305 square ....

nicksm3 · 07-25-2020, 12:04 PM

This topic is a meeting of the minds

So who's done it? Also ...who has done it with MCS suspension?
For this to be accomplished, spring perch needs to be raised some. I'm on 6" 2.25 900lb springs. Currently run on 18x10.5 et33 with 20mm spacer upfront on 285 Hoosier slicks. Had a tire blow out at the Glen last session of a 2 day event. Tire got severely hot, expanded and hit the spring perch.
285 square feel great, but I want to step up.
Obviously shorter spring will compromise travel...would love some feedback of the .....Minds.
Thank you.

//steve\\ · 07-25-2020, 12:27 PM

With that heavy of a front spring I doubt you'd have issues with it fully compressing by going shorter. Spring manufacturers should be able to tell you what the block height is of any given spring so you can see just how much travel you may lose.

nicksm3 · 07-25-2020, 05:49 PM

Quote:

Originally Posted by //steve\\

With that heavy of a front spring I doubt you'd have issues with it fully compressing by going shorter. Spring manufacturers should be able to tell you what the block height is of any given spring so you can see just how much travel you may lose.

I agree, very good point ! This is what MCS sent to me when I emailed them

SYT_Shadow · 07-25-2020, 06:42 PM

Wyatt is awesome

You need a 4.5in spring if you use the slinky style helpers

nicksm3 · 07-25-2020, 07:24 PM

Quote:

Originally Posted by SYT_Shadow

Wyatt is awesome

You need a 4.5in spring if you use the slinky style helpers

Yea he's good people!
I am using the helpers....was actually thinking of ridding the helpers completely

nicksm3 · 07-25-2020, 07:35 PM

Quote:

Originally Posted by SYT_Shadow

Wyatt is awesome

You need a 4.5in spring if you use the slinky style helpers

Also...4.5" springs are impossible to obtain.

SYT_Shadow · 07-25-2020, 08:13 PM

Quote:

Originally Posted by nicksm3

Yea he's good people!
I am using the helpers....was actually thinking of ridding the helpers completely

I think i have a 5in front spring + helpers. The stack height is such that the collar sometimes hits the tires if they are 285, but not the wheels.

If there's no such thing as a 4.5 inch spring then i guess you have to lose the helpers.

I should have measured today, I swapped the MCS 2WNR for the 3WR on the F80 CS.

dogbone · 07-25-2020, 09:42 PM

If you want 305, go with a 5” spring and ditch the helper springs. That’s what I did. No issues.

tsk94 · 07-26-2020, 08:08 PM

Only go to a shorter spring if you can do so without comprising shock stroke. It depends on your current spring, but you might be able to get a 5in spring that allows full stroke. If you can't, then stick with your setup. Going to a 1 size bigger tire is not worth it if you need to compromise the performance of your suspension (reducing stroke) to do so.

What's your clearance like to the fender? Since you don't got room to move in, do you got any room to move out? How much camber you running?

Shmelgy · 07-26-2020, 08:33 PM

I have mcs and went with a shorter spring with no helper, like dogbone mentioned. I run 305 Pirelli DH with no problems. As you can see in the pic attached, the perch sits above the tire

SYT_Shadow · 07-26-2020, 08:35 PM

Quote:

Originally Posted by Shmelgy

I have mcs and went with a shorter spring with no helper, like dogbone mentioned. I run 305 Pirelli DH with no problems. As you can see in the pic attached, the perch sits above the tire

What do you do about the springs in full droop? Do they clang when they resettle?

Shmelgy · 07-26-2020, 09:01 PM

Quote:

Originally Posted by SYT_Shadow

Quote:

Originally Posted by Shmelgy

I have mcs and went with a shorter spring with no helper, like dogbone mentioned. I run 305 Pirelli DH with no problems. As you can see in the pic attached, the perch sits above the tire

What do you do about the springs in full droop? Do they clang when they resettle?

Anytime I jack up the car, I lower it slowly. Haven't had any issues

nicksm3 · 07-26-2020, 09:19 PM

Everyone here has such great feedback, guys thank you.
I'm running -3.7 camber upfront so I have room even if I run spacers.
On my e36 I ditched the helpers and went shorter spring like 3 years ago..no issues at all...like a member said earlier..just lower the car down slowly when it's jacked up.

Kelse92 · 07-26-2020, 11:33 PM

Quote:

Originally Posted by Shmelgy

I have mcs and went with a shorter spring with no helper, like dogbone mentioned. I run 305 Pirelli DH with no problems. As you can see in the pic attached, the perch sits above the tire

305/645 diameter correct? Just want to clarify to be sure since there’s 660’s and 680’s out there if anyone ever references back to this thread someday.

Also, anyone out there running the KW’s with big tires? I’ve got the shorter eibach spring and recently raised up my ride height but I think I’m cutting it a bit close. Looking to dump the helper spring on mine but not sure there’s enough threads on the shock body to raise the spring perch enough and maintain similar to my current ride height.

