Plastic Fantastic 2

[mfain]

today's announcement - which I'll follow up in 3 or so months when it all comes to pass

I bought PF3. A 68 C3 - or rather, a C3 tub and doors. I'm going to build a frame which copies PF2, then flare it like before. Not sure whether it will be BB powered or not - the 'next' BB I'm building will likely land in PF2.... I might see about building something like what mfain built for his 56...

A couple of thoughts. Think light weight from the start. It is easier to assess every part during initial construction than it is to go back and mod things to reduce weight later. If you can reduce the weight of every part by even 10%, and eliminate things that you don't need to go fast, you wouldn't believe how light a car can get. Light is fast and also easier on parts and consumables. Try to get as much weight as low and far aft as you can - a slight rear weight bias gives you a lot better handling options. Big tires, but avoid offsets that hinder proper suspension geometry like not being able to achieve minimal scrub radius. Build in clearance for full tire motion at full compression. Plan for aero - include strong, accessible places to bolt things like wings and splitters, and try to keep things from hanging down under the car that would keep you from having a clean, flat belly pan that does wonders for reducing aero drag. Decide if it is going to be a track car or dual purpose - that will make a big difference in construction. I have taken one car from "driver" to full-on track car and that is the hardest way imaginable to get there. Looking forward to seeing progress.

 

[SuperBuickGuy]

A couple of thoughts. Think light weight from the start. It is easier to assess every part during initial construction than it is to go back and mod things to reduce weight later. If you can reduce the weight of every part by even 10%, and eliminate things that you don't need to go fast, you wouldn't believe how light a car can get. Light is fast and also easier on parts and consumables. Try to get as much weight as low and far aft as you can - a slight rear weight bias gives you a lot better handling options. Big tires, but avoid offsets that hinder proper suspension geometry like not being able to achieve minimal scrub radius. Build in clearance for full tire motion at full compression. Plan for aero - include strong, accessible places to bolt things like wings and splitters, and try to keep things from hanging down under the car that would keep you from having a clean, flat belly pan that does wonders for reducing aero drag. Decide if it is going to be a track car or dual purpose - that will make a big difference in construction. I have taken one car from "driver" to full-on track car and that is the hardest way imaginable to get there. Looking forward to seeing progress.

I fully, fully, fully agree.

I'll be spending a lot of money on Dynamic Corvette CF parts. They even make doors out of carbon fiber

that said, my goal is compete in the outlaw class - because there's no chance this car will weigh anywhere near the 3200 lb minimum.

Which may mean I'm building a car for which no class exists - but with that said, Wilwood Corvette Challenge is of interest to me, and also speed trials.

Wonder how much a titanium frame would cost..... I'm serious about the CF stuff, but how far I take this? I don't know. I'm at the point where I really want to start enjoying what I build... so PF2 isn't for sale anytime soon... nor is the FJ40... or the Blazer... or the 50 Sedanette... lordy I have a lot of projects.

That said, the wagon and Spider may find new homes to the right buyer.

I also have this "wanna build" a COE motorhome from my current motorhome.
We will see.... at this point, getting the shell here and starting the titling process are first steps.

_______
and in that vein. What I've learned from this car.
1) BBC are faster then LS motors
2) BBC motors weigh 50 lbs more dressed then an LS.
3) that the Camaro suspension has more aftermarket and that I can buy stronger parts
4) I'm going to take full advantage that I can more the firewall and step in the floor - while I'm not large compared to many of my friends - I'm not small at 6-1 and 220 lbs....

 

[SuperBuickGuy]

saving this for later. I blew yet another rack seal - I'm putting a pressure reducer in the pump but that will affect my hydroboost brakes... which leads me to consider simply making the rack manual

[video=youtube;sJNZ3xgjaf4]

ory[/video]

 

[phantomjock]

Its not "just weight," 10 pounds --> 1 HP, but HP too.

