Lock up vs. Non l/u efficiency when unlocked

[Dusty Bradford]

If you get the unlocked slippage down you will have some lag. A restalled D5 should take the power but will spool even slower. The tightest your 10" can be made is another 200-300 tighter which would make it a 2100-2200 but 300 rpm would still be right at the edge of you being out of your power range with the stock cam.

To spool the 67 and reduce the slip your down to putting a cam and spring in it to support more rpm or leave the motor alone and go to a 9x11 or multi-disk so you can keep the rpms down to 4800-5200 in the traps. Of course you know what the tranny will need to make sure it takes the abuse of WOT locking.

The only other option is to back down turbo size so you can run a tighter converter and still have good spool-up. This would allow you to continue running unlocked but have better efficiency and still have 10 second capability. Unfortunately, to make it all work together to optimize everything will require some changes.

I should have added that this is the way I see it if you stick with a lock-up.

Swapping to a non lock, it's a whole new ballgame. A n/l can handle it.

 

[DougsfastZ]

Great thread. Really got me thinking on what converter to get with my soon to be stock head, stock cam TE45A combo. I was going to get an Art Carr "N" N/L converter around 3500 stall. I think after reading this, the stock cam may not let the motor have enough RPM through the traps..........

 

[Ed Valvo]

If Turbo Nasty switches to Non-LU, does he have to convert the tranny to non-LU? Or can he leave it alone in case he wants to switch back to a LU one day?

 

[bison]

If Turbo Nasty switches to Non-LU, does he have to convert the tranny to non-LU? Or can he leave it alone in case he wants to switch back to a LU one day?

He has to switch it to NL. Its easy to do and is just as easily reversed but the trans must be out of the car to do so.

 

[bison]

Great thread. Really got me thinking on what converter to get with my soon to be stock head, stock cam TE45A combo. I was going to get an Art Carr "N" N/L converter around 3500 stall. I think after reading this, the stock cam may not let the motor have enough RPM through the traps..........

Especially with an "N" which wont couple till well over 5500 rpm and even higher if your making anywhere near the power potential of the 66 p trim you are planning on using. I dont rec a p trim or larger for any stock headed and especially stock cammed application. All you are doing is narrowing the most usable powerband to a few hundred rpm since the turbo wont work well under 4600-4700 and less than 25 psi and the cam will limit the revving potential where the turbo really wants to be. Like around 5400-5500.

 

[DougsfastZ]

Especially with an "N" which wont couple till well over 5500 rpm and even higher if your making anywhere near the power potential of the 66 p trim you are planning on using. I dont rec a p trim or larger for any stock headed and especially stock cammed application. All you are doing is narrowing the most usable powerband to a few hundred rpm since the turbo wont work well under 4600-4700 and less than 25 psi and the cam will limit the revving potential where the turbo really wants to be. Like around 5400-5500.

I got the TE45A so I had a turbo I can grow into.

Any recommondations for a converter for the combo, I understand the combo is not optimal.

 

[silentbutdeadly]

My car falls into this category as well, interesting points.

 

[1KWIK6]

I got the TE45A so I had a turbo I can grow into.

Any recommondations for a converter for the combo, I understand the combo is not optimal.

I used a TCS 9X11 3,200 stall with that combo. I was able to get 10.80's @ 125+. Good luck to you!

 

[bison]

I got the TE45A so I had a turbo I can grow into.

Any recommondations for a converter for the combo, I understand the combo is not optimal.

A vig 5 disc or a 9x11. It will need to be locked to keep the rpm in the desired range. Id try to lock it so it drops to about 4600-4700 when you hit the switch. It will still be a tight call since the unlocked efficiency may be so crappy that it might need to be at 5600-5700 to get it down to 4700. By then the cam is out of steam and if you lock it sooner and it goes to much below 4500 the turbo will be out of its range. Id plan on running at least 25psi to get the compressor into its efficiency range sooner so when the rpm drop occurs locking it you get more out of it. Running a LU converter this way loses a lot of performance in 1st and second if it is not efficient when unlocked.

 

[DougsfastZ]

A vig 5 disc or a 9x11. It will need to be locked to keep the rpm in the desired range. Id try to lock it so it drops to about 4600-4700 when you hit the switch. It will still be a tight call since the unlocked efficiency may be so crappy that it might need to be at 5600-5700 to get it down to 4700. By then the cam is out of steam and if you lock it sooner and it goes to much below 4500 the turbo will be out of its range. Id plan on running at least 25psi to get the compressor into its efficiency range sooner so when the rpm drop occurs locking it you get more out of it. Running a LU converter this way loses a lot of performance in 1st and second if it is not efficient when unlocked.

Awesome info. What advertised stall should I shoot for, 3200?

 

[silentbutdeadly]

I have the Vigilante "O" Pump, 3400 stall. I have been locking the converter in 3rd at approx 5000rpm.

 

[quickt]

Awesome info. What advertised stall should I shoot for, 3200?

A tight as you can spool. I used a 2600 NL with a TE-45 and hammered 10.30s@135 If you want the turbo to come up like a blower car you will need a 3200-3400 and lock up.

 

[bison]

A tight as you can spool. I used a 2600 NL with a TE-45 and hammered 10.30s@135 If you want the turbo to come up like a blower car you will need a 3200-3400 and lock up.

+1 go for the tightest you can stand. If you wanted to spend some $ and went NL Dusty could spec out a 9.5" that would work well. You want to try and keep it between 4600 and 5300 as long as possible (preferably around 4800) throughout the run and be over 25psi boost. You may need to bump up the valve springs a little if they are questionable. The excess backpressure running 25+psi will work against the spring and if they are on the edge you may give up some rpm (which you cant afford to do at all with this turbo)and lose mph.

 

[DougsfastZ]

+1 go for the tightest you can stand. If you wanted to spend some $ and went NL Dusty could spec out a 9.5" that would work well. You want to try and keep it between 4600 and 5300 as long as possible (preferably around 4800) throughout the run and be over 25psi boost. You may need to bump up the valve springs a little if they are questionable. The excess backpressure running 25+psi will work against the spring and if they are on the edge you may give up some rpm (which you cant afford to do at all with this turbo)and lose mph.

I do have some low mileage 100 lb springs in the car now.

Thanks guys.

 

[turbo nasty]

This has turned out to be a great piece of info on the subject.
Anyone else

 

[JC3569]

converter

Great info!What would work the best for my combo.Garrett 44 50# 3"down pipe,tt chip and stock motor except 980 springs.Just wondering what convert to run. thanx joe

 

[Boost231]

i agree, great info. i thought my converter was the best thing out when i got it. now it looks like next year i will get one from dusty. also looks like im going to get a non lockup since it seems to out preform a lockup in every aspect except slightly higher cruise rpm which i dont care about.

 

[Dusty Bradford]

Great info!What would work the best for my combo.Garrett 44 50# 3"down pipe,tt chip and stock motor except 980 springs.Just wondering what convert to run. thanx joe

Either a 2400 or 2800 stall 10". The 2400 will spool good, the 2800 will 60 foot better if you have plenty of traction.

 

[TURBOPOWERED68]

Good reading
I just need the money or a test unit:biggrin: I promise to take pictures and write a testimonial and pay for shipping !!!!!

 

[Boost231]

shpping will cost you $550