72 Rsr

[Porsche Doc]

Hey Guys I am building a 72 RSR and I can't deside what engine to put in it. I will be using the 72 Trans with ltd slip.
The car is going to be used for DE's and maybe some PCA or HSR races aswell as autoX.
I will be using headers with suppertraps.

Here are the choices of engines I have.
1. 2.7L In a little hoter spec than a RS maybe 250 FWHP or close.

2. 3.2L Stock with a chip.

3. 3.6L Stock with chip.

Let me know what you think! I have to deside soon as the chassis is getting close is sticking the power plant in.\

THanks!

[Jack Olsen]

In your shoes, I'd definitely go for the 3.2 or the 3.6. You're going to have a lot of frontal area and a lot of tire with that setup. The high-output small motors just don't have the 'umph' you're going to want, in my opinion.

The 3.2 swap is very straightforward, and the most cost-effective option on your list. The no-drama manners of a fuel-injected DME car makes it a pleasure every time you turn the key.

A 3.6 in a widebody 1972 is, well... pretty awesome.

...or so I've heard.

[rattlsnak]

If you're going to keep the 72 gearbox,(7:31R&P) then go with the 2.7 or 3.2. That will be a beast AutoX cross car for sure. You need a 8:31 with the 3.6, especially if its a 993 3.6 on the track.

[Bobboloo]

2.8 twin plug

Really though, a 3.6 is the best bang for the buck. I'm building a 2.8 twin plug and the long block is costing me easily over a $1500 more than the nice 993 longblock that's for sale in the classified section of this board as we speak. I know it doesn't make sense but if I was sensible I'd buy a Camry so there you go.

[LARRY SHARP]

I would wanna try it with a 3.6 and leave those tires on it

[obrut]

"PCA or HSR races"

the rules of both of these will decide what you can run, especially if you want to be competative.

i'm pretty sure HSR will be the most restrictive (i.e. period correct)

[rdane]

I own a 2200# 3.4.
I drove a 2100# 3.6 today

Screw the rules, buy the 3.6.

[randywebb]

Problem is that for autoX you need torque = cubes. But the bigger the engine, the higher class you will be bumped into. Terrible dilema, I know.

[ScottKelly911]

Speaking from experience, I'd go with the 3.6, but if you are going to race HSR look at their rules before you do anything, I hear they are more strict than most sanctioning bodies. But for fun factor go with the 3.6, and as we've all seen with Jack, the 3.6 is plenty competitive even when bumped up in classes. For DE, I would think that it's hands down teh best choice and for AutoX you'll love the torque curve compared to the others.

[bigrubberjeep]

I have a 85 3.2 widebody (heavy) just the thought of it being lighter (like a 74 would) kind of scares me.

I am sure the 3.2 on yours would give you everything you want as far as power, that translates to less fusing with the motor and more time working on your suspension set up when at the track.

[rdane]

You can never have enough power or torque...trust me

[jluetjen]

Read the rules before you make a choice. Otherwise you'll screw your plan from the get go if your car is not considered legal for the groups that you want to race with (namely HSR). Building a race car in clear violation of the rules just demonstrates a case of denial and the lack of understanding of what racing is all about.

PCA will let you race about anything with a Porsche badge on it, but if you want the extra weekends offered by HSR and the fun of racing against non-Porsches, it will need to be HSR legal. I forgot which Porsche manager described racing against other Porsches as being similar to "kissing your sister".

I suspect that HSR will limit you to a 2.7 derived option.

[SC-targa]

If you want to be period correct, they didn't make 72 RSR's. The RSR came out in 73 with a twin plug 2.8.

For a fun toy, do the 3.2. Plan what you want to do with it and then check the rules.

Regards,

Jerry

[ted]

Originally posted by SC-targa
For a fun toy, do the 3.2. Plan what you want to do with it and then check the rules.

