Kicked off phase II of my small bore race car project. Dropped the car off a couple hours ago.

I bit the bullet and I'm going route of a more thorough rebuild with the shop working on my car. We found some nice new Mahle 2.4 911 S cylinders and pistons ($$$ ouch). Dang those pistons and pins are light! Completely rebuilding heads and having them drilled for twin plug crankfire ignition. Will be going with hot cam setup TBD. Running about 10.5 to 1 compression.

Should make 230 HP with one plug standard ignition and a bit more with twin plugs! This little motor should do ok in propelling my roughly 2000 lb car.

Depending on my budget I may just go with standard ignition and run one plug to start and then upgrade to crankfire with twin plugs. Engine rebuild will be finished by mid January due to Holidays.

Rebuilt 901 tranny with MSX gears will hang off the back of the motor. Thinking about a LSD, but I'm unsure that it will fit my budget now.

When the car gets home I will be gutting doors and the rest of the interior for weight savings. Shopping for a race seat.

I think my car will actually be fast enough for me to get a wing now.

Great to hear about your start Grant. Should be fun next year!

Sounds like a good thing, but how are you gonna get 10.5 :1 compression outta 2.4L S P&Cs?

Hi Grant,

Nice to hear you finally joined the darkside!...

Trekkor....oh Trekkor....

Are they Mahle C's and JE P's? I don't remember a 10.5:1 911S combo, but I may be wrong...maybe shave the heads?

If you can afford it, get the LSD and run single plug and back off the timing to keep from blowing your motor until you can afford to get the last 10 percent out of it. With all of that power you're going to have, that car will spin those wheels like it's on ice.

40% or 80% torque bias or ZF style will all be good. FWIW, I had an 80% Guard (ZF style) LSD in my 901 and I really liked having it. Not only did it make a difference with putting the power down, it was nice when you let off the gas after high speed sections. It kept the car more controllable.

Sound fun...can't wait to see it out there next year.

Bill P.

I made a misstatement about these pistons and cylinders being for a 2.4 S. They are same bore as a 2.4 S, but they are for an earlier year 911 S motor apparently. When you put them on the longer stroke 70.4 MM crank you get more compression. Pistons need to be machined for clearance. Apparently these are fairly hard to find and allow you to make a high compression motor without shaving the heads. The cylinders are the Biral Mahles.

sounds exciting! i understand the 'budget' issue -- but i would consider lsd a priority for AX and hillclimb. otherwise, i doubt you'll ever be able to put down all of that 230 hp. With an open diff, you'll always be trying to tune your suspension around your corner-exits.

Yes LSD is top on my list if I can afford it. Anyone know where I might be able to find a deal on one? ...and yes the darkside has prevailed. I was almost to the point of selling the car and then I found myself hauling it up to Gary for complete engine rebuild etc.

It's tough to give up on the 914 "dream". Why else is Fritz gone and The Beast™ still here?.....

914's have a character....sometimes a mutha of a character...but character nevertheless....

Bill P.

2.2L S P&Cs will do the trick....and then some.

I still predict W2W in your future.
maybe you don't know it yet, but I'm guessing within 24 months you'll see the light...

especially after you drop another 17K into your um... what is it?

"budget $4,000 cheap -6 conversion?"



only my opinion... but you may want to go with the twin plug right from the start.
under track type conditions with 10.5:1 compression your going to have to use race gas. The twin plug is going to provide a margin of safety to a very expensive lump. After all of the outlay for the new motor, safety and insurance is a good thing.


my new quote

even if they don't start expensive, they ultimately end up that way
b

Grant, don't you need to plan for twin plug from the start? I thought the only reason for twin plugging was to run higher compression.

Just check out the turn 7 exit by the "champ" and you see why. Probably cost Nathan 2 or 3 seconds at Hoopa.

Oh, the Hoopa Hillclimb videos.

or Duracell

Mahle 2.2 S--old production cyl. were Biral -iron bore alum fins,
new production versions - nikasil bore alum fins
For the record;
Nikasil
From Wikipedia, the free encyclopedia

Nikasil is a trademarked electrodeposited oleophilic nickel matrix silicon carbide coating for engine components, mainly piston engine cylinder liners. It was introduced by Mahle 1967, initially developed to allow rotary engine pistons to work directly against the aluminum housing. This coating allowed aluminium cylinders and pistons to work directly against each other with low wear and friction. Unlike other methods, including cast iron cylinder liners, Nikasil allowed very large cylinder bores with tight tolerances and thus allowed existing engine designs to be expanded easily, the aluminium cylinders also gave a much better heat conductivity than cast iron liners which is an important factor for a high output engine.

Porsche started using this on the 1970 917 race car, and later on the 1973 911 RS. Porsche also used it on production cars, but for a short time switched to Alusil due to cost savings for their base 911. Nikasil cylinders were always used for the 911 turbo and RS models. Nikasil coated aluminum cylinders allowed Porsche to build air-cooled engines that had the highest specific output of any engine of their time. Nikasil is still used in today's 911s with great success.

Gary??? As in Renntech Gary? You were in town and you didn't call or write??? Oh the pain!!!

