Thinking about the 996 upgrade, need advice please
 

I've decided that I want to upgrade the performance on my '99 boxster, and I'm looking into doing the whole 996 engine swap over the course of the winter months. For starters I have a couple of quick questions, if later on down the line I found out that I'm missing a key element or if someone who has experience in this department could share any info. I would be grateful for any help. I was looking into either the 3.4 or the 3.6 upgrade, and was questioning which would be the best choice, and why? Another quick question pertains to the transmission. Currently I have the standard 5-speed tranny, and I've read from others who have completed this swap about the power loss with the original 5-speed transmission. I heard to remedy this would be to drop in an S 6-speed tranny. Could you actually substitute the transmission from the 996? Or would it be best to stick with the S transmission. Also, if I could do this in steps that could make this transformation a little bit easier for me, for example swap the transmission in the near future, then the engine swap in Feb. or March like I intend on doing.

Thanks for any help provided.

P.S. I forgot, which companies should I stay away from and which would be my best bet to discuss this project with? Thanks again.

HB

I believe your only choice for a 99 is a 3.4 liter. The 3.6 liters use E-gas, which only the 2000 and later Boxsters used. As for the stock transmission, I see no reason you can't use it - I've never heard of any power loss from the transmission. I do know that you have to get a different clutch.

I'm pretty sure if you want to drop in a a 996 or S tranny that you will need new halfshafts, as the base Boxster uses different size shafts than the other two. The only other issue I've heard about is cooling. The S and 996 both have 3 radiators, while the base Boxster only has 2. However, you can install a third radiator - I believe the kit is called the GT3 radiator kit, or something like that.

I've heard of people having good luck with Roock in Atlanta. However, keep in mind that it is a well documented process, and if your local mechanic is adventuresome, you could probably save some money. I know Roock charges something like $14,000, and they keep your old engine. If you did it yourself, you could probably find a used 3.4 liter engine for under $10,000 and sell your original engine on top of that. However, there are some pieces that Roock uses from the old engine that you would probably have to buy if you wanted to keep your original engine in saleable condition.

So far I have found out that 97-99 models you would have to change the transmission, driveshaft, upright, and add a 3rd radiator. I also found out that I could not use the transmission that comes in the 911, so I would have to use one from the Boxster S.

Seems to m that by the time you do this entire thing you should simply buy the 996!

http://boards.rennlist.com/upload/996C4015.JPG :rolleyes:

I'm not too crazy for the 911, unless it was a 911 turbo. ;) I bought the used boxster with the intent on doing the 911 turbo upgrade.

Every person I've heard of that has done the swap on a base Boxster has kept the stock 5-speed. I'm not sure why you think you need to swap trannys.

Hi HBacura

Been thinking of doing the 3.4 engine upgrade for a while, do you think two purchase from the same company, we can get a discount ?

I have 1997 2.5 tip

Read up, plus the S tranny is a stronger transmission then the base model tranny, which results in less power loss. I was also told when upgrading to the 3.6l the S would be better because the 5-speed can't hold the added torque as well.

https://rennlist.com/forums/showthre...threadid=34249

and

https://rennlist.com/forums/showthre...threadid=34893

Just curious about that statement- if you don't mind my asking...Besides the turbo, What exactly does the 911/996C4S not have that the 911Turbo does?

As far as we can tell its the same car, brakes, body, etc. less the turbo.

After reading the posts, it seems that you only lose, at most, 8 hp from the 5 speed vs. the 6 speed. I guess if that is worth installing a new transmission and halfshafts, go for it. My point was that a transmission conversion is not strictly necessary for doing the engine upgrade.

Of course, this is upgrading a base Boxster to a 3.4. The only 3.6 conversions I've heard of started with a Boxster S, so I suppose if you were going to go to a 3.6 in a base Boxster, it would be worthwhile to do the tranny upgrade.

However, in that case, it would probably be cheaper to sell your base Boxster and buy a Boxster S. You can find high-mileage S's in the high $20Ks these days.

