1.6 Vs 1.9 Vs 309 Beams

[Baz 421]

I agree, but again it depends what you want the car to do, if you like a twitchy rear end you can use it to your advantage, although on a fast road/track car i think i'd prefer the stability of a 309 beam. Eg. I use the throttle/trail braking alot for correcting the rear end on tight twisty sprint tracks which works well, but a 309 beam wouldn't allow it so much.

[James_R 3]

So you prefer a 309 beam but don't use one??

 

Think the wider tail just lets makes up for deficiencies (sp?) with fundimental technique/driving style, i/e braking not in a straight line, adjusting the throttle in a digital method (on/off) are things you dont' want to be doing, not saying they dont happen when things all go a bit out of shape, also grp A beam mounts regardless of width reduce these probelms, mainly by making the tail not steer for itself :s

[Baz 421]

I agree, but again it depends what you want the car to do, if you like a twitchy rear end you can use it to your advantage, although on a fast road/track car i think i'd prefer the stability of a 309 beam. Eg. I use the throttle/trail braking alot for correcting the rear end on tight twisty sprint tracks which works well, but a 309 beam wouldn't allow it so much.

 

Ok if we have to nitpick of someone else's opinion, although i woudn't expect any less these days James, i'll justify my opinion/preferences. Sprint tracks aren't particularly fast, as i said, tight and twisty, which with my driving style, i tend to late brake, carry too much speed into corners etc then lift-off/left foot/trail brake to my advantage, setting me up for the corner coming, or using the rear end coming round to point me in the right direction again, for this a 205 beam works well, hence now being undecided about fitting a 309 width beam on the car i use for sprinting. For a fast road/track car that corners at higher speed, the width of a 309 beam giving better cornering stability can only be a plus.

 

And as for your comment regarding driving deficiencies, braking in a straight line isn't always possible of course, if you're driving at the limit, to a clock, late braking etc, you do what you can, despite what you'd think/the general thought of where you would and wouldn't brake/turn in etc goes out of the window tbh. Practise is the best form of learning and everyone's confidence or ability is different, so perhaps different styles and techniques warrant a different opinion.

 

Really if you're talking about driving abilities, if one is that good, should be adaptable to either, it's akin to jumping in a different ride height 205, lowered or standard, they again have different handling characteristics, but the same principles, and physics still apply.

 

Anyhow, this topic has gone from the differences in width to the differences in handling between the 2, as usual!!

Edited August 13, 2008 by Baz

[Anthony 1,003]

It's down to personal preference and driving style really.

 

Personally, comparing a standard 205 GTi and standard 309 GTi beam, I prefer the handling with the 309 beam - you get more responsive turn-in, the tail feels more planted and less nervous on faster corners, but can still be steered on the throttle. Also, due to the stiffer torsion bars, it retains a good balance when coupled with front lowering springs.

 

I can however see why people prefer the 205 option, as there are disadvatanges to 309 beams - the handling of the car does change and the tail can be a little over-stable at lower speeds, and the increased width means that wider wheels and base model shells are problematic.

 

Of course, in the past 12-18 months, uprated torsion and anti-roll bars have become much more easily available and affordable, and it's thus possible to build a 205 width beam with the advantages that a 309 one offers. It's still considerably more expensive doing that way, and hence I still maintain that a 309 beam is an excellent budget upgrade for a typical road/track 205.

 

Basic summary:

 

1.6 GTi = 205 width, 19mm torsion and anti-roll bars, drum brakes

1.9 GTi = 205 width, 19mm torsion and anti-roll bars, disk brakes

309 GTi = 309 width (approx 50mm wider), 20mm torsion and anti-roll bars, disk brakes

[James_R 3]

Anyhow, this topic has gone from the differences in width to the differences in handling between the 2, as usual!!

 

It was about the handling differences when you look at the initial post.

 

Good point made my Anthony that the stiffer spring rate of the 309 beam helps balance out lowering springs on the 205's to reduce unndersteer, can also be achieved with a bigger ARB, but then you can fit a bigger ARB in the 309 beam and put even lower or rather higher spring rates on the nose without unduely making the front over stiff compared to the rear.

[Kobayashi 35 2 Cars]

from what i read here, a 309 rear beam could be an interesting alternative when mine needs replacement some day. especially in combination with the wider front track of my front beam.

 

but as i said, i have drum brakes in the rear, and i am not really interested in a conversion - will this be a problem?

are there any 309 beams with disc brakes which would make a both matching and uprated replacement?

[Kev-G 1]

So are 1.9 and 1.6 rear beams the same? bar the brakes obviously

 

Emlyn

 

Stub axles are different, but the 1.6 ones can be used with Discs.

 

From memory, very slight difference in the torsion bar size - 0.something (both 19mm) with the 1.9 being slightly thicker.