Is my explanation correct on why you need a lower stall converter with nitrous?
10-24-2009, 09:19 PM
#1
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Is my explanation correct on why you need a lower stall converter with nitrous? Didn't know where to post this so I put it here too.
I am having trouble explaining to a friend why a lower stall converter nets you better times when using nitrous. I told him it will flash to high and you can't use the nitrous as long. This is what I was thinking, the numbers are just an example. If I was not using nitrous and in 3rd gear at 6200rpms(not redline) with a 4000 stall I would cross the line at 122 mph(depending on tire size, gear, etc). But if I was using nitrous the 4000 stall will continue to slip to much from all the torque(now becoming a much higher stall than 4000) and when I reached 7000rpms(redline) in 3rd gear I would cross the line at maybe 128mph. Only 6 mph more when in fact I should have crossed the line at 138 mph when at 7000rpms, but since I was using the incorrect stall it kept slipping well before the intended mph could catch up to 7000rpms. Since the converter was slipping way to high I lost the ability to use nitrous for at least 10 more mph in 3rd gear. Does this sound correct?
I am having trouble explaining to a friend why a lower stall converter nets you better times when using nitrous. I told him it will flash to high and you can't use the nitrous as long. This is what I was thinking, the numbers are just an example. If I was not using nitrous and in 3rd gear at 6200rpms(not redline) with a 4000 stall I would cross the line at 122 mph(depending on tire size, gear, etc). But if I was using nitrous the 4000 stall will continue to slip to much from all the torque(now becoming a much higher stall than 4000) and when I reached 7000rpms(redline) in 3rd gear I would cross the line at maybe 128mph. Only 6 mph more when in fact I should have crossed the line at 138 mph when at 7000rpms, but since I was using the incorrect stall it kept slipping well before the intended mph could catch up to 7000rpms. Since the converter was slipping way to high I lost the ability to use nitrous for at least 10 more mph in 3rd gear. Does this sound correct?
Last edited by djm_e22; 10-25-2009 at 02:57 PM.
10-25-2009, 01:46 PM
#2
I'm no converter expert but it sounds like your headed in the right direction. I pretty much understand it the same way as you.
Basically a 3600 N/A converter will act like a 4200 (just an example) nitrous conveter because of the extra torque that the nitrous provides.
Try posting in the nitrous section or the trans/converter section because those guys will be able to tell you in detail whats going on.
Basically a 3600 N/A converter will act like a 4200 (just an example) nitrous conveter because of the extra torque that the nitrous provides.
Try posting in the nitrous section or the trans/converter section because those guys will be able to tell you in detail whats going on.
10-25-2009, 02:28 PM
#3
It has more to do with rear gear and tire height. My last car had a 4000 stall with a 4.10 gear and 28 inch tall tire, shifted and redlined at 7k (BBC). It had no problem making it threw the traps on the bottle.
With a GOOD stall from a GOOD company the stall should not be the problem..... there are guys runing around in cars that are pretty much daily drivers with 4400 stalls no problem, lot's of guys with big stall's and the bottle no problem.........
With a GOOD stall from a GOOD company the stall should not be the problem..... there are guys runing around in cars that are pretty much daily drivers with 4400 stalls no problem, lot's of guys with big stall's and the bottle no problem.........
10-25-2009, 03:02 PM
#4
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It has more to do with rear gear and tire height. My last car had a 4000 stall with a 4.10 gear and 28 inch tall tire, shifted and redlined at 7k (BBC). It had no problem making it threw the traps on the bottle.
With a GOOD stall from a GOOD company the stall should not be the problem..... there are guys runing around in cars that are pretty much daily drivers with 4400 stalls no problem, lot's of guys with big stall's and the bottle no problem.........
With a GOOD stall from a GOOD company the stall should not be the problem..... there are guys runing around in cars that are pretty much daily drivers with 4400 stalls no problem, lot's of guys with big stall's and the bottle no problem.........
10-25-2009, 03:15 PM
#6
I bet if you went with a 3000 or 3600 stall it would net you better times with nitrous. At least if that is trully a 4000 stall made for your combination. I know of guys who say they have a 4000 stall but than say they still have a 4000 stall after they lower their gears(higher numerically) or get taller tires. Both of these will cause your stall to become lower.
All the nitrous guys I know run 4500 or so plus stalls and the faster ones are in the 8's.
A 4000 stall is a 4000 stall, the tire height and rear gear does not effect this... the gear and tire effect what RPM you will be at going threw the traps.
