Hi Sifus,

Recently I have lowered my mazda 3 BM skyactiv with H&R sport spring. Fanstatic ride and just nice clearance for almost everything, except when full load need to go s shape over certain sharp tall bump. Also need to becareful with the uneven gap (like certain highway bridge that has the drain cover) or potholes.

Recently i have been aiming to reduce unsprung weight to improve braking and accelerating. I'm thinking to change the stock 18" wheel with 225/25/18 tyre to a flow formed 17" wheel with 235/45 profile. It could save about 4kg per wheel. But overall there will be about 8mm drop of ride height, due to overall smaller diameter of the 17" wheel. There is no 235/50 size for a lot brands, this is rather uncommon.

So I have a concern on the car's ability to clear steep slope / bumps after this. I'm thinking if I should try other lowering spring that's less aggressive than H&R or give up the rim changing idea.

H&R drops about 30MM front and 45MM back, progressive spring.

1) Ftuned CLS spring - claimed 2 fingers gap front and back, no actual measurement and no known spring rate.
2) ZerOne by TS - Taiwanese Triple S spring, drops about 15MM front and back. Spring rate is about 3.1k front, 3.3k back.
3) Eibach pro-kit - Drops about 25MM foront, 32MM back. Spring rate front is 3k to 5k, back is 2.5k to 3.5k.

Anyone here has experience with Ftuned or TS springs? H&R should has slightly higher spring rate than Eibach although there is no official rating, this is based on some mazda 3 user feedback. But I think changing to Eibach dont help a lot because the front drop almost the same as H&R.

I'm looking for something with milder drop and similar spring rate, the H&R is really good a reducing bodyroll and almost eliminate the nose dive during hard braking. Or should I just forget about the 17inch rim idea?

This post has been edited by Mitec.Love.Speed: Oct 11 2020, 02:25 PM