Tourqe Convertor Multiplier

[Pewter02Camaro]

I have heard of people not showing as much power on a chassis dyno because of the convertor, is this ture? If so is that because of the STR multiplier or because of the actual stall speed i.e. going from a stock stall to say a 3200. Also what is the STR of a stock convertor as well as stock stall?
I've been reading a lot of the convertor threads and could not find these answers. I am contemplating going with the s10 4x4 stall and dont want to "lose" power on the dyno. Any input will be greatly appreciated.

Jeff

[LETZRIDE]

Re: Tourqe Convertor Multiplier

I believe stock is about 1.6 or 1.8 (I think 1.6 though)

The reason you get less dyno numbers is because the dyno pull happens in third gear when you don't have your converter locked. Because of this your converter is slipping.

The lower the STR the more efficient the car is up top, the higher the STR the less efficient it is up top, but you make up for it with the gobs of torque on the launch...

if you get a multi clutch converter you are able to lock it up in every gear without damaging the converter, and then the converter doesn't really slip.

This is kinda why dyno numbers don't mean much, especially in auto cars...you could dyno lets say 250 hp before the converter swap and run 13.9, and then dyno 225hp AFTER the swap, but you'll be faster and run like 13.5

I know you don't want the standard stalls to be locked during a shift, but I still need to look into if we can lock it for all of 3rd, then unlock it for the shift, then lock it back up...


There are a bunch of guys on ls1tech who lock there converters at the track just to trap higher mph times (because now you won't be slipping )...but its not reccommended

[97rs4life]

Re: Tourqe Convertor Multiplier

yea I dyno low for what I have into my engine because of my PI Vig. converter. Sucks when people ask you how much power you are putting down, but then it is funny when you reel off nice times and then tell them your rwhp. lol

[Pewter02Camaro]

Re: Tourqe Convertor Multiplier

So if i went with a s10 4x4 convertor is the STR the same? And if so would it be worth it just to get the 3200 stall speed? or am i just barking up the wrong tree. I'm also trying to not spend a ton on it either. I guess what im trying to say is should i do a convertor?

Current mods are as follows:

K&N FIPK, P&P upper and lower intakes, Worked heads, light P&P, #105 springs, cut guides, 3 angle valve job, GT2 Cam, OE-R lifters, Yella terrra 1.7rockers and pushrods, rebuilt shortblock with balance shaft delete, electric water pump, possible long tubes funds permitting, 3.42 gear, stock trans doing vette servo soon, 100 wet shot, MSD dis-4, Full tune, probobly forgetting somthing...

Thoughts?

[ssms5411]

Re: Tourqe Convertor Multiplier

The 4cly. 2.2 S-10 conveter is going to be like the same STR I would think since it is a factory stall , it raises the RPM since it was made for a 4cyl. , best thing to do is a aftermarket stall, or check in your area, I found a machine shop who builds there own 9.5" stalls for $290 and its about 20 mins. from my house.

[LETZRIDE]

Re: Tourqe Convertor Multiplier

So if i went with a s10 4x4 convertor is the STR the same? And if so would it be worth it just to get the 3200 stall speed? or am i just barking up the wrong tree. I'm also trying to not spend a ton on it either. I guess what im trying to say is should i do a convertor?

Current mods are as follows:

K&N FIPK, P&P upper and lower intakes, Worked heads, light P&P, #105 springs, cut guides, 3 angle valve job, GT2 Cam, OE-R lifters, Yella terrra 1.7rockers and pushrods, rebuilt shortblock with balance shaft delete, electric water pump, possible long tubes funds permitting, 3.42 gear, stock trans doing vette servo soon, 100 wet shot, MSD dis-4, Full tune, probobly forgetting somthing...

Thoughts?

I personally wouldn't bother doing a stall unless it was an aftermarket stall with a higher STR..just raising rpm for launch does little to nothing...gotta look at it like this.

