Calvin Myrick
Vicki Johnson
Senior Project
20 April 2023
How I Doubled the Horsepower of My Volvo 940
Introduction
This article is about what it took to build a reliable drift car to go sideways and take to a track. About a year and a half ago I started to spend more time with my friend Justin Duddie who specializes in the custom fabrication of Volvo parts, and he had found a Volvo 240 for only $900. The goal with his car was to build a very reliable, very fast, very safe and road-legal race car. He started the cheapest way he ever could have and then slowly got carried away and made the most beautiful Volvo I've ever seen. Watching his progress and how far he took it, I began to enjoy the pain that comes with this work, and I wanted to try doing something similar myself. A Volvo 940 turbo showed up on my Facebook, and the next day we went with a trailer and got the car for 300 dollars. It was listed as “not running,” but with a 7-year-old battery and new fuel, it started on the trailer. My end goal with this cheap car was to build a reliable, safe, and fun drift car to compete at a closed course event this summer. I named the car “Ricky the Red Racer.” My biggest tasks and challenges were replacing the turbo and learning how to replace the head gasket. With a lot of time, love and a relatively small sum of money, I was able to replace the turbo, the head gasket, and other features and get Ricky one step closer to being safe for racing.
Initial Challenges
I started to have challenges from the beginning. I drove the car home for the first time and during that drive, I started to see my first problems. My turbo was blown up and leaking oil. The car was leaking every fluid it had– coolant, gas, oil, everything. I had to replace almost every piece of rubber that corroded away. Within a week I had taken everything apart. I installed new high-pressure oil lines. The car had some problems, and I learned how to run gas lines and every little thing I didn't know. One of the challenges was replacing the turbo.
One of the biggest goals to get the car ready to race was to replace to the turbo. A turbo or turbine is mounted to the exhaust manifold, as hot exhaust gasses comeout of the engine they are pushed into the turbine housing. As it turns the turbine, it spins a shaft connected to the other side of the turbo. This side its connected to the intake side of the engine. As more air gets pushed into the exhaust side it spins the intake side and pulls cold air into the engine at a much greater rate depending on how much exhaust is coming through. “A turbo compresses exhaust gas as it exits and sends it back into the engine. The increased airflow sends more fuel into the engine, giving it more power” (“What is a Turbocharged Engine?”).
The Volvo that I bought already came with a turbo from the factory. It was designed to be reliable and good for highway commuting. I had to replace the existing turbo with a higher quality turbo so I could get the wheels to spin faster. So I started with a Garret turbo, a brand in the 90s that specialized in air craft parts for the military. Garrett Ai Research is a company that started with aircraft oil cooling in the 50s and 60s and over the years started making car parts and the best quality turbochargers (Wikipedia contributors). With a bigger housing and bigger ports, more air can go in and out of the turbo. Getting more air in is the start to making more power and changing your power curve. The stock turbo that Ricky came with had coolant lines, but the turbo I was putting in place didn't have to have them. I had to relocate the coolant lines back into the reservoir. I also had to make new intake piping so the turbo would fit and the air would flow as well as it could. Normally the factory turbo runs about 7 PSI (boost/manifold pressure). The best option to change the power curve and make more horse power, is to swap the turbo and the fuel injectors. With a stock Turbo ECU that is plausible to an extent. It can adjust to different amounts of fuel with bigger injectors and is still able to run, but it is hard to monitor.
Getting the right parts for a car is important, and at first I looked for good used parts for Ricky. Going to the online forums is a good way of researching the right size of parts and the companies to get them from. I used the SwedeSpeed forum to determine the right size turbo. The turbo I replaced that stock turbo with was much bigger. Once that was installed, I then installed a boost controller (to control my PSI) and started running 15 PSI. Ricky the Red Racer started around 168 WHP (wheel horse power, how much power is making it through the transmission to the wheel and getting transferred to the ground) and after only that I believe in making around 200. The end goal is 300 to 350. This was the first turbo I put on the car. It lasted 3 months but it started having problems from the start. I should have started with new parts instead of trying to save money with used parts off of Facebook.
Starting Over Again
Used parts aren’t always the best way to go. My new (used) turbo only lasted about 3 months until it shredded itself open. I thought it hadn't been used too much, but I really didn't know what this turbo had been through. I believe I lost oil pressure for long enough to lose oil completely to the turbo. Without oil in the bearing, it was spinning 70,000 rpms with metal touching metal. The waste gate was stuck closed and shredded the turbo. The waste gate lets the extra presser release after you let of the pedal (Griffiths). Its on the exhaust side of the turbo. It threw metal into my engine and began to stop the turbo from spinning. It turns out my “super nice turbo” was blown and was leaking oil into the intake ports and slowly doing damage. I had to fix the turbo yet again, and this time I had to do it the right way. I needed a blowoff valve to release the extra pressure from inside the intake manifold and, hopefully, prevent the turbo from breaking down. But either way, I had to take it all the way back.
