Dynamometer Results & Comparisons - locking a converter on the dyno

Can this cause damage to your converter? How much more horse do you see by locking you converter? I am Dynoing on a dynojet on 6/13 and I want to lock the converter for one pull, but I dont want to damage it. thx in advance.

Usually you gain about 3-5% more rwhp with TC locked (and less torque).

I believe it is a little harder on the tranny, but I think it is moreso at the end of the run when you let off - and it's not like its the worst thing you can do to the tranny. Just shift into neutral at the end of the run to let the motor slow down.

If you are worried that you are going to cause serious damage, don't worry. Its not any worse stress really than just being on the dyno in the first place.

thx for the info

I would lock the convertor the whole time you tune so that way when the convertor is unlocked, its a gaurentee it wont ping. Plus, if you tune it locked, its basicly fully loaded.

Rick

I would lock the convertor the whole time you tune so that way when the convertor is unlocked, its a gaurentee it wont ping. Plus, if you tune it locked, its basicly fully loaded.

Rick
Why is it a guarantee that the car wont ping if you tune w/the converter locked?

Why is it a guarantee that the car wont ping if you tune w/the converter locked?

BEcause a locked convertor will produce more load on the car just like a 6-speed will. Its more of a direct drive, instead of a slip.

BEcause a locked convertor will produce more load on the car just like a 6-speed will. Its more of a direct drive, instead of a slip.
ok. thanks. 1 Last question though, is it bad for the converter?

ok. thanks. 1 Last question though, is it bad for the converter?


YES. The lockup clutch in a torque converter is TINY. It's an EMISSIONS device. It is not made to carry the load of the car at WOT. There is no need to lock it up other then for Brag racing.

If that clutch comes apart, so will you transmission. Do NOT do it unless you are prepared to replace your transmission for 3-5% more HP on a Dynojet.

YES. The lockup clutch in a torque converter is TINY. It's an EMISSIONS device. It is not made to carry the load of the car at WOT. There is no need to lock it up other then for Brag racing.

If that clutch comes apart, so will you transmission. Do NOT do it unless you are prepared to replace your transmission for 3-5% more HP on a Dynojet.

i was going to say something to the same effect.

unlocked it is!

YES. The lockup clutch in a torque converter is TINY. It's an EMISSIONS device. It is not made to carry the load of the car at WOT. There is no need to lock it up other then for Brag racing.

If that clutch comes apart, so will you transmission. Do NOT do it unless you are prepared to replace your transmission for 3-5% more HP on a Dynojet.


You have to lock the convertor if you do steady state tuning. This is the only way you will be able to tune all parts of the table.

Rick

what is steady state tuning?

what is steady state tuning?


Steady state tuning means that you are tuning the whole table. My dyno allows me to lock in at any RPM and tune everything all the way down to 400RPM's. This method is done by engine builders and car builders like GM and everyone else. Thats how they build tables for your PCM.

I dont fully agree with locking the convertor is a bad thing. Look how many people lock the convertors for drag racing. Even all the turbo guys do it.

Rick

well, I go tomorrow at 9:30 am, so I will let you all know how it goes.

Locking the converter under light throtte is fine. IMHO, locking a converter at WOT is bad news especially if there is a brake on the dyno. No need to get data from cells the car will never hit. Just make sure the tables are smooth. :)

Man, there's a lot of diff. opinions on this one. I lock the converter when I'm steady state tuning on my Mustang 1100SE eddy current dyno. When I do power pulls I just lock the car in 3rd gear with the scanner and leave the converter unlocked. Most of the time locking is ok, but I have had a tranny burp fluid out (overheat) before with the coverter locked. Steady State is something most Dyno Jet owners don't know about. It's the only way to tune an EFI system, especially for street applications. If your only doing the 1/4 or the 1/8th then you can tune just for the cells that you hit by tuning your log files with a wide band. While this will get you close on the street, it will never replace a good steady state tune on a real dyno ie Mustang, Dyno Dynamics, Superflow. When in steady state you can see the hp and tq at that instant and add or subtract timing to see where your max. power is at. This allows you to not have too much timing and run the risk of detonation. There are other advantages there too.

