Subaru swap

[BRAAP]

I disagree with the mating to a different tranny lowering the engine, at least by any significant amount….

 

If anyone finds any holes in this, please, by all means fill them. This pertains to a rear wheel drive Suby Z car conversion, not an AWD version.

As installed in a Subaru car, the Suby crankshaft centerline is nearly 4” inches above the half shaft centerline, (for all intents and purposes, the half shaft centerline of the Suby transaxle is being viewed spatially on the same plane as the tranny output centerline in a front engine/rear drive platform, like the Z car). On this alone, if we can mate the Suby engine to a Z car transmission vs using the Suby transaxle, that means that heaviest single item in car, (the engine), can be lowered nearly 4”. Lets get a little deeper into the center of mass of the engine. The center of mass for a Suby engine is right at or just slightly above crankshaft centerline. For a SBC, the center of mass is approx cam centerline which is 5” above crankshaft centerline, (for the L-6, the center of mass is going to be at least 5” or higher above the crankshaft centerline). The SBC/L-6 is approaching twice the mass of the Suby, and that center of mass is 5”+ higher than the Suby!

To be able to drop a mass of 200-300 lbs a mere 2” lower in the chassis of a 2000-2400 lb car is quite significant, with the Suby, we are looking at substantially more than 2”, more on the order of 5”+ compared to a SBC conversion or the L-6, VERY significant! Add to this the lighter overall weight of the Suby, and its CG would be further rearward…. For a rear wheel drive Z, win win win…

 

…

I also don't see being able to lower the Scooby engine, due to the crossmember being in the way, unless it really is short enough to be completly behind the crossmember. I know I measured one of these engines a while ago, as I was going to buy a Forester and swap a V6 into it...

 

 

 

 

The Suby engine “should”, (I use the term “should” loosely) have no issue being installed 100% behind the cross member. The Suby is quite a bit shorter than a Small Block Chevy, and in the JTR position the damper of the SBC sits right over the rack. The T/C rod mounts will be an issue for a Suby conversion though. A fabricator worthy of installing a Suby engine in an S-30 could redesign the front of the S-30 so the T/C rods go forward as in the S-130/Z-31 cars, (I happen to know a competent fabricator that installed a complete S-30 cross member and rear facing T/C rod set up in 510 with a VG30DETT in the engine bay, i.e. it can be done.)

 

… Just also consider that you can place the engine too far rearward and make the car handle poorly. By taking too much weight off the front wheels, the car will want to push more through the corner, than it would with more weight over the front axle. You would then have to weight transfer using the brakes instead of simply letting off the loud pedal, which will in the end make for slower lap times…

 

 

 

Too far rearward and the car will handle poorly? This area of chassis design is very deep water and blanket statements like that are indicative of little to no first hand experience in that field. Nothing wrong with that, but before making such bold claims, be absolutely sure of the information you are presenting first. On this forum are some very educated chassis gurus and if you search, not just this forum, the topic of ideal weight distribution is on going discussion and different for various applications. To use your analogy quoted below, “when’s the last time you heard of a poorly handling Porsche 911?”

 

 

Some of you expressed concern with hanging the weight of the engine in front of the front axle, when's the last time you heard of a poorly handling Scooby? The fact that the front wheels are powered will help pull the car through the corner, besides that engine by the looks of it is quite light, and from what I remember the engine length isn't that far forward….

 

It’s not that a it wont handle well, but by keeping the polar moment of inertia short, the transitional handling will improve as the tires aren’t being asked to work as hard during transitional handling. There is much more to this than just PMoI. In an AWD, especially a FWD arrangement, I agree, weight on the drive wheels is important. I’m sure the chassis gurus will have more to add…

 

…

BTW, it seems that there are a few people that think I'm raging on this swap or somehow saying that it's a bad idea, please don't read any more into what I write than what is there, I am only pointing out other aspects of this, or for that matter, any swap. I think it would be a good swap, I just think that maybe some of the reasons are for the wrong reasons. I've seen far too many people start stuff like this to realize that there really is no benefit over taking an easier path, or that the "problem" they were trying to "fix" was made worse. I've been around cars long enough to have seen this re-occur more often than you might believe.

 

Thank you for clarifying the intent behind your posts and thank you for contributing. You may not be trying to or wanting to “rage” on this swap, but your posts were coming across more as, “the glass is half empty”, not so much constructive, regarding the feasibility of this conversion.

