Lockup at strip.

[carolinaturbo]

I had a guy tell me that locking the converter at the strip well give you two tenths. Is this true and will it hurt the trans. an if not how do i do it.

 

[TurboDave]

Depends on the converter. It may or may not help the ET. If it's a good sturdy unit designed for WOT lockup, you'll pick up a couple mph after some practice.
If it's a stock converter or another brand not designed to handle that kind of abuse you'll pretty much wear the clutch out after 15-20 runs or so.

So, unless you have a converter designed for it, I would advise against it.

 

[bison]

2 usually and up to 4 mph maybe depending on the converter efficiency unlocked. But i have never seen 2 tenths. Usually about .1.

 

[Fuelie600]

I used to run a 5 disc Vigilante. Car always slowed down when locked. I tried many different points of lock up without good results. Worked great on the street though. Your results may vary. Brian

 

[Boost231]

I used to run a 5 disc Vigilante. Car always slowed down when locked. I tried many different points of lock up without good results. Worked great on the street though. Your results may vary. Brian

it varies car to car. only way to find out is to try and see if it works for you.

 

[Grumpy]

GN .2-.3 and 2-3 MPH anyway .... TTA .3-.4 and 3-4 MPH anyway ... I drove around with a LU switch in my hand for 15 years on stock converters in ALL my cars .. I did have a tranny cooler

 

[Fuelie600]

GN .2-.3 and 2-3 MPH anyway

 

[Grumpy]

what there to be confused about ??? ya don't think a stock D5 can take a beating ??? WRONG beating these cars since 1986 .. I think I know what works and what doesn't

 

[turbojimmy]

I agree with Grumpy - .2-.3 and 2-3 MPH. The difference is very obvious in your timeslips - just do it. I most recently lost 2-3 MPH when my 5-disk Vigilante STOPPED locking up (not sure why it stopped locking up - may not have been the converter itself, but it's fixed now). My brother has been locking his 100k+ mile stock D5 in his 12.0-second T-Type and it's still working fine (knock on wood).

Jim

 

[turbo nasty]

Forced L/U killed my d5 TCC. Have a Pats now have yet to try foced at WOT on this one

 

[BlackMetal]

Frankly I'd rather get the better ET/MPH from real mods instead of beating on a TCC like that. As others have mentioned there might be a few race converters available that are meant to take the beating (multiple clutch discs, etc) but other than that I wouldn't do it. Just my opinion, plenty of guys do it and say they get away with it.

 

[mikestertwo]

Frankly I'd rather get the better ET/MPH from real mods instead of beating on a TCC like that. As others have mentioned there might be a few race converters available that are meant to take the beating (multiple clutch discs, etc) but other than that I wouldn't do it. Just my opinion, plenty of guys do it and say they get away with it.

+1

 

[turbojimmy]

Frankly I'd rather get the better ET/MPH from real mods instead of beating on a TCC like that. As others have mentioned there might be a few race converters available that are meant to take the beating (multiple clutch discs, etc) but other than that I wouldn't do it. Just my opinion, plenty of guys do it and say they get away with it.

It depends on how you define 'real mods'. Even if you mod a car to get a better ET/MPH w/out locking the converter you're still wasting power through TC slippage. You need to address the power being wasted by the stock TC - either by swapping it out for a more efficient non-LU or getting a LU that can withstand the abuse. Until you do, you can lock up the stocker until you break it.

Jim

 

[Fuelie600]

what there to be confused about ??? ya don't think a stock D5 can take a beating ??? WRONG beating these cars since 1986 .. I think I know what works and what doesn't

A little testy Dan? They way you worded it, you gave me the impression that locking a convertor is a sure gain. It's not. I have also been running these cars since '85, and I have experience with running lock ups, and non lock ups. I mention nothing about a D5. Brian

 

[carolinaturbo]

I didnt mean to get anybody mad. Just want to know a little info on things I was hearing. I do love to here all the different replys though. I am new to the gn world. Always ran sb chevys. I love the gn and I purchased my first one about 6 months ago. Please excuse me if i tend to ask some stupid Q. Thank you.

 

[bison]

I didnt mean to get anybody mad. Just want to know a little info on things I was hearing. I do love to here all the different replys though. I am new to the gn world. Always ran sb chevys. I love the gn and I purchased my first one about 6 months ago. Please excuse me if i tend to ask some stupid Q. Thank you.

Your questions are good bro. There is not always a performance gain though. Sometimes there is a little et reduction. I have never seen over .2 while locking a D5 though. I have seen nearly 3mph though. I made 18 passes on a D5 back in 99 on one day at the strip and the difference locked to unlocked was about a tenth and 2 mph average. This was on a stock turbo, engine except springs, and a dutt neck intercooler. Mph went form 109-110 to 111-112 after locking. Thats about the extent i ever played with lockup. All the other engines ive built smoked out the D5 TCC in under 50 lockups. The factory converter does well for a long time in cars going under 115mph in the quarter being locked. Ive seen race units fail to lock completely in other applications when they should have. Some of the high quality non locking converters out there these days will slip under 4% in high hp cars that go 150mph and are lighter than lockups and promote better 60's when everything is dialed in.

 

[77 cruiser]

This is the diff. unlocked & locked on a chassis dyno. Does that tell you something?

 

[turbo nasty]

my theory is leave the forced l/u out of the chip at WOT and I keep it for when I will need a lil extra via a switch. Just make sure your trans and parts can take the added umph for your given power.

 

[Chuck Leeper]

??

This is the diff. unlocked & locked on a chassis dyno. Does that tell you something?

Jim, is this a LS based engine?
The reason I ask is, I see timing appears to be VERY conservative @ 29* total.

 

[77 cruiser]

No, it's just an old school SBC. That's where it did the best at.