Dyno at 85-90%% throttle valid?
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
Dyno at 85-90%% throttle valid?
I was fiddling with the linkage running from the blower base to the carbs today and noticed that the rod that runs down from the carbs is contacting the side of the blower case before the carbs reach WOT.
The carbs have another 12-15 degrees rotation still left in the butterfly shafts.
The question is, is there enough of a difference between 85-90% throttle and full throttle to make much of a difference on the dyno? I know it sounds silly, but I'm doubting I could feel much of a difference between 90% OT and WOT.
The carbs have another 12-15 degrees rotation still left in the butterfly shafts.
The question is, is there enough of a difference between 85-90% throttle and full throttle to make much of a difference on the dyno? I know it sounds silly, but I'm doubting I could feel much of a difference between 90% OT and WOT.
Last edited by RobbSalzmann; May 13, 2012 at 05:20 PM.
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Do You have dual 750's? The super charger sites have the math. Like 406 X 8psi = so much cfm. Other than the math they also list the vacuum. If you are under carbed vacuum rises with PSI and rpm.
Hey I put my gauges in on Sat. It was a fun day with my buddy
Hey I put my gauges in on Sat. It was a fun day with my buddy
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
Dual 650's. I was thinking what you suggest here, I just couldn't get it into words.
So it's possible (I'll have to check the math), that the CFM is the same at 90% OT and WOT - Is that what you mean above?
About the guages, I hope you'll start a thread and post some pics.
I've been experimenting with the flare tool and it makes very nice holes for my guages- but I'm waiting to see yours so I have something to live up to. I've also been learning Stainless JIC (AN Fittings) fabbing and have started making up custom linkages with mini hiems and stainless tube.
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Somewhere along the line I started thinKing that you had a 427 SBC.
But anyway from your blower math site dual 650 cfm = 1300 and I would think that the CFM of flow is not really changing that much higher in the last 10-15% of throttle blade movement. I would call the dyno numbers valid. With the given 105% VME.
Just a little more boost and those 650's are going to be the restriction
But anyway from your blower math site dual 650 cfm = 1300 and I would think that the CFM of flow is not really changing that much higher in the last 10-15% of throttle blade movement. I would call the dyno numbers valid. With the given 105% VME.
Just a little more boost and those 650's are going to be the restriction
Last edited by gkull; May 13, 2012 at 01:57 PM.
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
Somewhere along the line I started thinging that you had a 427 SBC.
But anyway from your blower math site dual 650 cfm = 1300 and I would think that the CFM of flow is not really changing that much higher in the last 10-15% of throttle blade movement. I would call the dyno numbers valid. With the given 105% VME.
Just a little more boost and those 650's are going to be the restriction
But anyway from your blower math site dual 650 cfm = 1300 and I would think that the CFM of flow is not really changing that much higher in the last 10-15% of throttle blade movement. I would call the dyno numbers valid. With the given 105% VME.
Just a little more boost and those 650's are going to be the restriction
The carbs may already be a slight restriction. At boost they howl like injured moose. But my exhaust is also a bit on the restrictive side, using capped auger baffles.
Since I'm not racing the car and I can accelerate hard enough without actually exceeding the speed limit much to let the boy racers know not to bother, i'm ok with they way it runs for now.
Even with careful application of throttle, I'm at the ragged edge of having traction. Any more efficiency and it'll feel like I'm driving on ice all the time.
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I never had traction even with my wimpier 427 with my 3500 -3800 9.5 inch TC and 4.11 rear end. It was hard to drive fast. It was a good training car on how to use steering and throttle to keep it going straight.
The best thing I ever did was to install a 5 speed. Even with added HP when compared to using a power robbing auto tranny the traction goes up because you don't have to deal with the lower rpm TQ multiplication of the Torque Converter
The best thing I ever did was to install a 5 speed. Even with added HP when compared to using a power robbing auto tranny the traction goes up because you don't have to deal with the lower rpm TQ multiplication of the Torque Converter
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
Interesting, I hadn't thought of it that way. As it is now, I somewhat ease off in first, let the kick in the pants shift to 2nd happen, then if I'm going to get on it, I go.
DO you have any thoughts about what 5spd to use?
DO you have any thoughts about what 5spd to use?
Last edited by RobbSalzmann; May 13, 2012 at 05:19 PM.
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Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
tko 600 with the .82 OD with a 3.55 or 3.73 rearend. I have a 3.55 with the .64 OD It makes the first 4 nice spreads for around town and I can go to the track and do nearly 160 in fourth gear. It's nice. the Big 4-5 jump and unless you are doing higher speed freeway. I have a higher rpm N/A motor and I can drive all day loping down the road at 85 - 100 like on my drove down I-5 in california where people drive 100 mph.
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Over 1000 hp cars can run tko 600's I've got the high end 850 hp clutch and all SFI stuff and it was a $6000 conversion. The only other tranny I really looked at was a $10K complete seqential clutchless. but you would be rebuilding it every year and rearend parts.