turbo lag. man vs auto

[blktalon3]

Is their any difference in lag with an auto vs a manual.

 

[Cassera]

I would say since the automatic 1g's have a 13b turbo which flows 360cfm's are less laggier than the manual transmission 14b turbo which flows 465cfm's.

So overall since the 13b is smaller it would spool faster....although the 14b spools really fast as it is.

CFM= Cubic feet per minute

 

[pj91gsx]

The spool time may be better for a smaller turbo, but the turbo isnt flowing as much air as a bigger turbo. So enough though your spool time is better on the small turbo, the bigger turbo still wins in airflow. 10 psi on a 13b is different airflow rating than 10 psi on a 16g.

 

[Cassera]

Yeah, I would just go with a 14B if your looking for spool time because the 13B doesn't spool much faster than the 14B and by the time it spools it will max out really quick....Mind as well go with 14B which has some more output.

Are you getting an automatic just because it spools faster? Or is this just a curiosity that you have?

 

[blktalon3]

I asked that the wrong way. I've already got a auot with an scm6152r ball bearing turbo its not hitting full spool until about 5500rpm I'm just wondering if it's because I'm an auto or do I have another issue. The turbo is working fine. Feels good around town just from a complete stand still when I floor it it seems like its taking longer than it should to reach full spool.
Thanks

 

[Cassera]

I cant take credit for this answer...nor can I approve of this answer, but it seems logical

Check it out for yourself
turbo spooling.. differnce between manual and auto? - LS1TECH

Manuals don't hold the boost as well between shifts. You can powershift ,keep your foot to the floor to help this out and ball bearing turbos generally stay spooled up better and recover quicker.You can downshift in manuals to get quicker spool up.Of course this don't work going up thru the gears which is when you need the two step or antilag.

Autos will generally build boost quick and quite a bit of it ,depending on stall converter. They will keep boost up between shifts. Autos give a bit more driveline loss than manuals..usually estimated at about 5 per cent diff in our cars.

automatics are good cause u can build boost off the line. just brake torque it. my gsx would build about 6-7 psi b4 i would launch

Now that I took a second look.....THAT TURBO IS HUGE! Its only right for turbos that size to spool late but I cant make a diagnosis on a car I have never seen or dont know the circumstances of.......Try a boost leak test.

Do you have any cams installed? I don't see any in your profile. Also consider a twin scroll manifold. It will help with spool.

 

[GDNF2ET]

I asked that the wrong way. I've already got a auot with an scm6152r ball bearing turbo its not hitting full spool until about 5500rpm I'm just wondering if it's because I'm an auto or do I have another issue. The turbo is working fine. Feels good around town just from a complete stand still when I floor it it seems like its taking longer than it should to reach full spool.
Thanks

You need a higher stall torque converter to help spool that turbo..I hope you don't still have the stock cams in it

 

[blktalon3]

I'm working on the TC and yep stock cams. Does the higher stall converter help mainly with just brake boosting or with other things as well, driving around town, etc...

 

[thiazole]

An automatic will help spool up in virtually all conditions, especially if you have a looser torque converter. Consider the following situations - you are on the highway in your highest gear with the rpms at 3000. You need to pass someone so you push the throttle about half the way to the floor. In a manual, because 3000 rpm is so much lower than where you are building boost, your car won't respond. In an automatic, your converter will be locked up, but as soon as you start pushing the gas a bit, the converter will unlock and instantly your rpms will jump - probably to 4000+ where your turbo will spool much more easily allowing your car to accelerate the way you want.

Now lets say you are on the street going 35mph in 3rd or 4th gear and some ricer gets beside you and you assume with his joke of a car that he wouldn't try to race you. You are wrong - he jumps on it and starts pulling cars on you. In a manual, you floor it, but your rpms are too low so nothing happens - you have to down shift. By the time you do, the ricer is already pretending victory flashing his brake lights and refuses to race again. In an automatic, you floor it, it automatically downshifts, and good bye ricer.

Lastly, you are at a stop light and said ricer is beside you, but you again wrongly assume he doesn't want to race. He launches, but with a manual, it is already too late for you - the time it will take you to rev the engine enough to launch, he is already gone flashing his ricer brake lights at you. In an automatic with a sufficient torque converter, you floor it, your rpms instantly climb to a level where you make boost and the ricer is in your rear view mirror in no time.