[Gollum]

Whoa, check this out.

 

http://www.canardzone.com/members/PhillipJohnson/Engine/subaru_eg33.htm

 

He states the widest point is 22 inches... that's quite a bit smaller than I could have imagined. Are the 6 cylinders smaller?!

[Guest TeamNissan]

That would be very interesting lol. at 22" doesn't it fit?

[RTz]

He states the widest point is 22 inches...

 

Well, now... that's an interesting little tidbit.

[Gollum]

Might be true too!!!! Crazy.. I never would have guessed.

 

Look at how much gap there is in this engine bay with the 6 cylinder in there.

 

http://www.xxtuning.com/xxgallery/details.php?image_id=772

http://www.xxtuning.com/xxgallery/details.php?image_id=775

 

I'm still baffled over here, so if someone has dimensions to prove me wrong, please.

 

EDIT: In my limited research I've found that the newer EZ series is much shorter than the EQ, and quite a bit lighter too. It' has COP and I can't seem to find any specs on how wide. People just say "similar to the 4 cylinder" variants. Blaa

 

Second Edit:

 

Take from this site:

 

http://linaracing.com/impreza-h6-conversion-faq.php

 

What are the exact dimensions of the engine?

I have measured these, and won't have any others for a very long time. (till the engine comes out... maybe next year)

 

Across front: 32.25"

Across body: 29.75"

Across tranny attachment: 14.75

Between motor mounts: 14"

Front to rear: 18"

Height, sump to intake: 25.5"

[RTz]

Might be true too!!!! Crazy.. I never would have guessed.

 

Tough to swallow, isn't it?

 

My EJ22 measures pretty close to 28" 'cover-to-cover'.

 

This twin cammer is 32.5" (sorry, can't credit photo)...

 

 

 

 

It would be really nice to have a confirmation on the 22".

[BRAAP]

*** edit *** Gollum posted this info already...

http://linaracing.com/impreza-h6-conversion-faq.php

 

Only 276 lbs in long block form.. Hmmm…

 

 

[Gollum]

My only conclusion is that 22 inches MUST have been a typo. That spec wasn't mentioned multiple times, so I guess just a typo would be possible.

 

I'd assume me meant 32 inches. Not 22. There's just no way you could get that size package with a near square design. It'd have to have a MUCH shorter stroke.

[Six_Shooter]

If anyone finds any holes in this, please, by all means fill them. This pertains to a rear wheel drive Suby Z car conversion, not an AWD version.

As installed in a Subaru car, the Suby crankshaft centerline is nearly 4” inches above the half shaft centerline, (for all intents and purposes, the half shaft centerline of the Suby transaxle is being viewed spatially on the same plane as the tranny output centerline in a front engine/rear drive platform, like the Z car). On this alone, if we can mate the Suby engine to a Z car transmission vs using the Suby transaxle, that means that heaviest single item in car, (the engine), can be lowered nearly 4”. Lets get a little deeper into the center of mass of the engine. The center of mass for a Suby engine is right at or just slightly above crankshaft centerline. For a SBC, the center of mass is approx cam centerline which is 5” above crankshaft centerline, (for the L-6, the center of mass is going to be at least 5” or higher above the crankshaft centerline). The SBC/L-6 is approaching twice the mass of the Suby, and that center of mass is 5+" higher than a suby

 

No it doesn't mean that the engine can be lowered 4". The half shaft/CV outputs are at the bottom of the bellhousing, which you already know, this is to line up the outputs closer to the wheel centers, and also very much due to the fact that two objects can't occupy the same space at the same time as another object. More specifically the front axle outputs and the related diff, can not be in the same line as the input shaft of the tranny itself. There is also the clutch (in manual trannies, that I will deal more with than the autos, though I am sure they are of similar design). Take a look at any FWD transaxle for similarities. The axle/half shaft/cv shaft outputs on the tranny are far below the crank centerline.

If I was even half decent with PS or even MS Paint, I could drwa up a few diagrams to show what I'm trying to illistrate.

 

I agree that the center of mass will be higher on V engine, than a flat engine, I am mearly talking about the actual mounting hight in relation to the crank center line. I know in some chassis' moving the mass lower has had an undesired effect on handling, lower is not always better.

