Three things are primarily responsible for power . . .

1. Compression, base + boost in my case

2. Cams

3. Plumbing Efficiency

As you can see I am maximising all of the above. To expect me to leave a couple easy HP on the table is ludicrous.

I am not running really high spring pressures since the engine will be kept under 7K RPMs so there are going to be no undue valve train stresses for me to worry about. Its not like the valves are opening up that much more than they did from the factory.

My point is you are NOT leaving ANY HP on the table. YOu have 800HP heads on a 600HP engine. Why not back off on an obvious extreem wear factor and match the heads to the job at hand?

Actually you have 800 HP heads at 0.4" lift, so say again why you need -.5" lift?

And if you up the boost enough you to can do what BMW did with a 1.6L 4 cylinder engine and get over 1300 HP.

.490" Valve lift is not an obvious extreme wear issue. The factory C2/C4 engine has .470" intake lift and that engine has little trouble with cams at 100k plus. The factory 3.8 RSR cams have .490 lift....
The only extreme wear issue I have seen is plugged oil lines or someone neglecting to change the oil.

That's what I said until I missed a shift!!!!

Brian

Excellent point. The factory engine generally will not instantly zing up to 9000 RPM like a well preped race engine can. So you should plan for this inevitable problem with adequate margins in valve spring performance. My race engine was designed to shift at 8000 rpm but I know it has seen 12000 rpm during one of these events (missed shift or brain fart or whatever). It survived without any problem. Also known to happen is to put the thing in 2nd gear when aiming for 4th on a downshift. What should have been 6500 RPM in 4th is OH MY GOSH rpms for a short time. Instantly tears guts out of the clutch but engine has survived-so far.

Its a bit difficult to misshift a 930 tranny between the big H pattern and the fact that the synchros become even more difficult when you want to really spin up the clutch disk by shifting from 4th or 2nd to 1st or 3rd into 2nd.

3rd to 2nd going down the back straight at about 120mph.

Brian

If Youall don't beleive in a missed shift youall havn't raced it yet.

Not to worry, youall will be a beleiver, soon nuff.

yeah it only took me about .25 seconds to make that shift from 3rd to 2nd when I intended to go to 4th...

Easier to do than people think...
And I was going in a straight line down the straight.
Just a simple slip.

Brian

I found an "80lb super heavy" spring in the shifter helps some.

Can you elaborate on the spring. Show me what you have in mind?

I'm currently considering a totally new shifter anyway.

http://www.hargettprecision.com/ProShifter.htm

Brian

Misshifts are usually always related to whats above the shifter knob, not what's beneath it. ;)

Oh I'll be the first to admit that I wasn't paying full attention. I was in a new car, on a new track so I had my eyes/ears senses pointed everywhere else except my shifting...

Brian

Its been a long time since I bought it but Weltmeister has or had an extra spring that could be added to the shifter to make it a much more positive move if down shifting. Well wortht he few bucks it cost.

I noticed our forum sponser has several shifters for sale. I cannot vouch for any, but maybe some that are familiar could pitch in.

I used to be amused by the shift gates used on Ferraris, but now that I am older and wiser I can appreciate them much more.

And yeh, its whats above the shifter that does the deed, but sometimes you need all the help you can get. That buzz you get racing makes the normal shifter spring feel totally dissapear and next thing you know is you blew it, again, untill you have raced a bit you cannot apprecitate what I am saying. And tracking is NOT racing its a couple of steps and a few cups of buzz juice short.

You can save yourself a few big bucks and just beleive it or find out the high bucks way.

Brian, GJF recently installed Mark hargetts shifter. You should read his comments about it. He thinks the world of it and that is saying something since it is coming from him. I saw some more of his cnc work Friday and I can say that he produces a quality product no doubt

Eric Hood

Since I was planning on balancing the clutch and pressure plate anyways I decided to do a little additional work to lighten up the rotating assembly a few pounds.

Lets just say that there is certainly a bit of extra meat you can remove from a 930 pressure plate without compromising its structural integrity.

The extra surface area and passages should also aid clutch cooling too.

http://forums.pelicanparts.com/uploa...1114394567.jpg

http://forums.pelicanparts.com/uploa...1114394601.jpg

http://forums.pelicanparts.com/uploa...1114394616.jpg

Looks beautiful. Do you champher the edges? I haven't seen anythng on shot peening in your engine. Did you shot peen the crank? The flywheel? Rocker arms? If not I would suggest Metal Improvement Company, a nationwide high tech, mostly mil spec, company with reasonable prices.

http://www.metalimprovement.com/

A side note: This is a subsidary of Curtis Wright, the real inventor of air cooled engines. Glen Curtis http://www.linkny.com/~curtiss/

http://glennhcurtiss.com/
museum has on display an air cooled engine that looks just like an early VW engine. Date approx 1925! Invented, Designed and fabricated by Glenn Curtis. The original fastest man on earth.

