Lowering engine

[arrowhead]

Well I have done my search have not been able to find anything related:

Why could I not or should I not lower my engine?

I know that all mounts will have to be modified and there is other work involved but by looking at it there seems to be no major problems. All mounts will be solid
modification or alterations will not be a problem if it can be done.

Maybe moving back about an inch if possible.


Thanks

 

[SkyGrowsCold]

One thing to keep in mind when lowering your engine is making sure your oil pan is still safe and out of harms way. Go check out any of the "stance" forums and you'll see a lot of people raising their motors because they like a really low car but are busting pans up.

 

[RamenPride]

Well I have done my search have not been able to find anything related:

Why could I not or should I not lower my engine?

I know that all mounts will have to be modified and there is other work involved but by looking at it there seems to be no major problems. All mounts will be solid
modification or alterations will not be a problem if it can be done.

Maybe moving back about an inch if possible.


Thanks

Why would you want to lower your engine?

Anyway, you can only lower it so far until it hits the crossmember unless you plan on making a new one. The oil pan will also get wrecked because it will be lower than the front of the vehicle. If you move it back an inch the axles will no longer be in line with the engine and transmission (ie they'll be at a forward angle) which I suspect will cause the CV joints and tie rod ends to wear faster.

 

[Mrdocprofessor]

i assume for a lower cg seems like a reasonable thing to do if it can be done safely ,and how the heck could moving the motor have anything to do with tie rod ends?

 

[stars]

First if you want to lower your cg just cut your springs. Second these cars already set low enough and any lower they will shear the bottom off your oil pan. Remember, your engine needs to rock forward and backward, better allow for compensation for that. Also if you allow the rubber bushings to wear out, you have already set about 1 inch lower so problem solved thanks to worn out engine mount bushings =)

 

[WES_393]

I'm assuming this is to get the low center of gravity such as the RX7/RX8 have with the engine being behind the front wheels and the bulk of weight being below the horizontal midline of the chassis. For our cars, that's just not going to happen. The crossmember that sits below the trans has about 2 inches of clearance from the trans itself. Unless you made a custom crossmember to let the trans sit lower, but you wouldn't get away with more than an extra inch or two from doing that. The motor could be moved back as well. But this would be extremely limited since the bell housing would hit the main beam of the subframe long before the intake manifold ever touched the firewall. Sure, you could modify that main beam, but now your sacrificing rigidity for stability. It doesn't make sense.

And then you run into the issue of the drive shafts. The engine, trans, and differential are basically one unit. You might be able to get away with the engine being lowered since the joints in the CV could compensate the same as lowering the entire car. However, moving the engine and trans back would put the axles at multiple angles in which U-joints are not meant to move. RWD cars have an output shaft to the rear differential that can compensate for lowering an engine. The driveshaft could also be shortened to allow the eninge/trans to be moved back. However, with FWD or AWD, you don't have the luxury of a longitudinally mounted engine/trans.

So after all the work of custom motor mounts, custom suspension work, ensuring the driveshafts are straight, fabbing up a new crossmember, and modifying the main subframe beam, you still have an engine that is in front of the front wheels with the bulk of the weight being spread across the horizontal midpoint of the chassis. Only now you have to worry about damaging vital parts of the engine and trans because of the low clearance. If you have the means and knowledge to do all of this correctly, then yes it's possible. But unless your car is the time attack world champion and you need to shave off an extra .5 seconds to secure next years win, then I would say it's not worth it. You would benefit much more from lowering and stiffening the suspension.

Sorry for the long post, but you asked

 

[arrowhead]

One thing to keep in mind when lowering your engine is making sure your oil pan is still safe and out of harms way. Go check out any of the "stance" forums and you'll see a lot of people raising their motors because they like a really low car but are busting pans up.

The pan will be no problem this will be a track only car probably will have a dry sump anyways.

Thanks,\.

Why would you want to lower your engine?

Anyway, you can only lower it so far until it hits the crossmember unless you plan on making a new one. The oil pan will also get wrecked because it will be lower than the front of the vehicle. If you move it back an inch the axles will no longer be in line with the engine and transmission (ie they'll be at a forward angle) which I suspect will cause the CV joints and tie rod ends to wear faster.

