Hello Everyone! I recently Joined the forum and wanted to make a build thread to introduce my 1970 Oldsmobile Cutlass S, aka "The Oldsmobeast." The story of this car really starts out in the mid 80's, when my father was a teenager. He wanted to get an old muscle car to work on, so he saved up working odd jobs, and was able to buy an aspen green 1970 cutlass supreme convertible from his neighbor.

After working on the car for a few years the day he got his license the '70 vert burned to the ground due to a cracked rubber fuel line, which was sadly caught on camera by a neighbor!


Following the heartbreak of this incident, my dad was able to buy a '67 442 from someone in the town he grew up in, and still has the car to this day.

When I entered my early teenage years, I wanted to follow in my father's footsteps and find an Oldsmobile of my own to work on. Being a young kid, I worked what odd jobs I could and saved every penny from birthday and Christmas to try to get some money together.. In late 2011 I had around $1100 saved up and stumbled across an astro blue 1970 Cutlass S on eBay, located around 45 minutes from me which was listed for $1500. I asked my parents to borrow the $400 difference, however they told me that since my birthday and Christmas were only a month away I should wait and would have the money then. To my dismay, the listing for the '70 disappeared two days after I had seen it. Heartbroken that I had missed out on that car, I decided to postpone my search for a car until after Christmas. Fast-forward to Christmas day, and I was excited to add a little money to my project car fund. After opening boxes of socks, a calendar, and small odds and ends, I finally made it to the last box I had to open, which was a small jewelry box. I immediately ripped it open, and did not find money, but a square and an oval key. My dad said that he had decided to give me our old 1977 GMC Sierra truck. Excited, I ran out back to try to open up the door to my new project. However, when neither key worked, I walked back out front and to my amazement, that astro blue 1970 Cutlass was sitting in our driveway.

My dad had gone to look at the car the day after I showed him the ad, made a deal that day, and then hid it in our neighbor's garage. Our original plan was just to make it drivable, fix any structural rust, and create a car that I could cruise around in. We started by pulling the car off of the frame to fix the floor/trunk rust as well as clean up the frame. We also decided to replace the tired 350/th350 with a 330 we found online, and backed it up with a 2004r transmission.



Following this I spray painted the car black to make it all one color, and would touch it up as we did metal work on various areas of the car. We went through the wiring to make sure the essentials functioned (lights, brake lights, turn signals, etc). and I was finally able to drive my car! I drove it like this for around a year.


The car was a super reliable cruiser, however we still had more work to do to clean it up, so we decided to move onto fixing the rot in the quarters and rockers.



Now that most of the metal work was done, I decided I wanted the car to have more power! So during senior year of High school I bought a 455 core, and swapped in a new rear end, which was a 3.73 posi. I slowly began to collect parts for the 455, and near the summer of 2016 I was finally able to put it in the car.

Now in college, I decided I wanted to focus on making the car look a little more complete, so turned our attention to the paint. I got an all fiberglass w-25 hood off of craigslist for around $150 (It had been cracked in half) which we combined with a steel hood to make a steel bottomed W-25 hood. Whenever I had free time I would drive home and sand on the car. after months of sanding and bodywork, she was finally ready to paint! We build a homemade paint booth in our driveway and decided to repaint the car in twilight blue with black stripes, as I preferred the look of that color over the factory astro blue. Around this time we also decided to do a pro touring build with the car, with the intent of racing it on road courses and autocrosses some day, so we added in a competition engineering half roll cage, corbeau cr1 seats, the UMI Performance cornermax kit, UMI tubular rear control arms, UMI sway bars, UMI rear lowering springs, and forgestar f14 wheels (18x10 rear and 18x8.5 front.)








once the paint was complete I reassembled the car and decided that I just wanted to focus on driving it for a bit, and not worry about continuing to work on it. The car was around 80% done, however it still needed certain trim pieces and interior pieces to be complete. Around this time I swapped a th400 (on loan from my father's 67) to handle the torque of the now 463 BBO. I then cruised the car like this for around a year and a half, until an amazing opportunity came up. A journalist for the hot rod network reached out to me and said he wanted to feature my car in car craft magazine! I was excited for the opportunity, and realized that I now had to put the small missing pieces on the car. We spent the winter of 2018 wrapping up small misc. things that needed to be done on the car so that it would be ready for it's feature shoot, which also included adding a few new things like a holley digital dash and holley sniper fuel injection. The magazine shoot was done in march of 2019 and it was featured in the December 2019 issue of Car Craft Magazine!