Shmelgy · 07-26-2020, 11:37 PM

Quote:

Originally Posted by Kelse92

Quote:

Originally Posted by Shmelgy

I have mcs and went with a shorter spring with no helper, like dogbone mentioned. I run 305 Pirelli DH with no problems. As you can see in the pic attached, the perch sits above the tire

305/645 diameter correct? Just want to clarify to be sure since there’s 660’s and 680’s out there if anyone ever references back to this thread someday.

305/645/18. I am running 18x10 et25 though, not 10.5. Pretty sure there's no spacer now since I bumped up to 305

slicer · 07-27-2020, 07:25 AM

Pirelli DH 305 runs relatively narrow. It's actually narrower than a 295/30/18 A052. Pics for reference.

fsmtnbiker · 07-27-2020, 01:10 PM

Great comparison slicer ! Is the 295 AR1 also on an 11" wheel? Looks like it, mine were not quite as stretched on a 10.5"

I'm going to try fitting the 315 AR1s soon. Hopefully they run true to size like the 295 does.

315/30-18 Hoosiers on 18x11 ET25 wheels don't quite fit under stock fenders. No way its going to fit up front, even with camber at -3.7 its still a ways outside the fender. In the rear it might work with a ET30-33 wheel and a lot of camber.

SYT_Shadow · 07-27-2020, 02:16 PM

Quote:

Originally Posted by SYT_Shadow

I think i have a 5in front spring + helpers. The stack height is such that the collar sometimes hits the tires if they are 285, but not the wheels.

If there's no such thing as a 4.5 inch spring then i guess you have to lose the helpers.

I should have measured today, I swapped the MCS 2WNR for the 3WR on the F80 CS.

I went out and measured, I have a 5" spring plus the slinky style helper spring. The perch of course interferes with the tire

kayha12 · 07-27-2020, 06:58 PM

I'm running kw cs without helper springs
Apex 18 x 10.5 +27, 5mm I feel like would clear but I have 12mm on and have been okay the last 2 events in this crazy heat

295/30 hoosier a7

kayha12 · 07-27-2020, 06:59 PM

Look up Jakob66, check out his time trial build thread, he made 315 square fit I believe

tsk94 · 07-27-2020, 08:44 PM

Quote:

Originally Posted by kayha12

Look up Jakob66, check out his time trial build thread, he made 315 square fit I believe

Jakob cut his fenders to fit them. He removed/cut the lower vertical lip portion of the front fender to allow the tire to be pushed outward to fit the 315's. Only way it's possible to fit wider then a 305 on OEM fenders.

Debated doing this myself, it's just a question of it turning out and looking half decent.