Crossmenber has already been taken out to be replaced by another, remember this are CV joints and can take much more angle than universal joints, tie rods will not be affected,

Thanks

First if you want to lower your cg just cut your springs. Second these cars already set low enough and any lower they will shear the bottom off your oil pan. Remember, your engine needs to rock forward and backward, better allow for compensation for that. Also if you allow the rubber bushings to wear out, you have already set about 1 inch lower so problem solved thanks to worn out engine mount bushings =)

Oil pan no problem.

Respecfully disagree on engine movement that is a no no, as I first posted mounts will be solid all the way around .

Thanks

i assume for a lower cg seems like a reasonable thing to do if it can be done safely ,and how the heck could moving the motor have anything to do with tie rod ends?

Amen

Thanks

 

[RamenPride]

and how the heck could moving the motor have anything to do with tie rod ends?

You're right, it doesn't. I was at work and didn't have a chance to think about it.

 

[greengoblin]

Well I have done my search have not been able to find anything related:

Why could I not or should I not lower my engine?

I know that all mounts will have to be modified and there is other work involved but by looking at it there seems to be no major problems. All mounts will be solid
modification or alterations will not be a problem if it can be done.

Maybe moving back about an inch if possible.


Thanks

If anyone has moved the engine in our cars I have never seen info posted anywhere.

There is no reason you could not move the engine down. I think a dry sump pan would be the way to go.

Moving it back would be a bit harder. There is not very much room between the fire wall and the engine in a 2g. You would have to cut the fire wall . That's not too big of a deal. The engine mount on the drive side will be the the hardest since the cleves is intergrated into the strut tower. I think you could just use an offset mount to fix that though.

If you move the engine back then you will have to have a custom driveshaft made. If moving it down you will also need to make sure all your driveline is in alignmet but I'm sure you know that.

The only reason not to is the complexity of doing versus what you'll gain. I chose not to do it on my car for aero reasons.

All in all it's a good idea. From your previous post I know your build a full track car. You just want to make sure it will not interefer with other aspect of your build. Most on here will tell you that it's not worth doing but they will be the one that for the most part do not do custom one off work. I'm not knocking anyone just point out the obivous .

Goodluck if you go this route Arrowhead and post up that you do .

 

[arrowhead]

I'm assuming this is to get the low center of gravity such as the RX7/RX8 have with the engine being behind the front wheels and the bulk of weight being below the horizontal midline of the chassis. For our cars, that's just not going to happen. The crossmember that sits below the trans has about 2 inches of clearance from the trans itself. Unless you made a custom crossmember to let the trans sit lower, but you wouldn't get away with more than an extra inch or two from doing that. The motor could be moved back as well. But this would be extremely limited since the bell housing would hit the main beam of the subframe long before the intake manifold ever touched the firewall. Sure, you could modify that main beam, but now your sacrificing rigidity for stability. It doesn't make sense.

And then you run into the issue of the drive shafts. The engine, trans, and differential are basically one unit. You might be able to get away with the engine being lowered since the joints in the CV could compensate the same as lowering the entire car. However, moving the engine and trans back would put the axles at multiple angles in which U-joints are not meant to move. RWD cars have an output shaft to the rear differential that can compensate for lowering an engine. The driveshaft could also be shortened to allow the eninge/trans to be moved back. However, with FWD or AWD, you don't have the luxury of a longitudinally mounted engine/trans.

So after all the work of custom motor mounts, custom suspension work, ensuring the driveshafts are straight, fabbing up a new crossmember, and modifying the main subframe beam, you still have an engine that is in front of the front wheels with the bulk of the weight being spread across the horizontal midpoint of the chassis. Only now you have to worry about damaging vital parts of the engine and trans because of the low clearance. If you have the means and knowledge to do all of this correctly, then yes it's possible. But unless your car is the time attack world champion and you need to shave off an extra .5 seconds to secure next years win, then I would say it's not worth it. You would benefit much more from lowering and stiffening the suspension.