After the magazine shoot, the car remained unchanged for the next year and a half, as I focused on just enjoying the car and finishing college, which brings us to the summer of 2020. Once I finished college and started my first proper job out of school, I finally had the means to do the last few things I wanted to do to the car. These things included a t56 magnum transmission, Sparco racing seats, fully boxing the frame, an 18x11 squared wheel setup with 315 tires, and bigger wilwood brakes front and rear. We began the latest update of the car in December of 2020, and are actively still working on it!







For those interested in following the build, I have an Instagram page (The_Oldsmobeast) as well as a YouTube channel (The Oldsmobeast) which both document the build of the car. I will update the thread as we go along, as we are only a few weeks away from getting the car back together! we are scheduled to be competing in the northeast musclecar challenge in September, as well as various good guys autocrosses throughout the year.

 

Here are some more pictures, as I was limited to how many I could put in the original post!

 

Nice transformation and very cool story.

 

Cool car! Any idea what the Olds engine puts out HP wise?

How is the Holley EFI system working?

 

Thank you!

 

Thanks! No idea what it currently makes power wise. I'm hoping to get it on the dyno in early June (once the clutch and transmission are broken in).
Here are a few more specs:
463 CI
Edelbrock performer rpm heads (stock)
Edelbrock performer rpm air gap intake
Crane cam, part # 800661, .536/.560 lift, .238/.248 duration @ .050
Eagle cast crank, Eagle forged rods
SRP flat top pistons
Harland Sharp roller tip rockers
Mondello Pushrods
Canton racing baffled oil pan
Melling high volume pump
Compression ratio is approx. 11.3:1 with the current Cometic head gaskets.

And so far the Holley efi has been great! its been on the car around 3 years now, and aside from having to deal with rfi issues at first, it has been very reliable. The car fires right up, idles great no matter the conditions, and has fantastic throttle response. I also use the efi system to control the dual electric fans as well as the ignition timing, which it does a great job of doing.

 

Nice job, I really like the interior changes you made.

 

Great story, I really enjoyed the history of your journey with the car. Good work!

 

OMG that ragtop burning is just tragic. Breaks my heart. Glad to see you both kept your Oldsmobile drive.

Great job on your car. I really like that you kept the bones. Love the colors. Looks great. Factory console. Like I said I like that it still looks Iike a 70 Oldsmobile. It looks like a great driver. It looks like you built it for you. Not a purists car. Good for you.

 

The car and paint look great I like the story and the upgrades youve done...couple more iterations and youll need to start tracking your vertical mileage

 

Thanks, and definitely! This iteration probably still won't be the last one!
Thank you! I wanted to maintain as much of the factory interior appearance as possible, only changing what I needed to make it capable on a road course!
Thanks!
Thank you!

 

She’s a beauty, nice job.

 

Great Story and awesome car.

Can you tell me more about what RFI issues you had and how you fixed them?

 

Thank you!
Sure! Our primary rfi issue was that the car would suddenly lose all sensor information while running, and cause the car to stumble. the issue would only last for 1 second and randomly occurred, but still needed to be immediately addressed. We rerouted a lot of the wiring, moving it as far away as we could from any "noisy" wiring, such as the coil, distributor, etc, which resolved the issue.

 

Nice car!
I can relate to the car burning. I had a '68 Toronado when in high school that needed a valve job. I exchanged the heads for remanufactured, cleaned & painted the upper half of the engine, engine compartment, etc. It was beautiful. All I needed was a new carb. While I was at the auto parts store, my brother tried to move the car with no carb on the manifold. I did not disconnect the battery because I would be back in less than 30 minutes - big mistake. My brother just kept cranking & the fuel pump kept pumping until the fuel vapor & the spark found each other. The whole engine compartment went up in flames. I arrived to find the local police & fire there, with a garden hose inserted into my intake manifold & water burbling out. Very depressing. I did rebuild it,

 

Thanks, and sorry to hear. Glad you were able to rebuild it!

