Vorshlag LSX kit

[modernbeat]

Not a sponsor here, so no.

[Captain Snooze]

Originally Posted by cf6mech

..my car weighed 2682 and now weighs 2814..

60 kg increase!! That's just crazy (in a good way). To think that 4 extra cylinders plus transmission plus a metric truckload of power only costs that much weight. Light weight seats, battery, wheels and bam! You're at zero gain.

Sounds mean too!

Originally Posted by Captain Snooze

Can you tell us if there will be replacement bracing for the the indicated oem bracing shown in pic?
Ta.

[ZDan]

Originally Posted by modernbeat

I think it went from 55% front weight with the flat four to 53% front weight with the LSx.

Very cool if true... Other swaps have gone the other direction, to 56/44.
What measures were taken to move the c.g. aft? Engine weighs more and its c.g. is further forward, transmission weighs more and is further aft, but still well forward of vehicle c.g. => no way an LS3/T56 Mag transplant into an 86 moves c.g. aft without other stuff going on! A/C delete, battery moved to trunk, etc.?

FTR the c.g. of an FD RX-7 moves forward a good 1.5% with LS/T56 transplant keeping all else equal. Not that its that a huge deal on a car that starts at 48F/52R :P

[Jaden]

Originally Posted by ZDan

Very cool if true... Other swaps have gone the other direction, to 56/44.
What measures were taken to move the c.g. aft? Engine weighs more and its c.g. is further forward, transmission weighs more and is further aft, but still well forward of vehicle c.g. => no way an LS3/T56 Mag transplant into an 86 moves c.g. aft without other stuff going on! A/C delete, battery moved to trunk, etc.?

FTR the c.g. of an FD RX-7 moves forward a good 1.5% with LS/T56 transplant keeping all else equal. Not that its that a huge deal on a car that starts at 48F/52R :P

For the overall CoG to move aft, the weight only has to move aft relative to the weight it's replacing, not aft of the cars CoG...

Jaden

[cf6mech]

Originally Posted by Captain Snooze

60 kg increase!! That's just crazy (in a good way). To think that 4 extra cylinders plus transmission plus a metric truckload of power only costs that much weight. Light weight seats, battery, wheels and bam! You're at zero gain.

Sounds mean too!


Attachment 113552

Vorshlag, unlike some swaps, shoved the LS as far back against the firewall as possible, to the point of totally trashing a set of proto type motor mounts with hours upon hours of development work invested when they discovering they could gain another couple inches aft, another consideration is this isn't a Tremec T56 which some are using which requires remote shifter that puts the weight more forward, but the Tremec Magnum XL which is longer, making it direct shifting/more aft weight/better feel/and worth every penny in this swap in my opinion.....They have been doing swaps for years and understand the minutia to making it right the first time. As far as the factory bracing, I will be replacing it with a strut tower brace.

[cf6mech]

Originally Posted by ZDan

Very cool if true... Other swaps have gone the other direction, to 56/44.
What measures were taken to move the c.g. aft? Engine weighs more and its c.g. is further forward, transmission weighs more and is further aft, but still well forward of vehicle c.g. => no way an LS3/T56 Mag transplant into an 86 moves c.g. aft without other stuff going on! A/C delete, battery moved to trunk, etc.?

FTR the c.g. of an FD RX-7 moves forward a good 1.5% with LS/T56 transplant keeping all else equal. Not that its that a huge deal on a car that starts at 48F/52R :P

Read the build, it will make more sense if you read the whole build, there was a lot of work involved in moving the CG as far aft as possible, another consideration is the tranny it's not a T56, but the Tremec Magnum XL direct shifter...i.e. another gain in moving cg aft. Before the swap I already had Recaro seats and a battery relocate to the trunk. You guys gotta realize how heavy that little boxer engine weighs and how far forward they placed it.

[ZDan]

Originally Posted by Jaden

For the overall CoG to move aft, the weight only has to move aft relative to the weight it's replacing, not aft of the cars CoG...

I understand that, but the point was how much heavier the T56 Mag is vs. the stock trans. If it *is* significantly heavier, then it is likely is moving c.g. forward even if it's located further aft than stock.

Let's say the 140 lb. T56 is 40 lb. heavier than the stock transmission (wag). Stock trans looks like its c.g. is ~16" aft of front wheel centerline. Say T56 c.g. is 6" aft of that (probably optimistic), 22" aft of front wheel centerline.

Stock trans weight distribution on the front/rear wheels would be 84 lb. front, 16 lb. rear (100 lb. * 16"/101" wheelbase)
T56 Mag would be 109.5 lb front 30.5 lb. rear.

Stock weight is 2750 with 55/45 distribution, 1512.5 front/1237.5 lb rear.
T56 Magnum would change the weight distribution to 1538/1252, or 55.1/44.9.

