Boxster V8

[Nerv]

Hello everyone.

We are designing a prototype kit for an engine swap into the 986 Boxster.

As of right now we are orienting the kit toward the 2.5L (non S) models as they are the cheapest to source and are starting to become more and more common with damaged engines. Even without damage the OEM engine is less reliable than other engines, requiring expensive parts and aftermarket attention just to make them reasonably reliable.

As has been seen online, a few V8 engines have been put in this car with varied degrees of success. The kit we are building uses an Audi 4.2L all aluminum V8 from the same period as the vehicle.

This engine will have a CNC machined custom oil pan designed for drysump with integrated bosses for a mount functionally similar to the OEM Boxster engine mount. We are still figuring out the details for the kit as we produce it, but at this point we wanted to get some feedback from Boxster owners as to whether or not anyone would be interested in this package.

The package will include everything it will require to install the engine in the vehicle with no fabrication or modification required to the OEM vehicle. In this respect, the entire swap can be reversed if desired. The engine will produce around 350HP as a target for the first kit, depending on testing with the 5 speed transmission's strength. The engine kit will have a standalone ECU with programming and wiring designed to interface with the OEM VME so that gauges and all vehicle systems will operate as normal. A/C will be retained, as will power steering, with suitable lines and fittings as required.

From our initial calculations, this configuration should weigh very close to the same weight as the OEM engine.

The Audi 4.2L Engine was selected due to it's light weight, short overall length, matching transmission housing bolt pattern and low cost. By replacing the large cast intake of the Audi engine with independent throttle body assemblies, we hope to lower the weight of the engine further and improve throttle response as well as maximum engine output. The dry sump system will also improve engine output and make the package more suitable for serious track use.

We will be posting photos of the test vehicle as we progress. Any feedback is always welcome!

Nerv

[Deserion]

Best of luck with your project!

Question, though. Is the Audi V8 a bit too large to fit well in the engine bay compared to a GM LSx mill?

[Pdwight]

I want to watch this

[Dlirium]

Great! Always looking for a viable alternative for when my 3.2 eventually goes...a few questions and comments tho..

1) Who is "we"? is this something you've done before with other platforms?

2) Agreed with Deserion - why not go with the cheaper, smaller, lighter LS-x platform? there is even an e-ROD smog compliant version you might be able to work in for those of us in the US that require it

3) I think you should target the S models, they have the 6 speed tranny that can actually accommodate the HP increases we'd like to see. 350 hp is a little light if one is going through all the trouble of a V8 swap anyway. Might as well get the HP as well - especially if these are going to be dedicated track cars.

4) Price point will be very important to differentiate from others in this space. With a lower HP and less "accessible" (Audi vs Chevy) option, I'd be very interested in the "bang for buck" alternative you are proposing.

Looking forward to updates! I have been seriously considering this change for quite some time and would love to see another option!! Please post updates frequently...

[The Radium King]

the ls is smaller? the ls kit from renegade requires cutting the bulkhead, whereas the audi fits with no cutting ...

[jb92563]

Sounds interesting but like the others said, only 350 HP barely makes it worth while
unless the price is cheap enough.

A replacement engine for someone thats had a catastrophic failure for under 6k might seem like a viable alternative.

Much more than that and you could buy a newer used Boxster with decent miles on it and sell the old one as a roller for the racing folks.

What sort of price point are you thinking for this Audi engine.

I assume your talking about a rebuilt, overhauled Audi engine?

Definitely keep us posted on progress with pictures, specs etc.

[Pdwight]

If the entire operation could be accomplished for 4 to 5$ K (not including labor) 350HP would be very attractive to this S owner when one day my Boxer has no fight left in him.

[Dlirium]

Originally Posted by Pdwight

If the entire operation could be accomplished for 4 to 5$ K (not including labor) 350HP would be very attractive to this S owner when one day my Boxer has no fight left in him.

agreed, given that other solutions are that much just for the conversion kit (not including the engine). Best price I've been able to come up with for a mild, 475 hp LS conversion is about $12k, so HIGHLY unlikely this solution will be under $10k.

Note - another thing often left out is the price of the custom exhaust work that will need to be done...plan on $1500 for that too.

[mikeman]

FWIW, if I was going to do the v8 swap, and was on a budget, I'd be looking at a used/refreshed L33 aluminum 5.3 with an LS1 intake and a/m cam. Should be about 400hp, and nowhere near as expensive as an LSx. With the Renegade mounts...


