PZ ground Clearance

Place for discussions about the RX-8
User avatar
BarbedWire
Former Member
Former Member
Posts: 47
Joined: Sat Mar 20, 2021 10:25 pm
Location: Wiltshire
Has thanked: 26 times
Been thanked: 8 times

PZ ground Clearance

Post by BarbedWire »

So I'm a reletively new PZ owner, and I've found a couple of speed bumps that make contact with the underside of the car (not sure what yet, but it sounds like metal so I'm assuming exhuast). One of them is on the only road to my kids nursery/pre-school so no way to avoid it. Do other PZ owners have this problem, or have I just found some particularly offensive speed bumps?
Mohuss
Non Member
Non Member
Posts: 66
Joined: Mon Jun 12, 2017 9:24 am
RX-8: PZ
Colour: Galaxy Grey
Location: High Wycombe
Has thanked: 9 times
Been thanked: 5 times

Re: PZ ground Clearance

Post by Mohuss »

Im always particularly cautious going over speed bumps for this reason, i find myself crawling over speed bumps when im driving mine.

Sent from my SM-G988B using Tapatalk

These users thanked the author Mohuss for the post:
BarbedWire (Wed Apr 28, 2021 4:55 pm)
User avatar
Conan
Club Member
Club Member
Posts: 6743
Joined: Tue Jun 28, 2011 9:22 pm
RX-8: 231
Colour: Brilliant Black
Location: Cotswolds
Has thanked: 26 times
Been thanked: 310 times

Re: PZ ground Clearance

Post by Conan »

Hi,
First thing is to put the car on flat level ground and measure from the center of the wheel hubs straight up vertical to the underside of the arches.
Post up all four measurements and let’s see where your at. I do have a few tips to solve the problem once you have done this.
Regards
Pete
PS : Are you running a OEM cat ?
These users thanked the author Conan for the post:
BarbedWire (Wed Apr 28, 2021 4:55 pm)
Events Coordinator. 2014 to 2017

I’m an expert in nothing....I have made mistakes in everything
User avatar
SmuttyHutty
Former Member
Former Member
Posts: 3566
Joined: Thu Oct 01, 2020 7:45 am
RX-8: 192
Colour: Nordic Green
Location: Suffolk/Cambs border
Has thanked: 252 times
Been thanked: 206 times

Re: PZ ground Clearance

Post by SmuttyHutty »

Just for reference, my PZ is 360mm from the centre of the centre caps to the underside of the wheel arch in all 4 corners. Front shocks are new. Rears look fine.
These users thanked the author SmuttyHutty for the post:
BarbedWire (Wed Apr 28, 2021 4:57 pm)
Dom-PZ
Club Member
Club Member
Posts: 259
Joined: Sun Sep 30, 2018 10:20 am
RX-8: PZ
Colour: Brilliant Black
Location: Swindon
Has thanked: 10 times
Been thanked: 15 times

Re: PZ ground Clearance

Post by Dom-PZ »

Whereabouts in Wilshire? Happy to compare it with mine if you're ever near Swindon. I don't have issues with speed bumps here that my MINI has trouble with
These users thanked the author Dom-PZ for the post:
BarbedWire (Wed Apr 28, 2021 5:06 pm)
User avatar
New Duke
Former Member
Former Member
Posts: 3387
Joined: Sat Dec 03, 2016 8:38 pm
RX-8: R3
Colour: Sparkling Black
Location: Colchester, Essex
Has thanked: 691 times
Been thanked: 558 times

Re: PZ ground Clearance

Post by New Duke »

If they're big (speed humps come in all shapes and sizes) and you're going at more than a crawl then yes that's normal.

If you have aftermarket suspension and/or exhaust/ components then that can exacerbate it. So does partly depend on aftermarket parts fitted by previous owners.

