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Yes it is. I race it with no air cleaner, K&N stub stack on the carb, and a ram air base that has a seal to the hood.
Remove the stub stack... Mill the choke horn.
 
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Discussion Starter #42
Remove the stub stack... Mill the choke horn.
That thought has crossed my mind a few times.... might be able to do it before the end of the season to test it out.
 

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Discussion Starter #43
you already identified two problems yourself... have you figured out why, and fixed them?

#1 car spun on your best past

#2 engine braking up on the top end of track
We'll find out tomorrow at the track lol This car has a real fine line of bog and spin. The spin is quicker.
 

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Do you have a spacer under the carb? Has the intake been port matched to the heads?
 

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Discussion Starter #45 (Edited)
Do you have a spacer under the carb? Has the intake been port matched to the heads?
Yep it has an HVH 4 hole street sweeper. I have messed around with 1" open, 2" open, 1" open under the 1" 4 hole... best performer is the 4 hole for me. The Intake ports I matched to the heads when I ported them. I opened the heads up to a 1262 to match a victor JR I have that I eventually will try lol. I bought it used and the port alignment was horrible with the stock GT40 port. So I brought the heads out to match it so I can interchange it with the air gap.

Had an awesome day at the track yesterday. Nobody was there and made 16 passes. Practiced the power shifting. DA got up to almost 2000' and still ran a 12.2... Thats promising for me. Still bog or blow the tires off. Tried a bunch of tire PSI from 17-26. Screwed up filming a few but put a few up on youtube. Ran some 12.1's early in the morning. My PB run of 12.10 was negative DA to compare to yesterday.

 
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What clutch are you using? Seem like far too much base pressure for your power level.
 

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Discussion Starter #47
What clutch are you using? Seem like far too much base pressure for your power level.
Its a Ram HD 600 pressure plate with a different disc from Black Magic. I forget exactly what the disc is... have to check my emails.
 

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Its a Ram HD 600 pressure plate with a different disc from Black Magic. I forget exactly what the disc is... have to check my emails.
Grab some pressure plate shims from Cale and start adding. The hit is too hard.

Video the tach next time to see what the RPM drops to on the launch and between gears. It's a poor man's Racepak. ;)
 

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Discussion Starter #49
Grab some pressure plate shims from Cale and start adding. The hit is too hard.

Video the tach next time to see what the RPM drops to on the launch and between gears. It's a poor man's Racepak. ;)
Yeah thats what I do.. its tough to see on youtube but on the my phone I can zoom in and see the RPM's drop on the launch and see it in the 60'. When is goes down to 3200-3500 rpm the 60's are garbage. When it spins and drops into the 4000's its usually a better pass. I also need to build a more stable camera mount that will pass tech.

I'll check out the shims... didnt even know they were a thing. Thanks!
 

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Yeah thats what I do.. its tough to see on youtube but on the my phone I can zoom in and see the RPM's drop on the launch and see it in the 60'. When is goes down to 3200-3500 rpm the 60's are garbage. When it spins and drops into the 4000's its usually a better pass. I also need to build a more stable camera mount that will pass tech.

I'll check out the shims... didnt even know they were a thing. Thanks!
Yup -

Wheel speed versus clutch slippage. Better to look into the clutch than relying on the track you get the wheel speed. Especially NED where it's hit or miss on track prep.

Once you start to see the 60 and 330s being quicker and more consistent, then let's talk about getting you more power.
 

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Discussion Starter #51
Yup -

Wheel speed versus clutch slippage. Better to look into the clutch than relying on the track you get the wheel speed. Especially NED where it's hit or miss on track prep.

Once you start to see the 60 and 330s being quicker and more consistent, then let's talk about getting you more power.
Sounds like a plan!

My PB came during the No Time event when they have special track prep come in..Andrew Demarco preps it I believe. I hit a few 1.65's that day. Yesterday I was in the 1.7's all day. A couple high 1.6's Yesterday the track was there then it wasnt then came back lol. Makes it tough for consistent changes.
 

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Sounds like a plan!

My PB came during the No Time event when they have special track prep come in..Andrew Demarco preps it I believe. I hit a few 1.65's that day. Yesterday I was in the 1.7's all day. A couple high 1.6's Yesterday the track was there then it wasnt then came back lol. Makes it tough for consistent changes.
David and Andrew sure have things figured out when it comes to track glue but you won't race under those conditions very often. Hence the need for some clutch adjustability. You should ask Cale about the Powerforce pressure plate, somewhat similar to what we use in the Coyote Stocker. You can make many adjustments by changing counter weights and launch RPM.

 

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Discussion Starter #53
David and Andrew sure have things figured out when it comes to track glue but you won't race under those conditions very often. Hence the need for some clutch adjustability. You should ask Cale about the Powerforce pressure plate, somewhat similar to what we use in the Coyote Stocker. You can make many adjustments by changing counter weights and launch RPM.

We talked about those in the spring... they were out of my budget lol I'm wondering if my clutch cable set up could be part of the issue as I had the same problem with a stock pressure plate.
 

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Yep it has an HVH 4 hole street sweeper. I have messed around with 1" open, 2" open, 1" open under the 1" 4 hole... best performer is the 4 hole for me. The Intake ports I matched to the heads when I ported them. I opened the heads up to a 1262 to match a victor JR I have that I eventually will try lol. I bought it used and the port alignment was horrible with the stock GT40 port. So I brought the heads out to match it so I can interchange it with the air gap.

Had an awesome day at the track yesterday. Nobody was there and made 16 passes. Practiced the power shifting. DA got up to almost 2000' and still ran a 12.2... Thats promising for me. Still bog or blow the tires off. Tried a bunch of tire PSI from 17-26. Screwed up filming a few but put a few up on youtube. Ran some 12.1's early in the morning. My PB run of 12.10 was negative DA to compare to yesterday.

Good driving and shifting! Its got that small bog... but now your getting somewhere.. awesome!
 

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Its a Ram HD 600 pressure plate with a different disc from Black Magic. I forget exactly what the disc is... have to check my emails.
It really grabs it too hard.
Know anyone with a 750 you can borrow?
 

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Discussion Starter #56

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With a dual plane you can usually go to a larger carb. I've run them on mine many times and the engine certainly seemed happier, never did a dyno comparison, but sure felt faster.
 

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I’m Also having a hard time getting the right wheel speed/clutch slip and fighting the bog.
I’m wondering if our power to weight ratio have too small of a window to dial it in??
Keep at it.
 

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Discussion Starter #59
With a dual plane you can usually go to a larger carb. I've run them on mine many times and the engine certainly seemed happier, never did a dyno comparison, but sure felt faster.
Interesting. You know what I think I'm going to finally do? With probably only 1 test session left before the track closes for 6 months, I think I'm going to swap the Victor JR on and finally test it out against the Air Gap. I have so much Air Gap data now I should be able to see which is better for my combo.
 

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Interesting. You know what I think I'm going to finally do? With probably only 1 test session left before the track closes for 6 months, I think I'm going to swap the Victor JR on and finally test it out against the Air Gap. I have so much Air Gap data now I should be able to see which is better for my combo.
That Victor Jr might work against you for eliminating the bog on the launch.

Get those pressure plate shims. You need to test clutch slippage/hit to keep the engine in the powerband.

😎
 
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