Hmm.. actually that sounds like a good plan.

[Pdwight]

2005 Chevrolet 5 3 L33 Vortec Engine with Computer and Wiring LS1 LS2 LSX | eBay

Less than 350HP

[The Radium King]

also requires cutting the front bulkhead to fit. also requires a transmission adaptor to mate to the Porsche 5- or 6-speed. also requires, because all the accessories are hung off the front, remote electric power steering pump and remote electric water pump. also note that the renegade website makes no mention of the electronic geewhizzery required to make the two work together.

the audi fits, is cheaper, mates directly to the transmission, and shares common bosch ancestry with Porsche. problem is, the audi will be work to get to 350 hp, and a custom intake manifold (itb manifold no less) can't be cheap ...

[mikeman]

Originally Posted by Pdwight

2005 Chevrolet 5 3 L33 Vortec Engine with Computer and Wiring LS1 LS2 LSX | eBay

Less than 350HP

yeh stock...
good little thread over here:

L33 5.3 na performance build recipe - LS1TECH

Here is my aluminum 5.3 build:

18K mile 2007 LS4 (aluminum 5.3 w/799 heads): $1000 for engine transmission/harness/ecm.
LS7 MAF: $60 for sensor and pigtail
LS2 TB, Intake, & Injectors: $375
224/232 DoD camshaft, springs, pushrods: $750
LS7 exhaust manifolds: $150
Reworked stock harness: $50 (for pins and heat shrink)

Never pulled the heads or did any porting, just bolted together and tuned.
So $2385 for the basics, or $1810 after I sold the transmission for $575. Best part is when I break it, I can just get another LS4 engine, swap over the parts and do it again. Resulted in 382whp at 6800 rpm and 335 wtq at 5000

and CarCraft..

Dyno Numbers
Test 1 was the baseline test for the stock 5.3L with a GM Performance Parts single-plane intake manifold, a Holley 750-cfm carburetor, and a set of Hooker 13/4-inch headers complete with a 21/2-inch exhaust system and Flowmaster Super 44 mufflers.

Test 2 was the same engine with the only addition being the Comp Thumper hydraulic roller camshaft.

*snip*

TEST 2
peak HP 433@6800rpm
peak TQ 381@5400-5600rpm

Read more: 325 Chevy Small Block Engine - Bolt On A Cam And Heads And Add 120+HP - Car Craft Magazine

[Pdwight]

That sounds as antiquated as a 8-Track player...Fuel Injection would be the only way to go IMHO

[Nerv]

In response to your initial questions:

"Who is we?"

Nerv Automation: We are a small mechanical design/engineering company here in Canada focused on prototype design and development. Most of our work is oriented in mobile oil-well stimulation equipment as well as automated manufacturing machine control programming and operation. This Boxster is a side project which makes use of our equipment, software and abilities. We felt if we wanted this solution, perhaps others would as well. This is what we would like to know.

"why not go with the cheaper, smaller, lighter LS-x platform?"

Unfortunately, the LS-x, which we initially considered, is not cheaper, smaller, or lighter as a complete platform for use with the 012 transmission in a Boxster application.

Smaller: Not in length which in this application is critical. The only dimension the 4.2L is larger than the original 2.5L Porsche is vertically, and that is only an inch with the stock intake manifold, which will likely not be retained.

Lighter: - It is not, especially when you redesign the intake manifold for the Audi, that manifold is a pretty heavy chunk of aluminum. (We will provide a weight for that assembly for reference later) When the entire completed package weight is considered the engine will work out to be lighter than a LS-x engine setup that works with the 012 transmission. For example, no transmission adapter needs to be used with the Audi, saving weight (and length) from the engine and transmission combination. The Audi has an integrated oil cooler/filter setup that is retained in this design thus negating the need for an external unit and the associated lines for it. These are already included in the weight of the engine that is typically mentioned online, the LSx will still need this.

