This August, our Lindsey Racing 951 Headers are on sale at $100 off our already low price. These headers are meant as a direct replacement for the factory 951 headers that are getting older and older every day. Our unique one piece flowing runner design sets it apart from the crowd.

Our Lindsey Racing Billet Fuel Rails are seen on more and more cars all the time. With 10% off this August, we expect to see a few more out there!

The Mafterburner Fuel Controller is by far the choice of 951 owners. Live tuning makes this device a breeze to use vs. units that require you to tune while you're sitting still. All the live information displayed on the screen and loggable makes adjusting a breeze. At 10% off this month, it makes it even more attractive. If you have been thinking about ditching your "other" piece and upgrading, now is a great time.

To introduce our new handling of Race Communications Equipment, we are kicking this off with a 10% discount on any Radio Kit we offer in August. I think it's going to be like a computer or cell phone. Once you get one, you wonder how in the world you ever survived without it.

Now that Porsche no longer offers the original A/C delete bracket, we only carry the one. So we bumped up inventory and are putting them on sale. Our A/C Delete Bracket is 10% less this August.

AUGUST CUSTOMER CAR OF THE MONTH

ENGINE MODS:

Lindsey Racing Built 2.8L
Lindsey Racing Stage II Cylinder Head
Lindsey Racing Super 75 Turbo
Lindsey Racing Solid Lifter Package
Lindsey Racing Racing Valve Springs
Lindsey Racing Camshaft
Lindsey Racing Mass Air Flow Kit
Lindsey Racing Mafterburner Fuel Controller
Lindsey Racing Hard Pipes
Lindsey Racing Stage II Intercooler
Lindsey Racing Two Piece Cross Over Pipe
Lindsey Racing Billet Fuel Rail Kit
Lindsey Racing Injector / Knock Harness
Lindsey Racing Adjustable Cam Gear
Lindsey Racing Dual Port Wastegate
Lindsey Racing Exhaust
SPEC Stage III Clutch
SPEC Steel Billet Flywheel
Bosch 044 Fuel Pump
Extrude Honed Intake Manifold

SHOP TALK

Two years ago we completed a turbo'd 968 project. This 968 came stock with a dual mass flywheel and a solid disc clutch. The dual mass flywheel is essentially two halves with a cushion or damper between the two. This absorbs the shock of engagement as would a sprung disc. Or so it would seem. We installed a SPEC Stage IV clutch kit on the car with a Single Mass Aluminum Flywheel. The Stage IV is the same as a Stage III only it has a solid hub disc. We weren't quite sure what to expect on a street car since this is usually a set-up we would recommend for a track only car. On the 968, there is no room for a sprung hub between the flywheel and the pressure plate so there is no choice in the matter.

From the first moment the car was driven, the smoothness of the clutch was realized. We have installed Stage III clutches before and experienced them from the first miles, along with the break in period, but not a Stage IV kit. We were absolutely amazed at how smooth this clutch was. It didn't make sense as it went against everything we felt would happen. How could a solid disc clutch engage smoother than a sprung disc we wondered. From mile one! Was this the ideal set-up for a street car as well? The 968 does have a shorter 1st gear and a slightly different pressure plate clamp load.

To answer those questions, or at least learn more about it, we elected to install Stage IV clutches in two in house projects just finishing up. A 1989 2.8L 951 and a 1986 3.0L 951 project. While at the time we release this letter the 3.0L car is not off the car hoist yet, the 89 2.8L car has accumulated several hundred miles and even attended it's first autocross event.

We have been in constant contact with the owner as he has been accumulating break-in miles on the engine and clutch. Every few days, I asked for a report on the clutch and here is what he came back with in his own words.

Brand New:

At first the solid puck clutch was VERY difficult to get a good start with. It was so "grabby" it made me feel like I didn't know how to drive a standard. I had to rev it up to at least 3000 rpm to get the car rolling without bucking. With all the lightweight rotating mass in my motor upshifts would buck a little going to second or third if I didn't shift fast enough and the rpms dropped below rev match for my speed. On downshifts I had to rev match perfectly or it would buck. Basically I thought this clutch is not for me.

