1,600 pounds and LS power!! Brunton M-spec

[subtlez28]

My first exposure to a Brunton Stalker was at a track event, several years ago. The particular car I saw was a Stalker with an LS3. It set fast time of day. It was light, simplistic, and it was powered my my favorite breed of engine. I was racing an LS1 powered 02 Z-28 at the time (the reason for my screen name). I loved the broad power band of the LS1, but wished I didn't have to carry all the Camaro's weight around corners and into braking zones. The Stalker was a car that was less than 1/2 the weight of my Camaro (3,600 pounds w driver), easier to work on, and undeniably faster. I was smitten.


After a couple years of messing with other projects, and even dabbling in off-road Jeeps and UTVs, it was time to get back to the road course. I looked into Cobra replicas, but after digging deeper into the Stalker idea, and speaking directly with one of the owners, Glen, it was clear that the Stalker better fit my wants. And after speaking with Glen, I knew their new M-spec chassis was the way to go. GM LS powertrain, independent suspension at all corners, and a real roll bar that looked like it belonged there. The canti-lever suspension was a huge deal to me. Plus, it is made right here in the good old USA!:flag:

The Classic Stalker uses as solid rear axle (out of an S-10) and front spindles form an S-10 or G-body. These parts are hung on a fabricated chassis on fabricated control arms. The new M-spec uses a CTS rear diff with Miata uprights. Front spindles on the M-spec are also Miata pieces. They good news is that makes consumables like bearings and rotors cheap. And the geometry of the Miata stuff is quite good. Though the pieces seem a bit small for us muscle car guys, remember they only have to suspend and stop 1/2 the weight of even an extremely light muscle car.


We worked out a deal and I flew down to Florida, rented a Penske truck, and met the Mineharts in person. It was great dealing directly with the owners of the company. Glen and Scott are enthusiasts, who know their stuff, and seem to enjoy sharing their product w like minded car nuts. They really made the whole purchase and pick up easy and personalized.


I got to tour the shop, and more importantly got a ride in an M-spec! A quick ride shotgun w Scott made it clear that I had made the right choice. I've had some fast cars, and have had friends w even faster cars. In fact I had just got to drive a friend's new ZL1 Camaro. This Brunton thing blew everything else out of the water! At the time their test car was running a stock, truck 5.3 liter LS engine, right down to the truck cam (though w LS1 intake and headers). My mind was struggling to comprehend what a 6.2 liter LS with say, 500 hp could do!


I couldn't wait to turn my new bare chassis into a running car to find out!!



We strapped it into the cube van, and my brother and I road tripped back to the frozen tundra of Wisconsin.



Picking it up in December meant family commitments kept me from getting started right away. Having it set idle in the clutter of the garage was difficult.











I spent what felt like forever organizing the garage and hanging the body work up on the walls, safe and out of the way. Eventually, I was able to start fabricating some aluminum panels.


Step one, flip it over, and build the floor:





Working with the aluminum was well within the grasp of your basic, do-it-your-selfer.


The pretty bare aluminum and Clecos really made me feel like some pro race car builder. LOL


As a testament to just how light the Brunton chassis is, after building the floors, I was able to just roll the chassis over, and pick it up (one end at a time) and set it on saw horses!



Building the panels just takes patience and basic tools like a jig saw, drill, and clamps. Brunton has videos available to walk a new builder through the process, and are there to answer emails and even phone calls to help you though.


I've had a couple of friends helping me out from time to time, which really helps keep the motivation up. Just focusing on one task or panel at a time keeps you from getting overwhelmed.







I bounced around a little and mocked up the front suspension:





The canti-levers are so well fabricated, I cannot bring myself to paint them!


But I took the rest apart and another friend (networking is key) powder-coated the control arms and spindles.









Wow, according to the date stamp on my photo, this 6.2L L92 has been waiting patiently on a stand for almost 5 years now!! For anyone unfamiliar w the L92 it is essentially the truck version of the LS3. It has the same aluminum block and cylinder heads (though w solid rather than sodium filled valves). The L92 uses VVT (variable valve timing) via a cam phaser. It makes 403 hp in stock form w truck accessories.



Due to the cramped nature of a Se7en chassis, the VVT had to go. That extra 1/2 inch that the cam phaser took up behind the water pump was just to much. The good news is that opens up pandora's box because a cam swap is necessary. I decided to go with a stock LS9 (the ZR1 Corvette's supercharged engine) cam. It is shockingly low priced ($120) and is similar in specs to an LS7 cam. Two friends of mine (andrewb70 and Bow Tie 67) are running LS7 cams in their L92 swapped muscle cars and got 420 RWHP (that should be more than 500 HP at the crank). I also picked up some Texas Speed valve springs.


Bow Tie 67, came up to offer his experience w internal engine work.

Here you can see the cam phaser with the timing cover removed:



Sadly, we were not able to put a cam back in. I had purchased a stock LS7 cam. But when I opened the box, it was not a GM cam, and it was damaged. So, I'm waiting on the new LS9 cam to arrive.









We were able to swap out the valve springs.





And we swapped out the stock rod bolts for Katech ones. This is a supposed weak point of LS engines, so I figure $200 on extreme quality rod bolts is reasonable insurance.


I also installed the Corvette style oil pan (loosely) and pick up. The engine will get a Corvette harmonic balancer and water pump also to clear the chassis.

Side note, I ordered LS9 push rods and timing chain with the cam. Further research shows them to be the same GM part numbers as the L92 timing chain and push rods. Looks like GM puts the good stuff in the truck engines too!