As far as cost is concerned, this kit is making cost and necessary fabrication some of it's primary advantages. (It is too early to give an estimate price). The engine itself is very economical to buy if you buy a used offering. Here in Canada you only need to go to online salvage yard resource to see examples of this. These engines are very reliable in the state of tune they will be run, and all of them are attached to automatics in Audi's (ABZ 4.2L 32V here in N/A) so they are less likely to have been revved as hard as they a manual transmission vehicle would have been. If you do blow one up, replacing it with another will be cheaper than rebuilding, though rebuilding is possible. Initially we had purchased a LSx with the intent on going this route but truthfully it is more expensive overall and it will be difficult to make it otherwise. Not modifying the car physically in any fashion is one of our highest priorities, while retaining the same weight and balance as the original. Yes, every HP per dollar over 400HP is cheaper relatively with the LSx, but the goal here isn't primarily to make high power. We wish to provide good power output for the base Boxster's existing package (brakes, driveline) while providing a large increase in reliability as well as lowering the running costs of the vehicle and still keeping focus on excellent track ability (A tall order in of itself). The LSx lubrication system is also unsuitable for serious track use without modification and is more difficult for us to modify in the manner we are with the Audi due to engine architecture, this would increase costs of the kit with the LSx.

Another reason the Audi engine was chosen was due to the 5 speed transmission. The Audi does put out less power and torque than the GM LS2 (for example) and as such is going to be easier on the transmission. The 012 5 speed is lighter than the 6 speed and is cheaper. Yes, it is much weaker, but in this application it may be found to be suitable. Obviously there will be no problem using the 6 speed with this kit but we hope to make it possible to use the 5 speed if desired. We want an engine solution for the base Boxster so all 986 cars are covered. If you own a base Boxster and need to replace the engine, we want this to be a logical alternative to keep the cars on the road and out of the salvage yards.

It should be noted though that the Audi engine is capable of higher output than has been quoted here. If the owner wishes to upgrade the drivetrain as required to support the higher output, it can be done. We will have an "S" package suited for "S" cars after this initial kit is complete.

I'll keep you all posted on our progress. The custom dry sump/front engine mount/oil pan assembly is one of the first major items we are focusing on. This will increase the reliability of engine even more and really aid drivers in spending their track budget on more fuel, tires and brakes rather than broken parts and engines.

Nerv

[Dlirium]

Originally Posted by The Radium King

also requires cutting the front bulkhead to fit. also requires a transmission adaptor to mate to the Porsche 5- or 6-speed. also requires, because all the accessories are hung off the front, remote electric power steering pump and remote electric water pump. also note that the renegade website makes no mention of the electronic geewhizzery required to make the two work together.

the audi fits, is cheaper, mates directly to the transmission, and shares common bosch ancestry with Porsche. problem is, the audi will be work to get to 350 hp, and a custom intake manifold (itb manifold no less) can't be cheap ...

I'm pretty interested in the 4.2 because of those reasons above. 350 hp is no slouch either, the hassle to get more HP out of an LSx may not be worth it if this mounts up that easily. How different is the S vs non-S tranny mount? is that part of the issue with starting with non-S?

Be ready to upgrade brakes if you are putting this in a "non-S" as well. I really do feel like, with the good brakes and upgraded tranny, this should start as an S project...

[Tucker2]

Yeah...this is a pretty groovy idea you guys are working on...but I think you need to *at least* keep the S considered in parallel. In the end I would imagine the majority of your demand for something like this will be from S owners. Especially if...as you hint to....you can boost output to closer to 400.

[Timco]

For the cost of this swap, it will need to go into an s to have the brakes and other offerings the s has like 6sp trans.

[Ford68xl]

I don't ususally post, but this topic is one I have been researching for some time. If you were to come up with V8 solution for the base model 986's for less cost than Renegade, then I would be very interested since I already own a base model. For me, 350 HP would be more than enough. Heck, 300 hp with reliability would do just fine. Please keep us posted as to your progress.

[mikeman]

Originally Posted by Pdwight

That sounds as antiquated as a 8-Track player...Fuel Injection would be the only way to go IMHO

Of course..
for engine dyno testing purposes, as in the article, it keeps it simple and repeatable.

[jb92563]

I like where this project is going and it may just make those rollers worth a bit more with a nice power boost as well.

I have an S and think that by the time you get this all worked out, I might want to consider this option as the engine ages and needs major repairs.

The plug and play wiring and tranny connection aspect is very good.

If you can get the price around $6k or less I think you will have a real winner as all the aging Boxsters start looking for new engines.

I'm curious now and looking for info on this engine and found this:
http://www.clubgti.com/showthread.php?244292-Audi-32v-4-2l-V8-engine

Of Note: Lower Reving ~6800? , Good torque midrange