Stock stall is 1.6 ratio
Aftermarket mine is 2.2 ratio

Lets say you make 200 rwtq at 3200 rpm(keep the numbers simple)

Lets say both stalls stall to 3200 rpm

with the stock stall you will have 1.6 x 200 = 320 tq at the output shaft

with the aftermarket stall you will have 2.2 x 200 = 440 tq at the output shaft

120 tq difference at exactly the same stall speed on the exact same car...

I guess I just think like, if you're going to do the work, why not actually do the work? To me going to another factory type stall with the same STR is like going from 3.08 to 3.23 gears...if you're gunna do gears, do gears if you know what I mean...

But this is my opinion and how I look at things...

Careful of shops that do there own stalls...I have heard horror stories, even with some of the sponsors who did stalls...I can't remember exactly which one, so I won't throw out names since I don't want to soil anyones reputation by accident.
But if your converter goes bad, kiss that transmission of yours good-bye to...

Search tq converters over on ls1tech and you'll find a number of guys who bought from one of the sponsers (used to be sponsers) and the converters went sour and took out a number of trannies on guys...

I'm not saying don't buy from side shops...just be weary...I had an offer for a converter for around 200 something dollars locally as well...I opted to go with a TCI from abbott instead...

[bigbrian442]

Re: Tourqe Convertor Multiplier

[QUOTE=LETZRIDE;966298.just raising rpm for launch does little to nothing....[/QUOTE]


Half a second is not little or nothing. 15.4 to 14.9 from just changing from a stock converter to a S10 converter.

[ssms5411]

Re: Tourqe Convertor Multiplier

Letzride, theres nothing wrong with shops that do their own stalls if its in his area , the shop I talked to making the 9.5" stalls use the same parts by TCI and Yank but can cut costs down by not having to advertize all over, they just do ebay and here locally. They do their own machine work and are known locally in AZ for over 10 years now for LT1's, LS1's and any vehicle who wants a stall made and seem like they do quite well from the size of their shop and couldn't believe how clean it was. Have same warranty as TCI and the others, actually better. Within their warranty even if you go over the rated HP like if it is built for 600 HP , they will still replace their stall with a new one, they like the feedback on stalls and track times(don't care about dynos, so if I get one put in they want to know how my stall did from a stock 12" to their Billet 9.5" stall with a certian STR, so they keep track of this so they know what to suggest to the next customer. Its a nice shop and its the one that will do built trannies by request like a 600 HP tranny for $1030 and have the same 1 year warrranty and no core needed bbut still wanted track numbers form before and after, he said he has done 3.8 camaros before but not turbo charged so I think he wants to post results of their 3.8 convertor , like they do with their LT1's, LS1's and LS2's. So when I told him i would turn the boost up in this winter he wanted me to get some turbo runs in with the 12" and then get the 9.5" stall and run the same boost to see the gain I think the weigt diffrence alone is 15-20LBS from a 12" to a 9.5" and still has a lock up on it. I have 3.73's right now and I just found my other used Toren LSD and 3.42 gears( look great still was surprised) which I'm going to install in a 3.23 LSD 10 bolt to see how big of difference in the spool time will be. I have nothing else to do and aslong as I can sit there and not get my back into too much trouble it will give me something to do. I also didn't know who can only do certain STR's with certain stall speed. He had a chart he looked at to see what worked together.

[LETZRIDE]

