Go Back  R/C Tech Forums > General Forums > Nitro Off-Road
Carb Inserts...how to tune when changing them >

Carb Inserts...how to tune when changing them

Community
Wiki Posts
Search

Carb Inserts...how to tune when changing them

Thread Tools
 
Search this Thread
 
Old 06-22-2007, 07:15 AM
  #1  
Tech Addict
Thread Starter
iTrader: (4)
 
pumpkinfish's Avatar
 
Join Date: Feb 2004
Location: Schwenksville, PA
Posts: 609
Trader Rating: 4 (100%+)
Default Carb Inserts...how to tune when changing them

I am going to be trying out a few different size carb inserts in my C6 to make it a little more controllable in my 8ight. I will be going from the stock 8mm to 7mm or 6mm. When I am going to the smaller inserts, which way should I adjust my tune? I've never played around changing these things, but the C6 is a beast in the 8ight and I'm trying to limit the wheel spin.
pumpkinfish is offline  
Old 06-22-2007, 07:21 AM
  #2  
Tech Master
iTrader: (7)
 
Nitro$junkie's Avatar
 
Join Date: Jun 2006
Location: Gold Coast, Australia
Posts: 1,420
Trader Rating: 7 (100%+)
Default

Lean HSN

Less air = Less fuel
Nitro$junkie is offline  
Old 06-22-2007, 08:49 AM
  #3  
Tech Elite
iTrader: (17)
 
rezenclowd3's Avatar
 
Join Date: May 2006
Location: Solvang, CA
Posts: 2,367
Trader Rating: 17 (100%+)
Default

Use more throttle control! The trigger is not an on/ off switch.
rezenclowd3 is offline  
Old 06-22-2007, 09:35 AM
  #4  
Tech Adept
 
Hockey 85's Avatar
 
Join Date: Oct 2006
Posts: 124
Default

Originally Posted by rezenclowd3
Use more throttle control! The trigger is not an on/ off switch.
haha rezenclowd3. Yes you would lean the high speed needle as nitrojunkie said. Another advantage of a smaller carb insert is better run time
Hockey 85 is offline  
Old 06-22-2007, 12:55 PM
  #5  
Tech Addict
Thread Starter
iTrader: (4)
 
pumpkinfish's Avatar
 
Join Date: Feb 2004
Location: Schwenksville, PA
Posts: 609
Trader Rating: 4 (100%+)
Default

I also race 1/10 elec buggy so I know about throttle control...lol! I think the C6 is overkill in the 8ight but perfectly matched in my truggy. I just wanted the same engine for both because I am familiar with the C6. Last summer I ran truggy only and for the new buggy I didn't want to have to learn the characteristics of a different engine.

Thanks for the tips guys!
pumpkinfish is offline  
Old 06-22-2007, 01:34 PM
  #6  
Tech Elite
iTrader: (17)
 
rezenclowd3's Avatar
 
Join Date: May 2006
Location: Solvang, CA
Posts: 2,367
Trader Rating: 17 (100%+)
Default

Good, Im glad that you run a 2wd vehicle. Hmmm..I was thinking of buying a C6BB for my 8 when my WS7II dies...I also come from 2wd racing, but well see. I know that the WS7II/ III rocks in my 8, but its past the 3 gallon mark and quickly fading because of a mistake I made when I first got it.

I just couldnt resist the thottle control comment however You know, its funny, I havent driven my AD2 this season, and am finding my throttle control and steering to get sloppy because of the ease of driving a 4wd buggy. (also the 8) I will be breaking out the AD2 more often to compensate and gain my control back.
rezenclowd3 is offline  
Old 06-22-2007, 06:37 PM
  #7  
Tech Addict
Thread Starter
iTrader: (4)
 
pumpkinfish's Avatar
 
Join Date: Feb 2004
Location: Schwenksville, PA
Posts: 609
Trader Rating: 4 (100%+)
Default

rezenclowd3, I too broke out my GT2 this past weekend and found that I was driving very sloppy Even though I am driving a 1/10 elec almost weekly, I just could not get in the rhythm of 1/10 gas truck like I used to be. I made the B-main but was so sloppy the 4th place I was in before I broke was below my standards and disappointing. I believe I have been running truggy and 1/8 buggy too much It is hard to break the point and shoot habits.
pumpkinfish is offline  
Old 06-22-2007, 11:58 PM
  #8  
Tech Elite
iTrader: (17)
 
rezenclowd3's Avatar
 
Join Date: May 2006
Location: Solvang, CA
Posts: 2,367
Trader Rating: 17 (100%+)
Default

I totally agree man. Point and shoot. Although I have found my 8 to be so much less time consuming to upkeep...I have not been in the mood to rebuild my diff in my stadium truck. I hate ball diffs....when they blow anyway! I actually bought a whole new diff for my AD2 (~$50) and it is still not smooth, and my slipper (also new) doesnt slip like it did when the kit was new...Time for a new kit. I would like the GT2 but I have over $400-$500 in spares for the AD2 (my track eats up anything but buggies and truggies) I will land fine but a rock will be in the way and break the a arm or pivot block.

