How would an iron block affect handling?
Thread Starter
Joined: Jan 2002
Posts: 4,069
Likes: 74
From: Casselberry FL
How would an iron block affect handling? If one switches from an aluminum to an iron block, will it upset the handling? Will the drag racing solutions of a lighter hood, lighter accessories, relocating the battery, lightweight k-member, etc truly nullify the 70lbs weight gain?
I would probably have to stop autocrossing the car with a 408ci iron block and switch to road racing.
I would probably have to stop autocrossing the car with a 408ci iron block and switch to road racing.
People race with iron blocks all the time, so I wouldn't get too worried about it. You'll have trouble getting rid of enough weight to cancel out the extra block weight. I'd focus on revising the suspension.
The '93-97 F-bodies had iron blocks, so their suspension components are a good starting place, especially the aftermarket stuff.
The '93-97 F-bodies had iron blocks, so their suspension components are a good starting place, especially the aftermarket stuff.
Thread Starter
Joined: Jan 2002
Posts: 4,069
Likes: 74
From: Casselberry FL
What would I need to change on my suspension to make up for the additional weight? I've got stock springs & Koni DA's...would I just need higher rate springs? Would I need to change the rear suspension?
So far as racing, I figure I can barely harness 400rwhp on the 315 victoracers on an autox, much less 500+rwhp. I just thought the bigger block would be more suited to RR than autox.
So far as racing, I figure I can barely harness 400rwhp on the 315 victoracers on an autox, much less 500+rwhp. I just thought the bigger block would be more suited to RR than autox.
Stiffer front springs and likely a bigger front swaybar depending on what you currently have.
I went the other way on my 3rd gen, swapped from an iron L98 block to an aluminum LS1. I originally had 650 lb/in front springs, 36mm hollow front swaybar, 120 lb/in rear springs, 1" solid rear swaybar. It understeered badly w/ the lighter engine, but ride height was only 1/8" higher than w/ the iron block.
I could either go softer on the front suspension, or stiffer on the rear, to correct the understeer. I liked my front spring rate so I left that alone. I went down to a 34mm hollow front bar, it helped a bit but still had a push on turn-in. I started testing rear springs with what I could lay my hands on, a set of 175 lb/in and a set of 250 lb/in springs. The 175s pretty much neutraled it out with street tires, but I liked the 250s as the car had just a hint of oversteer on high speed cornering...I could manage it w/ the throttle very predictably.
In your case, you have a problem I didn't...your front springs may not be able to handle the added weight. Ride height may be too low, or it may bottom out on the bump-stops over bumps. That limits your options if so, you'll have to add spring rate up front and then start tuning from there. Stock '93-97 front springs would be a good starting place, and they should be available cheap.
I went the other way on my 3rd gen, swapped from an iron L98 block to an aluminum LS1. I originally had 650 lb/in front springs, 36mm hollow front swaybar, 120 lb/in rear springs, 1" solid rear swaybar. It understeered badly w/ the lighter engine, but ride height was only 1/8" higher than w/ the iron block.
I could either go softer on the front suspension, or stiffer on the rear, to correct the understeer. I liked my front spring rate so I left that alone. I went down to a 34mm hollow front bar, it helped a bit but still had a push on turn-in. I started testing rear springs with what I could lay my hands on, a set of 175 lb/in and a set of 250 lb/in springs. The 175s pretty much neutraled it out with street tires, but I liked the 250s as the car had just a hint of oversteer on high speed cornering...I could manage it w/ the throttle very predictably.
In your case, you have a problem I didn't...your front springs may not be able to handle the added weight. Ride height may be too low, or it may bottom out on the bump-stops over bumps. That limits your options if so, you'll have to add spring rate up front and then start tuning from there. Stock '93-97 front springs would be a good starting place, and they should be available cheap.
I have revalved bilsteins from Strano Parts. They are also used on the LT1 cars.. I also have a S/T 35mm front sway bar. I am still debating on running a bigger rear. So far the car feels good.