BMW Electric Brake pump? I recall pappy has. Now, I have too.
5-8 hp required to drive a typical Type II pump at 5,000-rpm shaft speed loaded at 700 psi - more pressure with Hydroboost? Then, more HP consumed.
If you can deal with amp loss (weight in battery bank - then pull the core on the Alternator. Another 5-8HP.

On my new project [yes and overdue an update on the vette too], I'm doing some "livability" mods on a Chevy LS powered ClassB. It is our new tow vehicle.
Just now I'm going electric radiator fans and eliminating the mechanical. Can be 5-8HP cost for the electric fans - but not the 20-40 HP costs from the mechanical fan/clutch.
Full Disclosure - up to 30 Amps! Could be a problem balancing use vs Alternator, etc..

But, a YT Dyno-test shows any savings are all along the RPM range - not just top end.

More out there...
YMMV - but it is the Outlaw Division.

Cheers - Jim

 

[rtj]

Wonder how much a titanium frame would cost..... I'm serious about the CF stuff, but how far I take this? I don't know. I'm at the point where I really want to start enjoying what I build... so PF2 isn't for sale anytime soon... nor is the FJ40... or the Blazer... or the 50 Sedanette... lordy I have a lot of projects.

Fabrication would be painful with Ti. But, a full chrome moly tube frame with complete cage would be stiff, light, and economical.

Interesting that you say the big block beats LS. I’m assuming it is the raw torque. I keep watching prices on alum big blocks skyrocket, it is kind of difficult to watch.

So now that you’ve run the wing and the spoiler, how do they compare?

 

[SuperBuickGuy]

Fabrication would be painful with Ti. But, a full chrome moly tube frame with complete cage would be stiff, light, and economical.

Interesting that you say the big block beats LS. I’m assuming it is the raw torque. I keep watching prices on alum big blocks skyrocket, it is kind of difficult to watch.

So now that you’ve run the wing and the spoiler, how do they compare?

BBC - NA. LS is a fantastic platform for turbos, but I've been watching a really nice 70 Chevelle that has all the protouring mods at Optima. He's not doing well because he either is in boost lag or on boost and either breaking something or out of control.

Spoilers... I think it helps on the track, but is really of marginal benefit on autocross.
Spoilers part 2 - I think Optima likes spoilers because it says 'racecar' In their challenge Compare Chad Ryker's 67 Camaro which has all the aero with Ryan Breezy's 69 Camaro that doesn't but rather has traction control and ABS. Ryan is faster this year, can't wait to see them head to head but so far.... I don't see aero being much of anything... I know, I know heresy.

 

[Red77]

I'll second the chrome moly. I have a cousin that builds drag cars and you can make it super strong AND light where mild steel just can't compete. He built a full tube chassis Vega for one of his customers back in the 90s when I was helping around the shop and it was super light compared to the mild steel ones he had built before. Smaller tubing can do the same job when it is a higher strength material. It's a little more difficult to weld than mild steel, but MUCH easier than titanium.

 

[69427]

Its not "just weight," 10 pounds --> 1 HP, but HP too.

BMW Electric Brake pump? I recall pappy has. Now, I have too.
5-8 hp required to drive a typical Type II pump at 5,000-rpm shaft speed loaded at 700 psi - more pressure with Hydroboost? Then, more HP consumed.
If you can deal with amp loss (weight in battery bank - then pull the core on the Alternator. Another 5-8HP.

On my new project [yes and overdue an update on the vette too], I'm doing some "livability" mods on a Chevy LS powered ClassB. It is our new tow vehicle.
Just now I'm going electric radiator fans and eliminating the mechanical. Can be 5-8HP cost for the electric fans - but not the 20-40 HP costs from the mechanical fan/clutch.
Full Disclosure - up to 30 Amps! Could be a problem balancing use vs Alternator, etc..

But, a YT Dyno-test shows any savings are all along the RPM range - not just top end.

More out there...
YMMV - but it is the Outlaw Division.

Cheers - Jim

My perspective on all these YT fan videos: Whether the fan is on an engine dyno or a chassis dyno, I don't see that the results are applicable to much more than deciding which fan to use on a stationary engine driving an irrigation pump out on a desert crop field. There's absolutely no comparisons to airflow or where the horsepower is going.

