Carb CV spring changes

[tonykof]

I've read up on this as much as I can & I'm still trying to get my head around what kind of changes to expect from changing Carb CV springs...

Do softer springs generally richen up the the 1/8-1/2+ throttle range?
Is it an even change or does it lean up the light throttle & richen the mid throttle? This is what I need.. I am hoping a change to either a red or silver would slightly lean the btm of the needle input & richen the top..? (I read this in an old post but I'm not sure if that is accurate..?)

Here's where I'm at for A/F ratio's at about 10 degrees
Idle - 13.5-14
Very light throttle - 10.5-11
Light steady throttle - 12-13 (cruising about 45-50mph)
Medium steady throttle - 14.5-15.2 (cruising steady 75-80 mph) Seems like a guy would like to see this around 13...?
3/4 thottle to WOT - 11.1-11.5

Present setup with 10-12 lbs
20 pilots 1 1/2 turns on fuel screws
Needles back in stock position w/green springs
Back to 135 mains - had 132.5's

I believe I'm okay with my pilots & mains & may still need a little more work on my needles..
I have the following springs that I could try:
Stock
Silver
Red
Blue

BTW: I'm now running a Vortech Bypass valve & Tru-boost controller, hence the changes..
Note: Used to run blue springs with needes raised 1 notch (richer) Ran good, maybe a little rich but never burbled etc..

 

[HURRICANE]

Your going the wrong way on the CV springs.We have stiffer springs that will help you.The springs that you're looking at are all softer.The hurricane Turbo springs are on our web site.

 

[tonykof]

Your going the wrong way on the CV springs.We have stiffer springs that will help you.The springs that you're looking at are all softer.The hurricane Turbo springs are on our web site.

I'm confused..Wouldn't it be even leaner on the needles with stiffer springs?
Are you saying stiffer springs & raise the needle?
Thanks Tony

 

[rxrider]

I run Hurricane's turbo springs, they work.

 

[rxrider]

tonykof - you're pig rich down low at light throttle. I would go to hurricane's turbo springs, stock pilot jets 17.5, pilot screws at 1-3/4 to 2 turns out. Raise the needles to get more fuel in the midrange with the turbo springs if needed, mine is also like yours in the midrange 1/4-1/2 throttle steady cruise. I would also consider putting the 132.5's back in as you are still rich on WOT. 11.8-12.0 would be perfect at WOT.

 

[tonykof]

I run Hurricane's turbo springs, they work.

RX,
What was your situation? same as mine, started out rich on the needles going leaner as throttle position increased?

It confuses me that really great tuners can have such different opinions on this.. Ted Jannetty, Mike Knapp & others say put as soft a spring in as you can find...?

Hurricane, I can't find the springs on your website..

 

[rxrider]

I have tried the Holtzman Green and Silver, stock springs, stock spings cut 20 millimeter, stock springs cut 32 millimeter and now I have Hurricane's turbo springs in, they got rid of the pig rich bottom I had, especially WOT from a standstill it went low 10s burbling with the springs I used before, not so with the turbo springs. Now my light throttle slow speed AFRs are at 12-13.

My carbs are at stock settings except from Turbo springs and 132.5 mains. I guess I have to adjust when I have got more seat time on it, I only have 40 miles or 60 kms on it so far this season. I will post results in my turbo garage thread when I have some data to share.

 

[HURRICANE]

The turbo spring are in clutching and traction and they are $59.95

 

[BigDog05]

tonykof: I never had any luck with the green or silver springs either. They worked good if you were already under boost and accelerated, but were terrible from a dead stop.

From a dead stop, the A/F gauge would drop to 10 and the sled would only pull about 8400-8800 RPM, like it could not pull the clutch weight. It would pop and fart and then finally clean out and take off.

The turbo rear mount seems to be worse until it builds boost.

I put a set of Hurricane springs in 2 weeks ago and the holeshot is very good now. I only got a chance to make a couple of 600 ft runs because of bad snow, but the sleds launches to about 9800 RPM and climbs to 10200 at about 600 ft.

This is at approx 2800 ft elevation, stock mains, 17.5 pilots at 1.5 turns off seat. I can adjust the WOT A/F with the pitot jet in the charge tube.

I may have to raise the needles one notch rich, for mid range cruising but
no snow to test. With these springs I'll be able to fine tune the clutch now.

 

[BigDog05]

Tonykof or rxrider: Did either of you guys get to do any midrange testing with Dave's springs?

As stated in my last post, setup is: 135 mains, 17.5 pilots, fuel screws 1.5 turns off seat, needles in middle position, 2000-2900 ft elevation

Hole shot and low speed running is excellant, tuning WOT with pitot jet is easy also.

Midrange is lean. No boost to 1-3 lbs boost is 14.2 to 15.4. I raised the needles 1 notch rich and it got real bad rich at low speeds. 5-25 MPH

Would going to a bigger pilot, or making the fuel screw richer, help the midrange. Or am I past that area. Then put the needles back to middle position.

Plugs look a little too white for my liking. No signs of deto but very white.

 

[rxrider]

I would recommend you to jet down on your mains instead of reducing fuel pressure with the pitot. When reducing float bowl pressure via the pitot jet to get your WOT in order you will also reduce fuel pressure to the mid which will be lean. Give it a try

 

[BigDog05]

rxrider: The carbs are setting on the work bench so I'll put in a set of 132.5 that I have. Would you leave everything else the same?

With the smaller mains I should be able to start with a 300 in pitot?

 

[Skydog]

Yea these were not out yet when i was working on my RX1 but the stock springs worked the best for me. The soft springs never worked at all for me!! Get some of Daves springs and roll out!! Or i mean BOOST OUT!!!

Skydog

 

[rxrider]

Put in the 132.5s, leave everything else the same, change only one thing at the time. The 300 pitot jet will raise the fuel pressure in the float bowls, right? Then yes

Ride it and check what the results are. Adjust the pitot jet to you get your WOT AFRs in check, then check out the lean mid problem area, if it's getting better you know what to do next. Keep us posted

I adjust mains, needle, pilot screws, in that order on a carbed engine.

 

[BigDog05]

rxrider: Thanks, sled back together with 132.5's. 10 days ago we had at least 2 1/2 ft of snow in the mountains. Last Saturday it was 48F and has been warm and rainy all week.

Hopefully we will get more snow soon.