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HybridZ

Powerglide on L28 turbo


thor280

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I don't know about bolting a PG up to your I6, but I have to ask "why?"

 

Granted, the Z is a pretty light car... but the gearing in the PG just isn't very condusive to accelleration. The only drag racers I see using them are running very light cars with enough power that having a lower first gear would only hurt them.

 

I'd go with a built TH-350 or 400 if you really want a durable automatic trans for the strip.

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I run a PG, works great, should solve your cv breakage problem. You'd have to run an adapter plate to mate the L28 bolt pattern, no matter if you went th350 or PG, same tranny bolt pattern. There is not that much difference in gear ratio's, 2.54 first gear 1.54 for second in the th350, I think, and 1.76 or 1.82 for the glide unles you go to custom gear set then you can get into the 2's for a low gear. High gear is still 1:1. So, it's like inbetween 1st and 2nd gear on a 350. The 1.82 set would handle about all the L6 could put out, but if it's a v8 I'd go with the stronger 1.76 gear set. Both are interchangeable as a unit. If you get a turbo splined input shaft then converters are alot cheaper and you can buy/sell easier. Also more durable than the stock input shaft.

 

The glide weighs about 110 to 120 with converter, mine does at least, so there is some weight savings, also there is some HP savings as well as the glide doesn't soak up as much HP as the 350 or 400.

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Granted, the Z is a pretty light car... but the gearing in the PG just isn't very condusive to accelleration.

Wrong!

 

240Z Turbo ran a TT stroker with a modded JATCO and best the car would do is 11.1s. Switch to a PG with no other changes and the car ran 10.60s! Imagine that, only 2 gears and taller 1st gear to boot. His overall 1st gear ratio change was equivalent to going from a 3.70 to 3.0 with the JATCO and still the car went QUICKER. The notion that you need stiffer gearing in a turbo car for better acceleration is false. Put the engine under load and let the turbo do the work and you will be rewarded.

 

The poster did mention "track" but not any other driving conditions so whether the PG or a 3-spd or OD tranny is the right choice is still in question.

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Scottie,

 

You're right, I'm assuming drag racing. I didn't know we were necessarily talking about a turbo engine here. Even so, I still think that given adequate traction and maintaining a load on the engine to spool the turbo (i.e., not over gearing), that having more gears in close ratio to play with will still get you better accelleration by keeping you in your best powerband for more of your run.

 

I could be wrong. Most times I've seen people run quicker with a PG swap is where they were over-geared previously or having traction problems with the setup.

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We're running sbc v8. Scottie is right, the notion that using a PG would be detrimental is just plain wrong, been proven so that's that. An adapter can be made or bought is my understanding. Somebody already did it and if it were me I'd make one out of 6061 1/2" plate using a bellhousing from the L28 and sbc as bolt patterns.

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Scottie' date='

 

You're right, I'm assuming drag racing. I didn't know we were necessarily talking about a turbo engine here. Even so, I still think that given adequate traction and maintaining a load on the engine to spool the turbo (i.e., not over gearing), that having more gears in close ratio to play with will still get you better accelleration by keeping you in your best powerband for more of your run.

 

I could be wrong. Most times I've seen people run quicker with a PG swap is where they were over-geared previously or having traction problems with the setup.[/quote']If we are talking about an L28 breaking T5s and Nissan 5 speeds, it has to a be a turbo. I'm running 300hp in my L28ET and have never broken a tranny. There just isn't an N/A L28 capable of that much power.

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Yes , my car is a 83' ZX turbo with quite a bit of work . ie , TEC-3 , 70-1 turbo , 72 lbs

fuel injectors , P90 head ported & polished , TopEnd perf. custom grind cam . intake was modified . The car is laying down some serious power now . I should've mentioned that I

purchased one of the Top End Perf. clutches ( good for 500 hp ) and it won't grip . I send it back and they're sending me a new one . I have to install and hope that it doesn't slip. That is another reason why I'm looking into going automatic . Again thanks for the input guys .

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With the right converter that setup should really haul arse. W/o even knowing the best so far, I am willing to bet you will see .5 improvement like 240Z Turbo. If you are concerned about street and highway driving then you might want to consider a TH200-4R with OD and even lockup if you so desire. Remember that a non-lockup converter with a high stall will have a fair amount of slip so take that into consideration when factoring final drive for trap speed and cruising.

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Not to change the subject of this thread, but anyone wanting an overdrive trans on their L6 can use an early 4N71B. Mid 80's from Maxima or Pathfinder. It's a direct bolt up to the L6. Some other mods are necessary. I've done it and it works great. 65 mph @ 1200 rpm.

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This is not a daily driver anymore . If they catch you street racing down in Miami , you just lost your car . It's setup for track now . It would be nice to research that TH200-4R , OD would be nice in case I do decide to drive it on the street occassionaly .

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INFO:

 

Ok, For the flex plate adapter, contact WILCAP...they have the pattern already on file, will provide the flex plate adapter AND the Chevy Blank (without the starter ring gear, you use the stock auto flexplate too) for $165. I just got mine a couple of months ago... The part is NOT listed in their catalog, so you'll have to call them about ordering one. (Sorry for the two horrible pics below)

 

TC_Side.jpgTorque Converter Side

FP_Side.jpgFlex Plate Side

 

A Special Thanks goes out to James Thagard for taking the initiative to get these parts made by Wilcap and TCI, as well as providing the pics below.

 

TCI has the bellhousing adapter already made as well, but they're a bit too proud of it for me. I have a friend with a CNC machine shop who is capable of making it for me, so I'm gonna try to go that route first.

 

transide.jpgTranny Side

engside.jpgEngine Side

 

IGNORANCE: (Mine, that is)

 

Now, for the ignorance part. Why would you use a 200-4R instead of a 700R4? Doesn't the 700R4 have the tailshaft bearing whereas the 200-R4 does not? Also, aren't the 700R4's more readily available (and cheaper)?

 

Don't flame me here guys, I'm in the process of getting the bellhousing adapter fabbed to put the 700R4 behind the L28 for my 82ZXT project.

 

Warren

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Why would you use a 200-4R instead of a 700R4? Doesn't the 700R4 have the tailshaft bearing whereas the 200-R4 does not? Also' date=' aren't the 700R4's more readily available (and cheaper)?

 

Warren[/quote']

Warren, good post.

 

700R4s might be cheaper but I am not sure if they are more readily available. Remember that the 700R4 has only a Chevy bolt pattern while the 200-4R has a BOP bolt pattern. I might be underestimate the number of Chevys or it just means there are more of them in the junkyard :D. One of the primary reasons for a 200-4R over a 700R4 (for a turbo car, i.e., is the gear ratio spacing. The 700R4 has a 3.06 1st gear vs a 2.74 and while that sounds like it is better for acceleration, for a turbo car it is not and that ratio also makes for a wider gap to 2nd. The 200-4R is slighter shorter and lighter but not enough to make a difference in a swap.

 

I am sure others will disagree.

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