Hello all. I’ve been working on this purchase/build/plan for many years (afraid to admit how long I’ve been contemplating this) and some of you know I was very close (and planning to order a car from Greg) last year but unfortunately had a setback with the unexpected passing of my father and then a job change all within a month or so of each other.

But now I’m back on track....we’ll, getting back on track and hoping to order in January with Greg. I have a deposit in with Pat for a motor after much consideration and debate on AC vs WC - decided AC for $$$ and wanting to keep the car more period correct with AC....still on the fence really but going forward with AC and feel confident I’ll get a great motor out of Pat/CB Performance so I’m sure I’ll be happy.

But now the next question- pay the extra charge to go with IRS?  Feels like I’m already choosing quality options - CB motor, under dash brake location, German square weave.... handling is important to me so shouldn’t I pay the extra for IRS??

I look forward to your thoughts. Thanks everyone. 

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aircooled posted:

Absolutely IRS !  Front too if you can bear it.   Greg is currently building me a Spyder with IRS and IFS as we speak. Congratulations and Welcome to the Madness Blake !!

Bruce. (now water-cooled)

You should call yourself "The SOC'er Formerly Known as Air-cooled Bruced" and use some type of symbol for your name. It worked, I think, for Prince.

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Possibly because of my driving style being less aggressive than lots of other Speedster Owners the only time I really noticed a significant difference between the IRS Speedsters I've had (several of them) and the swing axle Speedsters I've had (lots of them) was when I added a camber compensator to one of the swing axle cars and then drove with Robert and Teby. Otherwise, for me and my driving style, there wasn't that much of a difference.

The vast majority of the 3,000 plus Vintage Speedsters out there are swing axle and, it's just my guess, but the majority of them are probably satisfied with how they handle.

If you're just a pleasure cruiser and never plan to try to keep up with Robert or Teby, just get a swing axle car and spend about $100 bucks on a camber compensator. Since you are getting a Pat Downs motor, you're probably not just going to be a cruiser,so get the IRS. 

A swing axle car can be modified to handle well and it takes the usual mods to get it there; 3/8" - 3/4" front anti-sway bar, stiff rear camber compensator, stiffer torsion bars, stiffer shocks, wider wheels (which will probably need to be custom because of the limited space you have to work with) and, as important as anything, wider, 40-series low-profile tires.  Do all that, and it will hard-corner at about 75% of the ability of an IRS car that has been modified with 3/4" anti-sway bars front and rear (camber compensators aren't used on an IRS car), stiffer shocks, stock torsion bars and the same wheels and tires.  BOTH of those cars will ride stiffer than stock - just the nature of the beast.

The biggest difference is always seen at very hard cornering limits - The geometry of the swing arm rear is such that the inside rear tire on any corner is going to try to tuck under the car as the inside of car lifts because of cornering G-force.  As the side of the car goes up, the axle tucks the wheel under the car and the tire rides up onto the sidewall, losing traction.  

On the other side of the car, the G-force is pushing the outside wheel up into the wheel well while applying lots of lateral force to the bottom 1/4 of the tire, causing it to roll up onto the sidewall and lose traction (sound familiar?).  All of this can be felt in the steering wheel and in your butt as it begins, but the transition from weakening traction to no traction happens in an instant with almost no warning.  The technical term is a "transition from understeer to oversteer", meaning that you go from the front end plowing sort-of straight ahead as you turn the steering wheel more and more to the side (understeer), to the rear end losing traction and letting go and coming around to meet the front (oversteer).  It ain't pretty and can cause excessive staining of your pantaloons.  Also, because of that swing-arm geometry there is also a tendency of the car to roll up onto the outside sidewalls of both front and rear wheels, lose road grip and allow the car to roll over.  Your day just went from bad to worse.

IRS can do the understeer/oversteer thing, too, but it takes a hell of a lot more G-force to make it happen.  That's why swing arm cars often have trouble keeping up with "spirited" and well-set-up IRS cars.  IRS cars, by the nature of the suspension, corner flatter with more of the rear tire rubber on the road at all times because the wheel is only allowed to go straight up and down, not swing under as the swing arm cars do, so it takes a lot more force to push laterally onto the tire sidewalls (and you can feel the transition to the limit of the sidewall in your butt).  You can still feel the under/over transition as it begins to happen, but it is slower and actually more controllable such that the car can be steered with the throttle foot by applying more (to induce oversteer) or less (to allow understeer) throttle and/or hold the car right on the brink of oversteer for the fastest line through the corner.  IRS cars are much harder to cause to roll over.  Possible, yes, just much harder to induce.

