Porsche Enthusiasts Club Forum

It is currently Sun Aug 03, 2025 8:49 am
Classic Line Insurance


All times are UTC




Post new topic Reply to topic  [ 15 posts ] 
Author Message
 Post subject: 26.8mm vs 30mm roll bar
PostPosted: Tue Jan 14, 2014 11:57 am 
Offline

Joined: Sat Apr 02, 2011 2:26 am
Posts: 162
TIPEC membership: 0
Is the hollow 30mm much stiffer than the 26.8? is it so stiff that it is going to cause under steer on anything but smooth dry tarmac?

I run a 16mm rear bar. I also have a 18mm one I can fit to match a 30mm.


I have found a few things I favour from swapping other things around-

I like the MO30 coilover set up better than all but Gaz. (which I wont fit as its not Period)
Im happy with the standard 86 turbo brakes, the big "250s" were expensive to maintain for not a huge difference in performance.
I prefer no ABS.

I have driven a couple of cars with the 30mm bar, but it is hard to feel the difference to my 26.8 as my car is lower/stiffer with different size tyres ect.

Is it worth seeking one out?


Last edited by sumpcracker on Tue Jan 14, 2014 1:55 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Tue Jan 14, 2014 12:08 pm 
Offline

Joined: Sun Feb 24, 2008 7:16 pm
Posts: 1891
Location: UK
TIPEC membership: 0
sumpcracker wrote:
Is the hollow 30mm much stiffer than the 26.8? is it so stiff that it is going to cause under steer on anything but smooth dry tarmac?



Probably, I suspect a 968 MO30 rear bar would be a match for that front, early Turbo's had 18mm rear bars I believe.


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Tue Jan 14, 2014 12:09 pm 
Offline

Joined: Sat Apr 02, 2011 2:26 am
Posts: 162
TIPEC membership: 0
Or -

Ha, what im saying is, after much parts swapping and p1ssing about I have decided the best fast road / nice to use 944 chassis for me is a light 86 car with no ABS, standard size Brembo, MO30 suspension standard 968 roll bars and 23.5 (951) torsion bars.

Is a 30mm front bar going to ruin this? I do not have one to try.


*EDIT
That was a fast reply.
Im using non MO30 968 bars now, they are a big difference over original 944. I just thought as the 30mm was hollow it may not be much stiffer?


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Tue Jan 14, 2014 1:14 pm 
Offline

Joined: Wed Dec 05, 2012 9:04 am
Posts: 392
TIPEC membership: 0
I believe a hollow tube is stiffer than a solid bar, at least if they have the same mass.


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Tue Jan 14, 2014 1:35 pm 
Offline

Joined: Sun Feb 24, 2008 7:16 pm
Posts: 1891
Location: UK
TIPEC membership: 0
Road or track ? I'd say a poly bushed 26.8mm bar is plenty stiff enough for the road.


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Tue Jan 14, 2014 2:06 pm 
Offline

Joined: Sat Apr 02, 2011 2:26 am
Posts: 162
TIPEC membership: 0
Its a Road car. Gets used on the track very little. It does big miles round Europe, but it is most days driven with some enthusiasm, Its a good all rounder as it is. I will fit one next time we get one in and see how it goes, easy enough to swap back if major understeer is an issue.

I just looked here-
http://www.924.org/techsection/Suspensi ... ration.htm

I see the 25.5 and 26.8 are also hollow...


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Tue Jan 14, 2014 2:58 pm 
Offline
Moderator
Moderator
User avatar

Joined: Sun Nov 04, 2007 7:43 pm
Posts: 12842
Location: Chatham, Kent
TIPEC membership: 4190
Sumpcracker, working at the mo but measure the wall thickness of the hollow one & let me have it & I'll search the formula out this evening.

_________________
Jim

http://tipec.net/region_southeastlondon.php

2018 Mitsubishi Outlander PHEV
2005 Porsche Cayenne S SOLD
2000 Jeep Grand Cherokee SOLD
2010 Mazda MX5 Mk3.5 2.0 Sport Tech SOLD
2000 Porsche Boxster S SOLD
1987 Porsche 944
2019 Abarth 595C


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Tue Jan 14, 2014 4:17 pm 
Offline
User avatar

Joined: Thu Oct 07, 2010 12:38 pm
Posts: 838
Location: Somerset
TIPEC membership: 6379
sumpcracker wrote:
I just looked here-
http://www.924.org/techsection/Suspensi ... ration.htm

I see the 25.5 and 26.8 are also hollow...


Hold caution to that data which is based on US 924/944 and not the RoW spec cars we have in the UK.

