LS7 Boxster? That's what they told me...
 

Got this email today. 500hp NA Boxster? Yes please.

Not a Boxster though. Only a Boxster S. I'm in regular contact with these guys. No kit for a lowly 97 or 98 base model like ours.

sorry should have included the entire email:

Have they told you they will create a kit for a base Boxster? They have communicated with me within the last two months reiterating they need an S's 3rd radiator and bigger brakes for the conversion, although I think the base brakes are fine and the 3rd radiator can be added...

I know it's completely anecdotal, but I've seen more Corvettes and Vipers off into the weeds at the track than any other car. I think these big torqey engines without yaw control can make it very easy to overload the car's traction.

A Boxster with over 400 lb-ft of torque would take either a very patient or very talented driver.

I'd be interested to hear from the guys who track more regularly than I do about this but in my experience, there's a trend.

Hmm. Anyone wanna buy a 3.4 conversion? :) JK I would really have to see the finished product before diving into that. Besides, I only own metric tools. What the hell would I do with a LS motor, I have no clue how to work on it. :dance:

That's the beauty of an LS series motor. You don't have to work on it. The design has been refined over many years and the motors are near-bullet proof.

Plus, the oil changes are cheap!

That's cause American cars are built for the straights. That would never happen in a GT-R

Boxster S vs Elise vs S2000 Touge Test & Track Battle - Best Motoring International - YouTube

Good driving in this video too. He also talks about how... bad... American cars are

From Video: "I like the feel of the S 2000, especially through my dandelion picking / fish scaling gloves" or maybe that was just my thoughts... I have a pair from Italy I never wear that are like putting on another skin.

Bingo! The Chevy LS motor is as bulletproof as it gets. Scott and I are friends and share some of the leadership duties in PCA Zone 8. If he says it's not quite ready... it's not ready. To put one of these motors in a base Boxster I would want S cooling with 3rd rad and larger diameter plumbing, S brakes, and "S" 6spd trans with LSD. The 5spd is not ready for this kind of torque and would overheat and grenade in short order IMHO. Find a nice "S" roller and have at it.

RE: "putting it in the weeds"
Any car with over 400hp is pretty easy to put in the weeds and requires patience and talent. The king is the tail-happy Viper but Vettes and GT3s certainly get their share of Ag time. :)

It's not just the engine power, the Corvette suspension package is notoriously unforgiving at the limit. Also, many LS iterations have oil control/pressure problems when tracked.

Topless:
So the LS series motor will fit within the confines of the 986 engine compartment? Any major mods required to get it in?

Besides the tranny and cooling, any other major issues?

A while back somebody posted about the 4.2L audi v8 as an alternative; plenty of HP but less torque than an LS series.

One reason the LS motors will fit where others won't is the relatively small heads. An Audi V8 with DOHC cylinder heads might well be heavier and certainly would be larger and harder to fit in the engine bay. Even though the LS "only" has pushrods, the redline is within ~500 rpm of my '00 S engine ... and the car would probably be faster even shifting at 3500. The only downsides I can see to the LS motor are that the CG of the motor would be higher, and it wouldn't make those sexy flat 6 noises.

Oh yes! Scott is in the final stages of development on this. He already has an LS powered 996 which had an m96 motor also. The major issues of cooling, motor mounts, trans adapter, electronics are sorted. The devil is in the little details that separate a "project car" from a bulletproof everyday driver. It is close and he has a drivable LS Boxster prototype now. The V8 actually weighs less than my 2.5L. :)

hmmm.........

looking at the 996 install it seems pretty involved. we're not just talking motor mount and transmission adaptors. it looks like most of the ancilliaries are pulled of the ls motor to make it fit - kit requires remote-mounted electric water pump and power steering. it's $7k just for the parts. add a strong motor and you are pushing twice that.

I have driven ZO6 & Vipers and they do indeed have the torque to break the rear tires loose just about anytime the steering wheel is turned. Of course the front engine placement doesn't help.