 

Very nice! Love your car. Not sure how I missed this. I sent you a PM too. I have some random questions about your 18x11 BFG Rivals S 1.5s on the front. I finally ordered my 18x11s for the front and plan on running the same tire for track days. My question is - how are these for street driving? I will be using them for autocross and I'm sure for that they will perform very well on dry track days. But how about on the street? I saw some of your videos where you are driving on back roads. Are these tires as harsh as I've heard from others? Do you feel every bump in the road? Also what about highway driving? Do you have issues with tramlining?

(Tramlining is the tendency of a vehicle's wheels to follow the contours in the surface upon which it runs. The term comes from the tendency of a car's wheels to follow the normally recessed rails of street trams, without driver input in the same way that the train does.)

.....with the 315s where the steering wheel turns in your hand pretty hard with the grooves in the highway? I read some negative feedback on the Rivals S 1.5s for harshness on the street and really bad tramlining with wider front wheel/tires combos (over 275 fronts). Was curious if you have experienced any of this and if so how bad it is.

Thanks!
-Joe

 

Very nice car. I've seen some of your YouTube videos and hoped that you were a member here. Just found this thread myself and now know the back-story on this car. That's a great bait-and-switch your dad pulled on you. Keep up the good work!

 

Just replied to your message! The rival s 1.5 isn't too bad on the street, it's no worse than the other 200tw tires as far as noise and harshness on the streets goes. My car is pretty rough on the street, but alot of that is from the chassis stiffness (solid body mounts, high spring rates, etc), and not really from the tires. I don't put too many miles on my car since the alignment will eat up the tires if I drive it often, and I've been too lazy to change the alignment between a street setup and an autocross/road course setup. The car likes to tramline a little bit, but most of that is from the alignment, and not the tires. It tramlines just as much on the 315s is it did when I ran a 255/35/18 front tire on my old "street" setup. The car likes to naturally follow the grooves/crown in the road, but it never grabs the wheel out of my hands or anything extreme like that.

 

Thank you! I'm not on this forum too often, but figured It would be fun to hop onto an Oldsmobile forum once in a while. And agreed, my dad definitely had me fooled!

 

Well I know it’s been a while since I have updated the thread, but here we go! I got the car back together in mid june, and tested it out on the lime rock autocross track the following week (the video is available on my youtube channel). Sadly a month of rain killed any local autocross plans that I had. I also had to sort out a bad wheel hop issue, where the car would violently shake under heavy braking. In september we brought the car out to the northeast musclecar challenge at PITT Race, which is a three day competition consisting of one day of road racing, and two days of autocross. My dad and I were co driving the car for that event, but sadly after my dads first session we had numerous issues, with a coolant hose splitting in half, and having oil pressure issues. This winter we are pulling the 455 out, and deciding what to do next. My main goal for this winter is to make the car more reliable and sorted, so that I can run a full season of events next year. Here are some pictures from this summer/fall. Ill post this winter as the car is updated!

 

Hi Pat - thanks for the responses and great pics! You mention "high spring rates" - curious what rates you're running front and rear if you don't mind sharing. I saw in one of your videos you're running the UMI kit and I see on their website they mention spring rates up to 850. Wondering if you're running with 850s front and if so what rate in the rear?

Thanks!
-Joe

 

No problem! Im always happy to talk about pro touring stuff. I am currently running 850 in/lb springs in the front, which is what comes standard on the coilovers in the UMI cornermax kit. UMI runs 1100 in/lb on the front in most of their cars, so I’ll probably order a set to play around with. In the rears im currently running 140 in/lb (non coil over setup). When I make the move to the rear viking triple adjustable coilover in the spring, I’ll probably go to 180 in/lb for the rear to start, and adjust front and rear springs as I dial in the car at each event.

 

Thanks Pat! Appreciate you sharing. As I mentioned in the PM I'm running MUCH softer springs for the reasons I explained (Mark Savitske setup/suggestions). Since most of the other highly competitive GM A body autocrossers out there with stock frames are running similar setups to yours, I may need to eventually change to a much stiffer setup but want to see how it does "as-is" first once I finally get out on the track and start dialing everything in.