Just don't see the transmission giving any weight distribution benefit, particularly if the T56 is significantly heavier. If they're the same weight and it's moved aft, that would move c.g. aft a small amount, tenths of a percent. I'm betting it's a wash between the added weight and it being moved aft.

[Floggin Tires]

Yeah,
For the reliable, huge, torque increase vs weight increase.
In my opinion it's an absolute hell yes.
With proper suspension, fuck yes.

How long can you consistently beat on a 400ftlb FA?
How long can you consistently beat on a 400ftlb LS?
Which engine has more meat left on the bone?

As said before transmission choice is also tits.

If the numbers are true. I would assume you could reduce the total weight back to stock. Without losing any luxuries/amenities.

[ZDan]

Originally Posted by cf6mech

Read the build, it will make more sense if you read the whole build, there was a lot of work involved in moving the CG as far aft as possible, another consideration is the tranny it's not a T56, but the Tremec Magnum XL direct shifter...i.e. another gain in moving cg aft. Before the swap I already had Recaro seats and a battery relocate to the trunk. You guys gotta realize how heavy that little boxer engine weighs and how far forward they placed it.

I read the build and I've seen the pics, and I'm totally positive on this project! Totally awesome and I'm all for it I just don't see how weight distribution will not move forward unless other measures are taken.
The XL has an extended tail housing, doesn't move any major masses aft relative to the regular T56 Magnum.

FA20 may be heavy for an aluminum 2.0 four cylinder, but it is certainly lighter than a 450 lb. LS engine.
The boxer may sit relatively forward, but it's a lot *shorter* than an LS. So that even with the cylinder heads back against the firewall, there's no way the LS c.g. is aft of the FA20's, indeed it looks to be forward of it.

The 86 swap is the opposite of the BMW swap case, where the stock engine is much LONGER than an LS V8 and might actually be heavier. In that case, c.g. moves aft no question.

I could see how moving the battery from the front of the car to the back could get you back to stock distribution or slightly better, though.

Anyway, killer project and I'm looking forward to seeing it run!

[cf6mech]

Originally Posted by ZDan

I read the build and I've seen the pics, and I'm totally positive on this project! Totally awesome and I'm all for it I just don't see how weight distribution will not move forward unless other measures are taken.
The XL has an extended tail housing, doesn't move any major masses aft relative to the regular T56 Magnum.

FA20 may be heavy for an aluminum 2.0 four cylinder, but it is certainly lighter than a 450 lb. LS engine.
The boxer may sit relatively forward, but it's a lot *shorter* than an LS. So that even with the cylinder heads back against the firewall, there's no way the LS c.g. is aft of the FA20's, indeed it looks to be forward of it.

The 86 swap is the opposite of the BMW swap case, where the stock engine is much LONGER than an LS V8 and might actually be heavier. In that case, c.g. moves aft no question.

I could see how moving the battery from the front of the car to the back could get you back to stock distribution or slightly better, though.

Anyway, killer project and I'm looking forward to seeing it run!

You might not see why but the scales don't lie. I'm sure Mr.Fair, upon his completion of the build thread will have explanations for you and us all, it will be coming out soon. As I have noted before Vorshlag weighs everything.

June 24 at 12:36pm

Terry Fair A stock BRZ/FR-S has a F/R ratio of 56% front / 44% rear. It is now 52% front / 48% rear with the V8.

[Jaden]

Originally Posted by cf6mech

You might not see why but the scales don't lie. I'm sure Mr.Fair, upon his completion of the build thread will have explanations for you and us all, it will be coming out soon. As I have noted before Vorshlag weighs everything.

June 24 at 12:36pm

Terry Fair A stock BRZ/FR-S has a F/R ratio of 56% front / 44% rear. It is now 52% front / 48% rear with the V8.

I had started to respond as to why but then stopped. It has to do with the double fulcrum that two axle vehicles have.

Think of it as two sideways L's where the long part of the L represents the frame of the car and the little part of the L representing a line going to the ground at the axle line.

The front rear bias will be based on a division of where the balance of the weight resides on the length of each L, so shifting backward a balance point on the two L's can have a significant effect on the F/R bias because it affects both the fulcrums balance points, not just one.

Jaden

[Floggin Tires]

Correct

[cdrazic93]

I dont really care where the COG is, im just happy its well under 3000lbs. a good suspension system will help alleviate any under steer from front weight bias.

[civicdrivr]

Originally Posted by cdrazic93

I dont really care where the COG is, im just happy its well under 3000lbs. a good suspension system will help alleviate any under steer from front weight bias.

And honestly, if you're understeering, just give it a boot-full of throttle and oversteer it out