Check also for failed exhaust hangars which would let the exhaust slump.
These users thanked the author New Duke for the post:
BarbedWire (Wed Apr 28, 2021 4:57 pm)
User avatar
warpc0il
Spin Doctor
Spin Doctor
Posts: 32532
Joined: Sat Sep 06, 2008 10:56 pm
RX-8: 231
Colour: Lightning Yellow
Location: Groomsport, Co Down, NI
Has thanked: 444 times
Been thanked: 2080 times

Re: PZ ground Clearance

Post by warpc0il »

My S1 with Eibech ProSport springs will catch on "pillow" humps, if I tried to bridge them.
Need to run one wheel off the side and one over the middle.

At our old house, it would beach trying to cross the pathway onto the drive, if I had a full tank and fuel and/or a passenger.

When Ray came over, his was worse and I fitted a length of 40mm board in the gutter to save his dropped nose and side-skirts.

The only cars that grounded after that, coming onto the drive, were a PZ with two cracked rear springs :shock: , and a GT40 replica that stood no chance getting over the path and later got beached just by the road camber on the junction down the road [-X
These users thanked the author warpc0il for the post:
BarbedWire (Wed Apr 28, 2021 5:06 pm)
Dave
The Spin Doctor ™
uǝǝɹɔs ɹnoʎ ʇɹǝʌuı ǝsɐǝld :ɹoɹɹǝ
User avatar
BarbedWire
Former Member
Former Member
Posts: 47
Joined: Sat Mar 20, 2021 10:25 pm
Location: Wiltshire
Has thanked: 26 times
Been thanked: 8 times

Re: PZ ground Clearance

Post by BarbedWire »

Conan wrote:Hi,
First thing is to put the car on flat level ground and measure from the center of the wheel hubs straight up vertical to the underside of the arches.
Post up all four measurements and let’s see where your at. I do have a few tips to solve the problem once you have done this.
Regards
Pete
PS : Are you running a OEM cat ?
I'll do this at the next opportunity, I don't have any level ground at home unfortunately.
Stock cat as far as I know.

Sent from my Pixel 4 using Tapatalk

User avatar
BarbedWire
Former Member
Former Member
Posts: 47
Joined: Sat Mar 20, 2021 10:25 pm
Location: Wiltshire
Has thanked: 26 times
Been thanked: 8 times

Re: PZ ground Clearance

Post by BarbedWire »

New Duke wrote:If they're big (speed humps come in all shapes and sizes) and you're going at more than a crawl then yes that's normal.

If you have aftermarket suspension and/or exhaust/ components then that can exacerbate it. So does partly depend on aftermarket parts fitted by previous owners.

Check also for failed exhaust hangars which would let the exhaust slump.
I had thought about exhaust hangers. I'll see if i can get underneath and check them all, minging out side at the moment though!

Sent from my Pixel 4 using Tapatalk

User avatar
BarbedWire
Former Member
Former Member
Posts: 47
Joined: Sat Mar 20, 2021 10:25 pm
Location: Wiltshire
Has thanked: 26 times
Been thanked: 8 times

Re: PZ ground Clearance

Post by BarbedWire »

I've tackled the speed bump again today, having replaced dodgy mixed rear suspension with refurbished stock PZ shocks and springs (thanks Neil). I managed to find a path of maximum clearance. It's a tarmac sausage type, but the whole road is poorly laid (private land) so it's sunk under the normal tyre tracks. It's single track so width is limited, but keeping as far as I can to one side reduced the scrape to barely noticeable.

I'm pretty sure the front suspension is stock PZ (I can see yellow shocks), but I will check. I have the rest of the set I got from Neil to fit if it's not stock.

I did also clip a pillow hump this morning, so wil adjust my approach to those too! The RX-8 is by far the lowest car I've owned.

Sent from my Pixel 4 using Tapatalk

User avatar
BarbedWire
Former Member
Former Member
Posts: 47
Joined: Sat Mar 20, 2021 10:25 pm
Location: Wiltshire
Has thanked: 26 times
Been thanked: 8 times

Re: PZ ground Clearance

Post by BarbedWire »

Dom-PZ wrote:Whereabouts in Wilshire? Happy to compare it with mine if you're ever near Swindon. I don't have issues with speed bumps here that my MINI has trouble with
I'm near Salisbury. I don't go north very often, but looking forward to meeting up with some other owners at some point.