 

To be able to drop a mass of 200-300 lbs a mere 2” lower in the chassis of a 2000-2400 lb car is quite significant, with the Suby, we are looking at substantially more than 2”, more on the order of 5”+ compared to a SBC conversion or the L-6, VERY significant! Add to this the lighter overall weight of the Suby, and its CG would be further rearward…. For a rear wheel drive Z, win win win…

 

Not exactly. For handling, possibly for overall weight transfer to gain traction while acceleration, quite possibly not.

 

Can you recall those drag cars, from the late '50s and up to somewhere around the mid to late '60s that used straight axles in the front? The reason for this, was to get the weight in the front as high as possible to promote weight transfer, to gain traction. At some point the rear axle was also moved forward for the same reason. Yes I know technology has changed since then and understanding the reactions of chassis' is quite a bit better, but the idea of this still has to be understood. With the weight higher the moment was already closer to being able to lift the front end or rather get that weight be more on the rear wheels than the front wheels. This is great for straight line, usually not so much for handling, imagine trying to take the corkscrew at Laguna Seca in one of those cars?

With todays technology, we can usually open enough power, and with the better understanding of suspensions, get the car to weight transfer with the engine lower, but in the case of the S30, it's still a 38 year old design, and unless this is going to be re-worked may not work well with a lower center of mass, it may work awesome, but these are the things that need to be considered.

 

 

 

 

 

 

The Suby engine “should”, (I use the term “should” loosely) have no issue being installed 100% behind the cross member. The Suby is quite a bit shorter than a Small Block Chevy, and in the JTR position the damper of the SBC sits right over the rack. The T/C rod mounts will be an issue for a Suby conversion though. A fabricator worthy of installing a Suby engine in an S-30 could redesign the front of the S-30 so the T/C rods go forward as in the S-130/Z-31 cars, (I happen to know a competent fabricator that installed a complete S-30 cross member and rear facing T/C rod set up in 510 with a VG30DETT in the engine bay, i.e. it can be done.)

 

Yes, I can't really see any reason why the engine shouldn't fit behind the crossmember, but this IS something that needs to be determined. If I was going as far as moving the TCs to the front of the axle, which while we're talking about that would require quite a bit of frame strangthening forward of the axle, as the say bar aready puts enough stress on that area (), but to continue my thought, for myself I would probably convert to a double A-arm suspension, as it would be more adjustable, for tuning the chassis, and can usually fit wider wheel and tire combos, when designed with that in mind. This would depend on where the front of the heads would actually sit, if it would interfere with an attachement point of the upper A-arms, which it very well could.

On the other hand a properly designed fram rail that passes around the heads, could incorperate a TC attachment point still rearward, where it will transfer loads into the chassis better, without the need to re-inforce the "nose" of the car with extra weight. That is afterall what is trying to be accomplished in moving the weight rearward, as I understand it. Again this is what I mean by considering everything. The rear ward attachment point would be below the heads, and may need to be moved a little bit forward (as compared to the stock location), to gain the full arc through the movement of the chassis, without using a bent TC rod (to clear the head in suspension full compression), that could cause ground clearance issues.

 

 

 

Too far rearward and the car will handle poorly? This area of chassis design is very deep water and blanket statements like that are indicative of little to no first hand experience in that field. Nothing wrong with that, but before making such bold claims, be absolutely sure of the information you are presenting first. On this forum are some very educated chassis gurus and if you search, not just this forum, the topic of ideal weight distribution is on going discussion and different for various applications. To use your analogy quoted below, “when’s the last time you heard of a poorly handling Porsche 911?”

 

I have quite a bit of experiance with this and quite a bit of theory study as well. I don't say something unless I'm sure of what I'm saying. You're also misconstruding what I am saying, take that 911 and take off most of the front weight, it won't handle well without good front grip, which removing that weight will reduce. To combat this wider front tires will be needed, that does a few things, adds weight, and increases the contact area to the road surface, because to gain more traction on a lighter axle, more contact area is needed. There's a balance to this, but the basics still hold true.

 

 

 

It’s not that a it wont handle well, but by keeping the polar moment of inertia short, the transitional handling will improve as the tires aren’t being asked to work as hard during transitional handling. There is much more to this than just PMoI. In an AWD, especially a FWD arrangement, I agree, weight on the drive wheels is important. I’m sure the chassis gurus will have more to add…

 

Yes there is much more to this than what is on the surface, that's what I'm pointing out and have been all along.

