AWD V-8 GTR? Possibly Possible.

[The Dark Side of Will]

Kit? That's an entirely new level of PITA.

I was under the impression that the GTR drivetrain was bomb-proof.

I don't think that ratios suited to a 2.6 litre I-6 would produce the most satisfactory result with a V8. What are the transmission ratios?
After looking at the available ratios and transmissions for my AWD project, I keep coming back to the T56 as the best choice for use with a V8.

The ZF that I'm going to use to get "Project: Bad Idea" on the road has a ratio spread of 4.2 with a 1:1 5th gear. The E30 M3 Getrag 265 I have in the shed has the same ratio spread, but a 3.38 first instead of 4.20 and a 0.81 fifth instead of 1:1.
No matter what diff ratio I consider with either of these transmissions, I can never get both a low enough first gear to really take advantage of the combination of power and traction AND a tall enough top gear to get the best gas mileage.

The tallest domestically available front diff is 3.07. With the ZF, that gives me a 12.89 overall first and a 3.07 overall fifth. That's shorter than the 282 in a FIero... The 265 with the 3.07 is better, but not great. Overall first would be 10.89 and fifth would be 2.49. The 10.9 first is about the right range, but the top gear is still *WAY* to low for the engine/car combo..

I'm in touch with an E39 M5 owner who swapped his factory 3.15 rear out for a 2.65 and loves it. He says the S62 easily pulls the 2.2 overall 6th at highway speeds in the 4000# body. He got back lost acceleration with ported throttles, headers, light flywheel and other bolt-on mods.

So I keep coming back to the T56 as the transmission with the closest set of gears in the lower ranges, and a tall enough top gear to get the kind relaxed cruising and gas mileage that the engine can deliver. An LS1 F-body T56 with 4.11 gears would give me 10.9 overall first, but a 2.06 overall sixth. The 4.11 can be had in an E30 rear case, but would have to be built in the V8 style front diff case. A close option would be 3.91. That's available in the V8 front case, but would need work to go into the E30 rear--Either a custom built rear diff or an E28/E34 subframe swap to accept the large case 3.91 diff from an E34 M5.

Interestingly, the Getrag 260 in my E34 has a ratio spread of 4.7. The 260 was used before the ZF... It's curious that BMW would go to a transmission with a narrower ratio spread when wide ratio spreads are supposed to be the way to get good economy and performance...

[The Dark Side of Will]

The T56 shifter could be solved as pictured above, by mounting the shifter on the main case. If you're lucky, it *might* be possible to mount the T-56 shifter, via an adapter plate, to the Skyline T-case and have it be just like stock.

Bellhousings can be fabbed in-house or farmed out. There are companies that will take your specs and produce a custom spun steel bellhousing for racing use.

The front diff might be problematic as pretty much everything domestic I know about stock is left drop. The Mercedes 4matic stuff is right drop...

Actually, I'm pretty sure AWD Cadillacs are right drop... Check out this auction: http://cgi.ebay.com/ebaymotors/220715867419 It doesn't show the diff, but it does show the AWD pan. There obviously isn't enough room for a diff on the left side next to the oil filter, and the bolt pattern is much larger on the right side. I believe I've also seen an auction for a complete AWD Caddy drivetrain with the T-case and front diff still installed... I think it was right drop. I have no idea what architecture the diff is, however, or whether a 4.11 is available for it.
The Cadillac website lists 3.42 gears for the current STS-4 with 3.6 DI V6.
Here we go... The Northstar pan definitely looks like its right drop: http://cgi.ebay.com/ebaymotors/150637296842
Obviously, if you go with the Northstar, you can use that supercharged engine... Ditch the SC and turbo it!

Another option for the front diff is to use the Ford 8.8 from an Explorer pictured above, but as a right drop with a reverse rotation gearset.

To field a kit, you'll need several things:
-T-56 to Skyline T-case adaptation: Adapter plate, shifter rework, (custom output shaft?), (transmission build to install custom output shaft and shift shaft?)
-Custom oil pan for right drop AWD
-(diff build for gearset installation?)
-Front driveshaft
-Custom engine mount brackets
-(Custom headers?)
-Custom midpipe for manifolds or headers
-Electrical design to allow LS1 electronics to run Nissan gauges (dual sensors?)
-The usual array of fuel, cooling system and A/C plumbing...

I think it's doable, and I'd like to work with you on the designs for the custom parts. The shop where my dad works can make all the custom adapter plates, oil pans, mount brackets, etc.

