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Cal-look/High Performance => Pure racing => Topic started by: j-f on February 27, 2008, 10:33:38 am



Title: IRS or swing axle?
Post by: j-f on February 27, 2008, 10:33:38 am
Hello,

I'm completing my next project on a 58 sedan. It's a real puzzle. I buy the body without shelf  last years, doors, decklid and interior this winter etc...

Engine will be something like a 1915 with W125 or Fk8 - 1.4. The car will be treats as a 70's cal look.

I have a late 70's shelf. But, I was wondering if an IRS will not be better? Which gearbox is stronger? 



Title: Re: IRS or swing axle?
Post by: Neil Davies on February 27, 2008, 10:49:06 am
I'd be tempted to build it swing axle if thats what bits you've got, but weld in the mounts for IRS into the pan just in case you want to change at a later date - saves blowing the car apart again to do more welding on the pan.  ;)


Title: Re: IRS or swing axle?
Post by: Zach Gomulka on February 27, 2008, 17:53:29 pm
IRS weighs about 40lbs more and has more parts to break. But it does handle much better and keeps the tires flat on the ground when you launch. Six of one, half dozen of the other...


Title: Re: IRS or swing axle?
Post by: j-f on February 28, 2008, 09:12:52 am
OK. Thanks.

That's 2 good answers.

Good Idea Neil to weld the the IRS mount on a swing axle shelf, "just in case" . 

And Thanks Zach for the info. I thought that an IRS was not good for 1/4 mile . But, that's logical. IRS don't makes this /  \ at launch. :)

I was planning to use 924-944 steel rear arm to have from a simple way rear discs brakes and use the 944 front brakes.
 But I don't know if it's useful on a such car? I plan to use it as a weekend warrior with some strip action. (I'm not far from Bitburg, so I can race sometimes on a year).


Title: Re: IRS or swing axle?
Post by: Black Sheep on February 28, 2008, 09:38:30 am
I.R.S tends to make more sense at the top end when you come off the power , OK it weighs more but Ritchie Webb put his cab in the 9's and that is no light car ! as for 944 arms on a early car its gonna put the wheels right out in the arch's and that will affect your decision on wheel and tyre size . personaly I run IRS with a 901 box with 20mm narrowed Arms on the 49 and I find this works just fine , if you do decide to weld in the mounts dont forget to clearance the rear forks for the IRS CV's .
Good luck .


Title: Re: IRS or swing axle?
Post by: qubek on February 28, 2008, 10:08:41 am
I thought that there are various types of 924/944 rear arms, steel and alu, narrow and wide, and that you can find one being at the same time narrow (Bug size) and alu.


Title: Re: IRS or swing axle?
Post by: nicolas on February 28, 2008, 10:29:10 am
irs is overall a better design and if you break something most of the time it is the CV joint and not the gearbox. mark herbert was in favour of te IRS after he rolled his black bug with swingaxles.
swings are very good as well and have been favoured by dragracers for a long time. it is more nostalgic to run it if you are after that. but equally a lot of early shells were put on a later chasis...
as far as gearboxes are concerned, both can be made as strong, but the later IRS have stronger first and second (some) so that is an option.
i have a IRS in the squareback and am not happy with the so called benefit of them over the swinaxles. my fastback (swing) hadles better then the IRS square. i am even thinking of reversing it and putting it back to a swingaxle. the main problem is that the arms are not alligned like they should and the wheels have some serious negative camber.

but the idea of welding in the brackets is a good idea and if you make up your mind you can go either way. and switch if you want

 


Title: Re: IRS or swing axle?
Post by: Sam K on March 09, 2008, 22:25:11 pm
The one thign nobody mentioned yet is how much easier it is to change IRS trannys. I've blown 11 swingaxles in my '67. 9 of them were supposedly "built" trannys too. That's why my future race bug is a 63 on a 73 pan and it will have a bus gearbox and porsche 930 CV's. I'm not fooling around with this one!


Title: Re: IRS or swing axle?
Post by: Neil Davies on March 10, 2008, 10:58:17 am
The one thign nobody mentioned yet is how much easier it is to change IRS trannys. I've blown 11 swingaxles in my '67. 9 of them were supposedly "built" trannys too. That's why my future race bug is a 63 on a 73 pan and it will have a bus gearbox and porsche 930 CV's. I'm not fooling around with this one!

I know of people who A-frame race cars, have broken CVs or axles and still been able to A-frame the car home. Can't do that with swingaxle! ;)


Title: Re: IRS or swing axle?
Post by: Zach Gomulka on March 10, 2008, 17:23:30 pm
I hate having to dig into the CV's... fucking grease everywhere!