Sorry for the long post, but you asked

Wes
Not only the mazda but all RR car benefit from this and ours with all this weight in front of the axles would benefit even more.
U joints which is not our case should have at least a 5* and that is why on rwd cars you adjust your pinion angle beside other reasons. The car will be fully caged so it will not depend of any of the factory reinforcements.
Maybe I should have mentioned before, please check my build journal under
98 Talon Tsi road racer.
No I am not looking to be neither one of what you mentioned, this is normal part of building a road race car, we go to a lot to get as much balance as we can. Everything you mentioned is in the plans as normal except what you mentioned about straight driveshafts that is something you do not want.

Thanks

If anyone has moved the engine in our cars I have never seen info posted anywhere.

There is no reason you could not move the engine down. I think a dry sump pan would be the way to go.

Moving it back would be a bit harder. There is not very much room between the fire wall and the engine in a 2g. You would have to cut the fire wall . That's not too big of a deal. The engine mount on the drive side will be the the hardest since the cleves is intergrated into the strut tower. I think you could just use an offset mount to fix that though.

If you move the engine back then you will have to have a custom driveshaft made. If moving it down you will also need to make sure all your driveline is in alignmet but I'm sure you know that.

The only reason not to is the complexity of doing versus what you'll gain. I chose not to do it on my car for aero reasons.

All in all it's a good idea. From your previous post I know your build a full track car. You just want to make sure it will not interefer with other aspect of your build. Most on here will tell you that it's not worth doing but they will be the one that for the most part do not do custom one off work. I'm not knocking anyone just point out the obivous .

Goodluck if you go this route Arrowhead and post up that you do .

As you well know one of the first things taken into consideration when building a RR car is engine location whether is a tube or a modified body as in my case, I have a FWD not an AWD and even if I where to go AWD having a custom driveshaft made would be no problem, all the cars I have built have had a custom made one,
Please look at my build under the build journals and you will see why modifying the firewall would not be a problem for me, although I dont think I could go that far back,
Thanks for understanding that it is well worth it.

I am almost 100% SURE this has been done with these cars before, it is so basic, BUT maybe they forgot to mention it.
It is hard for me to understand how a track car would be build w/o taking advantage of this.

Could you expand on why you chose not to, you mentioned aero.

Thanks, if you come up with anything else please let me know and if you have any ideas how to best do it also, let me know.

 

[greengoblin]

As you well know one of the first things taken into consideration when building a RR car is engine location whether is a tube or a modified body as in my case, I have a FWD not an AWD and even if I where to go AWD having a custom driveshaft made would be no problem, all the cars I have built have had a custom made one,
Please look at my build under the build journals and you will see why modifying the firewall would not be a problem for me, although I dont think I could go that far back,
Thanks for understanding that it is well worth it.

I am almost 100% SURE this has been done with these cars before, it is so basic, BUT maybe they forgot to mention it.
It is hard for me to understand how a track car would be build w/o taking advantage of this.

Could you expand on why you chose not to, you mentioned aero.

Thanks, if you come up with anything else please let me know and if you have any ideas how to best do it also, let me know.

Bringing the engine down would interefer with my plans for my front diffuser. I really can't go into detail as Andrew who design my aero package made it clear not to. Sorry.

Kevin

 

[arrowhead]

Keeping little secrets from us, well I respect your position.

If you have any ideas just let them fly.

I will keep studying this and see what happens.

 

[PieEyedPiper]

Why wouldn't we want our driveshafts to be in alignment? Surely the further you get from 0* (or 180) the less desirable it is, no?

 

[viperlp01]

The pinion angle should be at a minimum of 5* but it is actually better to go with a little more angle. An example is big trucks. Look at the drive shaft angle that they have and how the diff is parallel with the body. Look down the center of your GSX next time it is on a lift. You will notice how far from straight the drive shaft is.

Pinion Angle Explained

 

[PieEyedPiper]

The pinion angle should be at a minimum of 5* but it is actually better to go with a little more angle. An example is big trucks. Look at the drive shaft angle that they have and how the diff is parallel with the body. Look down the center of your GSX next time it is on a lift. You will notice how far from straight the drive shaft is.

Pinion Angle Explained

Thanks for the link. Sounds like 0 is actually ideal, but you can tweak it to suit your driving preferences or depending on the purpose of the vehicle.

My driveshaft is a freaking arrow compared to these these jacked-up, diesel powered, 30-60-90 triangles that roll around everywhere.