And, of course, there is the 1/4 mile track - as long as your stall speed is sufficient, you can make whatever boost you want - you just power brake and push the throttle enough to build the boost you want to build. And if you find that you still can't build enough even when flooring it, you can always use anti-lag. And the best part is, instead of having to choose between hooking up and bogging, spinning your tires but maintaining boost, or slipping the crap out of and destroying your clutch to keep your rpms up, your torque converter will hold you at that rpm and your 60ft times will be better than ever (and more consistent than ever).

 

[Cassera]

Now lets say you are on the street going 35mph in 3rd or 4th gear and some ricer gets beside you and you assume with his joke of a car that he wouldn't try to race you. You are wrong - he jumps on it and starts pulling cars on you. In a manual, you floor it, In an automatic, you floor it, it automatically downshifts, and good bye ricer.

Lastly, you are at a stop light and said ricer is beside you, but you again wrongly assume he doesn't want to race. He launches, but with a manual, it is already too late for you - the time it will take you to rev the engine enough to launch, he is already gone flashing his ricer brake lights at you. In an automatic with a sufficient torque converter, you floor it, your rpms instantly climb to a level where you make boost and the ricer is in your rear view mirror in no time.

Everything you said was true.....As for the quoted part,

 

[thiazole]

I'm working on the TC and yep stock cams. Does the higher stall converter help mainly with just brake boosting or with other things as well, driving around town, etc...

Since I didn't directly answer your question, I've never had a high stall lock up torque converter, but in my old Chevelle, I had a regular 3500rpm stall converter and it was a blast to drive. It was a lot like a regular torque converter as long as you weren't stepping on the gas much, but the second you put any gas down, the rpms would instantly jump to and hold 3500rpm until your speed naturally moved you above those rpms. It basically felt like getting a 100 shot of nitrous oxide - you go from nothing to balls to the walls almost instantly when your torque converter stalls. The downside to a non-lock up is that your torque converter flares a lot - you drive into a head wind, and your rpms will climb a bunch. It can make highway driving not very fun, especially if you car doesn't like higher rpms. My Chevelle had a 427 that didn't like revving, and sometimes on the highway, if I was on any kind of slope or driving into a head wind, I'd be running 3500 rpms in high gear just to do 60. If your engine is ok with revving a little bit, then it won't bother you as much. Presumably, with a lock up converter, it will lock up on the highway and won't flare for head winds or minor hills.

Everything you said was true.....As for the quoted part,

Those are all pretend scenarios, of course, to demonstrate the versatility of a higher stall torque converter in an auto transmission.

 

[pboglio]

Short answer is "No", the automatic spools at the same rpm as a manual or close enough that it makes no difference. My 13g hit 17 psi at 2500 rpms, 14b at 2800 rpms, small 16g clipped and at 3300 rpms. You have a large turbo and taller gearing (i.e. 4 speeds vs. 5). Bad spooling turbo and tall gears aren't your friend on the street, though not having to lift between shifts definitely helps. Time to look for a quicker spooling turbo.

 

[KazooGS-T]

Everything you said was true.....As for the quoted part,

Seriously, that's kind of hypocritical as I'm sure almost everyone has done some "spirited driving" before, and some do it much more than others, with a more controlled/private environment.

As for the stall, they do help out a good bit, IPT claims gains of .5 to 1 full second off of E.T.'s... You are given a much better ability to build boost/be in your power band.

You need to pick up some cams and a TC, for sure.

 

[thiazole]

Short answer is "No", the automatic spools at the same rpm as a manual or close enough that it makes no difference. My 13g hit 17 psi at 2500 rpms, 14b at 2800 rpms, small 16g clipped and at 3300 rpms. You have a large turbo and taller gearing (i.e. 4 speeds vs. 5). Bad spooling turbo and tall gears aren't your friend on the street, though not having to lift between shifts definitely helps. Time to look for a quicker spooling turbo.