Title: Re: IRS or swing axle?
Post by: Bernard Newbury on March 10, 2008, 20:33:01 pm
I have raced my car with both swingaxle and IRS(091 box) and prefer IRS. I had a few axle breakages last year due to a well prepped track and new slicks but have now changed to Porsche 930 with lightened cvs and rifle drilled 300m axles. It feels a lot more stable at the top end and the added advantge of not having to set the rear end up every time you take the tranny out. Bernie


Title: Re: IRS or swing axle?
Post by: j-f on March 10, 2008, 21:43:35 pm
I have raced my car with both swingaxle and IRS(091 box) and prefer IRS. I had a few axle breakages last year due to a well prepped track and new slicks but have now changed to Porsche 930 with lightened cvs and rifle drilled 300m axles. It feels a lot more stable at the top end and the added advantge of not having to set the rear end up every time you take the tranny out. Bernie


Thanks all to share your opinions.  ;)

That's was what I though.

I will go for an IRS.  ;)


Title: Re: IRS or swing axle?
Post by: benssp on March 11, 2008, 14:57:35 pm
I have raced my car with both swingaxle and IRS(091 box) and prefer IRS. I had a few axle breakages last year due to a well prepped track and new slicks but have now changed to Porsche 930 with lightened cvs and rifle drilled 300m axles. It feels a lot more stable at the top end and the added advantge of not having to set the rear end up every time you take the tranny out. Bernie
Axle changes now take minutes, between me and bernie we can change an axle before carols made the tea! hopefully the new setup is bulletproof, only time will tell :)


Title: Re: IRS or swing axle?
Post by: Rennsurfer on March 11, 2008, 16:29:43 pm
The one thign nobody mentioned yet is how much easier it is to change IRS trannys. I've blown 11 swingaxles in my '67. 9 of them were supposedly "built" trannys too. That's why my future race bug is a 63 on a 73 pan and it will have a bus gearbox and porsche 930 CV's. I'm not fooling around with this one!

Excellent post on all points. I haven't heard of anyone using 930 c.v. joints since the old days. They're not cheap... but, ya get what ya pay for.


Title: Re: IRS or swing axle?
Post by: benssp on March 11, 2008, 16:42:27 pm
Type 2 c.v's work well on a car with less horses than bernies 300-400, offer to buy a friend with a van new C.V's and use worn original T2 units

I think Richie Webb is using Porsche 944 C.Vs


Title: Re: IRS or swing axle?
Post by: Zach Gomulka on March 11, 2008, 16:50:51 pm
After rebuilding my own axles and type 1 CV's, Im scared to even peel out! Those things dont look like they should be able to handle stock hp ::) I think type 2 CV's will be in my future...


Title: Re: IRS or swing axle?
Post by: SteveW on March 11, 2008, 21:04:34 pm
Type 2 c.v's work well on a car with less horses than bernies 300-400, offer to buy a friend with a van new C.V's and use worn original T2 units

I think Richie Webb is using Porsche 944 C.Vs

Yeah he said to me use 944 Stub axles with 944 cv's at the axle end and stock bus ones at the box end!

Steve


Title: Re: IRS or swing axle?
Post by: Steve D. on March 11, 2008, 22:32:14 pm
As long as you don't have an offroad car, stock cv's will take way more abuse than you think.  The angle of the axle is what makes the cv work- any normal ride-height car is going to put the cv's almost perfectly perpendicular with the axle.

250+hp with a puck clutch is probably close to the limit of a stocker, more with a rag disk.


Title: Re: IRS or swing axle?
Post by: Torben Alstrup on March 12, 2008, 01:06:12 am
250 hp with stock CV´s would be pushing your luck IMHO. But with 181 (100mm inner CV´s and 80 mm outer) axles it works. I have personally been into that. Approx. 230 hp on a 1910 T4 with a solid shoot of gazz. (the tranny broke before the axles.) And a similar hp 2386 NA. No problems. What you need to do is to buy raceware hubs. The stock will destroy the shafts in about a season.
And I´m ALL with Bernie. The car is much more steady at the end of the track, when you let off the throttle. If I was to race again, I would definitely use IRS despite the extra weight.
T


Title: Re: IRS or swing axle?
Post by: Neil Davies on March 12, 2008, 11:23:39 am
This is a really good discussion, with lots of good information. So, can we decide on an ultimate combination for a sensible budget car? Assume an 091 bus box (it's what I want to put in the '51 anyway!) ;)

What seems to be favourite at the moment is Porsche 944 stub axles and CV joints at the wheel end, stock bus CVs at the box end. Bugpack I know do the weld-in brackets to convert a S/A pan to IRS. Glenn (49-rag) said about 944 arms widening the track by about 20mm. What arms do we go for then? 924? Stock 1302/1303?


