Need Help With Replica Richard Petty 1970 Plymouth Superbird

[raven214]

I'm not sure if this is the right place for this post but I think it is the closest fit. I need help from the researchers out there. Let me explain:

I've been inspired by some of the builds here and I want to build a replica of Nascar's 1970 Plymouth Superbird. It just so happens this make was driven by Richard Petty in a simple one-color "Petty" Blue" livery. The problem I'm having is more of a research issue than anything else. If anyone wants to take on this project in its entirety please feel free!

Color

I've got a good color thanks to this thread:
https://www.gtplanet.net/forum/thre...ourite-paint-chips.294421/page-5#post-9139826
Any other suggestions?

Tires

I've seen some pictures where they look stock metallic and others where they were painted blue. I'm going with the Nascar PDI rims (exact name eludes me at the moment) painted to match the body.

Specs

This is my main issue. I have been searching Google but have not been able to find the Nascar specs for this car.

For the street version,
http://myclassicgarage.com/marketplace/knowledge_base/1970-plymouth-superbird lists engine options of 375, 390, and 425 HP. Wiki: http://en.wikipedia.org/wiki/Plymouth_Superbird lists a curb weight of 3841 lb (1742 kg) and references the Hemi 426 as the "competition engine", which if I'm not mistaken is the 425 HP variant.

This gives starting numbers of 425 HP / 1742 kg. Without Nascar specs, the next question is how much did Nascar modify cars in 1970? I know the cars were much more "stock" than the purpose-built race cars they feature today, but does that mean car specs were basically the same as street versions?

Tune

This is of lesser concern to me but any and all help would be appreciated once the specs are established.

 

[DigitalBaka]

Tidbit I found from an interview with Larry Rathgeb, who was in charge of stock car engineering for Chrysler during this time:

Q: How much reserve power was left in the 426 Hemi for future increases by the end of the 1970 NASCAR race season?
A: The way we all felt at that time was we really didn't want to do any more to increase power unless it was exceptionally safe. We were running around 585 to 595 horsepower in our race engines. Yeah, we had some 600 and 610 horsepower motors but they weren't very reliable. We felt it was better to use the horsepower required than the horsepower available to win races.

Read more: http://www.hotrod.com/web/113_0508_wing/#ixzz2uY3IRMDu

 

[DaBomm4]

I didn't know the information that @DigitalBaka found for you when I assisted someone else with a starting base. Here is that thread.
https://www.gtplanet.net/forum/threads/i-want-to-recreate-pettys-superbird.295802/#post-9185254

 

[raven214]

Thanks for the info @DigitalBaka - that link looks familiar. I think it's the one that keeps crashing my browser when I try to open it (on my phone).

Thanks for the link @DaBomm4 - I did several searches but didn't come across that thread or i would've just posted there. 👍

The closest info I found in my research said that Nascar engines were producing about 650 HP in the mid '70s so that all makes sense showing the gradual progression in technology.

 

[raven214]

Pardon the double post - it is much easier to do it this way on my phone. Ok, so we've got 585 HP now we just need weight.

@DaBomm4 I noticed you did Stage 3 weight reduction. Is that based on any real weight information or just for the sake of the tune?

550pp Superbird 616 hp, 646 ft-lb


Oil change

Weight Reduction Stage 3

Carbon Hood

Window Weight Reduction

Engine Tuning Stage 3

Sports Computer

Intake Tuning

Triple-Plate Clutch Kit

Carbon Drive Shaft

FC LSD

FC Transmission

FC Suspension

Sports Soft Tires


Ride Height 105/115

Spring Rate 8.25/6.25

Dampener Comp 2/5

Dampener Ext 5/5

Anti-Roll Bars 2/4

Camber Angle 2.0/1.8

Toe Angle -0.08/0.10

Brake Balance 4/6


Final Gear 3.400

Top Speed 249

First Gear 2.300

Second 1.580

Third 1.100

Fourth 0.805

Fifth 0.615


8/8/10


Has a lot of power when going around corners so try not to go full throttle until you are straight. Can go 200 mph without a draft on Daytona.