[Atilla the Fun]

That 6L block with the 5.3 crank sounds like it would be the perfect engine for this swap. High rpm, high HP and lower torque to save the driveline.

Numnut, that still gives you a 6.0L. Only now you need Mallory metal to balance it. Not cheap.
If you go with big cathedral port heads, then the LS2 block has the advantage of lighter pistons. If you want the larger rectangle ports, then start with a 6.2 block. It offers the advantages of more strength and oil squirters in some apps. Cool the pistons under big boost.
Crank: '01-up 4.8L. The only LSx crank to have a 3.268" stroke. All the rest are 3.622" except the 7L at 4".
Rods: Similar thing again, the 4.8 got the longest rods, by far, while the 7L got the shortest. However, the gen 4 4.8L rods are stronger than the gen 3 4.8L rods.
Pistons: You can just use stock 6.0 or 6.2 pistons if aftermarket forgings aren't needed or in the budget. But if you don't find ultralight aftermarket LS2 pistons, you're back to costly balancing with Mallory metal.
The 7L 'vette happily pulls 7000 RPM, stock, with it's 4" stroke, and I've sampled a cam and heads LS2 pulling 7200, and seen an early 4.8 survive 7500 on a daily basis. How much more could you possibly want? Just drop in any 6.2L, let the rectangle port heads rob you of all that wonderful low-RPM torque that they are proven to cost, and enjoy 7000 RPM. Maybe that's not the RPM range that the Nissan got you used to, but it is plenty for over 600 HP N/A with just a cam, intake manifold, headers, UDCP and tune.

[crzyone]

Low torque/high hp is what I'm looking for. In a racing application, this is going to save my driveline. I don't care about low rpm torque, racing you never get below 4000rpm anyways. I meant to say 4.8 crank, I couldn't recall off the top of my head what Will listed.

[crzyone]

I'm not sure a Northstar would fit in the engine bay lol, interesting idea though. The plan is to make it light and simple, which a turbo Northstar is not.

I can buy used transmissions with transfer cases for $500 all day long. It might be worth buying one and shipping to you just for shits and giggles. Just to make measurments and see if what you are talking about is possible. The GTR driveline has a few "weak" spots. I'm only talking weak when you get above 600hp. The front diff can explode and send parts through the oil pan. This is solved with an aftermarket LSD with beefier carrier bearings. The prop shaft can break, but that's more of a problem with 6000rpm drag clutch dumps, not road racing stress. The real weak spot is 3rd gear which can break if you shock load it with crazy shifting. The fix is an R33 gear box with wider, beefier synchros and an OS Gilken gearset. This is all moot if I go with a T56.

So, that Northstar pan has a right side front diff eh? and it looks like it's bolt on which is what I'm looking for. Just need to attach it to the trailblazer oil pan somehow.

I would like to use the T56, but I thought it would be ultimatly harder to use the GTR transfer case and keep the intelligent awd. If it's possible, and you have it worked out in your head then great, that would be the way to go. My RX7 gets it's new engine tomorrow then I'll be pulling the GTR's engine. I'll scope out the damage and if it's minor fixes, I will still run the RB. When it grenades or is time for a rebuild I will be seriously considering the LS swap. If the damage is worse than expected, I'll be considering the LS sooner than later

The T56 shifter could be solved as pictured above, by mounting the shifter on the main case. If you're lucky, it *might* be possible to mount the T-56 shifter, via an adapter plate, to the Skyline T-case and have it be just like stock.

Bellhousings can be fabbed in-house or farmed out. There are companies that will take your specs and produce a custom spun steel bellhousing for racing use.

The front diff might be problematic as pretty much everything domestic I know about stock is left drop. The Mercedes 4matic stuff is right drop...

Actually, I'm pretty sure AWD Cadillacs are right drop... Check out this auction: http://cgi.ebay.com/ebaymotors/220715867419 It doesn't show the diff, but it does show the AWD pan. There obviously isn't enough room for a diff on the left side next to the oil filter, and the bolt pattern is much larger on the right side. I believe I've also seen an auction for a complete AWD Caddy drivetrain with the T-case and front diff still installed... I think it was right drop. I have no idea what architecture the diff is, however, or whether a 4.11 is available for it.
The Cadillac website lists 3.42 gears for the current STS-4 with 3.6 DI V6.
Here we go... The Northstar pan definitely looks like its right drop: http://cgi.ebay.com/ebaymotors/150637296842
Obviously, if you go with the Northstar, you can use that supercharged engine... Ditch the SC and turbo it!

Another option for the front diff is to use the Ford 8.8 from an Explorer pictured above, but as a right drop with a reverse rotation gearset.