So, all that said, so you understand the differences, we get to Troy's last paragraph:

"If you're just a pleasure cruiser and never plan to try to keep up with Robert or Teby, just get a swing axle car and spend about $100 bucks on a camber compensator.  Since you are getting a Pat Downs motor, you're probably not just going to be a pleasure cruiser, so get the IRS. "

Blake posted:

 I have a deposit in with Pat for a motor after much consideration and debate on AC vs WC - decided AC for $$$ and wanting to keep the car more period correct with AC....still on the fence really but going forward with AC and feel confident I’ll get a great motor out of Pat/CB Performance so I’m sure I’ll be happy.

I look forward to your thoughts. Thanks everyone. 

When you wrote that you decided AC for $$$, I was confused.  I am under the impression that a Subaru engine producing the same horsepower as a CB aircooled engine will be much less expensive, and the Subaru will be more dependable and probably cost much less in maintenance.

 

Another thing to consider is what will actually be limiting cornering speeds in your car.

Many factors can contribute - basic suspension geometry (IRS vs SA), spring and shock rates, wheel alignment and ride height, tire size and tread compound, and of course, driver skill.

But none of these matter much in my car.

If the passenger's hand goes for the grab handle on the dash, coming into a corner, I've reached my maximum cornering speed. Period. Pushing beyond that in the slightest will have dire consequences far worse than rolling the car into the weeds.

There will be loud protestations followed by frosty silence. The mood at dinner will be different. Mocking references to the 'incident' will be brought up in polite conversations with friends - often weeks or months later. There is always a price to be paid.

This arbitrary cornering speed limiter is usually set far below any physical limits the car itself imposes. It's something to mull over seriously before you invest in any expensive hardware.

 

IRS= It's Really Superior.

It's also just a lil wider (in stock form), which means you'll be using narrower wheels and tires in back than you could get away with using the swing. And that's OK: the car will still handle better than a wide-tired swing axle car, and it will also look more "period correct" to anyone not standing directly under it.

That Vintage routinely cuts up IRS pans to convert them to swing axle cars is (imho) a low-grade felony. 

IRS= It's Really Superior. ...... good one. 

edsnova posted:

IRS= It's Really Superior.

It's also just a lil wider (in stock form), which means you'll be using narrower wheels and tires in back than you could get away with using the swing. And that's OK: the car will still handle better than a wide-tired swing axle car, and it will also look more "period correct" to anyone not standing directly under it.

That Vintage routinely cuts up IRS pans to convert them to swing axle cars is (imho) a low-grade felony. 

IRS= It's Really Superior. ...... good one.  

I also never figured out why they goto the work of converting the pan to Swing axle when they could so easily waltz over and have the rims fixed for the spacing difference  and probably for cheaper this keeping it as original is not giving the owner the best they can for a simple improvement. 

Todd M posted:
Blake posted:

 I have a deposit in with Pat for a motor after much consideration and debate on AC vs WC - decided AC for $$$ and wanting to keep the car more period correct with AC....still on the fence really but going forward with AC and feel confident I’ll get a great motor out of Pat/CB Performance so I’m sure I’ll be happy.

I look forward to your thoughts. Thanks everyone. 

When you wrote that you decided AC for $$$, I was confused.  I am under the impression that a Subaru engine producing the same horsepower as a CB aircooled engine will be much less expensive, and the Subaru will be more dependable and probably cost much less in maintenance.

Thanks everyone for your thoughts. Todd- the AC motor set up I’m planning is about $8,000 compared to about $12,000 to go with the water cooled after it’s all said and done. It’s been a long debate in my mind - AC vs WC. In the end I like the AC idea bcs it’s close to the original. Plus saving some money helps. 