 

[DaBomm4]

It was more for the sake of the tune because I never found any real weight either. When I was making that tune, I looked some like you have but I wasn't too concerned with it because the OP didn't seem concerned.

 

[raven214]

It was more for the sake of the tune because I never found any real weight either. When I was making that tune, I looked some like you have but I wasn't too concerned with it because the OP didn't seem concerned.

No worries. I just wondered if you had found something I didn't. I think I will try it with a stage 1 reduction in the belief that the cars were essentially unmodified, or that most/any weight savings would be balanced by the addition of a roll cage.

 

[raven214]

Alright, bear with me. I did some more digging on the weight question, and while I still haven't found exact numbers, I did find something... sort of.

When looking under the series name at the time, which I discovered was "Grand National", I found a restoration of a '68 Ford Torino here: http://www.race-cars.com/carsales/other/1227029039/1227029039ss.htm that lists its weight as 3950 lb. A quick search on Wiki: http://en.wikipedia.org/wiki/Ford_Torino gives the '68 Fairlane/Torino a curb weight of 2932 – 3514 lb (I assume accounting for station wagons and other variants). The entire range of the street car is below the restoration's value.

Assuming the restoration is in the ballpark of the real thing, this would suggest that the Superbird might have gained weight similarly when coming to the track only 2 seasons later. I could easily imagine racing parts in the 1960's being significantly heavier than their street counterparts to put up with the demands of racing. In my mind it makes sense. As this is all I have to go on at the moment, I'm now thinking of being more conservative and keeping the car at stock weight.

 

[Pete05]

Hey Guys,
Just wanted to point out that there has never been a 5 speed Nascar.
Even today they still only use a 4 speed called the Super T10.
I'd use the standard ratios given in the standard gearbox & fit the FC LSD with a tall ratio of 3.00 or less depending on where you want to run.
Good luck with the King's build

 

[raven214]

Hey Guys,
Just wanted to point out that there has never been a 5 speed Nascar.
Even today they still only use a 4 speed called the Super T10.
I'd use the standard ratios given in the standard gearbox & fit the FC LSD with a tall ratio of 3.00 or less depending on where you want to run.
Good luck with the King's build

Forgive me, I know next to nothing about the LSD besides the basic idea behind it. It can affect top speed?

 

[DaBomm4]

LSD does not affect speed/acceleration in real life or in game. The final gear is what I assume @Pete05 is referring to. When I tuned mine, I didn't think about the gear issue but what I would do to solve it is forget first even exists so that you have the high speed side of it. Do you guys think that would be an OK approach to this dilemma?

 

[raven214]

LSD does not affect speed/acceleration in real life or in game. The final gear is what I assume @Pete05 is referring to. When I tuned mine, I didn't think about the gear issue but what I would do to solve it is forget first even exists so that you have the high speed side of it. Do you guys think that would be an OK approach to this dilemma?

Sounds like a good solution to me - I like that better than pretending it's not there (ie not using it) as I usually drive automatic. 👍

Would it be possible to get first gear so "short" - I always have trouble with which is short and which is long - that it would basically amount to putting the car in gear?

 

[DaBomm4]

To put it best, the smaller the number, the longer it is, or how long it takes to accelerate. An example of this is put a car in high gear and try to accelerate versus first gear acceleration.

So, we probably want to tune first gear at the biggest number possible and then do some sort of 4 gear tune from there. I don't know if you know this but one thing you want to be careful of though, is when you adjust the final gear, if you lose some of the line on the top gear, that gear is no longer effective because it is out of the usable range of the car.

 

[Jbaffoh]

I'm not a big NASCAR guy, but I've always loved this car and decided to follow your leads.

I used French Blue (from the Triumph, not Lotus--one is closer than the other). I used PDI 525N rims, painted Royal Blue (from Lotus Europa) because I think that's close to the pic above. For unpainted rims, I would have used GT Chrome 009-N.

Tuning, I tried to stay away from items that did not exist in 1970. But I had to make exceptions (there is no way to reach 200 mph without the custom 5-speed tranny).