Aaron Lail
Tru Dyno Sports LLC
1901C Conover Blvd. E.
Conover, NC 28613
www.trudynosports.com
(828) 459-0088

Man, there's a lot of diff. opinions on this one. I lock the converter when I'm steady state tuning on my Mustang 1100SE eddy current dyno. When I do power pulls I just lock the car in 3rd gear with the scanner and leave the converter unlocked. Most of the time locking is ok, but I have had a tranny burp fluid out (overheat) before with the coverter locked. Steady State is something most Dyno Jet owners don't know about. It's the only way to tune an EFI system, especially for street applications. If your only doing the 1/4 or the 1/8th then you can tune just for the cells that you hit by tuning your log files with a wide band. While this will get you close on the street, it will never replace a good steady state tune on a real dyno ie Mustang, Dyno Dynamics, Superflow. When in steady state you can see the hp and tq at that instant and add or subtract timing to see where your max. power is at. This allows you to not have too much timing and run the risk of detonation. There are other advantages there too.

Aaron Lail
Tru Dyno Sports LLC
1901C Conover Blvd. E.
Conover, NC 28613
www.trudynosports.com
(828) 459-0088


You took the words right out of my mouth. I cant see why anyone would just settle for a WOT tune. I bought my Dynapack for that reason, Tuning. Any EFI car needs it. Thats what EFI is.

Rick

well, I ran it on the dynojet today and he did a 2nd gear pull. resulted in 363 rwhp, and 340 rwtq. He said that 3rd gear probly would have been 3%higher. That was with the converter unlocked. I just dyno'd, no tune.

well, I ran it on the dynojet today and he did a 2nd gear pull. resulted in 363 rwhp, and 340 rwtq. He said that 3rd gear probly would have been 3%higher. That was with the converter unlocked. I just dyno'd, no tune.
2nd gear? What the heck?

LOL. Yeah, WTF? Tell him you want your money back. You should have dyno'd in 3rd.

Most folks who are serious about tuning spend more time on the street/strip tuning then they do on the dyno. In this case, he was asking about WOT on a dyno. Specifically, a Dynojet. :)

2nd gear is :gay: I have only seen 3rd gear pulls on an auto..someone please explain!!!!!!!

3rd is your 1:1 gear. I believe you can convert the numbers from 2nd gear to 3rd (I'm not positive about this), but WHY someone would force you to dyno in 2nd is silly, unless they were so concerned about their dyno that they don't want it spinning that fast (which I doubt is right). You always dyno in the 1:1 (or closest to that) gear.

LOL. Yeah, WTF? Tell him you want your money back. You should have dyno'd in 3rd.

Most folks who are serious about tuning spend more time on the street/strip tuning then they do on the dyno. In this case, he was asking about WOT on a dyno. Specifically, a Dynojet. :)

thats why I bought my dynapack. I spend alot of time tuning every car. Works great.

Rick

how much you lose dynoing in 2nd?

Actually you wouldn't loose anything. Your torque numbers would be high though because your multiplying by the transmissions 2cnd gear ratio. I have heard of other Dyno Jet owner doing this before to try to get higher numbers to show up. Dyno Jet is mostly about marketing and less about quality tuning tools. Always do power pulls in 1:1 or closest to it. Steady State tuning on the other hand can be done in any gear because all your after is the Kpa or (load) of the engine. With eddy current you can hit all of these cells in any gear. Remember, just because a shop has a dyno doesn't make them a good tuner especially if they own a Dyno Jet. All it means is they had good enough credit to buy it.

Now before anyone gets their panties in a wad, some newer Dyno Jets do have eddy current, but they are still way behind on the technology in my opinion.