For the record Troy.....I have never had a problem following Teby or Robert. However flowing Teby's rich running engine is a quite a gas. As far as IRS vs Swing.... I have put several Porsches in the ditch in my days BM. Before marriage, before mortgage, etc. In fact it was part of the learning curve in the early 911/912 cars. My Speedster has a swing axle with camber compensator and anti sway bar. So far my on limits of courage or perhaps wisdom gained with age have kept me on the road. 

majorkahuna posted:

For the record Troy.....I have never had a problem following Teby or Robert. However flowing Teby's rich running engine is a quite a gas. As far as IRS vs Swing.... I have put several Porsches in the ditch in my days BM. Before marriage, before mortgage, etc. In fact it was part of the learning curve in the early 911/912 cars. My Speedster has a swing axle with camber compensator and anti sway bar. So far my on limits of courage or perhaps wisdom gained with age have kept me on the road. 

My driving speeds with 30 people following me is about 80% less aggressive than when just Teby and I are out ripping through the Sierras. At SOC events I have my corner limiter riding with me and for the reasons Mitch stated above she dictates my driving style. When it's just me in the car then it is just me at risk of dying so I push it pretty hard. 

@Blake I decided on IRS. Greg will narrow the trailing arms and with a set of Vintage 190's in a 5 1/2" width you'll be able to fit 185 tires under the rear fenders.  You could go with a 5X130 bolt wheel and then you could run a 15X6" wheel and maybe get 195's on.  As someone above said, you might be able to mod a set of wheels by having the barrel extended to the inside, but I haven't explored this with Greg or with a tape measure. For now I'm going with the 185's and I think on a car this light that it'll be fine even with Suby power. If it turns out I'm wrong I'll let you know.

Funny, just got off the phone with Greg. My body is going to go to paint this week!!! WhooHoo!!!!

Arden posted:

Seems pretty high for AC Vintage Motor cars only charges $ 3,900.

This would be a Pat Downs CB motor which from my research is the gold standard in AC motors. But you’re correct - Greg is giving me a credit of about $3-$4k for not going with his motor, however to be fair - he’s still installing this motor and doing everything else so I think it’s fair. 

JMM (Michael) posted:

@Blake I decided on IRS. Greg will narrow the trailing arms and with a set of Vintage 190's in a 5 1/2" width you'll be able to fit 185 tires under the rear fenders.  You could go with a 5X130 bolt wheel and then you could run a 15X6" wheel and maybe get 195's on.  As someone above said, you might be able to mod a set of wheels by having the barrel extended to the inside, but I haven't explored this with Greg or with a tape measure. For now I'm going with the 185's and I think on a car this light that it'll be fine even with Suby power. If it turns out I'm wrong I'll let you know.

Funny, just got off the phone with Greg. My body is going to go to paint this week!!! WhooHoo!!!!

That’s great! Thanks for explaining the difference in width, Greg and I spoke today and he said essentially what you said but after reading your comments I think I understand  it better. 

If he's willing to narrow the trailing arms-- there'd be no question for me.

Perhaps Troy is right regarding how most speedster owners drive, but irrational exuberance is something that tends to overtake most of us at one time or another. IRS provides a wider net to catch us while we play out our Nürburgring fantasies in glorified VWs. I feel the same way about rear discs. 

Stan Galat posted:

If he's willing to narrow the trailing arms-- there'd be no question for me.

Perhaps Troy is right regarding how most speedster owners drive, but irrational exuberance is something that tends to overtake most of us at one time or another. IRS provides a wider net to catch us while we play out our Nürburgring fantasies in glorified VWs. I feel the same way about rear discs. 

Thanks Stan. Yes - Greg will narrow the trailing arms as part of the modification. 

As Robert, Bruce, Stan, Ed and others have said- go irs! Not only is handling superior, the ride is a little more comfortable as well. If you do narrowed trailing arms now is the time to decide on whether a brake upgrade is in the cards, as discs (or bigger type 3 drums and shoes) will space the wheel mounting surface out 1/2-5/8" and that needs to be figured into the mix.

Right now on my older Intermeccanica body (with VW pan) I have short (swingaxle) torsion bars, cut down swingaxle spring plates, Beetle drums, stock irs trailing arms, late 6" Fuchs with 1" added to the inside so they're 7's (a la '67 911R) and 195/60's just fit, there being 1/8" spring plate clearance and less at the fender edge. I was hoping to use 205's but they wouldn't go. If you use adjustable spring plates you'll have less room, and if you go with irs (longer) torsion bars the early double spring plates will limit the tire width as well. The later single spring plates are more than strong enough, so that's the way to go. I never did have an irs torsion bar cap in my hands to weigh, but they are significantly heavier as well

For those in the conversation- there's no need to modify an irs pan for swingaxle; it's just a matter of ignoring the trailing arm brackets, using the shorter torsion bars, appropriate spring plates/caps and installing the transaxle. An irs pan under a swingaxle Speedster will have the trailing arm brackets as long as nobody's cut them off.

