The BBR sport springs look suspiciously similar to the H&R springs for sale at MX5parts. As the latter are quite a bit cheaper I was going to take a punt they are the same and give them a whirl.
Anyone know?
Adam
Hmm they well could be, it might be worth checking though if the BBR ones have a different spring rate…
The BBR set claim to have a progressive spring rate perhaps worth asking MX5parts or their supplier that question.
Been digging around.
Standard spring rates are 156 lb/in front and 80 lb/in rear = 27 N/mm front and 14 N/mm rear. Sport may be 100 lb/in = 17.5 N/mm.
H&R part numbers being sold by MX5 Parts are 28764 va and ha (vorne and hintern respectively, i.e. front and rear). These are H&R super sport lowering springs. H&R only list one spring for ND and quote 1.2 inch drop front and 1.1 inch at rear. Progressive rate.
BBR drop 30mm (as H&R) but look a lighter blue colour and don’t have any part numbers shown (careful photography?)
so - I don’t know. My thoughts are that the BBR are possibly their own specification (as claimed for their NC springs). The H&R look great quality and a firmer progressive spring rate than standard. As I’ve only read positive reviews of the BBR springs so far then I think i’ll get those. If they are the H&R I’ll post back here.
Cheers,
Adam
I tried to calculate the spring rate for the H&R (mx5parts) springs. They calculate to be 31.2 N/mm front and 16.6.N/mm rear based on the information in the TUV certificate. If correct that makes them only a little stiffer than stock, about 15 - 20%.
Without knowing the BBR spring dimensions this is just for interest. When I get a set of the BBR I’ll post the specs and rates.
Adam
Back again and questioning my calculations… posting the dimensions too so others can calculate for themselves…
| Rear | BBR | H&R | Front | BBR | H&R | ||
| Dia | 123.4 | 114 | Dia | 127.6 | 119 | ||
| Wire dia | 11.25 | 9.5 | Wire dia | 12.6 | 11.25 | ||
| Free Length | 300 | 313 | Free Length | 265 | 265 | ||
| Number coils | 7.8 | 6.75 | Number coils | 6.5 | 6.55 | ||
| Rate | 14.431 | 10.482 | N/mm | Rate | 25.273 | 19.378 | N/mm |
Getting fitted at the weekend. Will post some observations then and follow up with the calculations of the standard springs for a 2.0 Sport… After all of this it will be the ride and handling that matters to me not the dimensions. Geo setup is also on the cards.
Adam
Just to finish off this thread I thought I’d post a report after a week with the BBR springs fitted.
Job took about 2 hours without any sense of urgency or rushing - its a pretty easy job requiring just a couple of spanners, a jack and some spring compressors. The old Mazda springs look like pipe cleaners by comparison and substantially lighter for it - though I suspect more highly stressed. Now the car has settled on the springs it just looks right - not chavved or slammed or whatever else the term is, it just looks really sorted. If someone was unaware that it had been lowered they would not suspect unless you park next to a standard car.
The same cannot be said of the driving experience. Night and day would be my summary. Fan-freakin’-tastic!!! the car feels planted and really holds the road. Where before I found it nervous and unpredictable above about 60 mph and with a hint of understeer it is now resolutely more neutral. Understeer mostly banished. Car corners beautifully flat and can be coaxed in to a slight tail out attitude if you choose. Roll is very well controlled too.
The ride quality hasn’t suffered too much either. If ride comfort was 7/10 before its now 6/10. The test for me was my wife was a passenger in the car and did not complain - praise indeed!
On a more mundane note - the car doesn’t scrape its nose on speed humps or feel so low to be a liability.
I genuinely think these springs should be standard on the car. It has totally transformed my enjoyment of the car from slight disappointment and a longing for my old mk1 to real happiness and joy at driving it. It still lacks steering feel but it is now at least consistent and trustworthy in its responses. Perhaps most will think my criticism of the standard car harsh. I had even contemplated selling the car.
I am not a track day addict (never been) and don’t drive everywhere on the ragged edge, though I do like to drive country roads with some verve at the National speed limit and maintain that speed around the bends as well as on the straights. I can’t think that anyone who has a mk4 MX5 would not enjoy these springs - unless you enjoy the more pure 1.5 suspension set up.
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I found the post above really useful. I bought an ND Super 220 a few weeks ago. Previous owner went to the trouble of having the exhaust changed and adding Goodyear F1’s, however, he neglected to add lowering springs.
Coming from a 981S Boxster and Elise, I wasn’t expecting the ND to feel quicker or handle any better.
I love the ND power delivery and gear change but the body roll at the back especially, is disconcerting and robs the car of trust when pressing on.
Springs fitted by BBR tomo. I’m also hoping to swap out the super sport back box which sounds lunatic loud in conjunction with the revised manifold and centre section. Hopefully the GT exhaust is less offensive.
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Hi there,
I think you will be very pleased with the springs and the swap to the GT box (I did the same a while back)
I’m pretty sure there’s something wrong with your spring rate numbers, units or both. A spring rate of 156lb/in is going to be mega soft in the extreme.
Revised springs are transformative on the car. Should have been this way from factory. The excessive body roll from the rear as standard is a nonsense. I’ve seen it referenced in some tests on You Tube but it didn’t seem to bother the reviewers as much as it disconcerted me. The grip is there, but the roll totally out of step with a sports car.
For me this would be the most essential change to make on an ND assuming you enjoy driving as opposed to just bimbling around.
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