It all started about a year ago, when myself and a friend got into racing Spec Miata. Originally we had planned to just do some Chump Car racing, but after running the numbers realized it was about the same cost to simply build a car to full SCCA spec, and then we could compete in a real league, and would have a car we could eventually sell were we so inclined.

For anyone just getting into racing, the best piece of advice you will ever get is this: start with something cheap, and underpowered, preferably with a manual transmission and rear wheel drive, and never put a car on a track you can’t afford to total. A Miata meets all of these criteria, and you will become a better driver from having one. Doing open HPDEs at Sebring in the Spec Miata against much more powerful, but heavier vehicles like BMW M3’s and Mustang GT’s was eye opening that horsepower means nothing if you can’t drive the line, and ride the absolute edge of traction through the corners. On a tight, technical course like Sebring, a new Mustang’s 350 horsepower was no match for our 220k mile, 95HP Miata in every section but the main and back straight. There is no better feeling than passing someone in a car that costs 1/10th the price, and has 1/3 the power.

Eventually, however, the lack of power will start eating at you. Even though you can blast by people in the technical sections, seeing the Corvette’s just walk away from you in the straights, just for you to catch them again at the next corner is aggravating. So can do you do? Buy a big horsepower, but heavy modern sports car like a Mustang to be in the same situation? Can’t do that; you’re too accustomed to eating corners for lunch in a glorified go-kart. So then you need a car with lots of horsepower, but not a lot of weight. The only modern cars that meet those criteria are exotics, and unless you’ve got $90k sitting around for a used Ferrari, thats out of the question. We’re looking at a budget of $10k to $15k max.

The problem is all cars made after 1990 or so when “safety” became important are HEAVY, even with extensive lightening. The other problem is everything thats old, light and cheap generally has no horsepower and is going to be unreliable. The solution? Buy something old and light, and dump a cheap, powerful, modern engine into it. And so it begins.

The Engine

Right off the bat, we knew we were going to do an LS swap. For those of you already groaning “LS swaps are so played out and BORING” you’re absolutely right. Its the predictable choice. But its the predictable choice for very good reason. If you want big power, in a compact, reliable package, thats also light weight and has more aftermarket parts available than a Honda Civic, nothing else compares. These engines are mix and match, where you can put the heads from an LS 6.0L GTO engine onto a 5.3L so it’ll breathe better. Want more torque? Find some used headers from the Escalade version and slap them on. Need more high-end power? Pull the cam from a Corvette and put it into your Truck block. Its the Mr. Potato Head of engines.

The LS series of engines is also extremely compact, owed largely to it being a simple, push-rod style engine so there are no overhead cams taking up space on the heads so it’ll fit in basically any car you can imagine. And heres proof, using the most common 3 engines used for swaps of this kind into an E30. I know there are lots of variations of the LS and Ford engines, so these are just averages pulled off of Ebay listings for the more common variants. The cost is for a “long block” or full engine and accessories that should just need to be dropped in and have its wires and hoses connected:

Prices vary, but any way you slice it, the LS is going to be much cheaper per pony, plus GM put it in just about every vehicle they made for around 10 years, so you can find 20 sitting in any junkyard in town, instead of looking for very specifically optioned cars. For example, we found ours sitting in an otherwise totaled GMC Envoy 4x4 at a local “pick your part” junkyard which let us pull it out of the truck ourselves and take it away for a grand total of $250.

At this point, anyone who knows anything about LS engines probably just perked up a bit because the vast majority of the 5.3L LS1’s in trucks were iron blocks (heavy), but a select few were aluminum, the GMC Envoy 4x4 being one of them. This is because with the Envoy’s 4x4 system being horribly designed, basically running the front axle THROUGH the engine’s oil pan, there was too much weight on the front end, so they had to use the aluminum block to shed some weight. In fact, the aluminum variant is about 100lbs lighter.