The body from the turbo grasps my attention unlike the other 996s with it's rear air ducts. I know you can buy a body kit with them, but that's one reason. I'm not to crazy for sports cars that have a back seat even though I know you can fold them down. Plus when the rear spoiler of the 996C4s isn't engaged, I don't like the way the car looks. I don't really like the layout of the 911 being rear engine rear wheel drive. Mid-engine rear wheel drive has a much better advantage in the handling dept. then that of the bigger brother. I'm not trying to say your car is ugly or anything, these are just my personnal opinions. I do like the fact that the 4 does come with all wheel drive. If there is a way to keep the rear spoiler up at all times with the body kit from Gemballa I might end up taking in consideration about buying a 4 and making that my next project car later in the future.

I don't really like the layout of the 911 being rear engine rear wheel drive. Mid-engine rear wheel drive has a much better advantage in the handling dept. then that of the bigger brother. I don't mean to be facescious but why not didn't you say that in the first place instead of making up those excuses. How often do you ever intend to drive the car at the extremes where the polar moment of inertia will be a factor in the handling of your mid-engine car or are you just putting in the 996 engine because your car is rather ...er ahhh... slow (no offense). My point is for all the money you will dump into soemthing like engine, tranny, and labor (be it yours or someone elses) a Boxster could be stepped up to 996 engine performance level with some realitevely less extreme perfomance mods- like super charging for example.


The body from the turbo grasps my attention unlike the other 996s with it's rear air ducts. C4S is set up the same way, with rear ducts no bodykit required.

I'm not to crazy for sports cars that have a back seat even though I know you can fold them down. That is pretty tired and lame because the back seat can easily go away for less cost than swapping engines and transmission and there are NO BACKSEATS in the new GT3 street 996's.

Plus when the rear spoiler of the 996C4s isn't engaged, I don't like the way the car looks. So leave it in the up postion there is a switch inside that lets you do that

So is this the photo of a turbo or a C4S


https://rennlist.com/forums/attachme...&postid=665421

Hey,DoubleNutz...That mid-egine design makes for a totally different driving experience compared to the 996.I'll take a Boxster S over a 996 any day(that's my opinion)Not to mention thats there room to grow in performance with mods(ecu,intake,headers)to be as quick as a 996.I know of many others that chose the Boxster over the 996 as well.

DoubleNutz, I know the boxster is slow...hell I mentioned that in another thread that Helen started asking why you bought your boxster. But, lets talk about that good ol performance of the C4 for a minute. I don't know what type of person you are, but don't pick up the latest sport compact mag. Trust me IT MIGHT HURT YOUR FEELINGS. In a nutshell they compared 4 cars, one being the C4 and another being a freakin 34k mitsu. evo lancer. That 34k Lancer spanked the hell out of the C4 and what you paid plus 80k for your ride. It got spanked in accel, quarter mile time, 0-60, 60-0 times, slalom, skidpad, and freakin overall course time. Damn shame isn't it...a 4 door sadan spanking a car like that. So my question is why did you buy that C4??? Was it for status (which I could care less for status) or for performance (gee I hope not cause by the looks of things if you pay over 80k for a car that gets it's ass handed to it by a 4 banger with 4 grand worth of upgrades) doesn't say much about performance of your ride. Pretty much all you could say is "well at least at the end of the race I get to drive home in a porsche" I thought the whole flagship of porsche was supposed to represent great past time performance. Well maybe it was just the past time. I can't say that with the other better models like the 911 turbo, gt2 and 3, and the all new beauty carrera gt that's about to hit the shores. And, most of us know that porsche maintenance can be quite costly, so we don't drive our babies everyday unlike the EVO which is a great daily driven car (that again for some reason is a better performing car then the C4). Don't get me wrong that EVO IMO doesn't look to hot, but damn it owns the 911 C4 in every performance aspect there is. Now me with the boxster knowing that it is slow, and knowing just about everyone else knows it's slow. I have a great advantage dropping in a 911 engine, thus making it an ultimate sleeper just for ppl like yourself thinking that I would have no chance if it came down to a race. Not trying to burst your bubble or anything, just pointing out some real life facts. If anyone doubts this, just pick up the latest Sport Compact mag. and you'll see the results.

IMO This is hot

http://carad0.ipixmedia.com/abc/cara...124554-1_L.JPG

This is not

http://216.12.218.4/y2k-usa/03C4SSil293mi/MVC-001S.JPG