orthojoe

It's actually 28mm each side. Nspec run really wide!

ExMB

I want what you are on. That last comment just doubled the width; 10 mm tire rating width difference just now turned into 56 mm real life. And both are N-spec. Tsk, tsk, tsk.

What has mooty been feeding you?

orthojoe

Lol. You could be right! But, I think I just didn't word my post clearly. 56mm total is correct
Look at the tire rack site, though. Tread width is 12.1" n spec 305 and 11" n spec 295. That is 1.1" wider per tire.
N spec 305s are wider than non n spec 305
This is why my gt3 oversteered big time when I ran 295 on them

johnr265

Ok Joe, so I am curious. Seems, the DSC helped a lot but then the springs, less so. Did you do comparison, springs with DSC and springs without DSC? I understand the springs PLUS the DSC didn't seem that different but what about springs only without the DSC? Curious if you tried to do a comparison there. Thanks.

orthojoe

Good question. I have not tested springs without dsc. I have a feeling the effects may be similar individually.

lorennauto

Orthojoe, if you could only choose one, Springs vs DSC, which one would you choose?

MarcD147

I don't have either but when I was talking with the top engineer of a well known shop that runs club sports and Caymans they said the best two changes are shocks followed by LSD

They didn't mention dsc and when asked springs didn't get prioritized above the shocks or lsd

orthojoe

Hmmmm..... tough one.
Costwise they are similar after you take into account paying someone to install the springs. One is easily reversible and doesn't affect your ride. One is a tangible mechanical change and the other is electronic wizardry.

I don't know....

Eric5280

FWIW, I saw maybe half a second change with DSC.

392 lb front springs only + TPC rear toe links resulted in 2 seconds faster for me on RE71 tires.

orthojoe

Yeah, but I would argue most of those 2 seconds are the driver. 2 seconds is A LOT. You are moving into GT3 territory

ExMB

+1

In this case I would have to ask about the time difference between both tests. What were the track conditions? The tires? Etc.

I've run at HPR (I think that is the track you're implying) and have to agree that 2 sec is a lot of time on it.

DC640

Just wondering why just the front upgrades? Maybe less roll/pitch and It does help w tire wear and rear doesn't benefit much?

Eric5280

Hey Joe.

I hear ya, but I did 2:01.7 PB (.5 faster than no DSC) with DSC on Dunlops.

Swapped on RE71R's and could not break 2:03 for the life of me. Installed TPC rear links and front springs; 2 min dead in my very session out. Alignment was out a little which is why I credit the mods with approx 2 sec on RE71's.
Just my personal experience on RE71. Car much more stable, higher entry/exit speeds of turns. Very happy.

Eric5280

I agree with everything you are saying and run NASA TT in an E36 M3 where 2 seconds is an eternity.

Track conditions were actually worse on the 2 min lap because HPR ground down the hairpin at T8 for work and T4 just had a coolant spill the session before. You can see both in vid.

Just sharing my personal experience.

Eric5280

A fellow RL member (DSDDCD) had the idea and I stole it. We both thought rears were already stiff enough. Tom @ TPC agreed it would work well. Saved money, less mods. Love the balance, tire wear is a little better.

Bought on Amazon for $170. Swift part Z60-178-070