3.6 conversion advise needed

pjv911 · pjv911's Garage

In january I will be doing a 993 euro 3.6 conversion on my 69`. Im currentely seeking info on which transmission to use. I would like to use the 915 so I can keep costs down but I dont want to be limited as far as horsepower goes. I also plan to supercharge the motor the following year so the G50 seems the only logical choice. I have a local machinist who has shortend the mainshaft and housing on a G50 so it could fit behind the torsion tube in his sons 3.6 powered 76 euro car. He said its not so bad costwise but did not elaborate . I also think I am forced to use the G50 because of clutch holding capacity once over 400 hp. I will be dealing with Dr timmons so im sure when asked he will point me in the right direction. I just dont want to sound like a dreamer since it wont be till winter when he converts it for me. Any advise would be much appreciated. BTW is there a 6 spd that will work ? Is there any advantages ? Also what shifter do I need.

Kurt Williams

pjv911 · pjv911's Garage

bump

widebody911 · widebody911's Garage

Have to talked to Dr Timmins about your plans? I don't think there is anyone on the planet who knows more about 3.6L conversions (JEP III included)

pjv911 · pjv911's Garage

I just didnt want to give him the impression that im dreaming. I would do it now but I want to drive my car this summer. I dont know what kind of guy he is as far as conversation goes. I own a performance shop and deal with dreaming kids every day asking to many questions only to never hear from them again. I just dont want to come across like them. Im also considering just buying a nice rustfree roller rather than taking apart a perfect running 2.7 car. I would like opinions from this board as well as steve`s advise. It cant hurt to hear what others think.

Kurt Williams

glickster · 06-15-2002, 07:08 PM

My 3.6L conversion was performed last winter by DeMan Motorsport in Nyack, New York. Since my car already had the G50 tranny, we stayed with that. I do have a G50/50 (turbo) pressure plate mated to my clutch.

Rick DeMan is currently building an RS clone with a 3.6L for a customer.

My engine screams. Recent dyno showed 258 hp at the rear wheels (approximately 300 hp at the flywheel). Torque is over 241. I've got a chip, lightened flywheel, sport cams and some other doodads in there. If you'd like to come up from Long Island and have a look, let me know. If you are planning on attending next month's DE at Lime Rock Park (July 11-12), I'll be there.

Since you are open to suggestions, I would go with a 5-speed turbo tranny, G50/50 (as you are planning on supercharging in the future). Good luck!

CBRacerX · CBRacerX's Garage

I'm doing a 3.6 conversion on my '87 (working with Steve Timmins). What flywheel clutch and pressure plate (I know you mentioned the G50/50 PP version) did you use? We are trying to decide this now and your information could be very helpful!

BTW, did you do a 993 engine conversion or a 964 version? Great HP numbers!

Thanks,

Chris

Jack Olsen · 10:48 PM

Do a search here and on rennlist, using the user name Swampmonster as a search term. Swampmonster is a guy named George who has some kind of massively boosted V8 in his car. If anyone knows about snapping axles and other driveline components, it's him.

I think the basic wisdom is that you'll be well-served but broke if you do a G50 conversion, happiest if you do an 8:31 915 with some common sense mods (cooling, mostly), and that you'll sleep best at night with a tough-as-nails 4-speed Turbo box.

The G50 is very expensive, involving everything from reconfiguring the torsion bars to creating a hybrid pedal cluster to accomodate the different clutch. It's also heavier than the 915. Talk less to Steve Timmins, and more to Jim Patrick, if you hope to do this mod.

The 8:31 915 is allegedly good up to about 400 hp (maybe more, I haven't done much research on it). In my opinion, it makes the most sense for your application, but then it's the box I have, so take what I say with a grain of salt.

The four speed turbo transaxle is durable and, unfortunately, geared in a disappointing way. There are only four gears in it.

My .02

Jack Olsen · 06-15-2002, 10:54 PM

Here's Timmins' website's view on it:

Q: Which Transmission should I use? Can I use a 915 or do I need a G50?

A: We prefer the 915. For a clutch we use the Sachs Power Kit.
* 915 is fine up to about 300 HP. Although the G50 is s stronger box, plan on an additional $4,000-4,500 if you convert to that as well. That includes $2000 for G50 and rebuild, $2,000 in conversion parts.
* A G50 is 100 lbs heavier than a 915. On an average 911 that's like reducing the HP by 3-4%. Remember F=MA?
* The choice is up to preference and budget, but the 915s work well.

pjv911 · pjv911's Garage

Has anyone had experiance with supercharging an early car ?

CamB · CamB's Garage

Supercharging the early engine? Personally, I wouldn't want to risk a magnesium cased engine with forced induction.

Also, are you intending to use your '69, or a roller?? It might be easier to start with a '72 or '73 if can because there are a few things which fit better (915 and suspension, I think?).

Also, my '69 is getting its drivetrain replaced with a 3.2 and 915, and there were a few ways in which the '69 was lacking - mostly electrical (unusual engine bay harness) and (on a T) no fuel return line - Webers don't need it, plus the gauges are held in by little screws not the rubber ring. This means they are a b1tch to remove and replace, and the mechanic needed a few goes (out for refurb - in to check, out again, in again)...