The aluminum 5.3L usually sells for almost double or triple what a standard iron block goes for, but most scrappers who pull engines from junk yards and re-sell them don’t understand that the Envoy 4x4 is the aluminum block, so if you look for a bit, you can find and snag one for $250 at a Pull Your Part place, or just pay one of the scrappers $100 to do it for you if you don’t want to get dirty. Either way, you’ll have a $3,000 engine for under $500. You can also just go with an iron block if the extra 100lbs doesn’t bother you.

The Car

When figuring out what car to use in a swap like this, its largely about personal preference. This is still a budget build, so we wanted a donor that was light weight, had cheap aftermarket and used parts, somewhat modern suspension that

could handle the power, and ideally could be bought for under $1,000. Another requirement was that there needed to be a SCCA spec legal roll cage kit available. Theres an LS swap kit for basically every vehicle ever made (although we will be making our own) so we had lots of options. Seriously, just google “LS swap kit ” and you’ll probably find one, its insane.

Originally we wanted to do a Nissan 350Z but finding one cheap that hasn’t been in an accident is tough. Then we looked at older 240SX’s, but again same problem. Both of these options are also surprisingly heavy. Going with any of the common “drift bro” cars was also something we kind of wanted to avoid, so we started expanding our horizons until we found a 1986 BMW 325 sedan. Theres an entire Spec E30 class in SCCA and NASA, and these cars were prolific in the 80’s to early 90’s so theres tons of parts available in addition to roll cages and suspension kits. Also, weirdly, some of the brake and hub components are interchangeable with our Spec Miata, including the wheels. But the most surprising thing of all was the E30’s weight, which when stripped for racing comes in around 2,700lbs with the dash still intact, which is surprisingly close to the weight of a Miata. Compare this to the 3,600lbs of a Nissan 350Z, a “modern, lightweight sports car”. They don’t make em’ like they used to.

We found one for $800 than ran fine, had a nice leather interior, but had an issue with its automatic transmission. Seeing as how we would be ripping it out anyways, this was a perfect candidate since we could also sell the interior and engine for around $1,000 after removal, making this basically a free car.

Budget so far:

Engine: $250

Car: $800, less $1,000 for parts once stripped

Total: $50

So now we’ve got an engine from a junkyard, and a 30 yr old BWM with a busted transmission. If that doesn’t scream “race car” I don’t know what does. Next I’ll dive into breaking down the engine, and doing a few performance upgrades to hopefully squeeze 400+ HP out of this trash heap special.

I've been doing autocross (SCCA solo racing) for about 7 months now. I dove right in and I've done about 10 events now including a national tour event. Yesterday was the first day I did an instructional school (SCCA Starting Line) for performance driving and today was my first autocross after the school. I honestly feel like I learned more in the school than I did in all of other events combined.

I finished 7th today out of 50 in raw time and 13th out of 50 on PAX, which I'm happy with. But I'm most happy with how much more consistent my driving was. My runs today were 48.7, 48.5, 49.7 (that one I made a mistake on), 48.4, 48.2, and finally 48.1. I improved every run and my times were all pretty consistent. In the past, I would occasionally get lucky and pull together a good clean run, but I would almost never be able to repeat it - so this is a big improvement.

I also felt like I was able to read the course better and decide how I should approach elements without having to ask people what to do. Not that asking for advice is bad, but in general I understood the flow of the course better.

I still tend to overdrive the car a bit more than I should be and I need to work on braking earlier. I worked on that at SCCA Starting Line school too, and I was better about it today. But before the school I wasn't able to as clearly understand where I was making those mistakes. After my runs today I could look back and identify where I lost time.

Anyways, if you read all this, thanks, and thank you again to Mike King for the instruction yesterday. It made a big difference.

Check out more from Ben in our Street mod autocross series on our YouTube Channel.

Sarah and Ben join Grant in Street Mod competition for the season opener at SCCA Jax Solo Autocross. Follow them this season to see who comes out on top! Subscribe!

News

The Engine

The Car

Budget so far:

Spectro Racing ON YouTube

Partners