 

 

 

Thank you for clarifying the intent behind your posts and thank you for contributing. You may not be trying to or wanting to “rage” on this swap, but your posts were coming across more as, “the glass is half empty”, not so much constructive, regarding the feasibility of this conversion.

 

I'm not commenting on this anymore, you're beating a dead horse here, and is simply about symantics, and only reading what you want to read. When reading posts, or passages on the internet, or even in a book, it is usually the reader themselves that put the emphasis where they see, not always where the writer intended. This part is done.

[Gollum]

Can I ask a simple physics question here? Because lifting weight off the front being bad still isn't making sense to me. Usuaully when people ADD weight to the front they get more understeer. Which makes sense when you consider:

 

Weight is a race cars #1 enemy. The more weight you have the more mass you need to move around a track.

 

There are cars out there with very little weight on the front tires at all, like the lotus elise, and it has much smaller tires in front than in rear, suggesting it doesn't need AS MUCH contact patch to move that front end around.

 

I'm not saying you're wrong six shooter, I'm just saying that the way what you're saying comes across flys in the face of everything I've ever read, seen, even experienced.

[G.I.jonas]

Sorry guys but the ej engines are not 22",They are 32 cover to cover.

 

The eg33 is essentially a 2.2l ej22 with 2 extra cylinders - 2.2l X 50% = 1.1l.

 

2.2l + 1.1l = 3.3...voila the eg33,so you can expect the same width with the eg33 as the ej motors.and all ej motors are the same block so 2.0 2.2 and 2.5 are dimensionally the same.

 

The same goes with the er27 flat six.Based on the ea engines or 1.8 liters.

 

1.8 x 50% = .9l 1.8 + .9 = 2.7l...voila the er27.I will have to measure my ea motor in my suby and then we will also know the width of the er series motors.

 

Give up on all this measurement mumbe jumbo,we know it is close enough to be done by far.No sense tossing argument back and forth,this is hybridz if you want to do something cool then what you do is you biuld a car around an engine and quit trying to build an engine around the car.Most things that need to be done to the car are probably improvements to the vehicle anyway

 

 

*Edit sorry about the measurement thing,i read a few posts hastily.Regardless i stick to the rest of it.*

[JMortensen]

Six Shooter, you're saying some things that run against the prevailing wisdom and you're not backing yourself up very well. "Because I know what I'm talking about" is never adequate here.

 

Some examples of your questionable comments:

Just also consider that you can place the engine too far rearward and make the car handle poorly. By taking too much weight off the front wheels, the car will want to push more through the corner, than it would with more weight over the front axle. You would then have to weight transfer using the brakes instead of simply letting off the loud pedal, which will in the end make for slower lap times…

One of the hardest things for me to learn about road racing was that you CAN'T coast into a braking zone and be fast. You're either on the gas or the brake 99% of the time. Every once in a while you might find a turn that requires a slight breathe on the gas pedal, but NOBODY who is racing is going to be letting up on the gas and not hitting the brake and going faster for doing it.

 

Above and beyond that, weight transfer to the front happens when you hit the brakes, but that means that the front brakes do a lot more of the braking than the rears do because the weight transfers OFF of the rear and then they can't put in too much braking effort without locking up. If you have a heavy rear end (like pretty much any mid or rear engine race car) then you can apply more overall braking force because you can use the rear wheels for more braking than you would otherwise be able to. Rear weight bias is why the 911 is so legendary for it's awesome braking.

 

I know in some chassis' moving the mass lower has had an undesired effect on handling, lower is not always better.

Do you have an example where handling was degraded just from lowering weight in the chassis. That would be a new one on me. Everything I've ever read says that the lower the weight the less transfer to the outside wheels. The less transfer to the outside the more traction the inside wheels can use to increase overall grip. Again, backwards from the normally accepted ideas, just like your braking theory.

 

I have quite a bit of experiance with this and quite a bit of theory study as well. I don't say something unless I'm sure of what I'm saying. You're also misconstruding what I am saying, take that 911 and take off most of the front weight, it won't handle well without good front grip, which removing that weight will reduce. To combat this wider front tires will be needed, that does a few things, adds weight, and increases the contact area to the road surface, because to gain more traction on a lighter axle, more contact area is needed. There's a balance to this, but the basics still hold true.