Sent from my Pixel 4 using Tapatalk

User avatar
v-rex
Club Member
Club Member
Posts: 1570
Joined: Wed Jan 31, 2018 9:24 pm
RX-8: PZ
Colour: Brilliant Black
Location: Pinner, NW London
Has thanked: 513 times
Been thanked: 172 times

Re: PZ ground Clearance

Post by v-rex »

BarbedWire wrote:
Wed Apr 28, 2021 5:07 pm
Dom-PZ wrote:Whereabouts in Wilshire? Happy to compare it with mine if you're ever near Swindon. I don't have issues with speed bumps here that my MINI has trouble with
I'm near Salisbury. I don't go north very often, but looking forward to meeting up with some other owners at some point.

Sent from my Pixel 4 using Tapatalk
I'll be around Salisbury way on Sunday morning and have a PZ if you wanted to compare heights. I'll PM you my number if you want to meet up, let me know.
untakenname
Club Member
Club Member
Posts: 959
Joined: Wed Jul 02, 2014 10:18 am
RX-8: 231
Colour: Kuro Black
Location: London
Has thanked: 71 times
Been thanked: 90 times

Re: PZ ground Clearance

Post by untakenname »

Only thing that can be done (bar buying height adjustable suspension) is fit taller tyres.

My car catches on particularly large speed bumps when running Uniroyal Rainsports in 225/40R18 but can go over them fine with Goodyear Eagle Asymmetric 5's in 225/45R18.
These users thanked the author untakenname for the post:
BarbedWire (Wed Apr 28, 2021 9:11 pm)
79398
Former Member
Former Member
Posts: 2074
Joined: Fri Oct 09, 2020 9:46 am
Has thanked: 0
Been thanked: 1 time

Re: PZ ground Clearance

Post by 79398 »

Just been out to measure mine 340mm as measured using the same method.
Tein coilovers fitted.
User avatar
BarbedWire
Former Member
Former Member
Posts: 47
Joined: Sat Mar 20, 2021 10:25 pm
Location: Wiltshire
Has thanked: 26 times
Been thanked: 8 times

Re: PZ ground Clearance

Post by BarbedWire »

79398 wrote:Just been out to measure mine 340mm as measured using the same method.
Tein coilovers fitted.
The road in parked on (I know...) is not quite level, but mine measures 350 to 360 mm all round, so not outrageously low by comparison. I also though tyre pressures might make a small difference. I'm sure it's been discussed to death, so I'll do a search!

Sent from my Pixel 4 using Tapatalk
User avatar
Conan
Club Member
Club Member
Posts: 6743
Joined: Tue Jun 28, 2011 9:22 pm
RX-8: 231
Colour: Brilliant Black
Location: Cotswolds
Has thanked: 26 times
Been thanked: 310 times

Re: PZ ground Clearance

Post by Conan »

What did each corner measure ?
Approach it with an open mind rather than thinking about other peoples measurements ;)
Events Coordinator. 2014 to 2017

I’m an expert in nothing....I have made mistakes in everything
User avatar
BarbedWire
Former Member
Former Member
Posts: 47
Joined: Sat Mar 20, 2021 10:25 pm
Location: Wiltshire
Has thanked: 26 times
Been thanked: 8 times

Re: PZ ground Clearance

Post by BarbedWire »

Conan wrote:What did each corner measure ?
Approach it with an open mind rather than thinking about other peoples measurements ;)
I didn't think my tape measure to roughly the centre of the cap on a slightly sideways slope was accurate enough to warrant more than +/- 5 mm. I'll pop a tape measure in the car and measure more accurately next time I'm in the office where the car park is much flatter.

Sent from my Pixel 4 using Tapatalk