To field a kit, you'll need several things:
-T-56 to Skyline T-case adaptation: Adapter plate, shifter rework, (custom output shaft?), (transmission build to install custom output shaft and shift shaft?)
-Custom oil pan for right drop AWD
-(diff build for gearset installation?)
-Front driveshaft
-Custom engine mount brackets
-(Custom headers?)
-Custom midpipe for manifolds or headers
-Electrical design to allow LS1 electronics to run Nissan gauges (dual sensors?)
-The usual array of fuel, cooling system and A/C plumbing...

I think it's doable, and I'd like to work with you on the designs for the custom parts. The shop where my dad works can make all the custom adapter plates, oil pans, mount brackets, etc.

[The Dark Side of Will]

That 6L block with the 5.3 crank sounds like it would be the perfect engine for this swap. High rpm, high HP and lower torque to save the driveline.

Numnut,

Go easy, killer... I think we all knew what he meant

[The Dark Side of Will]

I would like to use the T56, but I thought it would be ultimatly harder to use the GTR transfer case and keep the intelligent awd. If it's possible, and you have it worked out in your head then great, that would be the way to go. My RX7 gets it's new engine tomorrow then I'll be pulling the GTR's engine. I'll scope out the damage and if it's minor fixes, I will still run the RB. When it grenades or is time for a rebuild I will be seriously considering the LS swap. If the damage is worse than expected, I'll be considering the LS sooner than later

For racing use, I can see keeping the GTR transmission.
For street use, the T56 is definitely the box to use. If you want to develop a kit and actually sell it to people, then you'll need to use the T56.

[Atilla the Fun]

That 6L block with the 5.3 crank sounds like it would be the perfect engine for this swap. High rpm, high HP and lower torque to save the driveline.

Numnut,

Go easy, killer... I think we all knew what he meant

I think you took it more questionable than he did, it's not like I called anyone a stupid s-o-b. Don't you ever use banter?
No matter what words I type, I'm good natured / conversational unless attacked or criticized. So read my posts as good natured conversation, okay?

Moving on, I'm wondering: Assuming the RB isn't really hurt, wouldn't selling it as a not-hurt engine precoup most of the costs of the LSx?
I'm not following this thread close enough to be clear on the strength of the RB's transmission, but if the rear diff has no ratios taller than 4.11:1, then the T56 is the only way to fly.
If the car is left-drive like cars intended for USA sale, then I'd want a front diff to be on the right side, to help equal out the left-right balance.

[Atilla the Fun]

As for the torque issue, the desired RPM range calls for an aluminum flywheel, and the T56's tall 2.66:1 first will also help reduce the strain on the drivetrain. Same for deep 4.11:1 at the diffs.
If this is to be a 600 HP N/A build, then I'd still insist on 6.2 liters. If it's getting boost, then Will's favored 5.1L makes more sense. But in light of the 1200 HP twin-T76 4.8L that was such big news so recently, the extra bore diameter isn't needed. The limiting factor there was the valvesprings. The best way to get more from that would have been custom rockers with a bit less ratio. 1.65:1 or less. Then do more spring.

[The Dark Side of Will]

Don't you ever use banter?

I do... maybe you need practice?

http://en.memory-alpha.org/wiki/Data's_Day_(episode)

Data tries out a friendly jibe: "My hair does not require trimming, you lunkhead." La Forge advises him not to try it on the captain

[The Dark Side of Will]

As for the torque issue, the desired RPM range calls for an aluminum flywheel, and the T56's tall 2.66:1 first will also help reduce the strain on the drivetrain. Same for deep 4.11:1 at the diffs.
If this is to be a 600 HP N/A build, then I'd still insist on 6.2 liters. If it's getting boost, then Will's favored 5.1L makes more sense. But in light of the 1200 HP twin-T76 4.8L that was such big news so recently, the extra bore diameter isn't needed. The limiting factor there was the valvesprings. The best way to get more from that would have been custom rockers with a bit less ratio. 1.65:1 or less. Then do more spring.

The big bore/short stroke engine only really makes sense if longer rods are available. I'm not sure if there are aftermarket rods available at the 4.8 litre length.
Building the BB/SS engine with normal length rods actually compromises RPM capability because the pistons end up with a larger compression height and thus much heavier than they would be with the longer rods.