When you look at your RPM this is really based off of your gear and tire..... find an oline gear calculator that gives you trap RPM and I am sure you will notice that the RPM chances when you play with the gear and tire size.... I don't think there are any that ask for stall size. Now if you have a worthless junk stall and does not want to lock or unlock then this can cause problems..
My stall was a COAN..... it did not get along will with the power my motor was making haha.
You might look at the pro's with nitrous cars and the faster guys on here with nitrous car's and see what stall range they run........ I don't know any serious racer that is under like 5000, 4500 and up for the serious street guys. Im sure my next build will have a 5000...
Last edited by JUICED96Z; 10-25-2009 at 03:23 PM.
10-25-2009, 03:19 PM
#7
Didn't know where to post this so I put it here too.
I am having trouble explaining to a friend why a lower stall converter nets you better times when using nitrous. I told him it will flash to high and you can't use the nitrous as long. This is what I was thinking, the numbers are just an example. If I was not using nitrous and in 3rd gear at 6200rpms(not redline) with a 4000 stall I would cross the line at 122 mph(depending on tire size, gear, etc). But if I was using nitrous the 4000 stall will continue to slip to much from all the torque(now becoming a much higher stall than 4000) and when I reached 7000rpms(redline) in 3rd gear I would cross the line at maybe 128mph. Only 6 mph more when in fact I should have crossed the line at 138 mph when at 7000rpms, but since I was using the incorrect stall it kept slipping well before the intended mph could catch up to 7000rpms. Since the converter was slipping way to high I lost the ability to use nitrous for at least 10 more mph in 3rd gear. Does this sound correct?
I am having trouble explaining to a friend why a lower stall converter nets you better times when using nitrous. I told him it will flash to high and you can't use the nitrous as long. This is what I was thinking, the numbers are just an example. If I was not using nitrous and in 3rd gear at 6200rpms(not redline) with a 4000 stall I would cross the line at 122 mph(depending on tire size, gear, etc). But if I was using nitrous the 4000 stall will continue to slip to much from all the torque(now becoming a much higher stall than 4000) and when I reached 7000rpms(redline) in 3rd gear I would cross the line at maybe 128mph. Only 6 mph more when in fact I should have crossed the line at 138 mph when at 7000rpms, but since I was using the incorrect stall it kept slipping well before the intended mph could catch up to 7000rpms. Since the converter was slipping way to high I lost the ability to use nitrous for at least 10 more mph in 3rd gear. Does this sound correct?
Get a converter that is built for nitrous, and you can stall it up to 5000 if you want, and it will work fine. The top end slippage, and the stall speed do NOT have any relation, which is what you are assuming.
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10-25-2009, 03:28 PM
#8
That is what happens when you use a converter that isn't built for what you are trying to do yes.
Get a converter that is built for nitrous, and you can stall it up to 5000 if you want, and it will work fine. The top end slippage, and the stall speed do NOT have any relation, which is what you are assuming.
Get a converter that is built for nitrous, and you can stall it up to 5000 if you want, and it will work fine. The top end slippage, and the stall speed do NOT have any relation, which is what you are assuming.
If you don't have a good stall that is built for your combo then you will have problems........
Like I said, there are guys with 4400's on the street no probem. There is a local Supra that I think has a 4800 or a 5000 going into it.
If you have a good stall then the gear and tire size is what creates the trap RPM, if it is a stall that is junk or not built for your combo then it is the stall.
10-25-2009, 04:33 PM
#10
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That is what happens when you use a converter that isn't built for what you are trying to do yes.
Get a converter that is built for nitrous, and you can stall it up to 5000 if you want, and it will work fine. The top end slippage, and the stall speed do NOT have any relation, which is what you are assuming.
Get a converter that is built for nitrous, and you can stall it up to 5000 if you want, and it will work fine. The top end slippage, and the stall speed do NOT have any relation, which is what you are assuming.
I meant was if you lower your gears(higher numerically) it will lower your stall and if you get taller tires or higher gears(lower numerically) it will raise your stall. If you say thats wrong than the Circle-D guy is an idiot. Plus I read several places that say if you lower your gears or lose some weight it will cause you to have a lower stall speed cause it is easier to move your car.
Last edited by djm_e22; 10-25-2009 at 04:38 PM.
10-25-2009, 04:41 PM
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That is what happens when you use a converter that isn't built for what you are trying to do yes.
Get a converter that is built for nitrous, and you can stall it up to 5000 if you want, and it will work fine. The top end slippage, and the stall speed do NOT have any relation, which is what you are assuming.
Get a converter that is built for nitrous, and you can stall it up to 5000 if you want, and it will work fine. The top end slippage, and the stall speed do NOT have any relation, which is what you are assuming.
