What suspension setup are you running? Im having issues with clearance. My car is an 87 IROC, with the following. LS3, T56, eibach sportlines etc

Things under the car are dragging over every single speed bump regardless of speed, angle etc.
The difference in weight from the previous motor to the LS3 make this even more of a challenge because the springs that are sold online have drops based on factory motors and not the LS. There is a considerable amount of difference between the two motors

Please help. Ive gone through so many threads, ive contacted Hawks. Im not getting what I feel like is a solid answer.

WHAT ARE YOU USING?

 

what motor was in the car before a 4 cyl?
post pictures of your car so we can see how low it is. this is much better than guessing.
what did hawks say? what solid answer do you feel you should get?

 

it had a 5.7L TPI motor with a automatic.
Bruce suggested Hotchkis 1In lowering springs. At the ratings/drop of those it would hypothetically give a bone stock 3rd gen car an .6in raise over the sportlines, right?

I dont feel confident with his suggestion because my car is far from a 5.7L with an auto

 

what parts underneath are actually dragging or having clearance issues? The body itself doesn't look that low... could be a cross member or exhaust fabrication issue

 

It doesn’t appear much lower than mine (26” at the top of the wheel arch), but I have long tube headers with V-band clamps at the collectors which I use as skid plates. I avoid speed bumps and dips like the plague, but track transitions still scrap. I can’t speak for suspension because mine is full custom and would not be relevant to your situation. I have friends that have had great success using weight jacks. Something to consider.

 

Im not sure what's hitting. But every speed bump creates a grind thats unsettling. Ive already had to remove my exhaust. Im now running straight longtubes only. But the exhaust that was on it snagged and began to completely drag down the road throwing sparks

 

Car doesnt look that low, as mentioned. Perhaps the exhaust wasnt tucked up close to the floorboards, like 1/4 from touching, close.
I have Ground Control weight jacks. Car is lowered some 1.5". exhaust/subframe connectors/x-member dont rub on speedbumps so long as i go slow over them.

 

My car is very low with rear Sportline springs and UMI front weight jacks. My exhaust hugs the bottom floor pan which I feel is the biggest issue with these cars. A custom crossmember or use of the Holley Blackheart system gives you room around that portion of the floor for exhaust routing.

 

In that case I think the first thing to do is get underneath and see whats hitting... and assess the lowest points - typically exhaust when using "LS Swap" y pipe routing

 

I have the discontinued Holley blackheart gives you really good ground clearance, especially if you have a trans x-member that has cutouts to tuck the exhaust up. My cats are the lowest point for me and occasionally do rub on higher speed bumps.

 

With a lowered car, it's normal to avoid speed bumps and steep lot entrances. If this is not possible, then you should not lower it.

If you want help, then you need to be more specific about what is bottoming. The solution is going to be a combination of driving habits, raising the car some, and relieving some clearance underneath.

 

This isn't my first car thats been lowered. This is my 3rd or 4th fbody that ive owned that's lowered. This is the only car ive had issues with.

If you OWN A LS3 SWAPPED 3RD GEN, PLEASE RESPOND WITH WHAT SUSPENSION YOU'RE RUNNING. THE REST OF YOU CAN KICK ROCKS WITH YOUR SNARKY REMARKS

 

I have yet to find a speed bump that doesn't drag with this car. Straight on, taking them on at different angles, less than 1 mph. Doesn't matter

 

I see your bad personality is still in tact.

 

absolutely

I see your reading comprehension has worsened

 

It seems as though getting under the car and looking at what's scratched up will give you your answer. I could tell you what was hitting under my car when I looked. What I did was lift the car up on jack stands high enough to look under. Crawling under will help a lot. Then look for fresh metal/areas of missing paint. You probably not gonna have to worry about the areas that aren't scratched. I'd look specifically for areas that are missing paint. Once you identify these areas of impact, I'd recommend getting out from under the car. Maybe at this point put the car down and drive with more awareness of the low hanging areas. The other option is, with the car up in the air, make adjustments to the areas that are hitting so they don't hit any more. This is what I did and now my lowered car doesn't have a scratched up undercarriage and can go over some speed bumps.

 

Deleted

 

Pics help too, but why only ls3 cars? Its probably more to do with the exhaust hanging too low, maybe. Thats usually the likely culprit.

 

any LS swapped cars with a T56 feel free to say what suspension you're running

So far, ive gotten nothing but suggestions, trolling, amd people asking me questions

It shouldn't be hard to say what suspension a person has

 

Sounds like the torque arm could be doing some self clearancing. Only way to sure is to get under the car and take a peek. My engine is an iron block 370 LS with a 4l80e and I'm lowered 1.5" without issue

 

check your PMs please.
Thanks

 

Your static ride height might not look exceptionally low but Sportline springs are a goofy design that ride the bumpstops on a regular basis. This is why your car is sledding so much. Almost any other spring will be an improvement.

​​​​Just assume you might have to trim length up front to get the look you want. Or you can do weight jacks but the spring rates are high. Or you can calculate what you need and select it from the Moog price list.

 

My C4 SLA/IRS suspension swap does not help your situation, which is why I didn’t include it in my reply. With an LS swap and long tube headers your exhaust is going to be your lowest point and that is what is scraping on speed bumps. It doesn’t get anymore definitive than that.

 

That's debatable. Could be scraping might be something else. He needs to get under the car. It's nothing but speculation

 

I have a LS T56 with koni yellows and moog springs on all 4 corners. Long tubes with a 3-5in Y merge and back down to 3 out to GMMG exhaust. I always take speed bumps at and angle or avoid but other than that nothing scraps other than driving fast through a dip in the road.

Everyone on here is just trying to help.

 

if i could give you multiple thumbs ups I would. Thank you, Sir

 

This is my setup which is about as tight as you can get to the floor and still have adequate exhaust size. Like others have mentioned I take transitions slowly and avoid any steep changes in angle. I can get over most speed bumps at an angle.

 

Mind taking some pics? A parking lot side shot and chin to ground clearance isn't very helpful
Underneath would be preferable. Without seeing what's hanging low for your car, we can't do much more than speculate

Low hanging exhaust is the usual suspect. Scraped up tubing will point out the problem areas. If it's banging on the rearend or suspension, then it'll also show marks. Since a local exhaust shop made the system, it's impossible for us to assess the system that you haven't shown any pictures of
Aftermarket torque arms can (but not always) also make a ruckus. They often strike the LR floor pan and slowly "self clearance"

Thumbing through your build thread, you have both. Neither problem is limited to LS3/T56 spcifically

Also, lose the chip on your shoulder. We're all enthusiasts trying to help you. Reading this thread, I didn't see any snarky comments before yours. Even if there were, you as an adult should be able to take the useful information from them. Lord help if you get a reply from sofa

 

Agreed. Pictures are needed.
It's not about what you have but rather what it weighs.
With an engine certainly heavier than the OPs (Gen 1 iron headed SBC at about 550 compared to the all aluminum LS3 at an estimated 500) and a transmission that's heavier also (700R4) all in a chassis that's been lowered 1.5-2", my very tucked up y-pipe still scrapes.
Where is it scraping? Pictures tell the story.












Front fender.

I've managed to speed bump flatten that spot where the beverage can is sitting.

 

in the end, it scrapes.
it sucks, but thats life.

unless youre jumping into parking lots and flattening the exhaust tubes, just go with it.
life it really too short to worry

in the custom world with air ride, we call it self clearancing...