I'm a bit like Jack on car building. I think its a pain that none of the different track groups share car class rules. Be prepared if you build it to HSR 2.7 specs you may be at a disadvantage at non HSR race days when you bring it out to compete with other widebodys.
As a referance, I have enjoyed tracking my 3.2 in an RS bodied 911. I'd think with an RSR and all that tire a 3.2 might border on boring,,

A 3.6 has mid range torque that is going to make that car come alive, and the FI will only inspire confidence to throttle steer that montser through 100mph turns.
Put some steak on it.

[mede8er]

I am facing this same dilemma......building a 3.6 widebody on an 82....gonna have to race with the non street legal boys I'm afraid.....

[ErVikingo]

I'd look at the HSR rules first (http://www.hsrrace.com/HSR/HSRHome.nsf/attachmentweb/EJEN-637HSK/$file/rules.pdf?OpenElement)

FYI, weight rules state that class 3I is a minimum of 2000#'s with RSR body and duck tail and max engine of 3.0 liters. They also specify (for the same class) that IROC cars will be a mininum of 2150#'s with Iroc body and Whale tail.

Most recent body style they'll allow on the classic classes is 74 3.0 Carrera RS IROC. FYI, engine size of 3 liters (95 x 70.4 is specified).

If you go too crazy you might have to race on Sports Challenge which is the catch all of everything else.

[Craig 930 RS]

Go big. Put some 3.8 cams in for added hair.

[rdane]

ya, of course it's just a a gussy upped CIS 3.0

[Porsche Doc]

WoW the 3.6 is really jumped a head.
I thought it would be a toss up between the 3.2 and the 3.6.
I am gona use this car mostly to just go have a big time with out breaking the bank. And I love building race cars.
It is really cool to have a job you can do that you love so much.
I feel very lucky get the to do it.
I don't care much if it is compitive or not. Just fast something I don't have to allways work on. I will be mostly be using it for DE's.
I will have leave the winning to my customers. I think its just right!
We have been racing with the PCA, HSR and a little SCCA for the last 20 years. I am well aware of the the rules.
This might be concered an Outlaw car. This car will weight right at 2000 lbs.

If I put in a 3.6 it is a little harder but nice power.
Yes, I will use a Carrera trans I have.
I will have run in GT2R in PCA. The only way I could win is no other cars or there bad luck. BUT who's knows!
I love going to the HSR events, Its like time warp thing to me!
I don't know much about the HSR West, but racing HSR here in the South. Jack Louis HSR Comp Director would stick it in a class kinda with like lap times and type. Running with Real RSR's and like cars. There is no way I would out run them and I wouldn't be elgable for place. But who knows maybe they will all break!
I think this would be the most bang for the buck. Aswell a lot of fun to drive. GooD power to weight TOO!

The 3.2 would be in the same boat as the 3.6 just less power.
And WE know how we all feel about the HP thing
Would run GT3R In PCA.

The 2.7 I have is a nice powerfull engine 220 rwhp and 200tq.
Less TQ than the 3.6 but about the same as 3.2
The 3.6 will put to the ground 250 rwhp and 230 tq with the chip and headers and suppertraps with no plates.
The 3.2 will put down 220 ish and 200 tq the same mods.
It is the closeest to the real deal. For the pureists and classing.
Be a GT4R in PCA I think it would be the most competive in this class.
BUT!
There is a 911 RSR that Garry Boss runs you guy have seen it's white with orange. HELL! Him and that car out runs most GT2 cars. Those guys are fast!
If he didn't shoe up I could do well even win one maybe!
It's hands down fastest GT4R car in the USA.

This project is on going and I have till after Christmass to deside.
Thanks for the coments. Keep them comming!
DON'T forget to Vote! there's a lot of watchers and a lot less voters.
Here is a few pics of some of the cars we built and race.
SeeYa! & HAPPY HOLIDAYS

[Phil Gilsdorf]

Regardless if you will be racing it or not, i think you'll have touble selling an early car with a 3.6. It's a bastard car that is not going to be competitive in any race class. In PCA GT4 at least most of the cars are running the old trailing arm suspension, in GT2 even the best setup early car with a 3.6 doesn't stand a chance against a 993 RSR.