When you get down to it, no LS based engine is going to rev like an RB26. Yes, you can build an LS based engine to rev to 9000... but getting the longevity out of the engine is the trick. With a huge lift cam and high redline, you'll need to replace the valvesprings twice a year, especially if you accumulate street mileage on it. Because of the lower valvetrain mass and less lift, the RB valvesprings aren't nearly as stressed as pushrod valvesprings will be and last a lot longer.

IOW, in selecting displacement and internal geometry, Levi will have to balance the potential driveline problems due to high torque vs engine longevity due to high RPM... There's no single right answer.

I did recently read on SpeedTalk about an LS7 build that pushed 697 HP at 6800 RPM... That's only 540 ftlbs...

[Atilla the Fun]

In the LSx world, everyone has gone off the deep end when it comes to connecting rods. 99.9% of them don't need aftermarket rods. Putting ARP capscrews has proven adequate for LS3s spinning 7500 on a daily basis. With the reduced stresses of the short stroke, your 5.1L should like 8000.
But with any of the FAST intake manifolds ( and what else would you use? Nothing else is any better ) the runner length is tuned for peak TQ around 4900, and peak HP around 6300. So choose a cam with an IC of 42-44 degrees ABDC @ 0.050".

[Atilla the Fun]

Don't you ever use banter?

I do... maybe you need practice?

No, mine's good. Anyone who ever spent 5 minutes with me will confirm it. You got any real friends?

[The Dark Side of Will]

Don't you ever use banter?

I do... maybe you need practice?

No, mine's good. Anyone who ever spent 5 minutes with me will confirm it. You got any real friends?

Just you, Atilla.

[The Dark Side of Will]

Supercharged Northstar with the AWD oil pan... Here ya go, Levi

http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0715867419

[Shaun41178(2)]

is it for certain that the RB motor is toast? like 100% ruined?

I think finding or rebuilding the RB is the best and easiest route to take. You don't want to mess with a swap. You want to drive it and race it. Not figure out a whole swap again like you did with your fieros. That was probably a nightmare.

Go the easy route and find an RB if this is no good. hell maybe its just the head that needs replaced or repaired. Much easier than a whole drivetrain swap!!!

[crzyone]

This is all speculation Shaun. Just mulling over the idea, it would be neat to be the only awd V-8 skyline but the physical work involved probably isn't worth it.

I have not even looked at my Skyline since I brought it home from the shop. I dropped it off at a racing shop in June, and in 3 months they didn't even look at it besides pulling a valve cover and finding the cam cap chewed up. I have not even brought myself to look at the car yet, no desire. Maybe this winter I'll have a better look at it. Worst case senario, it needs a new head. No big deal.



Will, that link doesn't work. I'm pretty sure a Northstar wouldn't fit, even the RB with it's accessories bolted to it is a tight fit.

[crzyone]

Ok, out of curiosity I went and pulled off my valve cover. I am amazed at what I've found.... Nothing. Absolutly no damage. All I can find is that I'm missing said cam cap. The guy said I needed a few new followers, a cam cap etc. There is no damage that I can see to any follower, and to put new ones in means reshimming the whole head.



Based on how chewed up that cam cap looks, I thought I'd see other damage. Nothing. Everything looks clean and literally unscratched. The only "damage" I found was my valve cover.




I am very tempted to buy an I6 cam cap, bolt it on and see if the ticking noise that I had goes away. Can you believe he wanted to pull my engine to look for missing parts, pull the head to look for damage etc etc... It would have been a $5k+ bill! I'm not happy. That was my entire race season down the drain...

[crzyone]

I don't want to type this post out again, so I will just paste it here.


[QUOTE=Willis;14315]I'm quoting this, and making a post. Draw your own conclusions, I have to have a chat with Cam at Lightspeed.

Compare above cam cap with another from my head.



There are 7 cam caps on a RB26 cam, #1 at the front and #7 at the rear. Appears I am missing #7 (not 6 like the pic Cam sent me). No damage anywhere to be seen in the head, none on the cam lobes, aluminum head or anywhere else. That cam cap must have been defective for all the damage it had to it...


Weird, there is I6, wonder where I7 went?


Only damage found. Looks like something round and not sharp was beat against my valve cover...



Until I talk with Cam I'm not getting into anything specific. Lets just say he didn't want me to pick up my car and made sure to be there before I showed up. I was told I had cam follower damage and that picture he sent was from my head. As far as I can tell, there is zero damage apart from a broken bolt on I6 cam cap which was likely making the noise I brought it in for.



From this link
http://www.straightpipe.ca/forums/showt ... 352&page=3


Seems like the local race shop tried to screw me over big time.

[crzyone]

Sorry for sidetracking your thread Will. I will separate it tonight.