So, it's really more about set-up & driving ability, when it comes to winning races.
Again, you need to get traction, and short bursts of acceleration to make fast lap times on a track.

When you say a 25 lb. car will be faster than a 30 lb car with the same power, that is definitely Not the case.
In that statement your assuming the cars have the same gears too I assume ... Correct ?
Now take both cars & one will go on loose gravel, while the other is on very clean pavement with grip ... Now who is going to be faster ?
Lets now assume the same race is for only 50-90 feet, as most track lanes are, who will win that race ?

These are just some of the MANY variables involved in this scenario.
Tuning, Pipe, Surface, Distance, Fuel, Driver ... All of these need to be taken into consideration, as I have beat MANY people with more HP on tracks with my stock engines.
 
You ask any racing team is weight a concern even in drag racing and I assure you they will say yes! Not only in top speed does weight make a difference but all so in handling and many other gains from a lighter car. If you take two identical cars and one weighs 25 pounds and one weighs 30 and you have competent drivers I assure you the lighter car will come in first and will be a BIG difference. When it comes to racing which I do every little up grade will make only some difference but when you add them all together it makes big difference. I have not only raced RC cars but all so full size motorcycles in my younger years.
Thanks for the input
Jeff
 
46u said:
You ask any racing team is weight a concern even in drag racing and I assure you they will say yes! Not only in top speed does weight make a difference but all so in handling and many other gains from a lighter car. If you take two identical cars and one weighs 25 pounds and one weighs 30 and you have competent drivers I assure you the lighter car will come in first and will be a BIG difference. When it comes to racing which I do every little up grade will make only some difference but when you add them all together it makes big difference. I have not only raced RC cars but all so full size motorcycles in my younger years.
Thanks for the input
Jeff
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I'm sorry this is not true in rc 5th scale racing. you look at the high end cars & they have optional add on weights for better traction = lower lap times. scroll downhttp://www.rs5-modelsport.com/index.php?option=com_content&view=article&id=315&Itemid=82.have you weighed that cylinder & head combo compared to stock. it looks to me it weighs more.
 
rager33 said:
I'm sorry this is not true in rc 5th scale racing. you look at the high end cars & they have optional add on weights for better traction = lower lap times. scroll downhttp://www.rs5-modelsport.com/index.php?option=com_content&view=article&id=315&Itemid=82.have you weighed that cylinder & head combo compared to stock. it looks to me it weighs more.
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The motor in question is just one of 5 I have built so far and have others I am building chasing the quest of the perfect motor for my needs. Yes at time adding weight is necessary in spots but is limited only as necessary I assure you weight is lost HP! Even in full size racing you do this but is very limited. All so on road racing is very different to off road as the track on off road racing is changing every lap you make.
Thanks for the input
Jeff
 
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46u said:
You ask any racing team is weight a concern even in drag racing and I assure you they will say yes! Not only in top speed does weight make a difference but all so in handling and many other gains from a lighter car. If you take two identical cars and one weighs 25 pounds and one weighs 30 and you have competent drivers I assure you the lighter car will come in first and will be a BIG difference. When it comes to racing which I do every little up grade will make only some difference but when you add them all together it makes big difference. I have not only raced RC cars but all so full size motorcycles in my younger years.
Thanks for the input
Jeff
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rager33 said:
I'm sorry this is not true in rc 5th scale racing. you look at the high end cars & they have optional add on weights for better traction = lower lap times. scroll downhttp://www.rs5-modelsport.com/index.php?option=com_content&view=article&id=315&Itemid=82.have you weighed that cylinder & head combo compared to stock. it looks to me it weighs more.
Click to expand...

46u said:
The motor in question is just one of 5 I have built so far and have others I am building chasing the quest of the perfect motor for my needs. Yes at time adding weight is necessary in spots but is limited only as necessary I assure you weight is lost HP! Even in full size racing you do this but is very limited. All so on road racing is very different to off road as the track on off road racing is changing every lap you make.
Thanks for the input
Jeff
Click to expand...

I have a pretty extensive background in racing too, not only in the R/C world, but in 1:1 dirt cars & NHRA drag racing as well. Although in theory the idea of saving weight is sound, and makes good sense, it's not always a means to faster lap times on a race track.

I could not tell you how many engines I have built, and I can assure you I have raced MANY people in R/C with more power & lighter cars, and won Many of those match ups.

If you care to watch all of this, it is a perfect example of what I am saying. Many of these drivers are sporting light cars, and OBR big power engines. My car is not at all lightened, and in fact I run rear tires & wheel up front, and along with that a stockish 28.5 engine built by me.


Here is my car, Also sporting a weight adding GoPro camera. Notice the non weight saving beadlocks, and also window nets. It was definitely Not on of the light cars on the track, but was the TQ to start the A-main race. ;)

HostileBashfest20092108.webp

HostileBashfest20092109.webp
 
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You were cheating its in the last photo sitting on the popcorn machine
You were using spray on butter to make car body slippery to go faster
One last question do you deliver popcorn I'm hungry
 
nitrocat said:
You were cheating its in the last photo sitting on the popcorn machine
You were using spray on butter to make car body slippery to go faster
One last question do you deliver popcorn I'm hungry
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That sure sounds good right now !
Unfortunately I do not deliver. ;) :D
 
Car Body

Hello were did you get the mud bus body for your car? Here on the east coast that is what they call them. I live in Syracuse NY were they hold the champion ship race at the end of the season.
 
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