But unlike a manual, your rpms rise when you step on the gas in an automatic because the torque converter unlocks and slips. Your clutch in a manual holds a constant rpm. So yes, they will spool the same at the same rpms, but you will get higher rpms when you step on the gas in an automatic and therefore will build boost faster. If you had a car with an auto and a car with a manual, and geared them so that 2nd gear was identical and both drove 20mph and both floored the gas, the auto would spool up WAY faster than the manual, because the rpm would shoot up in the auto while it would stay constant in the manual (except with a change in velocity). As far as the auto having taller gears, that only matters in 1st gear. Any other time, you can simply downshift, and an auto will downshift 3X faster than a manual. Besides, 1st gear is WAY too low in the manual anyway - seems like you can only hold low for a second or so before you need to shift when racing. There is a good reason a lot of people opt for a taller 1st gear when they get their manual trannies rebuilt.

 

[Cassera]

Seriously, that's kind of hypocritical as I'm sure almost everyone has done some "spirited driving" before, and some do it much more than others, with a more controlled/private environment.

Yeah, but you not allowed to speak freely about it on the forums....It does suck, but than again WE were the ones who signed up for THIS forum and I'm sure the owner made that rule for a reason although some may not agree with it. <---Well that's a whole other thread

Short answer is "No", the automatic spools at the same rpm as a manual or close enough that it makes no difference. My 13g hit 17 psi at 2500 rpms, 14b at 2800 rpms, small 16g clipped and at 3300 rpms. You have a large turbo and taller gearing (i.e. 4 speeds vs. 5). Bad spooling turbo and tall gears aren't your friend on the street, though not having to lift between shifts definitely helps. Time to look for a quicker spooling turbo.

Well actually with a automatic you can Break boost for the jump out the hole. That is after all what the OP was concerned about because he said it feels a little slow from a complete stand still.

 

[blktalon3]

Actually it brake boosts pretty good. I let off at about 10 psi 'cause I didn' want to heat the tranny up too much but it still took off like a bat out of hell. I was mainly talking about flooring it from a dead stop with out brake boosting it. I played with the timing some and knocked about 500 rpm off the spool time. I'm now hitting 22 psi about 5000rpm. I need to check for boost leaks again also. Tranny upgrades are next though. And as far as a quicker spooling turbo... naa,I love this thing, it hits like a ton of bricks when it does spool, not bad around town either and thats with a bone stock tranny. As far as the original question I was just curious, it wasn't bothering me that bad.
Thanks for all the input.

 

[pboglio]

But unlike a manual, your rpms rise when you step on the gas in an automatic because the torque converter unlocks and slips. Your clutch in a manual holds a constant rpm. So yes, they will spool the same at the same rpms, but you will get higher rpms when you step on the gas in an automatic and therefore will build boost faster. If you had a car with an auto and a car with a manual, and geared them so that 2nd gear was identical and both drove 20mph and both floored the gas, the auto would spool up WAY faster than the manual, because the rpm would shoot up in the auto while it would stay constant in the manual (except with a change in velocity). As far as the auto having taller gears, that only matters in 1st gear. Any other time, you can simply downshift, and an auto will downshift 3X faster than a manual. Besides, 1st gear is WAY too low in the manual anyway - seems like you can only hold low for a second or so before you need to shift when racing. There is a good reason a lot of people opt for a taller 1st gear when they get their manual trannies rebuilt.

The autos don't spool faster in any circumstances on a DSM. They were sold with smaller turbos for the very fact people who would buy an automatic were a tamer demographic and would want their torque coming in earlier than a 14b could provide.

The gearing isn't a huge deal since the lack of shifting eliminates several seconds of shift times. The problem I had was launching, but the newer launch control options and torque converter options kind of make this a moot point. Brake torquing can toss a auto tranny very quickly and I dont' recommend it without some serious mods to the tranny cooling system.

 

[thiazole]

The autos don't spool faster in any circumstances on a DSM. They were sold with smaller turbos for the very fact people who would buy an automatic were a tamer demographic and would want their torque coming in earlier than a 14b could provide.

The gearing isn't a huge deal since the lack of shifting eliminates several seconds of shift times. The problem I had was launching, but the newer launch control options and torque converter options kind of make this a moot point. Brake torquing can toss a auto tranny very quickly and I dont' recommend it without some serious mods to the tranny cooling system.