I based my tune on DaBomm4's tune, but made changes.

First, I used his suspension, but reduced camber to zero, front and back.

For weight reduction, I used stage three plus window reduction. No carbon hood. It's probably lighter than Petty's at 1306kg, but I couldn't reach 200 mph at Daytona without the reduction.

Power:

Stage three
Standard computer
Semi-Racing Exhaust
Isometric manifold
Standard Cat (can't we remove it altogether?)
Intake Tuning
Limiter: 94.7

This gives us 600 hp, 665 ft lb torque.

I used DaBomm4's LSD settings (haven't bothered to test them myself to see if they're optimal).

Twin clutch and no carbon shaft. 1970?

Tranny:

First set final gear to 5.000
Then Max Speed to 106
1: 2.668
2: 1.884
3: 1.447
4: 1.210
5: 1.018
Then set final to 2.015.

I'm reaching 202 at the end of straights in Daytona (test drive mode), and doing laps in the 45:400 range.

I think I'll test the LSD and see if I can lower this.

As far as suspension, I suck. All I know is zero camber works best for nearly everything I've done in GT6.

I want to learn more.

Edit: I've only tested this at Daytona. And, my cat was sitting in front of the tachometer on the screen, so I don't know how much reserve there is for drafting).

 

[Pete05]

I'm not a big NASCAR guy, but I've always loved this car and decided to follow your leads.

I used French Blue (from the Triumph, not Lotus--one is closer than the other). I used PDI 525N rims, painted Royal Blue (from Lotus Europa) because I think that's close to the pic above. For unpainted rims, I would have used GT Chrome 009-N.

Tuning, I tried to stay away from items that did not exist in 1970. But I had to make exceptions (there is no way to reach 200 mph without the custom 5-speed tranny).

I based my tune on DaBomm4's tune, but made changes.

First, I used his suspension, but reduced camber to zero, front and back.

For weight reduction, I used stage three plus window reduction. No carbon hood. It's probably lighter than Petty's at 1306kg, but I couldn't reach 200 mph at Daytona without the reduction.

Power:

Stage three
Standard computer
Semi-Racing Exhaust
Isometric manifold
Standard Cat (can't we remove it altogether?)
Intake Tuning
Limiter: 94.7

This gives us 600 hp, 665 ft lb torque.

I used DaBomm4's LSD settings (haven't bothered to test them myself to see if they're optimal).

Twin clutch and no carbon shaft. 1970?

Tranny:

First set final gear to 5.000
Then Max Speed to 106
1: 2.668
2: 1.884
3: 1.447
4: 1.210
5: 1.018
Then set final to 2.015.

I'm reaching 202 at the end of straights in Daytona (test drive mode), and doing laps in the 45:400 range.

I think I'll test the LSD and see if I can lower this.

As far as suspension, I suck. All I know is zero camber works best for nearly everything I've done in GT6.

I want to learn more.

Edit: I've only tested this at Daytona. And, my cat was sitting in front of the tachometer on the screen, so I don't know how much reserve there is for drafting).

I bet your cat knew what you were doing but wanted some attention . Having been a cat owner in the past, I'm having a good chuckle at this
As for the car, have you guys given any thought to as to wether Mr.Petty could actually go to 200mph? I'm not sure that was possible given he had to use a 4 speed, would've been over the scales at a lot more than 1600kg, using tyres from 1970 (cross-ply) and in the car. He may have but I think it's unlikely.
If your using an Auto, it would be better if you set 1st gear to the highest number possible if your going to replicate 1-4 gears using 2-5 in the game. That'll get you out of that gear the fastest so you can then drive it without it changing back to 1st if you want to use 2nd as you hypothetical 1st.
Good luck anyway
I'll be interested to take the thing for a few laps when you've got it sorted. I always use manual so will stack the box as a 4 speed and see how it handles the banks at Daytona

 

[DaBomm4]

The Superbird and Charger Daytona were banned from Nascar because they could go over 200 mph. The bans included at the same time were the "no special aero packs" and engines restricted to I think 305 ci. I am not sure if they were capable of 200 mph on their own or if it was in a draft though.
Edit: The fame behind the car is why I decided to deal with tuning the Superbird first in GT6.

