Subie Engine Modifications

I know Angela and a few others will disagree with me, but it IS possible to have too much power FOR THE CHASSIS.

My 1500 pound Spyder with 170-180 hp is right on the edge of the above statement. Somewhere between 8-9 pounds per horsepower. Any more would overpower the trailing arm front and swing-axle rear traction that's available. There are a few things that make it work though. Space-frame chromoly tube that doesn't flex. Gearing. Massive non-fading brakes. Rear suspension travel is limited to prevent tuck-under(positive camber). Correctly valved shocks and shock settings. Swaybar. Alignment, tire pressure and CORNER BALANCE(very important). The seat-of-the-pants feeling and seat time at the limit are also a factor. The 45/55 F/R weight distribution of the Spyder helps too, reducing the pendulum effect of a Speedster.

I think the only Speedster in the same ballpark is Scott's superlightweight. And maybe the aluminum-subframe car that Alan Merklin built.

The IM-6 is 2400-2500 pounds, still lighter or comparable to an early 911. Beck Speedsters have an advantage here as they end up around 1700 pounds in type1 configuration, only slightly more with a Suby. 

No matter what way you slice it, above 110-120 mph, directional control starts to be an issue as these little cars want to start to fly off the road.

Can my little car keep up with modern cars? Yes, to a point. I once spent an afternoon driving VERY hard with a VERY modified turbo Miata. It was putting down 245 hp at the wheels. It had big brakes, big swaybars, and 17" wheels and tires. Aftermarket ECU and turbo. I kept up with my friend no problem, but it was exhausting. We switched places and I led for a while. He kept up with me, but noticed how many corrections I had to make, whereas he was more like point and click through the turns. Arriving at the destination, he was fresh and relaxed, where I had sore arms and shoulders the next day. I think I had more fun. But I really had to work for it.

Corner weigh balance... something I would like to have done ... is it easy to do ? $?

Does your car have 911 suspension, Ray? If so, front is easy, each torsion bar has a screw to adjust them independently. If rear is IRS VW or 911 torsion bar, adjustable spring plates are the answer.

If torsion bar front, you can set the diagonal weights with the adjustable rear spring plates. Same thing I do on my car, but with coilover rear spring/shocks. It would be REALLY cool if someone put two adjusters on the lower beam and cut the spring leaves in half. This would make the front independently adjustable, like the 911 was from the start.

But what we all really want is what Beck is doing with the new coupe: tube frame chassis, independent A-arm coilover front, semi-trailing coilover rear, and rack and pinion. Couple that with mid or rear engine and multiple EXCELLENT powerplant choices, and you have a winner!

Ray, all you need is a little time and a set of scales. Cheapest I've seen today is $700 US. Make sure you disconnect sway bar links on one side front and rear, then reconnect when you are done.

Also, on corner weighting, car should be configured as it is most often driven. You know, you or equivalent weight in the driver's seat.

The way an IM is set up in the rear,  each (of 2) torsion bars is individually adjustable (without adjustable spring plates). There is a grub screw and locknut tor each side,  similar to an Avis adjuster on a VW beam.

Corner balancing an IM with a 911 from end is about as easy as it’s ever going to get. 

Thanks for the suggestions

As an aside The front torsion bar adjusters suprisingly can really alter the front end behaviour by shifting the weight of the car 

atill doing research on eho can do it here

calmotion posted:

@550 Phil balance is good description👍

Balance is overrated.

edsnova posted:

It's possible to have too much of a good thing. 

Maybe.  Thank goodness I haven't gotten there yet.