-Joe

 

No problem, happy to provide insight! Yeah alot of choices like spring rate, shock settings, etc have some science behind them, but are more often changed by “feel”, so I’ll be going though the same process of feeling out the suspension as I do more and more events, and make setup choices based off of that. I have seen people have success on “super soft” springs, and also people that have had success on insanely stiff ones!

 

That makes sense. I also wonder if running regular springs vs coilovers makes a difference in spring rates. Intuitively it seems like the much smaller coilover springs might need to be a little stiffer vs a full size spring. That was another thing Mark preached about. He said coilovers were/are the hot thing for everyone to run because they are so easily adjustable but he argued if you dial in the right standard spring height and rate combined with a high end adjustable shock, the regular spring would be better for lots of reasons. He talked about the weight of the car on the spring vs. the shock and how when most people adjust the coilovers for the ride height they want, the spring/shock combo is usually compressed too much and you don't get max performance out of the setup. Of course almost all high end autocrossers are running the coilovers front and rear it seems.

 

yeah in theory you could mimic a coilover with a coil spring and good adjustable shock, but you get the ability to adjust ride height, and therefore corner balance the car with coilovers (or some kind of weight jacking setup). Spring diameter shouldn’t be have an impact, if anything the smaller diameter spring is lighter, and as long as the shock/control arm is designed to handle the force, it will all be fine.the angle that the spring is mounted at will play a role though, as the more upright the spring is, the more rate will be required (since the force into the spring is directed in a more vertical manner). I agree about the spring/shock perhaps being better on the rear of the car though, as the stamped-steel shock mounts in the rear of the A-body frame was never meant to take a spring load.

 

Nothing better than seeing people driving and enjoying their cars. I love it. Always love reading your updates. Again good for you! Oldsmobile proud. 🤘

 

Thank you, I appreciate it! There will be lots more updates coming this winter and next year!

 

For those interested in my upcoming plans for the car:

 

Very well done, will be following on your upgrades.

 

Thank you! Glad you’re enjoying the content!

 

Nice video - thanks for sharing. One random thing you mentioned was the vibration at hwy speed. I had the same issue with my 6 speed trans and 4.10 rear when the car was in 6th gear. We tried EVERYTHING with pinion angles and nothing worked. Someone told us the driveshaft must be custom balanced at a much higher RPM for speeds since they spin so fast in 6th gear. Apparently a "standard" driveshaft is balanced at 3,000 RPM which is fine for non 6 speeds with the dbl OD but they require a high speed balance up to 9,000 RPM. We were not sure if this was BS or not. I was considering dropping big $$$$ for the carbon fiber QA1 DS but was worried about spending that much $$$ and possibly still having the vibration. So.. took the plunge and got 3.5" Chromoly 9,000 RPM balanced driveshaft from a place in CA for around $550 I believe. Zero vibration now in 6th gear. Of course your vibration could be for a totally different reason but thought I would throw this out for you in case the same might work for you. Also forgot to mention above I talked to QA1 about the 9,000 RPM balance and the rep there said he never heard of that and confirmed their CF DSs are NOT balanced to 9,000 RPM but he said they are known for being much "smoother/have less vibration" then other material driveshafts. I asked what about for 6 speeds with the dbl OD and unbelievably he said he was not sure of any clients with 6 speeds to confirm one way or the other so lost a lot of confidence with that statement. That was about a year ago so maybe it's changed. I would like to upgrade some day to a CF shaft for the weight savings but still not 100% confident there would NOT be a vibration now in 6th.

-Joe

 

Thanks for the info! I'll definitely look into this as I try to figure out the cause of the vibration!

 

Wow, very cool! I'm glad I looked at your thread. Your car is awesome. Boy what a tragedy that car fire was!!

 

Thanks, I appreciate it! And indeed it was!

 

Wow! Nice! Not sure how I missed commenting on your thread, but I vaguely remember seeing the fire pictures LOVE what you've done with your ride! Will be following along, now that it is back on my radar.

 

Thanks! Glad you’re enjoying the build!

 

For those interested in my wheel and tire setup, or are interested in doing a 315 squared setup on their car, here's a quick guide I had put together over the summer!

You Tube

 

Beautiful build and great story

There wasn't anything that nice running around Storrs when I went to school there....85 (ENG)....lol