You're an aviation guy. Let me just pose a scenario. Say you're outside the hangar some afternoon, polishing your Mustang. Some salesman stops by and says he has a prop he'd like to sell you. Promises it will free up at least a thousand horsepower at 2500 RPM on your Merlin. Curiosity, but a skeptical mind, makes you say, okay show me what you got. The salesman reaches into the back of his Camry and pulls out a prop that looks like it's standard equipment on a Piper Cub. Without bothering to put the engine on a dyno you realize that yes, you would have to agree with the salesman that his prop would free up some horsepower at 2500 RPM. But so what. Even though your four blade prop was "eating" up 2000 horsepower at 2500 RPM, you were getting something for that horsepower expenditure, namely speed and acceleration of the aircraft. And that speed and acceleration occurs because the prop is contacting air mass, and accelerating it rearward. (I know you know all this. Just humor me here.) The act of accelerating air rearward causes an equal reaction forward, pulling/thrusting the airplane in the direction you want to go.

A car fan is no different. It cools by grabbing and accelerating air mass rearward. This "eats" up horsepower, but it also provides thrust on the front of the engine. This horsepower drain will obviously vary with RPM and forward velocity, as the air coming through the radiator will vary with vehicle speed. While horsepower drain is too frequently complained about, like in these videos, horsepower consumption is not always a bad thing, evidenced by how much fun it is when a big prop consumes the power a Merlin engine makes.

My personal philosophy is to find the lightest fan setup that will cool my engine. Out on the track an electric fan is just ballast weight sitting at the worst place on a sports car, in front of the front axle. A flex fan, while despised by many, is incredibly light, and its horsepower consumption on the straights is minimal, and the ratio of productive/non-productive horsepower consumption is something no internet/YT racer will tackle or discuss.

Just my opinion and philosophy.

 

[69427]

A couple of thoughts. Think light weight from the start. It is easier to assess every part during initial construction than it is to go back and mod things to reduce weight later. If you can reduce the weight of every part by even 10%, and eliminate things that you don't need to go fast, you wouldn't believe how light a car can get. Light is fast and also easier on parts and consumables. Try to get as much weight as low and far aft as you can - a slight rear weight bias gives you a lot better handling options. Big tires, but avoid offsets that hinder proper suspension geometry like not being able to achieve minimal scrub radius. Build in clearance for full tire motion at full compression. Plan for aero - include strong, accessible places to bolt things like wings and splitters, and try to keep things from hanging down under the car that would keep you from having a clean, flat belly pan that does wonders for reducing aero drag. Decide if it is going to be a track car or dual purpose - that will make a big difference in construction. I have taken one car from "driver" to full-on track car and that is the hardest way imaginable to get there. Looking forward to seeing progress.

I agree on the focus on light weight. Absolutely. The advantages are many. I'm at 2695# (with a quarter tank of fuel and full factory interior) My engine is a fuel sipper, but the light weight gives me a respectable power to weight ratio.

 

[SuperBuickGuy]

I agree on the focus on light weight. Absolutely. The advantages are many. I'm at 2695# (with a quarter tank of fuel and full factory interior) My engine is a fuel sipper, but the light weight gives me a respectable power to weight ratio.

I wonder at how light I can get... I support the myth of factory appearing - so a tube frame ... I don't know, I'm not yet a fan (but my mind could easily change)

 

[rtj]

I wonder at how light I can get... I support the myth of factory appearing - so a tube frame ... I don't know, I'm not yet a fan (but my mind could easily change)

There is a tube frame c3 on grass roots racing the guy says is 2500 lbs. I was looking for a c3 with a howe chassis, this one popped up since it had a front clip.


https://grassrootsmotorsports.com/f...-corvette-finally-nears-complet/138279/page1/

 

[rtj]

Others found using this search: site: https://grassrootsmotorsports.com c3 corvette tube frame

 