Which is why race 911's always have much wider rear tires than fronts and the older air cooled ones had something like 38/62 weight distribution.

 

Sorry, but none of this stuff adds up. I didn't get into the Subaru mounting specifics because this handling theory stuff caught my eye first...

[Six_Shooter]

Six Shooter, you're saying some things that run against the prevailing wisdom and you're not backing yourself up very well. "Because I know what I'm talking about" is never adequate here.

 

Some examples of your questionable comments:

 

One of the hardest things for me to learn about road racing was that you CAN'T coast into a braking zone and be fast. You're either on the gas or the brake 99% of the time. Every once in a while you might find a turn that requires a slight breathe on the gas pedal, but NOBODY who is racing is going to be letting up on the gas and not hitting the brake and going faster for doing it.

 

I agree that in a race most drivers will either be on the gas or the brake, though I have seen many instances where there will be cosating into or through a corner happening, especially through the corner, where either no or very little throttle is used. I have also seen some instances where getting into a turn, with enough weight transfer by simply getting off the throttle is enough, move enough weight off the front wheels and you'll have to use the brakes to get enough weight transfer.

 

As far as I could tell this thread was started more for a street driven vehicle, which the set-up usually differs quite a bit from what would be used on a track.

 

Above and beyond that, weight transfer to the front happens when you hit the brakes, but that means that the front brakes do a lot more of the braking than the rears do because the weight transfers OFF of the rear and then they can't put in too much braking effort without locking up. If you have a heavy rear end (like pretty much any mid or rear engine race car) then you can apply more overall braking force because you can use the rear wheels for more braking than you would otherwise be able to. Rear weight bias is why the 911 is so legendary for it's awesome braking.

 

I can see that, and makes sense. But does that mean we should all turn our S30s into rear engine cars to simplay gain possible better braking?

It would seem that where one area had a possible gain, other areas might suffer.

Regarding the 911, I've known a few people who didn't like the handling of a 911, because they found that it pushed through the corners, until there was enough brake applied, and then coming out of the corner was found that the rear end wanted to kick out, and took a very careful modulation of the loud pedal.

 

 

Do you have an example where handling was degraded just from lowering weight in the chassis. That would be a new one on me. Everything I've ever read says that the lower the weight the less transfer to the outside wheels. The less transfer to the outside the more traction the inside wheels can use to increase overall grip. Again, backwards from the normally accepted ideas, just like your braking theory.

 

No, I don't unfortunatly. I don't have a braking theory, only weight transfer, you have applied it to braking theory.

 

Which is why race 911's always have much wider rear tires than fronts and the older air cooled ones had something like 38/62 weight distribution.

 

Sorry, but none of this stuff adds up. I didn't get into the Subaru mounting specifics because this handling theory stuff caught my eye first...

 

There is still that debate about what split (weight bias) is best, and it seems to come down to each vehicle, not just each type of driving/racing.

There's many factors that could be why one vehicle with a certain weight bias works better than others, like wheelbase, suspension type AND how/where in the chassis those suspension points are tied into, steering, where the weight is, not just hight or along the length of the vehcile but where to each side, and how those CGs will move, in relation to braking, acceleration, cornering, etc. I would also think there's much more to the wide® rear tires than simply braking ability. I'm sure it has something to do with planting the power and controling the rear end wanting to kick out in a hard turn.

[Six_Shooter]

Can I ask a simple physics question here? Because lifting weight off the front being bad still isn't making sense to me. Usuaully when people ADD weight to the front they get more understeer. Which makes sense when you consider:

 

Weight is a race cars #1 enemy. The more weight you have the more mass you need to move around a track.

 

There are cars out there with very little weight on the front tires at all, like the lotus elise, and it has much smaller tires in front than in rear, suggesting it doesn't need AS MUCH contact patch to move that front end around.

 

I'm not saying you're wrong six shooter, I'm just saying that the way what you're saying comes across flys in the face of everything I've ever read, seen, even experienced.

 

Yes, too much weight placed too far forward is probably worse, but I don't think that will really be a problem, with the inteded design of this swap, seeing as people want to use it (Scooby engine/boxter) in a RWD only application, and seems that it will be either completly or almost completly behind the front axle. The 6 cyl might have a harder time acheiving that though, being behind the front axle I mean, the weight forward I wouldn't see as a problem still. If these cars are considered to handle decently with the I6 where a lot of the engine is forward of the axle, then I can't see a flat 6 being a problem.