Even better they have a Laser peening process, the ultimate method to get all you can get out of your parts.

And finally, having gone as far as you have on an engine, Coatings should be considered.

Have the valve springs coated, the heads(combustion chamber, and ports) the valves, the pistons and skirts, and the headers. Especially important with any super or turbo charged engine.

We have a shot peening machine at work but I have decided not to use it on any of my parts.

I did debur the edges of the holes I put in my pressure plate which has added a bit of chamfer to the edges.

I have also been busy this week on some remaining clean up and rebuilding issues.

Since strokers powder coated bling posts have been impressive I have decided to work on my own bling by polishing my engine case with the most attention being given to the sections that will be visible once the engine is assembled. There are still some swirlies that need to be taken care of before I move on to the final stages but that' one of my chores for today. Its a shame that most of this will only be visible from underneath the car.

http://forums.pelicanparts.com/uploa...1114872694.jpg

I also would hate to bolt that up to a grungy looking transaxle so I also cleaned it up a bit. Here are a before an after pic to show the transformation.

http://forums.pelicanparts.com/uploa...1114873065.jpg

http://forums.pelicanparts.com/uploa...1114873101.jpg

Even though my transaxle is still in great shape I am replacing my ring and pinion with the 8:39 set from andial so I figured I would give the whole tranny a rebuild 'while I am in there'.

So far I have pulled the pumpkin and disassembled, cleaned and visually inspected its components.

Since I have limited slip I wanted to make sure the friction disks and other components were still in good shape.

Fortunately the clutch pack, spider gears and everything else was in great shape so its good to know I don't need to do anything but put it back together after I have a chance to magnaflux a few critical components.

I took my camera into work that day so I took a few pics to share with everyone.

Here is the pumkin
http://forums.pelicanparts.com/uploa...1114873810.jpg

And here are the greasy grimy guts
http://forums.pelicanparts.com/uploa...1114873843.jpg

And here is everything all nice and clean. Its great having access to an industrial parts cleaner.
http://forums.pelicanparts.com/uploa...1114873877.jpg

Thanx for nice pictures of LSD innards. Never seen them in person before actually ;-)

Just curious. Why not shot peen?

The rods and rocker arms are already polished so there are no surface imperfections that need to be corrected.

The crank was also in perfect shape so it just polished the journals and gave it a good washing.

I got a question for you Jack, when you flow test heads are you sucking the flow through in the right direction when testing exhaust flows or do you get your numbers from pulling the flow into the combustion chamber?

Flow is tested by sucking for intake and blowing for exhaust.

As to shot peening. It should be done after polishing, see tech article on Metal Improvement site for why. The peeing puts the metal under compression therby preventing propagation of any cracks. It is especially important to the radius edges of the crank throws and all of the connecting rods. Thats what Porsche does to stock S rods and racing cranks.

Hmm, the reason why I ask about the flow method is because I got done testing my exhaust flows and got a lot larger numbers than you posted in another thread.

Here is a graph of the flow numbers I got today from my tests. Unless my flow rig is leaking or setting up some strange turbulence they seem a bit high.

http://forums.pelicanparts.com/uploa...1114998115.gif

Speaking of my flow rig I took a few pics of the pieces I made to test the exhaust ports and manifold.

I tested one manifold port today and got a flow of 362 CFM which appears to gist with the other ported carrera manifold numbers I found on the board.

Here is a pic of the setup for testing the exhaust port . . .
http://forums.pelicanparts.com/uploa...1114998995.jpg

And my device for precise exhaust valve control . . .
http://forums.pelicanparts.com/uploa...1114999069.jpg

And a pic of one of my exhaust flow tests in progress . . .
http://forums.pelicanparts.com/uploa...1114999116.jpg

And here is one of my manifold testing set up . . .
http://forums.pelicanparts.com/uploa...1114999169.jpg

Several things are wrong about your setup.