This is true with EVERY cross-manufacture engine conversion. Physically mounting the engine is the easiest part. Making it function seamlessly is what takes most of the time and money. I always tell people that engine conversions should only be considered by people who intend to keep their car for the long term. Otherwise, the return on the financial investment will never be seen.

As far as an V8 in a Boxster, I think it is going to be a hard sell (for a few reasons), especially when it requires a 6 speed conversion (even more money invested). I think if you are making a conversion kit that can not easily be installed into the early 2.5 cars, you are seriously limiting your market considering those are the most affordable, and most likely cars to be used for conversions.

[QUOTE=Topless;300345]Bingo! The Chevy LS motor is as bulletproof as it gets. Scott and I are friends and share some of the leadership duties in PCA Zone 8. If he says it's not quite ready... it's not ready. To put one of these motors in a base Boxster I would want S cooling with 3rd rad and larger diameter plumbing, S brakes, and "S" 6spd trans with LSD. The 5spd is not ready for this kind of torque and would overheat and grenade in short order IMHO. Find a nice "S" roller and have at it.

More likely a Turbo/Gt3 6-speed if you follow Porsche's upgrade philosophy.

Kcpaz, wise words.
You have already walked down the cross platform conversion path so you know first hand that it is a LOT more complicated than it looks. 1000 little details that make you nuts. It is doable though and I expect Scott will be ready by the end of the year on this.

I would worry about the Boxster S transmission handling 450hp+ on a long term basis. A better choice would be a 996 Turbo transmission. Hey, no one said this was going to be easy.

But you have to ask yourself, why on earth do you need a Boxster that makes more than 450hp? These cars are not meant for drag racing. I can tell you from experience that 400 whp through a Boxster S G86/20 transaxle is very reliable and I will be raising the power soon to see what it can take.

The biggest problem I have with the V8 idea is the low end torque. THIS is what will kill the transaxle more than horsepower. That and driving style... which I think goes hand-in-hand with people who want V8's in their light weight, mid-engine Porsches (broad generalization I know)

I've already proved that the Subaru combination is reliable on a track car, and we are currently working on two street car conversions to prove that the concept works with all of the creature comforts like A/C, a full interior, mechanical power steering, and an air/water intercooler set-up that doesn't require the ridiculous roof scoop.

I have to laugh Kpaz, you ask him why he needs that kind of rear wheel HP then go onto to say you plan on putting more than 400 on your own car.

I noticed that also!

I think the desire for big power is one of those areas where " if you have to ask, you'll never understand".

Time to get out of the 90s.....

Indeed. I've actually taken a ride with Scott in this very car. It's got the LS-2 making about 400 hp. Well short of what you can do with an LS-7. Believe me, it was AMAZING! If I wasn't in CA, i'd be doing this in a heartbeat. It's about $5k for the complete conversion kit plus whatever LS crate motor you want to put in there (figure a nice LS-3 making 485 HP is about $15k).

You get all the benefits of a beautifully handling car, with the power to make it competitive at a very high level on track days. The weight difference is nominal, so it's like just adding pure power to your Boxster S.

Here is the latest video, btw:

Renegade V8 Boxster S Review - YouTube

I know this is an OLD thread, but any updates or additional info ?
I asked Scott @ Renegade about a 987 kit, and while he said it should work, has anybody done a 987 ?
I am basing my purchase of a Boxster on this LS swap, I prefer the 987, but ???

Hi RichInCanada,

no detailed infos about a 987 Renegade v8 conversion, but i would recommend this thread about a 986 Renegade v8 conversion: http://986forum.com/forums/show-tell-gallery/54328-boxsterls376-introduction-ls3-conversion.html

Regards, Markus

Thanks man, informative read, sounds like he'd be the guy to do it !
Just wonder if a 987 is do-able, maybe I'll PM him...