[SuperBuickGuy]

I've committed to buy it, now to get a day or two to go get it.... or wait for it to make its way up to a town near me

 

[69427]

I wonder at how light I can get... I support the myth of factory appearing - so a tube frame ... I don't know, I'm not yet a fan (but my mind could easily change)

I wonder at how light I can get... I support the myth of factory appearing - so a tube frame ... I don't know, I'm not yet a fan (but my mind could easily change)

My if-I-ever-get-the-freaking-time eventual goal is to make a replacement frame out of square/rectangle aluminum tubing (I've done most of the load/force and material weight calculations), and cover it with a coat of semi-gloss black paint to bland it out a bit. Right now I've got all the removable crossmembers duplicated in aluminum, for about 30-40 pound weight reduction. They're installed, except for the front LCA crossmember, as progress on that has been damn slow. I'm entertaining putting that on hold, and seeing if it's more efficient time wise to cut up and reweld a C5 aluminum crossmember. Any chance I could trouble you at your convenience to take some measurements of the spacings of the LCA mounts to see what alterations would be necessary to mount C4 LCAs to that crossmember? Absolutely no rush if you are able to help me out.

Thanks.
Mike

 

[SuperBuickGuy]

My if-I-ever-get-the-freaking-time eventual goal is to make a replacement frame out of square/rectangle aluminum tubing (I've done most of the load/force and material weight calculations), and cover it with a coat of semi-gloss black paint to bland it out a bit. Right now I've got all the removable crossmembers duplicated in aluminum, for about 30-40 pound weight reduction. They're installed, except for the front LCA crossmember, as progress on that has been damn slow. I'm entertaining putting that on hold, and seeing if it's more efficient time wise to cut up and reweld a C5 aluminum crossmember. Any chance I could trouble you at your convenience to take some measurements of the spacings of the LCA mounts to see what alterations would be necessary to mount C4 LCAs to that crossmember? Absolutely no rush if you are able to help me out.

Thanks.
Mike

it will be interesting to see what the respective weights will be with the frame I build for PF3. I know the mods I did made PF2 weigh less, but I have no idea how much. Not just that but I'm going to move the cross brace behind the driver to copy what GM did with the Camaro suspension - that will also save me some weight because the cross brace and the Camaro cross brace are in PF2.

 

[SuperBuickGuy]

time to do the maintenance and stuff to get ready for the rest of the season
as mentioned before, the rack is leaking... I have a 'new' 'lifetime warranty' one.

someday soon I'm going to make my 'spare' rack manual. I may also come up with another solution for the brake assist and ditch the hydroboost*
when I built the car, I verified I could pull the rack out from the driver's side... when I do the frame for PF3, this will happen too



volume reducer

the other thing I MUST fix is this rub. This is the 3rd time and there won't be a 4... so welding is going to happen




*I like the hydroboost, but I don't like the leaks and I'm concerned that the current 'fix' for the rack (reduce pressure and volume) will negatively affect braking. Right now it's absolutely perfect.... by reducing volume and pressure by 30%... tune in for updates.

 

[SuperBuickGuy]

today's fun, make sure the top doesn't blow off at 150.... like it started to...

inserts

and glue

and the hardest part is drilling in the acrylic
ultimately success came from a slightly smaller hole, heating the insert so it'd thread in, then backing it out a bit and stuffing epoxy in the outside threads

that ain't goin' nowhere.

in other news, new toy


I also finished up the rack install - I took pictures of the parts needed to reduce the pressure (rack needs 800 psi max, hydroboost can handle 1100 and the pump puts out 1350 - now 800)
of course the camera failed... I'll report back after driving it... I also lowered the front and aligned it. will drop the rear down as well... pictures of that part later

 

[SuperBuickGuy]

so I drove it last night. The reduced pressure doesn't affect braking (yay).

lowered it, levelled it, need to balance it and align it again.