Would you please explain a little about the differences of top slippage & stall, mechanically?
I guess I need to read more about how a stall works...
10-25-2009, 04:51 PM
#12
a stall has fins in it...way i understand is how much of a bend they have makes your stall speed...a 8 inch comverter can only bend the fins so much and as you make more power youll need a 9 inch or 10 inch one with more fins so they arent bent as much...the more they are bent the less efficient it is...
so if you get a na converter thats a 4000 (400 hp) and put 400 worth of nitrous to it (800 hp) it might become a 7000 converter...
normally the higher the stall speed the less efficient it is...in other words lose mph
so if you get a na converter thats a 4000 (400 hp) and put 400 worth of nitrous to it (800 hp) it might become a 7000 converter...
normally the higher the stall speed the less efficient it is...in other words lose mph
10-26-2009, 06:20 AM
#13
It's not exactly that way ratio wise, but you are correct on the size and fin angle.
bigger the converter it is the closer to complete lockup it will get, hence why promod converter's are 10.5 inch.
Bigger the converter, the more fins it has, the more effecient it can be.
bigger the converter it is the closer to complete lockup it will get, hence why promod converter's are 10.5 inch.
Bigger the converter, the more fins it has, the more effecient it can be.
10-26-2009, 01:22 PM
#14
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JL, so how does top end slippage differ from stall, mechanically?
Do many serious street/strip cars run lock-up converters?
- and do they lock up at the end of the track?
I've always been a stick guy, but am considering switching to an auto with OD
Do many serious street/strip cars run lock-up converters?
- and do they lock up at the end of the track?
I've always been a stick guy, but am considering switching to an auto with OD
10-26-2009, 01:25 PM
#15
Crap I'm an idiot I meant was if you have a 5000 stall built to stall at 5000 with nitrous than yeah that makes since, but if you have a 5000 stall built for n/a it will not work so great with nitrous. Is that not right?
I meant was if you lower your gears(higher numerically) it will lower your stall and if you get taller tires or higher gears(lower numerically) it will raise your stall. If you say thats wrong than the Circle-D guy is an idiot. Plus I read several places that say if you lower your gears or lose some weight it will cause you to have a lower stall speed cause it is easier to move your car.
I meant was if you lower your gears(higher numerically) it will lower your stall and if you get taller tires or higher gears(lower numerically) it will raise your stall. If you say thats wrong than the Circle-D guy is an idiot. Plus I read several places that say if you lower your gears or lose some weight it will cause you to have a lower stall speed cause it is easier to move your car.
Are you talking about what you can stall the car to on the brake before you launch or what it flashes to once the car starts to move? I can see gearing affecting the flash speed but if you ask me it is not really effecting the stall like you think, with a factory stall and different gears you will go threw the RPM's faster or slower.
With loosing weight the car will accelerate faster because there is less weight for the car to carry.
I think you are just looking into it a little to deep.
With a wider stall it can be more efficent but you have more weight/rotational weight.... in the end you have to find more of a middle ground.....
I would also rather loose MPH to gain ET...
10-26-2009, 01:40 PM
#16
Probably not the best explanation, if I had a pad and paper it would make more sense.
I'm with Juiced, the people I trust with converter's aren't sponsor's on here either... and in an effort not to offend I won't get into that much farther.
10-26-2009, 02:11 PM
#17
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Ok ok I think I finally got the answer I was looking for on why a high stall converter built for only motor purposes won't work well when using nitrous. Chris from Circle-D I'm sorry if I screw up what you said. First he told me mine is a 4400 on the nitrous but on motor it will be more like a 3600. If you were to use nitrous on a 4400 all motor converter the stall would jump so high in the rpms causing alot of slipping(being exremely ineffecient) which in turn causes up to 30% power loss through heat. So a 200 shot can lose about 60 horses through a converter not stalled correctly for nitrous.
10-26-2009, 02:34 PM
#18
Ok ok I think I finally got the answer I was looking for on why a high stall converter built for only motor purposes won't work well when using nitrous. Chris from Circle-D I'm sorry if I screw up what you said. First he told me mine is a 4400 on the nitrous but on motor it will be more like a 3600. If you were to use nitrous on a 4400 all motor converter the stall would jump so high in the rpms causing alot of slipping(being exremely ineffecient) which in turn causes up to 30% power loss through heat. So a 200 shot can lose about 60 horses through a converter not stalled correctly for nitrous.
Yep, and to me a quality stall will run at a minimum of $800, my next built will have a stall in the $1,200 and up range..... Thats all I will say on here about it to avoid offending someone.
Last edited by JUICED96Z; 10-26-2009 at 02:40 PM.