How big should I go/what STR?
02-09-2006, 05:21 PM
#1
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How big should I go/what STR? Superman had good feedback with his thread so I'll try my own......
Not sure which way to go for my stall, I get different opinions all the time. I have the LPE GT2-3 cam (207/220 .572/.592 118.5LSA) with Stg. 2.5 5.3Ls heads, milled for 11:1 comp, full bolt-ons and suspension (will spin motor to 6300-6500). 3.23 gear out back and on 17" DR (M/T radials). I want to setup the car for street-racing here in St. Louis (more than just stoplight to stoplight). My goal is to use the biggest stall/most efficient stall while staying on my 17" DRs on our prepped roads. I could care less about driveability, as long as the car can move out. The car will see a lot of track visits too, but I don't want a track-star that can't get out of it's own shadow on the street.
For example.....I looked at Yank's SY3500 w/ 1.63 STR. It'll get me off the line well, but it's not efficient on the big end. Their SS-series has good street manners, but will rip the tires into smoke because of the high STRs. Now their PT4000 has great efficiency in the mid-high end for awsome up-top pull, but is it too much off the line? What do you guys use? I'm looking for all suggestions, not just those I listed. Looking at Fuddle as well.
Not sure which way to go for my stall, I get different opinions all the time. I have the LPE GT2-3 cam (207/220 .572/.592 118.5LSA) with Stg. 2.5 5.3Ls heads, milled for 11:1 comp, full bolt-ons and suspension (will spin motor to 6300-6500). 3.23 gear out back and on 17" DR (M/T radials). I want to setup the car for street-racing here in St. Louis (more than just stoplight to stoplight). My goal is to use the biggest stall/most efficient stall while staying on my 17" DRs on our prepped roads. I could care less about driveability, as long as the car can move out. The car will see a lot of track visits too, but I don't want a track-star that can't get out of it's own shadow on the street.
For example.....I looked at Yank's SY3500 w/ 1.63 STR. It'll get me off the line well, but it's not efficient on the big end. Their SS-series has good street manners, but will rip the tires into smoke because of the high STRs. Now their PT4000 has great efficiency in the mid-high end for awsome up-top pull, but is it too much off the line? What do you guys use? I'm looking for all suggestions, not just those I listed. Looking at Fuddle as well.
02-10-2006, 08:08 AM
#2
just match the stall speed with your dyno graph.....a 36-4000 will all work well with that cam/gear. you just might get an extra tenth or two from the 4000 over the 3600. like you said, with your limit being those stock 17's w DRs, keep the str lower, somewhere around 1.8-2.2. i wouldnt go any higher, i had a yank ss3600 and theyed go into smoke even with a burnout on the street. with that being said, the PT4 gets my vote, itll be a little easier on the tires off the line, but really move once the car gets going
02-10-2006, 08:43 AM
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Originally Posted by s346k
3500 stall with 2.2 str.
should put you right smack in the middle of your powerband, and give you a nice launch. if you want to street race get a 6 spd.
should put you right smack in the middle of your powerband, and give you a nice launch. if you want to street race get a 6 spd.
What would be the downside to a 4000 w 2.2 str (compared to the 3500)?
02-10-2006, 11:40 AM
#5
Originally Posted by TheDIZZ01
For example.....I looked at Yank's SY3500 w/ 1.63 STR. It'll get me off the line well, but it's not efficient on the big end.
02-10-2006, 12:27 PM
#6
Originally Posted by Flame Throwing SS
That is incorrect! This one of Yank's first and very efficient converters. With 3.73 gear and the SY3500, very few M6 could touch it through the rpm range. I would say you need a 4000 stall, if you are dead set on Yank's, then an SS4000 or PT4000 would work well for you. Mind you, some have said that the PT4000 feel too loose for daily driving, but some do it.
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02-10-2006, 04:13 PM
#9
Originally Posted by Pimpium57
Jenibella, would the 4000 be too much for his 17" DR's? he should go towards the PT if anything, lower str and stronger pull to the redline. also, keep in mind his 3.23s and the fact that he doesn't care about around-town driveability.
Anyway, If he just street races, and mostly on Drag Radials, I would suggest he look into the SY4000. With a lower STR, he will not have to worry about blowing the tires loose from a stop, like a higher STR converter would. The SY4000 will feel softer than the other two, but since he doesn't care about streetability, it won't matter.
02-11-2006, 08:16 PM
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Originally Posted by Flame Throwing SS
Actually I am the crew chief for Jen, she goes by her own name.
Anyway, If he just street races, and mostly on Drag Radials, I would suggest he look into the SY4000. With a lower STR, he will not have to worry about blowing the tires loose from a stop, like a higher STR converter would. The SY4000 will feel softer than the other two, but since he doesn't care about streetability, it won't matter.
Anyway, If he just street races, and mostly on Drag Radials, I would suggest he look into the SY4000. With a lower STR, he will not have to worry about blowing the tires loose from a stop, like a higher STR converter would. The SY4000 will feel softer than the other two, but since he doesn't care about streetability, it won't matter.
Basically, you want as positive primary blade angle as possible for top end efficiency with the best compromise on STR for street launching. That said, a Yank SY3500 or custom Fuddle 3600/1.7 WOT LU would be a good starting point. If you go up to a 4000 using the same blade angles for efficiency then you will lose streetability as it will be very "flashy" in traffic, but would give you better WOT kick-downs from a rolling strart. A WOT LU feature would also help you above 5500RPM.
STR has little to do with rolling starts from 50mph. Its all about shift extension and efficiency. My vote:
Yank SY3500
FHP3600/1.7 WOT LU
or a 4000+ variant of either but will result in an even lower STR to maintain similar efficiencies.
02-11-2006, 09:21 PM
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Originally Posted by MNR-0
You are on the right track there.
Basically, you want as positive primary blade angle as possible for top end efficiency with the best compromise on STR for street launching. That said, a Yank SY3500 or custom Fuddle 3600/1.7 WOT LU would be a good starting point. If you go up to a 4000 using the same blade angles for efficiency then you will lose streetability as it will be very "flashy" in traffic, but would give you better WOT kick-downs from a rolling strart. A WOT LU feature would also help you above 5500RPM.
STR has little to do with rolling starts from 50mph. Its all about shift extension and efficiency. My vote:
Yank SY3500
FHP3600/1.7 WOT LU
or a 4000+ variant of either but will result in an even lower STR to maintain similar efficiencies.
Basically, you want as positive primary blade angle as possible for top end efficiency with the best compromise on STR for street launching. That said, a Yank SY3500 or custom Fuddle 3600/1.7 WOT LU would be a good starting point. If you go up to a 4000 using the same blade angles for efficiency then you will lose streetability as it will be very "flashy" in traffic, but would give you better WOT kick-downs from a rolling strart. A WOT LU feature would also help you above 5500RPM.
STR has little to do with rolling starts from 50mph. Its all about shift extension and efficiency. My vote:
Yank SY3500
FHP3600/1.7 WOT LU
or a 4000+ variant of either but will result in an even lower STR to maintain similar efficiencies.