150 Miles:

The clutch started slipping a little on take-off engagement. Pretty easy to get it rolling without bucking only revving to 2000 rpm. Upshifts are getting to where I don't even think about them. On downshifts as long as the rpm is above the rev match it does OK. Get a little low in rpms and it will buck downshifting. The only challenge at this point is cruising really slow in first gear like drive up windows and parking lots. Try to inch a little forward and it bucks. I am much relieved and my thought is that I could live with this clutch daily driving if it really helps with getting down the horsepower.

400 Miles:

The clutch is working pretty smoothly now. Still doing 2000 rpm roll offs. The only time I have trouble is starting out on a hill and that is usually because I am anticipating a problem and let the clutch out too slow. Most times it is not a problem. Downshift will still rattle my teeth if I miss the throttle blip and let the clutch out after the rpms have dropped past the rev match. Only one in ten times climbing my driveway do I get any chatter. It is getting smoother and a whole lot more livable as my daily driver.

675 Miles:

Took the car to it's first autocross with the new solid puck clutch. Launches were very snappy and no shuddering at all. Just rev it up and all but dump the clutch and the car would just go. Up-shifts were crisp and typically chirped the tires. Pretty impressive considering I was restraining myself from full throttle and short shifting at 4000-4500 for new motor break-in. I would describe it as a lot more positive engagement than the Escort sport clutch I had before with about the same horsepower at full throttle as I am now enjoying partial throttle and short shifting. Downshifts also worked well. It even grabbed without shuttering when I downshifted keeping the revs low to break the rear lose to start the car rotating. Of the 10 laps of 12 gear changes per lap it only shuttered once when I was going deep and hesitated letting out the clutch. The only thing I really noticed besides the crisp engagement autocrossing was no hot clutch smell while back in line waiting for my next run.

We (Dave and Mike) haven't driven the car since it's first few miles. We will each drive it again now that's it getting broken in and get a feel for the clutch and report back next month. But from the looks of things, we will likely be recommending this set-up for many of our customers on street as well as track applications.

We feel the need to talk about valve springs again. Recently a customer sent in a cylinder head for some upgrades. He wanted to retain the stock springs and save a few dollars on the engine build and put that money elsewhere. We then measured the factory springs to see what condition they were in, they measured a miserably low 100 pounds at installed height. This is WAY to little for a turbo car.

We usually don't measure the original factory springs unless the customer wants to reuse them. They would just enter the garbage can. We have seen plenty of springs in the 110 range, but this was much lower. It's possible this is not that un-common but since we don't measure what's not being used, we don't keep track. We wonder how much lower they may even go.

When we set up a head with stock OEM spring, we usually find ourselves in the 128 to 130 pound range. We feel this in satisfactory and safe if running 15-16 psi of boost.

If running more boost, we like to see more spring. We have our Lindsey Racing springs available in 140, 150 and 160 pound rates. We don't like to run anything stiffer than a 140 on the hydraulic lifter. We use the 150 and higher rates if doing a solid lifter set-ups.

We are concerned about the old hydraulic lifters not being able to take the punishment of the stiffer springs. We are also convinced the replacement INA lifters are not up for the job. It's turned into a catch 22. If we run a stiffer spring, we may damage the lifter and cam. If we run too weak a spring, its lifter may not follow the cam thus damaging the lifter and cam as well.

We try to get pretty specific about the engine's goals when offering a spring choice or suggestion to the customer.

In the mean time, we feel lubrication on either set-up is extremely important. We are very pro Joe Gibbs Racing Oil and have many customers that have switched over to it. Time will tell as with anything else, but proper spring selection and good lubrication are good insurance for a happy valvetrain.

FINAL THOUGHTS

Until next month, we wish you many safe and quick laps.

- The Lindsey Racing Crew