I think someone more experienced than I needs to give some guidance as to which year (if any) is easier.

dean · 06-16-2002, 04:33 AM

That is what I would do if I were you. Oh yea that is what I did.

Turbos are better than supers ;<)

Let the flamin begin

pjv911 · pjv911's Garage

CamB :
Im talking about supercharging a 96-98 3.6 with a G50 tranny in an early car. No magnesium case there. Has anyone ever built a 450 hp 2300 lbs street driven early car ?

Blown : I would think of turbocharging but I want instant responce ans ease of installation.

Kurt Williams

Bill Verburg · Bill Verburg's Garage

If you are serious about spending the $ for a supercharger then spend a bit extra and use a G50. I would also use coilovers and a cage tied into the suspension mounts to avoid the problem of torsion bar room at the trans (additionaly this opens the possibility of using a 6 spd).

None of this is necessary for a n.a. 964/993 swap where an aluminum case 915 is desirable and a mg case will work ok for a while.

glickster · 06-17-2002, 04:03 PM

CBRX,

We mostly used parts from Patrick Motorsports, including the lightweight flywheel, etc. Tell me what you need to know and I will get the part numbers for you; OR, you can call or email Rick DeMan at Demanmotorsport.com/ (845) 727-3070. That's in New York State.

He's the "guru" that did my 3.6L conversion. Very knowledgeable. The dyno readings are off of DeMan's dynamometer after installing the new clutch & G50/50 PP.

From what I hear, Timmons down in Delaware knows his stuff. For people doing 3.6L conversions on the left (west) coast, I recommend Steve Weiner in Oregon. He's also extremely knowledgeable and a real nice gentleman.

Good luck.

CBRacerX · CBRacerX's Garage

I appreciate the reply. My interest is in first what ring gear, clutch and pressure plate (you mentioned G50/50 here - a part number would be awesome!) you used. Seems like the flywheel is a Patrick Motorsports item - period. And that's ok, he makes nice stuff.

How about the intake - are you using a Varioram?

And exhaust, did you use 993 heater boxes or B&B or GHL or ???

Gee, I'm just full of questions, aren't I?

Thanks very much for all the help!!!! I am psyched about this conversion and your experience sounds great!

Chris

Wayne 962 · Wayne 962's Garage

Money-wise, you guys are talking some major dollars here. To install, and supercharge a 993 motor in your early 911 would probably cost $25-$35K when you're complete and done. Little stuff adds up to a lot...

-Wayne

glickster · 06-17-2002, 05:31 PM

CBRX,

Mine is a '90 964 3.6L. The SSI's from my 3.2 hooked right up. They run into a Dansk stainless steel dual in/dual outlet exhaust.

Several very knowledgeable folks have stated that the SSI's would be too constricting, and that I am in effect "choking" the engine. I'm pretty satisfied with the performance I've obtained thusfar, but I can also appreciate what those "gurus" are saying. I'm certain that if I ran with headers and supertraps (a true "freeflow" exhaust set-up) I'd easily be making something like 285 hp at the rear wheels instead of 260.

But, I drive my car on the street (actually drove up to the Watkins Glen DE and drove back home), so the headers, etc., are not realistic at this point. Believe me, it's loud enough right now. While I like my Dansk muffler, if I were starting this project from scratch, I might opt for a Monty stainless steel muffler. I just really like the way the Monty looks & sounds. But, I had the Dansk hooked up to my 3.2, and it all works just fine, thank you, with the 3.6L.

Internally, I've got Webcam's 993 "supersport" cams, heavy duty valve springs and rod bolts. Did I mention the chip? Redine is 7,000 rpm, with the "rev limiter" in the 7200-7300 range.

I'll get the additional clutch (parts) info for you in a day or so. If you're in a hurry, feel free to email Rick DeMan. He built the thing. Tell him what you're doing and that we've been chatting. Good night!

Jack Olsen · 06-17-2002, 05:52 PM

I put a stock 3.2 exhaust on my car (with a flowmaster) for about a year, and wasn't at all disappointed in the engine's performance with it. Getting the B&B headers added a lot, in terms of throttle response and top end, but that was just an extra bonus on the already-great performance of a stock 3.6.

If you don't do your upgrades all at once, you get to appreciate each one of them.

CBRacerX · CBRacerX's Garage

I'm curious to speak to someone who has done 993 heater boxes on an earlier engine (by either rotating the flanges or installing new exhaust studs) and made a catalytic converter fit on a 84-89 car. That is my current thinking, and I have looked at the 993 cat - it appears that it would fit in the engine compartment, but leaves no room for a muffler. So... the cat would have to be the muffler, with some swoopy outlet pipes made to come back under the rear valence.

Anybody got the goods on something like this?

Thanks!!!!!!

-Chris

JonT · 06-18-2002, 06:59 AM

I may be doing precisely this if I can't get my 993 headers to mate to my B & B dual in/dual out without too much work. You're right--no room for a muffler with the cat so it may be pretty loud, but I like it that way. I'll post as soon as everything is up and running.