Remove Inner Fenders for Autocross Car?

[sandiego74]

OK, some rambling thoughts...

Maybe trim inners as needed vs removing them. I think 315s will make a bigger difference than 30 lbs of inner fenders. You'll need wheels for 315s, and not crappy cast wheels. spend wheel money to save weight. Not cheap. But I'll take saving 8 unsprung pounds a wheel over that inner fender sprung weight. being ready to buy on black Friday can help.

All the fast cars I see are all running splitters and bigger rear spoilers or wings. I'm not doing that to my 77. But my 67 I will.

They are also running better steering boxes. 10:1, 8:1. I'm planning a 10:1 in my 67.

What trans are you running? The ST10 4 speed is lighter than the T56 I'm running now. So I plan on keeping it in my 67 once I get that racing. I want to keep that car at 3000, which I think is the cam t limit.

What engine are you running? What rad and fan? Is there weight to save there? Or more power?

Mmmm... more power. My 450hp sbc is out gunned more often than one might think. Damn new CAM cars have more factory power. I can't keep up with a 6th gen ZR1 as an example.

You'll need a higher clearance sway bar to run 315s. PTFB and UMI have alternatives there. My hotchkis bar was detrimental to wide tires. That's my only change this year, along with a frame brace. I can't talk myself into adjustable shocks quite yet, but I kinda need them. The 67 will have Viking Crusaders all around.

Are you keeping up with cam s and cam c cars? Where are you in the PAX? The cam T regulars i run with locally swap 1/2/3 most days, but we're 5+ seconds off PAX. And occasionally a guy with an insane Mustang shows up and smokes us. He's nice though lol.

Can you find other events than the local scca. See other cars, check your measuring stick. The events I go to at UMI are quite helpful and yet humbling at the same time. I'm thrilled to now be mid pack when I'm there. I know who my targets are now, and I reeled a few in last year.

I'm still not consistent enough. But I know it's there, I'm good for a hero run or 2 every day lol

I do realize I’ll probably be adding the weight back with the larger wheels and tires, but it’s still losing frontend weight, regardless.

Black Friday is actually where I got my wheels last, and plan to do the same for more this year.

The only major thing that is not stock is the engine; everything else, especially suspension, is PTFB and Custom Works catalog. I’ve got a WS6 bar up front and a TKO600. When I was running the car last in CAM-C, it was consistently one of the fastest in the run group. Everyone else, though, has high-dollar cars, and I’m on a budget, so it’s an apple-to-oranges comparison. Power is, actually, probably what I need most, since my original, tired, old 350 probably only puts out about 210 to the wheels. But, I’d rather do the engine last, since that will be the biggest chunk of change in the budget.

 

[oldman14ss]

bonzo, what frame brace ? where? you know im new to this. while im in pieces i would like to install an edge where i can. sway bar? i want to run fat tires also. i have an ls3 long block in wrappers waiting. wasn't trying to jack your thread but am interested in this type of racing with our cars. watching sebring as i speak . by the way thanks again.

 

[sandiego74]

bonzo, what frame brace ? where? you know im new to this. while im in pieces i would like to install an edge where i can. sway bar? i want to run fat tires also. i have an ls3 long block in wrappers waiting. wasn't trying to jack your thread but am interested in this type of racing with our cars. watching sebring as i speak . by the way thanks again.

I think he is referring to the frame braces that PTFB sells. They have one that ties together the horns of the subframe, as well as one that triangulates the subframe to the firewall and fenders. I have them, as well, and highly recommend them.

 

[oldman14ss]

sandiego74 im a big dummy what does PTFB stand for?

 

[sandiego74]

Y

sandiego74 im a big dummy what does PTFB stand for?

Pro-touring F-Body. Look up “PTFB” on Google and Dave’s website will pop right up. Most people prefer Keith at Custom Work’s Performance, but I’ve had excellent service from both of them.

 

[BonzoHansen]

I think he is referring to the frame braces that PTFB sells. They have one that ties together the horns of the subframe, as well as one that triangulates the subframe to the firewall and fenders. I have them, as well, and highly recommend them.

I have the ptfb adjustable cowl bars and the umi brace across the front of the frame.

 

[oldman14ss]

Thanks guys, your constant knowledge is priceless!!

 

[JMcDonough]

I took mine out and haven’t looked back. One fender did crack when I rolled the lip but I think that is unrelated (user error - first time rolling fenders) as the other side was fine. I do get some rocks and rubber inside the engine bay but I don’t street drive it much so no real worries there for my usage. I’ve run in the rain without the inner fenders without issue.

Aero might be more of a concern if I was also doing track events but at autox speeds, I’d much rather save the weight over the front wheels.

Other bonuses:
- makes working on the car much easier
- makes spraying the tires with water between runs much easier

 

[JMcDonough]

Black Friday is actually where I got my wheels last, and plan to do the same for more this year.

The only major thing that is not stock is the engine; everything else, especially suspension, is PTFB and Custom Works catalog. I’ve got a WS6 bar up front and a TKO600. When I was running the car last in CAM-C, it was consistently one of the fastest in the run group. Everyone else, though, has high-dollar cars, and I’m on a budget, so it’s an apple-to-oranges comparison. Power is, actually, probably what I need most, since my original, tired, old 350 probably only puts out about 210 to the wheels. But, I’d rather do the engine last, since that will be the biggest chunk of change in th

I do realize I’ll probably be adding the weight back with the larger wheels and tires, but it’s still losing frontend weight, regardless.

Black Friday is actually where I got my wheels last, and plan to do the same for more this year.

The only major thing that is not stock is the engine; everything else, especially suspension, is PTFB and Custom Works catalog. I’ve got a WS6 bar up front and a TKO600. When I was running the car last in CAM-C, it was consistently one of the fastest in the run group. Everyone else, though, has high-dollar cars, and I’m on a budget, so it’s an apple-to-oranges comparison. Power is, actually, probably what I need most, since my original, tired, old 350 probably only puts out about 210 to the wheels. But, I’d rather do the engine last, since that will be the biggest chunk of change in the budget.

I took a similar approach on the built process. Did the engine last. Went from a mild 350 to a relatively hot 377 build. On small courses the time at 100% throttle is relatively small to zero. Certainly more on bigger courses but with how much of the time in an autox course is combined longitudinal accel and turning, more hp has very diminishing returns, especially on 200tw tires. Plus it makes the car harder to drive because it’s easier to overwhelm the rear tires. I read that last year’s national champ had maybe 300whp.

 

[G72Zed]

"more hp has very diminishing returns, especially on 200tw tires. Plus it makes the car harder to drive because it’s easier to overwhelm the rear tires. I read that last year’s national champ had maybe 300whp."

I would of never thought this in all my years racing.....Except when I tried my hand autocrossing for the first time almost in my 50's.......

This was one of the biggest kick in go-nads I ever had, so true.

My son can do things with his 230hp Civic SI on the autocross track that is mind boggling to me.....especially to the competitors in the classes above with 2 to 3x the power, and more $ in just the rims and tires than his hole car!!!!!