So why don't you address my arguments instead of saying I'm wrong and just making assertions? When you are in an automatic and the torque converter is locked up (ie, just like a clutch) and you step on the gas, does the torque converter unlock or not? If it unlocks, does your rpm not then rise as the torque converter slips or not? And if the rpms rise (without the car moving faster yet), would the car spool faster or not? Does your manual do that? I don't know about you, but my car spools faster at 3500rpm than it does at 3000rpm. So if I'm cruising at 3000rpm in a manual and step on the gas, it will stay at 3000rpm and my turbo will spool more slowly. If it jumped to 3500rpm like an auto, the turbo will spool more quickly. Are you saying that is false - that turbos spool faster at lower rpms?

Also, we ARE mostly talking about looser aftermarket torque converters, although I've owned plenty of stock automatics and when you step on the gas while cruising, even if you are past the stall speed, the rpms rise quite a bit after the torque converter unlocks (and when it locks, it almost feels like you shifted into a higher gear because the rpms drop back down quite a bit). So tear down my logic instead of saying it is false without explaination:

1. When cruising, autos see a rise in rpms when you step on the gas and the torque converter unlocks and this rise in rpms will allow the turbo to spool faster: true or false.
2. Autos automatically downshift very quickly when you floor them and your rpms are too low, thus spooling the turbo quicker: true or false.
3. If you are taking off from a stop light slowly and are at say 1300rpm when you find the need to take off faster, simply flooring it will cause the auto to immediately climb to the stall speed and will therefore spool much faster than the manual which will be stuck at 1300rpm: true or false.

 

[FUNWHEELDRIVE]

So why don't you address my arguments instead of saying I'm wrong and just making assertions? When you are in an automatic and the torque converter is locked up (ie, just like a clutch) and you step on the gas, does the torque converter unlock or not? If it unlocks, does your rpm not then rise as the torque converter slips or not? And if the rpms rise (without the car moving faster yet), would the car spool faster or not? Does your manual do that? I don't know about you, but my car spools faster at 3500rpm than it does at 3000rpm. So if I'm cruising at 3000rpm in a manual and step on the gas, it will stay at 3000rpm and my turbo will spool more slowly. If it jumped to 3500rpm like an auto, the turbo will spool more quickly. Are you saying that is false - that turbos spool faster at lower rpms?

Also, we ARE mostly talking about looser aftermarket torque converters, although I've owned plenty of stock automatics and when you step on the gas while cruising, even if you are past the stall speed, the rpms rise quite a bit after the torque converter unlocks (and when it locks, it almost feels like you shifted into a higher gear because the rpms drop back down quite a bit). So tear down my logic instead of saying it is false without explaination:

1. When cruising, autos see a rise in rpms when you step on the gas and the torque converter unlocks and this rise in rpms will allow the turbo to spool faster: true or false.
2. Autos automatically downshift very quickly when you floor them and your rpms are too low, thus spooling the turbo quicker: true or false.
3. If you are taking off from a stop light slowly and are at say 1300rpm when you find the need to take off faster, simply flooring it will cause the auto to immediately climb to the stall speed and will therefore spool much faster than the manual which will be stuck at 1300rpm: true or false.

instead of TRYING to make pbaglio look like an idiot... and making yourself seem very very arogant, since you feel so strongly about your point, why dont you explain it better. He obviously disagrees with what your saying but dont make him like like an idiot while making yourself look extremely arogant at the same time.

 

[thiazole]

instead of TRYING to make pbaglio look like an idiot... and making yourself seem very very arogant, since you feel so strongly about your point, why dont you explain it better. He obviously disagrees with what your saying but dont make him like like an idiot while making yourself look extremely arogant at the same time.

How am I not explaining it? What part of higher rpms = faster spool is so hard to understand? I've repeated it in ad nauseum detail 3 or 4 times already. Do you think I like writing 5 paragraphs of detail just to get a 2 line "no I'm sure you are wrong" type rebuttal?

 

[habitatguy187]

Everything you said was true.....As for the quoted part,

Sorry I didn't realize you were promoted to Moderator.