Title: Re: IRS or swing axle?
Post by: SteveW on March 12, 2008, 11:33:57 am
I'm going to use stock bug A Arms which are the single spring plate type as they are lighter than the double type! Not sure if they are the best but i'd heard about porsche arms widening the track!


Title: Re: IRS or swing axle?
Post by: Bernard Newbury on March 12, 2008, 12:57:38 pm


What seems to be favourite at the moment is Porsche 944 stub axles and CV joints at the wheel end, stock bus CVs at the box end. Bugpack I know do the weld-in brackets to convert a S/A pan to IRS. Glenn (49-rag) said about 944 arms widening the track by about 20mm. What arms do we go for then? 924? Stock 1302/1303?
I used modified  stock A arms, 930 chromoly output flanges, 930 chromoly stub axles, 930 lightened GKN CV's (chromoly cages) and the axles were custom made in the States out of 300m. Unfortunately not the cheapest way round it but hopefully it will last  a bit longer then type 2. None of it is  Empi as I think Empi CV's, stub axles etc are Chinese. Type 2 lasted quite a while but as the traction got better then they kept breaking.  Bernie


Title: Re: IRS or swing axle?
Post by: 71CALRIPPER on March 12, 2008, 14:18:09 pm
may have some 930 CV joints for sale with CM cages if anybody is interested :)


Title: Re: IRS or swing axle?
Post by: SteveW on March 12, 2008, 16:11:14 pm


What seems to be favourite at the moment is Porsche 944 stub axles and CV joints at the wheel end, stock bus CVs at the box end. Bugpack I know do the weld-in brackets to convert a S/A pan to IRS. Glenn (49-rag) said about 944 arms widening the track by about 20mm. What arms do we go for then? 924? Stock 1302/1303?
I used modified  stock A arms, 930 chromoly output flanges, 930 chromoly stub axles, 930 lightened GKN CV's (chromoly cages) and the axles were custom made in the States out of 300m. Unfortunately not the cheapest way round it but hopefully it will last  a bit longer then type 2. None of it is  Empi as I think Empi CV's, stub axles etc are Chinese. Type 2 lasted quite a while but as the traction got better then they kept breaking.  Bernie

Bernie, which A Arms do you use? 1303? or are they all the same? I've found some at a good price but the seller only knows they come from a beetle!

Cheers
Steve


Title: Re: IRS or swing axle?
Post by: richie on March 12, 2008, 19:34:39 pm
Steve,theres early and late,the late being the single spring plate version,the easiest way to tell is the mounting holes for the spring plate form a triangle on the early ones[same as swingaxle],but 1 hole is offset on the later ones
cheers richie,uk


Title: Re: IRS or swing axle?
Post by: SteveW on March 12, 2008, 19:49:21 pm
Steve,theres early and late,the late being the single spring plate version,the easiest way to tell is the mounting holes for the spring plate form a triangle on the early ones[same as swingaxle],but 1 hole is offset on the later ones
cheers richie,uk

Ah cool these are single spring plate type I've found! £30 for both arms!

Cheers
Steve


Title: Re: IRS or swing axle?
Post by: richie on March 12, 2008, 20:21:16 pm
Steve,theres early and late,the late being the single spring plate version,the easiest way to tell is the mounting holes for the spring plate form a triangle on the early ones[same as swingaxle],but 1 hole is offset on the later ones
cheers richie,uk

Ah cool these are single spring plate type I've found! £30 for both arms!

Cheers
Steve

 :)  Thats all you need,cheers richie,uk


Title: Re: IRS or swing axle?
Post by: SteveW on March 12, 2008, 22:45:10 pm
Steve,theres early and late,the late being the single spring plate version,the easiest way to tell is the mounting holes for the spring plate form a triangle on the early ones[same as swingaxle],but 1 hole is offset on the later ones
cheers richie,uk

Ah cool these are single spring plate type I've found! £30 for both arms!

