THSCC Forums

Quick question so that I can confirm my understanding on SM rules. The specific example would be a SM2 car such as a Porsche 914/4. I am trying to determine how wide open the engine/transmission swap allowance is. I believe I understand the weight and displacement rules. I am curious about the following (from my hand-dandy PDF version of the 2005 Solo rules)…

From section 16.1.D it sounds like “Drivetrain” is pretty open. I looked in section 12 (definitions) to get an idea on what SCCA calls a “Drivetrain” (it is not listed in the definitions section). I assume this means engine, transmission, differential, etc. Section 16.1.D.1 is a little fuzzy to me with regards to the 914/4 and 914/6. the 914/4 was sold here in the use as a “Porsche”. It was a joint venture between VW and Porsche. Outside of the US it was sold as a “VW Porsche”. The issue here is the wording on join venture cars and who you can pick an engine from. The end result is that my target is the 6 cylinder 911 engine line and I think that is not a problem.

My real question is that when they talk in 16.1.D about the drivetrain being unrestricted (except for limitations mentioned above or ones that I think I understand), I want to make sure that they are allowing things like…

• Unlimited cam selection. Including non-OEM sourced profiles, etc.
• Misc. “Improvements” to engine. This includes both performance and reliability ones. For the 911 engine, this might be upgraded cam chain guides, reinforcement pins in the block, etc.
• Mix and match heads, blocks, pistons, etc. (as long as the block is a Porsche block)
• Ability to pick and choose which transmission I can use (there are various versions of the 911/914 transmissions) as long as it uses existing mounts.
• Ability to pick whatever gearing I want to use.

Basically there are various “recipes” for building reliable 911 engines for use on track or aggressive street use. Probably many of these recipes have little regard for things like SCCA rules in that they pick and use the best combo of parts to build a reliable engine. I want to know if I can do this in SM2.

As a follow up question (probably needs to be addressed in the track forum), where does an SM2 car fall (class wise) with regards to HPDE/Timetrial rules? From my limited viewing of the Timetrail results, it looks like they have *SP classifications. Note, that the car would have all of the required safety equipment for HPDE/Timetrail.

And no, I don’t have a car yet, but am working on it.

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Richard Casto
1972 Porsche 914
2013 Honda Fit Sport
2015 Honda Fit EX
http://motorsport.zyyz.com
Money can't buy happiness, but somehow it's more comfortable to cry in a Porsche than a Kia.

I'd be interested in seeing how you'd propose putting a flat six engine into a 914.

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Has no responsibility whatsoever.

Isn't that what came factory in the 914-6?[/quote]

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David Teague
2015 Lexus IS 250c
1994 Honda Del Sol HS 39
2009 Dodge Journey R/T
http://teaguefamily.us

That was an I-6.

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Has no responsibility whatsoever.

Um, didn't they optionally come that way from the factory??? Shouldn't be too much of a stretch...

Why would porshce make a one off I-6? Everything I remeber was it was a flat 6, heck even the standard 914 engine is a flat 4.

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David Teague
2015 Lexus IS 250c
1994 Honda Del Sol HS 39
2009 Dodge Journey R/T
http://teaguefamily.us

Is the car a porsche?

Was the engine BLOCK available in any car that said "Porsche".

If you answered yes to those two questions, then what you want is 100% legal (subject to the displacement and weight limits of the class).

Swapping a beetle 4 cylinder and a porsche 4 clyinder would be slightly shady and would need additional investigation.

Swapping a Subaru STi motor into a 914 would be fun, but not SM2 legal.

Swapping a Cayenne V8 into a 914 would be 100% legal (as long as it meets the other provisions of the rules).

Scott

Here's a 914-6 engine:

http://mk23.image.pbase.com/u8/9146gt/u ... hoto11.jpg

definately not inline.

Ja, eet vas der H-6 like der 911 vom die same era.

Porsche think I-6 bad in 1970, jou must be thinking BMW.

--Kevin H.

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2003 WRX (again!)

I gotta remember to leave the shrooms at home.

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Has no responsibility whatsoever.

If it were only legal in SM you could run the ultimate 914 conversion, a mazda rotary. It is lightweight and can make killer power. My dad's 914 had a rotary in it after he blew the 1.7 liter flat four at Lime Rock. He made a little over 200 horsepower and the car ran quite well up at Lime Rock. Now if I could only find a picture of the car spitting 3 foot flames out the exhaust under braking going into Big Bend.

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2010 Honda Fit Sport
Couple of bicycles

Everyone beat me to the punch.

Porsche built about 3000 914/6 with about 1/2 going to the US. It had the 2.0 L flat 6 engine from the 1968 911. They are so rare today that many 914 fans will refuse to hack one up to make a race car out of them. It is generally cheaper to convert a 914/4 to a 914/6 than it is to buy a real 6.

So, yes you can put the flat 6 in. Porsche even tried a one off with a 3L flat 8 out of the 908 race car ...

http://www.914club.com/specs/mod8.php

About every known motor has been stuffed into a 914. Including rotory and V8s. I saw an electric conversion on sale on eBay just the other day.

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Richard Casto
1972 Porsche 914
2013 Honda Fit Sport
2015 Honda Fit EX
http://motorsport.zyyz.com
Money can't buy happiness, but somehow it's more comfortable to cry in a Porsche than a Kia.

So, the Cayenne Turbo V8 with 450hp would be legal? That would probably hurry a 914 along.

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Rich
http://www.v8mongrel.com/

So Richard, planning a trip to the darkside are we??? Eeeeexxxxxcellent...

Biggest problem with the Cayenne motor is its weight. I think you need a 911 Turbo motor it is lighter and has basically the same amount of power.

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2010 Honda Fit Sport
Couple of bicycles