Though I gotta say, 2wd was so much more fun when the kit was built right. The look, the speed and handling just looked right.
rezenclowd3 is offline  
Old 06-23-2007, 06:37 AM
  #9  
Tech Addict
Thread Starter
iTrader: (4)
 
pumpkinfish's Avatar
 
Join Date: Feb 2004
Location: Schwenksville, PA
Posts: 609
Trader Rating: 4 (100%+)
Default

Originally Posted by rezenclowd3
I hate ball diffs....when they blow anyway!
+1

My GT2 is gritty but I am still plugging away. Maybe I'll see how long it goes until complete failure...ha ha ha
pumpkinfish is offline  
Old 06-23-2007, 09:51 AM
  #10  
Tech Elite
 
Corse-R's Avatar
 
Join Date: Aug 2001
Location: Madrid (Spain)
Posts: 2,121
Default

Just a word of caution regarding exchanging carb inserts in 2 needle carburetor...

If you go down from a let's say 8mm insert to a 7mm insert, the low-end needle and spraybar remains on the same position and because the reduced diameter of the insert, is located nearer to the projected surface of the carb insert.

Having it them nearer could lead to carb adjustment and fuel atomization problems, just remember that fuel converts into a mist entering on the engine.

If you have a 3 needle engine (the ones with the 'brass screw' you can offset the spraybar and modify when you want your carb being driven from the LSN to the HSN. C6 Engines comes with a 2 needle, don't know why they switched from 3 to 2 needles on their high-end engines where you want the maximum flexibility and performance.

Be forewarned that smaller inserts mean slightly more runtime and better low-end, but some engines react very bad to them and start being a bitch to tune them.
Corse-R is offline  
Old 06-24-2007, 06:54 AM
  #11  
Tech Initiate
 
paulj2's Avatar
 
Join Date: Mar 2007
Location: Twin Falls, ID
Posts: 30
Default

The new version of the C6, the C6-BBT7, comes with the 7mm restrictor, turbo plug button, and lightened head. The rest of the motor remains unchanged. You won't have a problem going to the 7mm restrictor. I don't have experience with the 6mm insert, but have the 7mm and turbo button set ups in both my C6BB motors. They work fine, no tuning problems.

I don't recall much of an adjustment in the tuning after the change to the 7mm.
paulj2 is offline  
Old 06-24-2007, 11:57 AM
  #12  
Tech Adept
 
wothrottle's Avatar
 
Join Date: Apr 2004
Posts: 197
Default

hey guys

do you always adjust the 3rd mixture screw according to the lsn?

I know how to tune the hsn and lsn,but is there also a method tuning the mixture screw? I´m running the os vspec btw.
wothrottle is offline  
Old 06-24-2007, 12:48 PM
  #13  
Tech Fanatic
 
Join Date: May 2005
Location: Lincoln Park-Chicago
Posts: 881
Default

The mid screw adjusts the point at which the engine switches drawing fuel from the LSN to the HSN as I understand it. Adjusting that seems to be an area that is rarely mentioned.
satoch is offline  
Old 06-24-2007, 02:48 PM
  #14  
Tech Elite
 
Corse-R's Avatar
 
Join Date: Aug 2001
Location: Madrid (Spain)
Posts: 2,121
Default

Originally Posted by satoch
The mid screw adjusts the point at which the engine switches drawing fuel from the LSN to the HSN as I understand it. Adjusting that seems to be an area that is rarely mentioned.
Yep, the 'Mid screw' basically moves the spraybar (where the fuel enters on the carb). Moving it you modify the point where the carb goes driven from the Low end needle to High speed needle.

If you have the so incorrectly called 'Mid rpms needle' you can change that point and helps to tailor the carb fuel curve and their metering.

Ever has been said to better to not mess with that screw because if incorrectly adjusted you can cause lean conditions on partial throttle or very rich conditions and the performance could be sub-par.

Didn't knew why the manufacturers decided to drop that screw, left to many people without a tunning adjustment.
Corse-R is offline  
Old 06-24-2007, 03:00 PM
  #15  
Tech Adept
 
wothrottle's Avatar
 
Join Date: Apr 2004
Posts: 197
Default

how do you adjust that screw?

if you insert a smaller venturi for example,what to do with that needle.
wothrottle is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.