 

We're not adding weight here, simply moving weight around, or removing it still.

[Guest TeamNissan]

[Six_Shooter]

 

 

 

That crank pully at 11" is I believe about the same distance that a SBC has, My V6s that I play with are about the same distance as well, and that is what I was getting at with the crank CL. Unless you use a shallow oil pan, it's really not going to be any or much lower, than other engines. I was actually surprised to this measurement at 11" on the Scooby engine. I figured it would have been a bit lower than that myself.

[Guest TeamNissan]

Its not about where the crank is, its about whats above it.

[Six_Shooter]

Its not about where the crank is, its about whats above it.

 

I understand that, but part of the discussion was also about mounting the engine lower by mating the Scooby engine to a convention RWD tranny, which is not the case, or at least not the 4" that Braaap believed could be done.

[JMortensen]

I have also seen some instances where getting into a turn, with enough weight transfer by simply getting off the throttle is enough, move enough weight off the front wheels and you'll have to use the brakes to get enough weight transfer.

Haven't seen that myself in probably close to one hundred autoxes. Maybe you could give me an example.

 

As far as I could tell this thread was started more for a street driven vehicle, which the set-up usually differs quite a bit from what would be used on a track.

So you're saying that ON THE STREET there is a car that has so much rear weight bias and so little weight transfer that you need to step on the brakes to get the car to turn? Again, never seen it. Do you have an example of this?

 

I can see that, and makes sense. But does that mean we should all turn our S30s into rear engine cars to simplay gain possible better braking?

It seems that some of us already have. Well, not rear engined, but rear biased. It isn't done just to improve the braking though. It also improves traction coming out of the corner.

 

It would seem that where one area had a possible gain, other areas might suffer.

Can you give me an example HOW other areas might suffer?

 

Regarding the 911, I've known a few people who didn't like the handling of a 911, because they found that it pushed through the corners, until there was enough brake applied, and then coming out of the corner was found that the rear end wanted to kick out, and took a very careful modulation of the loud pedal.

I used to be a Porsche mechanic, and my boss raced and quite a few of our customers raced so I was involved with setting up a number of them for racing, corner weighting, alignments, etc. I never saw or heard of any of them fixing a push by stepping on the brake. We used to put a hell of a lot of caster into the 911s though. 911's do require careful throttle modulation because of their rear weight bias and even more so on the older ones with the semi-trailing arm rear suspension.

 

No, I don't unfortunatly. I don't have a braking theory, only weight transfer, you have applied it to braking theory.

Weight transfer is weight transfer whether it be lateral or longitudinal. When you step on the brakes, it's longitudinal.

 

There is still that debate about what split (weight bias) is best, and it seems to come down to each vehicle, not just each type of driving/racing.

There's many factors that could be why one vehicle with a certain weight bias works better than others, like wheelbase, suspension type AND how/where in the chassis those suspension points are tied into, steering, where the weight is, not just hight or along the length of the vehcile but where to each side, and how those CGs will move, in relation to braking, acceleration, cornering, etc. I would also think there's much more to the wide® rear tires than simply braking ability. I'm sure it has something to do with planting the power and controling the rear end wanting to kick out in a hard turn.

Well since we're on a Z forum, let's apply these ideas to that platform and suspension. Remember that the wider rear tire thing was a response to you saying that you'd need a wider front tire to get more traction if you had less weight transfer to the front (which again doesn't make too much sense).

[Gollum]

Yes, too much weight placed too far forward is probably worse, but I don't think that will really be a problem, with the inteded design of this swap, seeing as people want to use it (Scooby engine/boxter) in a RWD only application, and seems that it will be either completly or almost completly behind the front axle. The 6 cyl might have a harder time acheiving that though, being behind the front axle I mean, the weight forward I wouldn't see as a problem still. If these cars are considered to handle decently with the I6 where a lot of the engine is forward of the axle, then I can't see a flat 6 being a problem.

 

We're not adding weight here, simply moving weight around, or removing it still.

 

Why are you talking about cars, like the subie and the Z? My question is physics related, and physics alone.

 

Tell me, how on earth does moving weight backwards remove traction up front. I'm not saying you're wrong, but I won't believe you until there's some equation with theory to back it up.