Homebuilt Factory Five 818 vs. factory-built Porsche Boxster | #TBT

Tom
By Tom Suddard
Jan 16, 2025 | Factory Five, Porsche, Boxster, comparison, 818 | Posted in Features | From the Feb. 2015 issue | Never miss an article

Photography Credit: Tom Suddard

Many cars have a clear adversary: Mustangs have clashed with Camaros for years. The Evo-versus-STI feud is still going strong. These pairings are more than just petty rivalries, though–they’re an exercise in measuring performance. After all, what’s a race without a well-matched foe nipping at your heels?

But what about a homebuilt roadster made from a wrecked Subaru? Is there …

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Comments
dculberson
dculberson PowerDork
10/6/17 2:34 p.m.

1000 pounds and 2 seconds faster on a road course. I would have thought the difference would be more pronounced. What does everyone else think?

tuna55
tuna55 MegaDork
10/6/17 2:44 p.m.

Agreed. That doesn't seem like a big enough difference. Same tire compound? 

Robbie
Robbie GRM+ Memberand PowerDork
10/6/17 2:59 p.m.

Same tire compound I think but Porsche's tires are wider by almost half an inch front and back.

Also, the Porsche has more HP, and more than a few years of sports car engineering prowess behind it.

Edit: doh! I only remembered the second half of the statement that seems plenty contradictory:

"Aside from a set of Bridgestone Potenza RE-11 tires, it’s still stock. Our 818 rolls on Yokohama Advan Neova AD08 R tires, making this a fair fight right down to the rubber."

tuna55
tuna55 MegaDork
10/6/17 3:09 p.m.

In reply to Robbie :

Oops missed that.

 

That makes it pretty disappointing.

 

z31maniac
z31maniac MegaDork
10/6/17 3:32 p.m.

Goes to show weight isn't that important if the car can handle it.

Kreb
Kreb GRM+ Memberand UltraDork
10/6/17 4:07 p.m.

I imagine that someone who isn't as dialed in with the Porsche as Shields might find the performance gap to be greater. 

Vigo
Vigo UltimaDork
10/7/17 7:25 p.m.

I agree, but someone with a lot of experience tracking any MR car has got to be closer than average to hopping into an 818 and doing well. 

I think one thing that's not really mentioned here is that the 818 seems intended to be a thrill machine, and it's a little incongruous to have a mostly stock powertrain in it. Add a little 'easy turbo power' and the gap could become fairly huge, especially on a faster track. Not very easy (or cheap) to add power to the Boxster. 

Brian
Brian MegaDork
10/8/17 6:03 a.m.

Track, 818. Street, Boxter. I say that having visited Factory Five two days ago. 

spin_out
spin_out HalfDork
10/8/17 6:25 a.m.

Danny your car is pretty

irish44j
irish44j UltimaDork
10/8/17 3:10 p.m.

 

If we're tossing out the "living with this car on regular roads" and really just comparing track capability, why not compare the 818 with a track-use Boxster S? From what I've read, a Boxster S stripped down to a "track spec but still street legal" (including a hardtop) gets down to about 2500lbs or less.

Also minor bone to pick that I didn't notice on the first read. For the FF you list the power as 225 (wheel) but list the porsche as 250 (flywheel). This is not apples to apples. 250 at the flywheel is more like 210 at the wheel for the Porsche. So anyone surprised about the "more powerful Porsche" being slower, should look again....  At very least you could have talked to your Porsche tuner buddies (I know you must have one) and found out what a typical "wheel" horsepower for the Boxster is.

Side note: remind me what engine/turbo is in your 818? 

In any case, not defending the Porsche per se, but I'm an analyst so I like to see comparitive analysis conducted using the same criteria and rating. I suspect that a 2500# Boxster S with the same level of "track" modifications as your 818 would probably beat the 818 on the track, or at least come close to it. Just speculation there, of course.

Both will badly thrash my 924S on the track, haha (and my WRX will absolutely annihilate it...)

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