 

[Jbaffoh]

The Superbird and Charger Daytona were banned from Nascar because they could go over 200 mph. The bans included at the same time were the "no special aero packs" and engines restricted to I think 305 ci. I am not sure if they were capable of 200 mph on their own or if it was in a draft though.
Edit: The fame behind the car is why I decided to deal with tuning the Superbird first in GT6.

I think I read that Petty was the first to break 200 in 1970, and then they changed the rules in 1971.

Yeah, I'd like to mess around and try to replicate a 4-speed.

Cross ply? I remember street cars were beginning to get radials back then--all the TV commercials made a big impact in this 10-year-old's mind.

My cat? She ALWAYS sits in that corner of the screen when I drive--and never otherwise. But it get's worse: Sometimes she sits on the center channel speaker in front center, fully blocking my most critical view, or she jumps on my lap and whips her tail across my eyes. Yes, she thinks I'm too old to play games.

 

[Pete05]

The Superbird and Charger Daytona were banned from Nascar because they could go over 200 mph. The bans included at the same time were the "no special aero packs" and engines restricted to I think 305 ci. I am not sure if they were capable of 200 mph on their own or if it was in a draft though.
Edit: The fame behind the car is why I decided to deal with tuning the Superbird first in GT6.

I totally understand the interest in this car. Absolute legend

 

[killerjimbag]

Found this also.
http://fastestlaps.com/cars/plymouth_superbird.html#comments

 

[raven214]

I tried out @DaBomm4's tune last night plus stock values for the custom trans set at about 217 mph top speed. I set HP to 585 and I used weight reduction stage 1 plus hood and windows, and ballast added back to make the balance 50:50. I was able to just touch 195 mph before going into the turns, which is good enough for me. I should add I'm focusing all my efforts at Daytona for now, and I'm using RH tires.

I had the same problem with the tune as I did with the stock setup - snap/breakaway overstear on corner exit. It's worse coming off turn 2. I can modify my line to help improve things but the car still gets very light and touchy as it goes through the transition from the banking onto the straight.

I'm not sure if this is sort of the "nature of the beast" and is something I just need to get used to, or if it can be tuned out - or at least improved. My goal is to get the car raceable for potential "old school" Nascar races online.

 

[DaBomm4]

One side note about that tune, I took it around Daytona a few times and around Trial Mountain a few times, more of a quick tune. Maybe try my settings from the FITT challenge at Daytona? If you mainly want it to go around Daytona a little better, I can try to mess with some settings on it.

 

[DaBomm4]

I have just done some messing around with the car on Daytona and then on Grand Valley full course, I am surprised at how well this suspension setup works on a course. Here is the tune.

535 PP
590 HP @ 5100 rpm
633.5 Ft-lb @ 4600 rpm
1550 kg

GT Auto
No Oil Change
Stock Size: PDI P525N
Parts
Fully Customizable Suspension
Racing Brakes
Fully Customizable Transmission
Fully Customizable LSD
Twin-Plate Clutch Kit
Engine Tuning Stage 3
Sports Exhaust
Isometric Exhaust Manifold
Sports Catalytic
Intake Tuning
Weight Reduction Stage 1
Carbon Hood
Window Weight Reduction
Sports Hard

Suspension
Ride Height 105/105
Spring Rate 7/7
Dampeners Comp 5/5
Dampeners Ext 4/6
Anti-Roll Bars 3/4
Camber Angle 0.0/0.0
Toe Angle 0.00/0.00
Brake Balance 6/4

Transmission
Initial Final 5.000
Top Speed 99
First Gear 3.577
Second Gear 2.200
Third Gear 1.600
Fourth Gear 1.200
Fifth Gear 1.000
Final Gear 2.100

LSD 10/10/9

Power Limiter 96.0%
Ballast Weight 39
Ballast Position 0