How am I not explaining it? What part of higher rpms = faster spool is so hard to understand? I've repeated it in ad nauseum detail 3 or 4 times already. Do you think I like writing 5 paragraphs of detail just to get a 2 line "no I'm sure you are wrong" type rebuttal?

And where did this guy come from?


Sounds like you're just trying to prove to everyone that autos are better. As far as that goes, do what you like. I like rowing through gears, but it's w/e.



And OP, I think your question as already been answered (no), but you need a stall like already stated.

 

[ramsack]

a torque converter will slip no matter what unless it has a lockup design and is told to lock up. stall isn't the same as the lockup clutch disengaging and having the revs raise. it is the point of most torque multiplied to the transmission through the torque converter at a certain point of the car starting to move. i would take an automatic for drag any day over manual. there isn't a single human being in the world that can shift a manual close to the speed an automatic can shift. btw i have a manual car.

i say if you have an automatic, stay with it if you like it. it can be made very fast, and the low-end torque potential is immense and as your rpms climb the engine speed and trans speed come close together. you win some good money bracket racing it.

 

[thiazole]

And where did this guy come from?


Sounds like you're just trying to prove to everyone that autos are better. As far as that goes, do what you like. I like rowing through gears, but it's w/e.

I do think YOUR 60' time and 1/4 mile time would be vastly improved with an auto... If you don't mind your current numbers, though, stick with the manual. I for one got tired of having to choose between raping my tires or bogging when launching my car at the track with that 1 in 10 "perfect launch" which is no better than an average launch with an automatic and a decent torque converter.

I'm not just an auto fan boy, though. There are definitely reasons to own a manual. Still, I suspect that most of the haters are people who have never even driven a car with an auto and a high stall torque converter.

 

[GDNF2ET]

Just to help clear one thing up; all 1g turbo cars ( 91-94) have non-lockup converters..
I had a bolt on 35r with the smallest exhaust housing and the highest stalling re-stalled converter available( Hughes) and it was not enough to brake boost the car off the line within a reasonable amount of time..Thats why I'm trying out the Hta68 this season when my tranny gets done..Hope this helps

 

[pboglio]

So why don't you address my arguments instead of saying I'm wrong and just making assertions? When you are in an automatic and the torque converter is locked up (ie, just like a clutch) and you step on the gas, does the torque converter unlock or not? If it unlocks, does your rpm not then rise as the torque converter slips or not? And if the rpms rise (without the car moving faster yet), would the car spool faster or not? Does your manual do that? I don't know about you, but my car spools faster at 3500rpm than it does at 3000rpm. So if I'm cruising at 3000rpm in a manual and step on the gas, it will stay at 3000rpm and my turbo will spool more slowly. If it jumped to 3500rpm like an auto, the turbo will spool more quickly. Are you saying that is false - that turbos spool faster at lower rpms?

Also, we ARE mostly talking about looser aftermarket torque converters, although I've owned plenty of stock automatics and when you step on the gas while cruising, even if you are past the stall speed, the rpms rise quite a bit after the torque converter unlocks (and when it locks, it almost feels like you shifted into a higher gear because the rpms drop back down quite a bit). So tear down my logic instead of saying it is false without explaination:

1. When cruising, autos see a rise in rpms when you step on the gas and the torque converter unlocks and this rise in rpms will allow the turbo to spool faster: true or false.
2. Autos automatically downshift very quickly when you floor them and your rpms are too low, thus spooling the turbo quicker: true or false.
3. If you are taking off from a stop light slowly and are at say 1300rpm when you find the need to take off faster, simply flooring it will cause the auto to immediately climb to the stall speed and will therefore spool much faster than the manual which will be stuck at 1300rpm: true or false.

Logic has to be based on some reality, I argue from first hand experience and leave logic to the philosophers. I'll go ahead and disagree with point 3). I've been in that situation many times and slipping isn't going to help you. In that scenario, you left foot brake and floor the throttle to load the motor and BUILD boost WHILE you are moving. In some case its better than downshifting, like when your already in 1st gear and have nowhere else to go, and its alot less upsetting to the chassis than a downshift.