Lowering question for GRP (and any others)

[crestima]

Completely normal, the Emira has a forward rake.

If you want an even ride height indeed you will need to lower the rears more than the front, but you are limited to 15-20mm of lowering in the rear.

Exactly, I figure rear/20mm, front/15mm to reduce and even out a bit more the rear-to-front arch gaps, while simultaneously leveling the car a bit more too. The only doubt I have, is if the reduction in the angle of that forward rake has any detrimental aerodynamic effect, but guessing not, since 5mm isn't that much, and besides, we're not taking Formula 1 here.

 

[Biggles of Norwich]

Hi Folks,

Quite a number of members have posted here having installed the GRP Lowering Sleeves. I decided to order them as well and received them fairly quick. I subsequently spoke to Greg who gave me a few helpful pointers on the coil-over removals and sleeve adjustments, but I'm still undecided as to how many millimeters to drop. I'm inclined to initially go 15mm and see how the arch gap looks.

I understand that the wheel arch/tire gap is a controversial theme with some finding the OEM gaps perfectly fine, but I, along with many others, do find that wide gap to take away from the car's sportiness. I particularly dislike the excessive gap, IMO, in the rear wheel arches where they are even more pronounced. Since I first observed it, my eyes keep constantly being drawn to that rear arch gap. This brings me to my point... in preparation for the sleeves' installment, I began taking some true measurements, the results of which are shown below...

Front Arch
View attachment 55826



Rear Arch
View attachment 55827

I was intrigued with the difference front-to-rear, so I took a level to the bottom lateral rail by the mid-section under tray. This rail has a perfect unobstructed groove where to place a level. What I discovered was this...

Not level, with a high bias to rear.
View attachment 55832

Proof that it wasn't the garage floor's fault.
View attachment 55833

This is to visualize the difference in level. The leveling gap approx. 5mmView attachment 55834


My V6 manual Emira is on Touring suspension and has OEM wheels with 12mm spacers on all 4 wheels.

These measurements brought me to the conclusion that the rear wheel arch/tire gap is indeed much greater (9mm) and not a mere visual illusion, and that, in general, the front of the car is lower than the rear.

A couple of questions for Emira owners here, if you can check:

1) Do you have the same difference in front-to rear arch gaps and, if so, do you know it to be normal?
2) Is your car leveled and, if not, do you know it to be normal?

My other cars are level from-to-rear, so depending on your feedback, I'm tempted to set the rear sleeves lower than the front, in order to compensate the rear height bias.

Your thoughts?

Did you measure with the car empty or loaded (driver and ideally passenger)? That would surely make a difference?

 

[crestima]

Did you measure with the car empty or loaded (driver and ideally passenger)? That would surely make a difference?

Empty.

 

[GRP]

For a street driven car losing the rake isnt a big deal but if you are canyon driving, tracking etc I would recommend keeping the rake front to rear, on our track car we actually add in an additional 5-10mm of rake during suspension setup, it helps with the handling more than you might think.

 

[crestima]

For a street driven car losing the rake isnt a big deal but if you are canyon driving, tracking etc I would recommend keeping the rake front to rear, on our track car we actually add in an additional 5-10mm of rake during suspension setup, it helps with the handling more than you might think.

Helpful feedback, thanks. In my particular case, I don't plan to ever track it, and I haven't found a single canyon in Florida so far (sadly so). Therefore, my priority by reducing less up front is to maintain reasonable ground clearance and minimize risk of bottom scrapping on those pesky parking tire barriers, speed bumps, high incline ramps etc, even if this comes with sacrificing some handling performance.