I researched for a couple days and I found a cheap and reliable brand “maxspeedingrods.” It is a 68mm bigger turbo than the first replacement and also had a new wastegate. The first turbo I had tried was a used turbo. You never know what you are going to get with a used item. This turbo was a brand new turbo. This brand wasn’t as good as the other one, but because it was new, it didn’t have any miles on it. This alone solved all the problems on the exhaust side of the engine. I did have to replace the flange (a flat metal gasket) which helped prevent exhaust leaks. I spoke with my mentor Justin Duddie, and asked him: “Other than swapping the turbo what is the most efficient way to make power?” Justin said, “A bigger turbo is going to need more air and the factory intercooler is really restrictive. The best thing to do is replace the intake piping and the intercooler so you can actually take advantage of the new turbo, other wise you aren't using it to its full potential. You should also replace your fuel lines and fuel rail so your fuel pressure is consistent.” I did replace all the intake piping to stop the air from leaking, and to get accurate mass air flow readings. This was very important to making the engine run correctly and getting the most from the work I had done.
Replacing the Head Gasket
Replacing the head gasket should have been the first thing I did when I got the car. When you have a car with 295000 miles you are going to need a new head gasket. However, at the start I didn’t know the head gasket was blown. A head gasket is a seal between the top and the bottom of the engine. It keeps the oil and coolant from mixing, and it is incredibly important to the engine's life expectancy. “The head gasket that comes from the factory is only made to hold a certain amount of boost pressure. It’s made pretty cheap and is made out of a soft malleable material and is there just to separate oil and coolant. A high performance or high boost head gasket is made out of layers of metal. Its a press fit gasket that is made to hold a lot of boost” (Duddie). My coolant reservoir was building pressure, so I knew it was time to replace the head gasket. Since the old waste gate was broken, there was too much pressure in the intake system and this probably caused the head gasket to break. So, while I was replacing the turbo again, I started to take the engine apart. I removed the top of the engine and cleaned it all the way up in order for it to seal and not cause more problems. I had to take every little thing off the engine and around it so i could get to the inside of the engine. I removed the valve cover and took out the bolts that held the top of the engine in place. I removed the old head gasket and installed a brand new one from FCP Euro a company that specializes in Volvo parts. While reinstalling the head of the engine (the top half), I had to torque the bolts in a pattern starting at 15 foot pounds, and then another round at 45 foot pounds of torque, and followed with a 90 degree turn with a breaker bar to fully seat the bolts in place. I learned that when you get a car with this many miles the first thing you should check is if your head gasket is blown. It stops your oil from gumming up and breaking down your engine. It's very risky to drive with a blown head gasket. You can severely damage your engine.
Making A Car that Lasts
Replacing mechanical parts is very important, and when it comes to safety, it’s the number one priority. When you get a car or anything for this cheap, you don't really know the history. You don't know where it's been driven or how hard someone was hitting the gas pedal. You have no clue what that car has been through, so you also have to check other things, starting with the safety features. I also checked the seat belts, the brakes, brake lines, I also put new wheels and tires on it. My window wouldn't close when I got the car, and I was missing a front blinker. So, after fixing or replacing all these little parts it is starting to look like a new car. Now I can look more at the performance of the car and doing things like rebuilding the engine so it can last longer. I spoke with Justin about other ways I can improve its performance and reliability. This was his advice: “The Volvo b230 is the most reliable engine that Volvo makes, but if your goal is to push as much horsepower as you can, you should replace the bearings and all the little pieces inside the engine. If you imagine the inside of the engine its metal rubbing on metal, no matter how much oil is in between them it will still start to break down. Replacing these parts before you get carried away will be the best investment you can make in order to make him more reliable.” In addition to replacing those parts, I’m also hoping to replace the ECU (electronic control unit) with a stand-alone ECU, thats fully programmable. Given all I had to do, I haven’t spent too much on it. I got the car for 300 dollars and at the start I spent about 200 more to make it drive. After all the gaskets and three months of time, I only came to the grand total of $1256.00. For cars and the power that I am making, that's pretty good. I can’t even compare to other cars around that price.
Conclusion
If I ever get another Volvo, I will know what to look for in the beginning. I would start with safety features and then work my way into fixing mechanical problems. I also learned that higher end parts will last longer. If you buy cheap parts, you will end up replacing them over and over again. I had gotten the car for 300 dollars and after 3 weeks I fixed everything I needed in the engine bay and then spent another couple of months with all the safety features. The car was driving and I was putting miles on the dash. This was my first rear-wheel drive car that I've ever owned. I didn't know what to expect, but I drove it all winter and made it through. I started around 150 horsepower and after all that I’ve done, I believe I'm around 275 horsepower. Although I hadn't doubled my horsepower, I still have more than enough. I will soon be ready to take my car to Canada this summer and go to a closed course to get Ricky the Red Racer sideways all around the track.
Work Cited
Duddie, Justin. Personal Interview. 4 May 2023.
Griffiths, Gary. “The Ultimate Guide to External Wastegates.” Turbosmart, Oct. 2022,
www.turbosmart.com/news/the-ultimate-guide-to-external-wastegates.
“SwedeSpeed - Volvo Performance Forum.” SwedeSpeed - Volvo Performance Forum,
Tightening Sequence for Cylinder Head Bolts. “Torque Spec Quick Reference.” Yoshifab.
https://yoshifab.com/store/webdocs/torquespecqrr.htm
“What Is a Turbocharged Engine?” Progressive, 2023,
“What Is a Turbocharger and How Does It Work? - Eagle Ridge GM.” Eagle Ridge GM, 16 Dec.
2021, www.eagleridgegm.com/what-is-a-turbocharger-and-how-does-it-work.
Wikipedia contributors. “Garrett AiResearch.” Wikipedia, 14 Feb. 2023,
en.wikipedia.org/wiki/Garrett_AiResearch.