I used swingaxle torsion bars and spring plates to save weight- the shorter bars are (iIrc) almost 1 lb (each) lighter, double irs plates weigh 2300 grams each, singles about 1700 g's and my cut down spring plates just under 1,000 grams (each!). The adjustable spring plates from Sway a Way I have weigh about 2550 (sorry, don't remember the exact numbers) and just under 2600 grams- they are really heavy!

To modify swingaxle spring plates for irs isn't that hard; they need to be shortened, narrowed (top and bottom) slightly (or you'll get less suspension travel) and new holes and slots drilled. And of course they have more holes- they're mine! 

lightened spring plate- cut down for irs

 

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Gordon Nichols posted:

Just curious, Al - Is there an estimated date to end to the hole drilling and get your IM on the road?

I'll probably never stop looking at parts while wondering what could be lighter, but yes, it would be nice to have it on the road soon...

Wasn't trying to be a smaht posteriah, just wondering if he'll beat Wolfgang out to be street registered.  I realize that there might be a tremendous amount of latitude in this (it's been 31 years and counting so far for Greg with no indication of an imminent conclusion), but winter is coming on and we all need something to keep us interested and logged in til the Spring, right?  Besides, they're both in their respective "rainy season" (I don't think Al ever exits Rainy Season over there) and they can pro'bly use something more to do 'inside', I guess.

I mean, I like a holy, lightened vee-hic-el as much as the other guy, but sooner or later the final hole gets drilled and either there isn't enough left of the car to put on the road (everything having been drilled to nothing) or there is enough left and the Canadian version of the RMV says something like, "Well, OK.....  It's your neck!"  

To paraphrase a sign from my office wall for many years; "There comes a point in time on every project when the final hole is drilled and it's time to go drive that thing!"

We could even get tee shirts for Carlisle and the Toasty Coast gatherings to give support to our favorite builder!

One from "the North" for Al:

Fanboys

And one from "The Okeefanokee" for Greg:

walt-kelly-07

Go, Greg!

Go, Al!

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IaM-Ray posted:

I find it interesting as well that a comparable 175hp Subie to AC that the AC is not a lot more expensive.  It is all well and good to keep the car as original, I did that the first time around... Just saying. 

That is what I was thinking, but what are the added expenses of a water cooled modern engine; ECM, cooling system, transaxle adapter plate, sensors and wiring?

Jim Gilbert - Madison, Mississippi posted:

Just how many holes are there?

How much weight have you saved?

Woke up. Got outta bed. Got to drill some more he said!

It's  holy car!

I read the news today, oh boy
Four thousand holes in Blackburn, Lancashire
And though the holes were rather small
They had to count them all
Now they know how many holes it takes to fill the Albert Hall

Stan Galat posted:
Jim Gilbert - Madison, Mississippi posted:

Just how many holes are there?

How much weight have you saved?

Woke up. Got outta bed. Got to drill some more he said!

It's  holy car!

I read the news today, oh boy
Four thousand holes in Blackburn, Lancashire
And though the holes were rather small
They had to count them all
Now they know how many holes it takes to fill the Albert Hall

Al drilled them allllllll

At Carlisle, I invited ALB to haul his Speedster South to NWF for the winter and we'd work on our cars side by side in my 30'x40' barn.  Me saying I'd spend July-August in Vancouver may have scared him off?

I did drive out to visit mine yesterday (about 45 miles inland).  It's still there but those Amish workers DrClock promised, haven't started work yet.  I aired up a low tire --- mowed grass and trimmed a tree but didn't wake the Speedster. Ha, of the 4 speedsters in my area, only PanHandle Bob's actually runs and is street-able!  

I recently had the state forestry guys out with convicts clearing a drainage ditch that runs thru my 12 acres (family members own bits of original 80 acre tract.  It was an $800k project they did in 1996 to handle road run off! Took them over a week with a big excavator and tractors.  Lead forester said I had every invasive species growing know to FL - yet no Kudzu. Chinese Tallon/popcorn trees really grow fast they were 6" in diameter!

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