1. Always have the spark plug in place.
2. Always have a simulated cylinder or actual cylinder attached to the head. The cylinder and head shrouds the exhaust port, a lot.
3. Sucking thru the exhaust may not be exactly the same as blowing thru it from the cylinder. For sure the flow is directional and a vacuum situation inside the cylinder probably isn't the same as a large volume of air blowing thru. I haven't looked at it very closly on an analytical basis, but I have seen the difference in actual tests. A commercial flow bench allows the easy reverse of air flow so there was no reason to check out the real reasons for the difference, I just checked to see and wallah, there was a significant difference.

ONly trying to help on the peening thing, I want you to get the best possible results, esp seeing all the very innovative work you have put into your engine. I have been an engineer for over 35 years and seen a lot of work by very talented people, you are way up there on the talent level, keep up the good work.

PS do a check on leakage, ie valves closed, check flow. Another sanity check, the exhaust will almost ALWAYS be less than the intake flow, esp because the exhaust valve is always smaller than the intake valve. And if that flow is more than 80% of the intake, be suspicious. 91% is not likely nor even desirable.

Well, I haven't had a chance to get back to my flow tests, but operation case bling bling is now complete.

http://forums.pelicanparts.com/uploa...1115176304.jpg

http://forums.pelicanparts.com/uploa...1115176706.jpg

http://forums.pelicanparts.com/uploa...1115176718.jpg

Wow , the bling is very much BLING BLING. How did you do it? Cool.

Way too much intensive labor involving power tools and abrasives. The most helpful of all the tools was a dremmel tool with a scotch brite like buffer on the end. I would guess the total time is well over 10 hours if I include the initial cleaning and deburring of the case.

I still have to pull the main oil galley plug and give the case a final cleaning but then it will finally be ready to put back together.

Its a nice change compared to the grey and grimy case I started out with. I will probably cry the first time I have to drive the car in the rain.

http://anthonyrawson.com/Cars/Engine...crossFloor.jpg

dude, those are the best looking cleanest cases I've ever seen. I thought I had mine looking good.

http://www.pelicanparts.com/support/smileys/clap.gif

Well, they looked so good after the initial cleaning and wire brusing I decided to go all the way. They are not super shiney, more like somewhere between brushed and polished.

You need to wax the case with a good polish to try and keep the aluminum from going to **** and coroding. This thing is not going to be fun to keep clean at all. You need to get yourself a bottle of Mr Buffer polish. It is the best stuff I have ever used by far. It will make your life much easier. The shine will come up with this as well. I can show you where to get it. He is a local guy who does all my polishing.

Eric

You've got too much time on your hands.

I have a muffler that appears like the one you have pictured with a 4" single outlet. Mine is just a shell, nothing inside at all. How is yours configured?

Its almost an empty shell, but the exit pipe fully extends into the canister and is slotted over its entire length. Very much like an internal supertrap system.

Well, during the last few days I have taken most of the tranny apart. Tomorrow I will be removing and breaking down the gearset.

Here are some pics of where it currently stands. I am suprised that everything is as grungy as it is. It must be the florida humidity.

http://forums.pelicanparts.com/uploa...1115437508.jpg

http://forums.pelicanparts.com/uploa...1115437527.jpg

Hmm, I must have had a flow leak or calibration errors on the above graphed exhaust flow tests since after testing all the heads I am only getting about 195 CFM @ .4" of valve lift which makes sense when comparing valve sizes, port lengths and assumed boundry layer thicknesses.

Unfortunately I am getting around an 8% flow difference between the worst and best flowing exhaust port so I guess I will be looking for the causes and trying to rectify them this week. As soon as I am done with lunch I will be checking all the manifold port flows to see if there is anything I need to tweak on them too.

I am also pleased to see that I am just a few views away from having the most viewed thread on the 911 engine rebuilding forum. Take that reringing alusils. :D

Have you flow tested your entire carrera intake? Did you see big differences between runners? Looks great Tony!

Uh-oh. Look who has the lead in the views race...

Yaaay, I'm winning big time. :D

Yup, I just got done tonight and here are the results.

The deviations from the average flow are the following.

#1 0.3%
#2 3.4%
#3 0.9%
#4 -2.2%
#5 0.0%
#6 -2.5%

Here is a chart of the numbers.
http://forums.pelicanparts.com/uploa...1116213971.gif

I also set up an excel spreadsheet today to calculate some speed -vs- rpm charts for my new gears. Here are the charts for those who might find them interesting.

http://forums.pelicanparts.com/uploa...1116211835.gif

http://forums.pelicanparts.com/uploa...1116211855.gif

350Hp930,
I was looking at your stock versus modified gear charts. Are you just changing the R&P?