ThunderMoose · 07-27-2020, 08:51 PM

I feel like such a loser with my 245's

07-25-2020, 12:04 PM	#1
nicksm3 Colonel 1075 Rep 2,537 Posts Drives: e92 m3 Competition Join Date: Jun 2014 Location: Westchester NY iTrader: (6)	305 square .... This topic is a meeting of the minds So who's done it? Also ...who has done it with MCS suspension? For this to be accomplished, spring perch needs to be raised some. I'm on 6" 2.25 900lb springs. Currently run on 18x10.5 et33 with 20mm spacer upfront on 285 Hoosier slicks. Had a tire blow out at the Glen last session of a 2 day event. Tire got severely hot, expanded and hit the spring perch. 285 square feel great, but I want to step up. Obviously shorter spring will compromise travel...would love some feedback of the .....Minds. Thank you. Attached Images
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07-25-2020, 12:27 PM	#2
//steve\\ Major $//steve\\'s Avatar$ 1092 Rep 1,040 Posts Drives: 2012 E92 M3 Join Date: May 2012 Location: Atlanta, GA iTrader: (2)	With that heavy of a front spring I doubt you'd have issues with it fully compressing by going shorter. Spring manufacturers should be able to tell you what the block height is of any given spring so you can see just how much travel you may lose. __________________ Steve::::2012 AW E92::::IG - @sjs0433
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07-25-2020, 06:42 PM	#4
SYT_Shadow ///M Powered for Life 12760 Rep 11,154 Posts Drives: E90M/E92M/M4GTS/M4GT4/M6/X5M Join Date: Sep 2010 Location: Greenwich, CT iTrader: (2)	Wyatt is awesome You need a 4.5in spring if you use the slinky style helpers __________________ DIY: S65 Rod Bearings E9X PFC Z54 BBK on F8X BK harness bar + seats: fit 6 tires in an M3 do88 Cooling Goodies GTS Twins: GTMore project
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07-25-2020, 09:42 PM	#8
dogbone Colonel 5576 Rep 2,866 Posts Drives: '09 E90 M3 - IB Join Date: Feb 2012 Location: 93 million miles from the Sun iTrader: (1) Garage List 2009 BMW E92 M3 [0.00] 2009 BMW E90 M3 [0.00]	If you want 305, go with a 5” spring and ditch the helper springs. That’s what I did. No issues.
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07-26-2020, 08:08 PM	#9
tsk94 Lieutenant Colonel 1727 Rep 1,716 Posts Drives: E92 M3, E82 128i, F82 M4, E36 Join Date: May 2017 Location: Calgary iTrader: (2)	Only go to a shorter spring if you can do so without comprising shock stroke. It depends on your current spring, but you might be able to get a 5in spring that allows full stroke. If you can't, then stick with your setup. Going to a 1 size bigger tire is not worth it if you need to compromise the performance of your suspension (reducing stroke) to do so. What's your clearance like to the fender? Since you don't got room to move in, do you got any room to move out? How much camber you running?
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07-26-2020, 08:33 PM	#10
Shmelgy B.E. 460 Rep 765 Posts Drives: F80 M3 & 1969 Mustang Fastback Join Date: May 2010 Location: City of Angels iTrader: (3)	I have mcs and went with a shorter spring with no helper, like dogbone mentioned. I run 305 Pirelli DH with no problems. As you can see in the pic attached, the perch sits above the tire Attached Images __________________ Current: 2022 TRX & 2010 GT3RS Past: 2016 M3 Individual Grigio Telesto Pearl, Sakhir Orange/Black Full Leather w/ CF trim, 6MT, ZCP, CCB, etc... Previous: 2011 E92 M3 Melbourne Red on Black 6MT ZCP. --> now 2010 dedicated track car
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07-26-2020, 09:19 PM	#13
nicksm3 Colonel 1075 Rep 2,537 Posts Drives: e92 m3 Competition Join Date: Jun 2014 Location: Westchester NY iTrader: (6)	Everyone here has such great feedback, guys thank you. I'm running -3.7 camber upfront so I have room even if I run spacers. On my e36 I ditched the helpers and went shorter spring like 3 years ago..no issues at all...like a member said earlier..just lower the car down slowly when it's jacked up.
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07-27-2020, 07:25 AM	#16
slicer Major General 3086 Rep 6,812 Posts Drives: GT3 Cup, X7, G80 M3 Join Date: Jan 2009 Location: Wisconsin - Instagram - @slicer_m iTrader: (39)	Pirelli DH 305 runs relatively narrow. It's actually narrower than a 295/30/18 A052. Pics for reference. Attached Images __________________ Past BMW's: E36M3, E46M3, E90M3, E92M3(x2), i3, F31 330i Touring, F87 M2CS, F97 X3M, G05 X5, Fall-Line E46 with S65 Swap Current BMW's: G07 X7, G80 M3 (LSB on Tartufo) Race Car: Porsche 992 GT3 CUP INSTAGRAM - @Slicer_M
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07-27-2020, 01:10 PM	#17
fsmtnbiker First Lieutenant 621 Rep 327 Posts Drives: E92 M3, Evora S, E36 Join Date: Jul 2013 Location: Phoenix, AZ iTrader: (0)	Great comparison slicer ! Is the 295 AR1 also on an 11" wheel? Looks like it, mine were not quite as stretched on a 10.5" I'm going to try fitting the 315 AR1s soon. Hopefully they run true to size like the 295 does. 315/30-18 Hoosiers on 18x11 ET25 wheels don't quite fit under stock fenders. No way its going to fit up front, even with camber at -3.7 its still a ways outside the fender. In the rear it might work with a ET30-33 wheel and a lot of camber. Attached Images __________________ Chris
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07-27-2020, 06:58 PM	#19
kayha12 Second Lieutenant 335 Rep 285 Posts Drives: M3 Join Date: Mar 2018 Location: Frederick, MD iTrader: (1)	I'm running kw cs without helper springs Apex 18 x 10.5 +27, 5mm I feel like would clear but I have 12mm on and have been okay the last 2 events in this crazy heat 295/30 hoosier a7 Attached Images __________________ NASA Mid Atlantic - *TT3 #97* '12 E92 M3 ZCP Sponsored by Andrewtech Automotive
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07-27-2020, 06:59 PM	#20
kayha12 Second Lieutenant 335 Rep 285 Posts Drives: M3 Join Date: Mar 2018 Location: Frederick, MD iTrader: (1)	Look up Jakob66, check out his time trial build thread, he made 315 square fit I believe __________________ NASA Mid Atlantic - *TT3 #97* '12 E92 M3 ZCP Sponsored by Andrewtech Automotive
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07-27-2020, 08:51 PM	#22
ThunderMoose Lieutenant Colonel 752 Rep 1,848 Posts Drives: PY E46 M3 and SG E46 M3 Join Date: Aug 2010 Location: League City, TX iTrader: (0)	I feel like such a loser with my 245's
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