Aaron-

Actually you wouldn't loose anything. Your torque numbers would be high though because your multiplying by the transmissions 2cnd gear ratio. I have heard of other Dyno Jet owner doing this before to try to get higher numbers to show up. Dyno Jet is mostly about marketing and less about quality tuning tools. Always do power pulls in 1:1 or closest to it. Steady State tuning on the other hand can be done in any gear because all your after is the Kpa or (load) of the engine. With eddy current you can hit all of these cells in any gear. Remember, just because a shop has a dyno doesn't make them a good tuner especially if they own a Dyno Jet. All it means is they had good enough credit to buy it.

Now before anyone gets their panties in a wad, some newer Dyno Jets do have eddy current, but they are still way behind on the technology in my opinion.

Aaron-

Yup. Agreed. Tuning is just what it says....tuning.

Actually you wouldn't loose anything. Your torque numbers would be high though because your multiplying by the transmissions 2cnd gear ratio. I have heard of other Dyno Jet owner doing this before to try to get higher numbers to show up. Dyno Jet is mostly about marketing and less about quality tuning tools. Always do power pulls in 1:1 or closest to it. Steady State tuning on the other hand can be done in any gear because all your after is the Kpa or (load) of the engine. With eddy current you can hit all of these cells in any gear. Remember, just because a shop has a dyno doesn't make them a good tuner especially if they own a Dyno Jet. All it means is they had good enough credit to buy it.

Now before anyone gets their panties in a wad, some newer Dyno Jets do have eddy current, but they are still way behind on the technology in my opinion.

Aaron-
Then I guess my car is no dyno queen. 363 rwhp was what it put down on the dynojet. Bob kennedy(dynoshop owner) had guessed that it would lose around 3% being dyno'd in 2nd. so he Figured it to 374 rwhp. From what you say, it sounds like the 363 is the more reliable number. The graph looked really good though, as the car pulled all the way up to 6700 rpms before leveling out. Tell me, when you tune do you use a weld in "bung" to measure the afr? When my car was tuned about a month ago, they did not use one, they may have put one in the tailpipe? I dont know. Most accurate reading would be before the cats though, right?

Yes for sure before CATS. If your sure that the AFR is close then at the tailpipe is ok for some WOT measurments but not for tuning, it may be a half point leaner than actual AFR. I always weld in an extra bung on any exhaust that I do, and have told my customers to do so in the future so as to be more accurate. I have several builders that bring their cars to me for tuning and most of them will now weld extra bungs in the exhaust for this purpose.

Aaron.

Based on your numbers I would GUESS that your loaded (actual) WHP would be more like 315-320hp could be as high as 330's. Now this is due to how Dyno Jet measures hp. They simply take a know mass (rollers) and calculate against a known speed and acceleration factor to come up with a hp number. This is called inertia and I'm sure there is a better explanation with more intense math on here somewhere. One thing that some may not know and that Dyno Jet will admit to with some pressuring is that they also input a fudge factor into their computing that basically calculates bHp or hp at the flywheel. Which with some of the numbers you see makes sense. Hope this helps some.

Based on your numbers I would GUESS that your loaded (actual) WHP would be more like 315-320hp could be as high as 330's. Now this is due to how Dyno Jet measures hp. They simply take a know mass (rollers) and calculate against a known speed and acceleration factor to come up with a hp number. This is called inertia and I'm sure there is a better explanation with more intense math on here somewhere. One thing that some may not know and that Dyno Jet will admit to with some pressuring is that they also input a fudge factor into their computing that basically calculates bHp or hp at the flywheel. Which with some of the numbers you see makes sense. Hope this helps some.
315-330? Are you trying to push me over the edge? jk. I dyno'd it a month ago on a dynamics, and it put down 354 on that one.

I always lock it on the dyno when tuning. There is no way I can tune correctly unless I do. I don't think its that bad for the converter, its already locked before going WOT.

Nowt if you lock it when you are already WOT, then I can see damaging you TC.