 

[SuperBuickGuy]

the problem - out of date seat belts

the solution

the "that escaladed quickly"




so why... I left the center open for better view - the problem was getting the battery out (under the floor) was a right PITA. Add to this issue that had I run the bar all the way across, horizontally, then I could simply tie the seat belts to the rear bar.... so that's what I'm going to do.
Problem 2 is the cross bar is really in the way... so I'm going to make the roll bar into a seat bar. I will still function to aid roof support, but give me a bit more room for activities. With that said, the targa bar on the C3 is pretty stout from the factory - so is a cage necessary for what I'm doing? I say no.

 

[SuperBuickGuy]

time to work on the seat belt bar/roll bar
the problem is simple - it's an utter PITA to get to the battery and getting to the top of the tank is nearly impossible while leaving the bar in..

so time to take the drop part out

and welded.... a few more things to do tomorrow then reinstall

 

[mfain]

When you build your next car, and assuming you intend to potentially track it in wheel-to-wheel events, you need to look at the SCCA and NASA rule books to make sure your roll bar (and cage) is compliant. Even some of the open road events require either the NASA or SCCA specification. This one does give some roll-over protection and works as a harness bar, but it would not pass the more technical inspection that generally requires "a diagonal bar from within 12" of the top corner (driver's side) to as low as possible on the passenger side of the hoop". That bar needs to be in a straight line (no offsets or bends at the harness bar) and in the same plane as the hoop. Stuff like that.

 

[SuperBuickGuy]

now with paint

the white isn't an issue unless the carpet moves - since I have spare black paint

better

almost there... I don't know what I did with the grommet for the passenger seat - so I ordered another...

ah well, I can bolt it all down ...

 

[SuperBuickGuy]

So today.... was supposed to Ax but it wouldn't stop rain and when it did stop raining, the thunder came rolling in. I need the practice but I'd rather not die - so did some side work
like my spoiler
when I went airborne at Thunderhill, I tweaked the front spoiler - it fell off when I rolled it back out of the trailer after the trip

so glue, clamp

rivet

then put a backer piece and reattach to the car

 

[bobs77vet]

getting back to your rack and pinion seal , i know you mentioned the hydro boost is that hooked up to the rack and pinion?

why not internally shim out the Power steering pump and reduce the pressure it creates?

 

[SuperBuickGuy]

getting back to your rack and pinion seal , i know you mentioned the hydro boost is that hooked up to the rack and pinion?

why not internally shim out the Power steering pump and reduce the pressure it creates?

I did, but I need to race it to see if the pressure reduction works.

 

[SuperBuickGuy]

did go play but I'm finally ready to go. Car is pretty much done and the motorhome is ready to go again. It wouldn't be me if it was completely done but it's close.
this was the 'final' thing, 5th point for the harness for the passenger seat



still waiting on a different bracket for the spoiler - but that really is pretty much it. Just need to drive it - which is my plan for the next few weeks.

 

[bobs77vet]

now you can strap in the car seats for the grand kids

 

[SuperBuickGuy]

now you can strap in the car seats for the grand kids

you know something I don't?

My mom asked, once, if she had any grandkids. I said "none that I know of"... she didn't ask again lol

 

[SuperBuickGuy]

Finally found a shop to do the alignment on my C3. I know, I should just go to Firestone, they'll have no trouble with this.... HA

so explanation.... the cams do NOT stay in place when you drive in a spirted manner... they will now


I'd replace that arm with something aftermarket but the aftermarket, strangely, doesn't have an arm for a retrofitted Camaro rear suspension in a C3 with coilovers.... sarcasm aside, coil overs aren't really something does with 5th gen Camaros, thus any arm expects you to use the struts.... which are not coilovers... so a bit of a tack and it'll stay now.


and you folks know who did the alignment Duke Langley - he runs a shop 20 miles from me, I figured I'd be pretty dumb not to get his hands on mine... also a heck of a nice guy with very fair pricing.
his 2002 Corvette is an utter beast

 

[bobs77vet]

very nice, when I lived in NJ I went to east coast supercharging once. that was really cool.

I would definitely let him work some magic and get some of his experience in setting it up