EDIT: I'm dragging this thread all over now, but I understand better why the trucks appear to have such extreme angle, but can in fact be at 0*.

 

[arrowhead]

Thanks for the link. Sounds like 0 is actually ideal, but you can tweak it to suit your driving preferences or depending on the purpose of the vehicle.

My driveshaft is a freaking arrow compared to these these jacked-up, diesel powered, 30-60-90 triangles that roll around everywhere.


EDIT: I'm dragging this thread all over now, but I understand better why the trucks appear to have such extreme angle, but can in fact be at 0*.

No, 0 will not work you need those degrees to make uJoints last also, having it in alignment means taking all the angles in consideration does not mean straight.
If the joints where straight they would wear in no time.

Thanks

 

[NWHTanK]

Well the problem with lowering your engine.the axel that is shorter bettween the trans and the knuckle. The cv joint on the trans side has very little movement to go down as not to hit the suspension crossmember front arm mount. While doing the srt swap had to take that into acount,along with other fittment issues.

 

[jrohner]

Every one of these cars I've ever seen has already had the oil pan all beat up -- lower the engine and the oil pan is GONE.

 

[bryanwheat]

The axles are going to hit the subframe if you drop the engnie any at all. They are already within an inch or 2 of touching it where the lower control arm bolts. You would have to make a lower mounting point for the control arm. Also you are not just dropping the engine, you are also dropping the transmission, transfer case and everything bolted to the engine. Once you lower the car, and the engine you are going to be working with very little ground clearence between the oil pan, exhast, transmission and transfer case. As stated before you are also putting unwanted stress on the u joints because of the increased pinion angle.

 

[arrowhead]

The axles are going to hit the subframe if you drop the engnie any at all. They are already within an inch or 2 of touching it where the lower control arm bolts. You would have to make a lower mounting point for the control arm. Also you are not just dropping the engine, you are also dropping the transmission, transfer case and everything bolted to the engine. Once you lower the car, and the engine you are going to be working with very little ground clearence between the oil pan, exhast, transmission and transfer case. As stated before you are also putting unwanted stress on the u joints because of the increased pinion angle.

Thanks for your reply
My car is FWD, were you able to do it on the srt.

That is one of the places I was looking at, but the solution does not look difficult,
how did you do it?, this is for a track car only and my minimum ride height could be 3" not counting the seam.

 

[NWHTanK]

Im doing a srt swap so install is custom. But from what I have noticed is that one of your axels will make contac with the lower control arm mount if u lower your engine and trans. When using the stock rubber engine and trans mounts will make it worse.

 

[arrowhead]

Im doing a srt swap so install is custom. But from what I have noticed is that one of your axels will make contac with the lower control arm mount if u lower your engine and trans. When using the stock rubber engine and trans mounts will make it worse.

Sorry, actually my previous post was really for you,.
There will be no rubber mounts anywhere, and my build is almost custom everything.

Do you foresee any other problems.

Thanks.

 

[NWHTanK]

I just dont see any way to drop. At most u could get a 1/8 inch and thats iffy at best. And not worth doing unless u were to move the engine and trans foward then tilte the back of the engine up. But then you are moving the heavy mass foward of axels center line makeing the car more nose heavy. And your mounts dont let u piviot the engine and trans like the srt mounts. So its just not worth doing.

 

[jtmcinder]

My only $.02 on this so far is this: given the importance of axle angles and no suggestion (so far) that this will be an AWD, consider rolling the engine a bit as you lower, to tuck the heaviest (lower) bits closer to the firewall than the head, because this will also raise the inboard ends of the axles.

 

[NWHTanK]

My only $.02 on this so far is this: given the importance of axle angles and no suggestion (so far) that this will be an AWD, consider rolling the engine a bit as you lower, to tuck the heaviest (lower) bits closer to the firewall than the head, because this will also raise the inboard ends of the axles.

No offense but I dont think that will work out either given the eclipse mount desighn. Thats why I stuck with the srt mounts. The eclipse mounts point in the wrong direction as to get tilt and if he is using soild insert will give him less movent. When I decided to do the srt swap I chose to use the srt mounts so that I could have more adjustability over the eclipse mounts and it also got rid of the cross bar from suspension cradel to lower radiotor support. The amount of drop he can get is not worth it.