Rob

Gary as in Gary Dielacher of GD racing. I presume Since he performed stage I.

Sounds really good.

i may have to step up

I desire the 220hp 2.0 LeMans SIX.


KT

I have 110hp and can't keep it from spinning on corner exits. The LSD will be the biggest change you make. The power means nothing if you can't hook it up. And to hook it up correctly you will need a LSD. YMMV, but it is to me the best upgrade you could have made. Find the dollars, save the weight or the seats or the wing, and get it done correctly!! But it is your dollars, spend them wisely.

Apparently you don't read the suspension set-up comentaries that go on here.
It's quite easy to keep the inside rear from unloading.....it may not fit your suspension philosopy, nor that of others here, but that's life.

Yeah I tuned out most of my wheel spin by firming up my front bar and I had 165 HP. The open diff only caused problems in a few places during AX and rarely on track.
I know higher HP will need to be tamed with LSD. 265/45/16 rear tires certainly help.

I got it all....no bragging, it's just that it is totaly unacceptable for AX.

Another key point that you go after regardless of the consequences.....deal with those later. Mine never totaly lifted, just spun the tire occasionally when the power went on.

I did drive another otherwise good handling car that lifted clear.....what an effin' disaster that made of a sweeper. I like to roll on power just before the apex.....the wheel lifted turning a nicely developing drift into a real clusterfuck of wheel sawing. The car's owner never had that happen....go figure.

Edit

Don't misunderstand, a TB diff is the hot setup for AX.
Just bring around 1800 bucks for the part & install.

I was factoring the price of the full motor and also the full tranny (with diff) when I came up with the 17K figure.

tranny's can add up fast. I bought higher priced gears and have some really unique machine work in mine, but it was 6K by itself.

you can add more if you want a trick clutch or frills.

my figure also included your seat and upgrades plus the twin plug is going to run you a penny or two for ignition bits.

seems that you and I have had this same debate before.
and the way I remember it you were estimating 4-6K the first time around.
I was estimating 10-12K for your phase 1.

who was closer?
brant

I have fixed my suspension setup, and I have choosen another way to fix the wheel lift just incase it should happen again, ZF Limited slip. I am not one to do things half way.

BTW, I have setup several track cars and for Road Racing PCA J stock, I never saw the issue. But auto-x it seems to make a huge difference! And if Grant is going to auto-x and want to be compitive he will need a way to put the power to the ground.

Whoa.. buy a used 3.0 and have it freshened instead of a high winding small 6??

It is hard to beat torque..


B

Youre right if I was being practical I'd go that route. Trekkor and others have all recommended that I go for a 3.0 or 3.2. However I like high winding small displacement motors - its a nostalgia thing, with no rational thought behind it. By the time I found a 3.0 and refreshed it I would likely be in similar price range if not more. This will be a fun little car with a motor built to last a couple seasons. I'll be ready to do something else along lines real fast car in a couple years with a 3.6 or 3.8 so I'll get my chance for torque later.

This car wont be as brutal as a fast 3.0 or higher displacement motor, but it will have ton of character. The car should still prove to be fairly quick due to its weight. Even with 165 hp it was wickedly fun for me. I just cant imagine it with 65 more HP and short ratio gearing!

Oh and I bit the bullet. I'm shopping for an LSD now.

That is easy Guard, Paul can hook you up. ~1800 not installed. The Quafe can be had for $1295, but my money is on the Guard or ZF. My ZF will be here tomorrow I am stoked

Yep. Tell Paul we want Boxster gearsets when you call him.

Then I need to talk to him about advertising with us



B

Sorry, I have no idea who Paul is? Perhaps a good reason to be a banner ad vendor.

Sorry..

Paul Guard (Guard Transmission)

He is in NorCal now. He sells the ZF "style" LSD's and has been in litigation for 8 years over his "Quaife" style torque biasing LSD.

Good guy. Know's his late model Porsche stuff.. his customers are primarily race teams and the such.


B

Stephen,

there is some proof that a TB diff can actually be superior to a ZF diff on mid engined, low and mid HP cars..

and I believe the $1800 quote is with installation.
both styes of differentials are basically the same cost to install

brant

Now, now, Brant......
I urge all AXers to go with the ZF style diff....the more locking the better....
as you should be doing with all your w2w competitors.

It is all about the combo! Each piece goes to make a whole. I guarantee that the ZF is a better choice for my combo. YMMV! I don't follow everybody's left brain thinking. And I likes it that way. I can come up with some pretty creative solutions and that is what I get paid to do. The TB only works if it has torque to reference (both wheels on the ground). With out it; it acts like an open diff. I have setup several PCA J class racers, in my time. With all the drivers I have put on the track, I never had a lift and spin issue. They were all very smooth drivers as am I. But Only when these cars get onto the auto-x have I seen this problem, and have see experienced them first hand.

BTW, I know how TBs work, I have one in my Jetta, and I like it. But the only time the front tires on a Jetta would come unloaded in a turn is if you hit a serious bump at speed. And my Jetta makes way more torque than your sixers. But I am down on the HP mark quite a bit.