Try this one although still a US based page with an eye on RoW/UK data may be helpful http://www.axux70.dsl.pipex.com/944t/su ... tm#968M030

_________________
Steve
1980 924 Turbo Series 1 - Alpine White & Guards Red
Omega forged pistons, Piper cam, K27/26 hybrid turbo, 951 ducted FMIC, custom intake, Mittelmotor/123ignition, Hayward & Scott, GAZ Golds, Fuch'ed, Quaife LSD


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Tue Jan 14, 2014 5:40 pm 
Offline

Joined: Sun Jan 24, 2010 12:07 am
Posts: 2381
TIPEC membership: 0
Iv got 30mm front roll bar and rear 18mm bar. I worked off the fact that the 88 cars came with 27/18 later cars 27/16 so my car would act like the later car, which Porsche change to promote under steer but then I'm running 285 rears

_________________
Zermatt 88 944 turbo
Augtronic ecu&map
3071gtx/0.63tial V band/38mm Dpw
3" fastroad exhaust
80lb injectors
Stage2 intercooler
Apexi ebc.
9xx quick shift/ front shift/fuel pump
M030 brakes/Coilovers/30mm front roll
18" JARA cups 225F/285R


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Wed Jan 15, 2014 5:54 pm 
Offline

Joined: Tue Sep 23, 2008 6:18 pm
Posts: 1955
Location: Sheffield: Rome of the North!
TIPEC membership: 0
A more slender front ARB can be stiffened through the use of simple brackets. Id be tempted to try this first given the price of 968 ARBs now.

After that Id probably case harden it.

_________________
Simon On The Edge..... In The Hedge!

1988 944 Turbo - the Pink Pig
1989 944 2.7
1985 944 It's alive!
1986 944 Automatic


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Wed Jan 15, 2014 5:57 pm 
Offline

Joined: Tue Sep 23, 2008 6:18 pm
Posts: 1955
Location: Sheffield: Rome of the North!
TIPEC membership: 0
Too hard a use and youll end up breaking bits and the bar end, though.

_________________
Simon On The Edge..... In The Hedge!

1988 944 Turbo - the Pink Pig
1989 944 2.7
1985 944 It's alive!
1986 944 Automatic


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Wed Jan 15, 2014 7:04 pm 
Offline

Joined: Sun Jan 24, 2010 12:07 am
Posts: 2381
TIPEC membership: 0
Iv got a set off them brackets, don't think I will use them now. So will sell on if anyone intersted.

Iv gone fresh stock rubber, power coat refurb on my 30 mm bar /18mm set up

_________________
Zermatt 88 944 turbo
Augtronic ecu&map
3071gtx/0.63tial V band/38mm Dpw
3" fastroad exhaust
80lb injectors
Stage2 intercooler
Apexi ebc.
9xx quick shift/ front shift/fuel pump
M030 brakes/Coilovers/30mm front roll
18" JARA cups 225F/285R


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Thu Jan 16, 2014 9:06 am 
Offline

Joined: Wed Dec 05, 2012 9:04 am
Posts: 392
TIPEC membership: 0
t3rra wrote:
Iv got a set off them brackets, don't think I will use them now. So will sell on if anyone intersted.

Iv gone fresh stock rubber, power coat refurb on my 30 mm bar /18mm set up


Any particular reason? Is it just because you feel a 30mm bar is enough
I was planning on using some of these brackets with my 25.5 or a 26.8mm bar, rather than paying the extra for a 30mm bar.


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Thu Jan 16, 2014 3:16 pm 
Offline

Joined: Sun Feb 24, 2008 7:16 pm
Posts: 1891
Location: UK
TIPEC membership: 0
Hallsy wrote:
t3rra wrote:
Iv got a set off them brackets, don't think I will use them now. So will sell on if anyone intersted.

Iv gone fresh stock rubber, power coat refurb on my 30 mm bar /18mm set up


Any particular reason? Is it just because you feel a 30mm bar is enough
I was planning on using some of these brackets with my 25.5 or a 26.8mm bar, rather than paying the extra for a 30mm bar.


I made some of these brackets but I'm not sure it's beneficial to have the bar rigidly mounted at that location.


Top
 Profile  
Reply with quote  
 Post subject: Re: 26.8mm vs 30mm roll bar
PostPosted: Thu Jan 16, 2014 3:27 pm 
Offline

Joined: Sun Jan 24, 2010 12:07 am
Posts: 2381
TIPEC membership: 0
I'm sure the god father ( Jon @ Jgm ) recently said he's not a fan off them.

I had 26.8 bar on car, had 26.8 poly bushes and the stiffen brackets. Ready 2 go on

After a few talks with with another owners change 2 968 he belived the roll bar upgrade was a huge part off the improved handling along with kv3

A bar came up on eBay not long after and I won it.

Stock rubber was cheaper then poly bushes. I was adviced that a lot off people swap old tired bushes for poly and think there amazing when a lot off it could have been the old for new.

I think the 968 bar will be anoth on fresh oem rubber without any noises, 2 be honest with the change in weather from b4 the roll bar change to after I can't say iv noticed. Car is just a road car

_________________
Zermatt 88 944 turbo
Augtronic ecu&map
3071gtx/0.63tial V band/38mm Dpw
3" fastroad exhaust
80lb injectors
Stage2 intercooler
Apexi ebc.
9xx quick shift/ front shift/fuel pump
M030 brakes/Coilovers/30mm front roll
18" JARA cups 225F/285R


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 15 posts ] 

All times are UTC


Who is online

Users browsing this forum: Bing [Bot], Majestic-12 [Bot] and 12 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group