Cheers
Steve

 :)  Thats all you need,cheers richie,uk

Thanks dude  ;D


Title: Re: IRS or swing axle?
Post by: Bernard Newbury on March 12, 2008, 22:58:40 pm
Steve,theres early and late,the late being the single spring plate version,the easiest way to tell is the mounting holes for the spring plate form a triangle on the early ones[same as swingaxle],but 1 hole is offset on the later ones
cheers richie,uk

Ah cool these are single spring plate type I've found! £30 for both arms!

Cheers
Steve

 :)  Thats all you need,cheers richie,uk

Thanks dude  ;D

Thanks for the replies Ritchie. I was going to suggest you would know as Marko did the job and I did not ask what A arms he used. When are you home? Bernie


Title: Re: IRS or swing axle?
Post by: richie on March 12, 2008, 23:36:57 pm
Steve,theres early and late,the late being the single spring plate version,the easiest way to tell is the mounting holes for the spring plate form a triangle on the early ones[same as swingaxle],but 1 hole is offset on the later ones
cheers richie,uk

Ah cool these are single spring plate type I've found! £30 for both arms!

Cheers
Steve

 :)  Thats all you need,cheers richie,uk

Thanks dude  ;D

Thanks for the replies Ritchie. I was going to suggest you would know as Marko did the job and I did not ask what A arms he used. When are you home? Bernie

Last night :( cheers richie


Title: Re: IRS or swing axle?
Post by: Lee.C on March 13, 2008, 00:03:21 am
Hmmmm some very interesting ideas for PROJECT 66 ;) :)


Title: Re: IRS or swing axle?
Post by: benssp on March 13, 2008, 10:18:45 am
Last night :( cheers richie

Welcome back, could've brought the weather with you! ;D


Title: Re: IRS or swing axle?
Post by: richie on March 13, 2008, 17:14:52 pm
Last night :( cheers richie

Welcome back, could've brought the weather with you! ;D

 :(  Shant be putting up with this for too long :o  It was really nice the last few days,just makes it harder to get motivated here!!!!!!!!!!!!

cheers richie,uk


Title: Re: IRS or swing axle?
Post by: Black Sheep on March 14, 2008, 09:16:10 am
I'm going to use stock bug A Arms which are the single spring plate type as they are lighter than the double type! Not sure if they are the best but i'd heard about porsche arms widening the track!

Ive got some narrowed single plate type Arms for sale . Taken 22mm or 7/8" if you are old  ::) out of either side for anyone who wants to stick some large rubber under their rear arch's  8)


Title: Re: IRS or swing axle?
Post by: richie on March 14, 2008, 12:51:36 pm
I'm going to use stock bug A Arms which are the single spring plate type as they are lighter than the double type! Not sure if they are the best but i'd heard about porsche arms widening the track!

Ive got some narrowed single plate type Arms for sale . Taken 22mm or 7/8" if you are old  ::) out of either side for anyone who wants to stick some large rubber under their rear arch's  8)

Glen PM me a price please?  cheers richie,uk


Title: Re: IRS or swing axle?
Post by: 58vw on March 15, 2008, 20:30:24 pm
narrowed arms and spring plates....thats what i need..


Title: Re: IRS or swing axle?
Post by: j-f on March 15, 2008, 21:02:24 pm
About the arms, I have heard that early 924s has the same width as 1302-03, disc brakes includes?

Do you think I will have clearance problems if I use this type of arms on a stock 58 sedan? I don't plan to use extra width tyres.


Title: Re: IRS or swing axle?
Post by: Black Sheep on March 16, 2008, 01:05:59 am
yes



Title: Re: IRS or swing axle?
Post by: Bruce on March 16, 2008, 02:15:07 am
.... I have heard that early 924s has the same width as 1302-03, disc brakes includes? 
Early 924s use Beetle TAs, and Beetle rear DRUM brakes (with a different bolt pattern).


Title: Re: IRS or swing axle?
Post by: j-f on March 16, 2008, 09:38:24 am
OK  :-\

49 rag, if you have some narrowed arms and plates for me and maybe some tips and advices, I'm interested  ;)



Title: Re: IRS or swing axle?
Post by: Black Sheep on March 23, 2008, 22:40:50 pm
Pix of one of my shortened and strengthened a arms
(http://i243.photobucket.com/albums/ff84/49-rag/IMG_1677.jpg)
(http://i243.photobucket.com/albums/ff84/49-rag/IMG_1678.jpg)
(http://i243.photobucket.com/albums/ff84/49-rag/IMG_1679.jpg)
Took a bit of work but hope you can get an idea from these pix what's involved  :) the end result is one tyre a inch further under that will take some serious abuse  ;)
Please ignore shity paint job John powder coated them in yellow for some reason  ::)