Re: Tourqe Convertor Multiplier

Letzride, theres nothing wrong with shops that do their own stalls if its in his area , the shop I talked to making the 9.5" stalls use the same parts by TCI and Yank but can cut costs down by not having to advertize all over, they just do ebay and here locally. They do their own machine work and are known locally in AZ for over 10 years now for LT1's, LS1's and any vehicle who wants a stall made and seem like they do quite well from the size of their shop and couldn't believe how clean it was. Have same warranty as TCI and the others, actually better. Within their warranty even if you go over the rated HP like if it is built for 600 HP , they will still replace their stall with a new one, they like the feedback on stalls and track times(don't care about dynos, so if I get one put in they want to know how my stall did from a stock 12" to their Billet 9.5" stall with a certian STR, so they keep track of this so they know what to suggest to the next customer. Its a nice shop and its the one that will do built trannies by request like a 600 HP tranny for $1030 and have the same 1 year warrranty and no core needed bbut still wanted track numbers form before and after, he said he has done 3.8 camaros before but not turbo charged so I think he wants to post results of their 3.8 convertor , like they do with their LT1's, LS1's and LS2's. So when I told him i would turn the boost up in this winter he wanted me to get some turbo runs in with the 12" and then get the 9.5" stall and run the same boost to see the gain I think the weigt diffrence alone is 15-20LBS from a 12" to a 9.5" and still has a lock up on it. I have 3.73's right now and I just found my other used Toren LSD and 3.42 gears( look great still was surprised) which I'm going to install in a 3.23 LSD 10 bolt to see how big of difference in the spool time will be. I have nothing else to do and aslong as I can sit there and not get my back into too much trouble it will give me something to do. I also didn't know who can only do certain STR's with certain stall speed. He had a chart he looked at to see what worked together.

didn't say they weren't good...just be careful...I've heard horror stories and Im giving a heads up, thats all...

Half a second is not little or nothing. 15.4 to 14.9 from just changing from a stock converter to a S10 converter

but you would get more from a stall with a higher str

[ssms5411]

Re: Tourqe Convertor Multiplier

[QUOTE=LETZRIDE;966355]didn't say they weren't good...just be careful...I've heard horror stories and Im giving a heads up, thats all...

I here ya man , good looking out , thanks. Someones got to do it though, LOL I wouldn't go with a S-10 stall , thought about it but for what this place does and its a 9.5" might as well give it a try.

[LETZRIDE]

Re: Tourqe Convertor Multiplier

Half a second is not little or nothing. 15.4 to 14.9 from just changing from a stock converter to a S10 converter.

And, to me like you get results with 3.73 gears, but you get better results with 4.56 gears....the reason people don't go with 4.56 is because of how high you rev and fuel economy...with a 3200 stall you will rev up pretty much the same and you fuel economy will be unaffected doesnt matter which one you go with...so IMO I just don't see why you would go with an s10 converter?

I guess if gains are there? but I dunno about a whole half second, are you sure none of that was weather related between the two runs?

[ssms5411]

Re: Tourqe Convertor Multiplier

The only problem with a S-10 converter is that it is stock and will only hold so much power and how long will it last esp. with some power to it(that what scares me), like my Dad said if you blow the converter you'll probably lose your tranny , So for a built converter thats rated at 600 HP for $200 more I'll go the safe route plus a 1 year warranty and a STR I want.

[bigbrian442]

Re: Tourqe Convertor Multiplier

I guess if gains are there? but I dunno about a whole half second, are you sure none of that was weather related between the two runs?

The DA was about 600 feet higher for the faster runs. Traction was also becoming an issue with the S10 converter and I had to back off on how hard I was launching.

I wouldn't suggest the S10 converter for a car with a power adder. I think the reliability would not be there.

[Pewter02Camaro]

Re: Tourqe Convertor Multiplier

I wouldn't suggest the S10 converter for a car with a power adder. I think the reliability would not be there.

Any less reliable than my stocker? Been beating on that thing since day one and it's still good. I guess i may not do a convertor then becuase i really am not lookin to spend a few hundred on one right now.

[LETZRIDE]

Re: Tourqe Convertor Multiplier

The DA was about 600 feet higher for the faster runs. Traction was also becoming an issue with the S10 converter and I had to back off on how hard I was launching.

I wouldn't suggest the S10 converter for a car with a power adder. I think the reliability would not be there.

I guess if I think about this a little more an s10 may not be so bad...the lower the STR the more efficient it is up top, so where a higher str will gain its advantage on the launch, an s10 with a lower str would gain a little on launch and not slip as much up top...so ok, I can see how the s10 might not be soo bad of a choice...I guess it all depends on how you are building the car to...