How LOW did you go, and are you happy?

[Josh69]

I posted this on lateral-g, but figured I'd hit up the peeps over here too.


Facing the dilemma, it's decision time on my suspension, and I'm trying to decide how low to go. I've had many low cars, so I know what to expect and the 'finesse' that is required in owning one.

The car is a '69 Firebird, pontiac motor. I called Hotchkis, who I'm told supplies DSE, and they told me specifically that both the small block and big block front coil springs are 600lbs. They liked that spring rate for both motors. The only difference is the free length (small block spring is shorter). This answers many questions I'm sure a few of us have had.

The car will be on 18's, so it's either the big block springs and 2" leafs, or the small block springs and 3" leafs.

My concerns are my front subframes and/or crossmembers dragging on bumps, my front spoiler catching, my exhaust, etc. The car is getting GW SFC's also, and a TKO (not sure if that crossmember is lower than the subframe or not). Will a 3" clear, or is a 2.5" exhaust recommended?

So, how low are you first gen owners, and are you happy being that low, or would you do it differently? What parts on the first gen chassis are of the most concern?

[trapin]

The bolt on parts you buy from Hotchkis and GW will lower your car but it will not be 'terribly' low where you're going to have to worry about undercarriage parts bumpin'. In fact, a lot of guys that use those parts don't think they're enough so they end up modifying them with lowering blocks or by cutting coils out of the coil springs.

This reminds me of something Mark Stielow once said, "It ain't a hot rod if the tires don't rub".

[harshman]

Determine your ride height before ordering springs. Install springs and wait for 30 days before trimming them – this will allow the spring to settle. You can also add small lowering blocks to the rear. All this advice comes from Tom "Chicane67"– the suspension guru. Also, to low can affect performance, and you can always trim more later than have to buy new springs. I have to replace my fronts due to too much trimming.

[Josh69]

I'd like to run the 3" drop leafs, so the front is the wild card. I can cut a coil, but I can't add one. After hearing directly from Hotchkis that the small block springs are shorter but have the same rate as the big block springs, that was good news as long as it wasn't crazy low...the car is going to be a driver, maybe 3-5K a year.

Coilovers just aren't in the budget right now.

[Neil B]

I have Hotchkis 2" drop small block springs in the front. My front fender sits 23.75" from the ground with a 26" tall tire. The big issue is my Hooker Super Comp headers. The driver's side collector hangs very low and the flange is only 2.5" off the ground. Speed bumps are a no-no with my combo.

[Josh69]

Harshman, what springs did you start with?

[69TAPoser]

Just to clarify, there is no such thing as a big block Pontiac. They are all the same block, just different bore, hence the recommendation for the same springs.

I went with DSE 3" drops in the rear and I chose coil-overs / GW Tubulars for the front. The main reason I went coil overs is I wanted the ability to "tune" my ride height.

I received my TKO600 last week from CC5 Speed with the crossmember. You will not have clearance issues with the TKO.

I am not "on the ground" yet so I can't give you ride hide details.

Phil

[Josh69]

My point is they recommend the BBC springs for the firebirds, but the SBC springs are the same rate, just shorter. So think of it like 2 different springs for the firebird, one is shorter, the other longer, same spring rate. Typical Pontiac engine weighs 640#, BBC is 675# and SBC is 585#, roughly, so the Poncho is in the middle. Add aluminum heads, and whallah, same weight as SBC. :)

[Josh69]

I have Hotchkis 2" drop small block springs in the front. My front fender sits 23.75" from the ground with a 26" tall tire. The big issue is my Hooker Super Comp headers. The driver's side collector hangs very low and the flange is only 2.5" off the ground. Speed bumps are a no-no with my combo.

What engine and springs do you have? I saw pics of your car in a thread about your wheels, it looks good.

Did you do any trimming or add any blocks?

[Neil B]

What engine and springs do you have? I saw pics of your car in a thread about your wheels, it looks good.

Did you do any trimming or add any blocks?

It's got a DZ302 shortblock with aluminum heads. No AC, no PS, or other heavy items on the nose. Hotchkis 1907F's in the front with no cutting. Stock rear leaf springs with 1" lowering blocks. Also, in the rear, my exhaust hits the side of the diff pumpkin on big bumps due to the lowering. I'd go this low again, but I'd choose a different set of headers.

[Josh69]

Cool, that's the best excuse I've had yet to buy aluminum heads! Haha!

[harshman]

The rear springs came with the car and are junk. I am swapping to Guldstrand slalom springs that will put my rear at about 14-14.5” from center of axle to lower finder lip (currently it is about 13.5”). Front is to low as well – tires rub and going over speed bumps is very trying. I'm replacing those with new coil springs also. All to get the car ready for ebay.

[Steve Chryssos]

Header collector clearance always seems to be the biggest problem. :hand: 4" minimum is preferred.

[jerome]

why not use circle track spring adjusters and 5.5x9.5 coils? cheaper, more adjustable, and more spring rate options.

[Josh69]

why not use circle track spring adjusters and 5.5x9.5 coils? cheaper, more adjustable, and more spring rate options.

I think that's the current plan after doing more research all day yesterday. I called ATS last night, they no longer make them, so I'll get the ones from Speedway and cut them to sit in the spring pocket like CarlC did on his website. I think I'm also going to do the 2" drop leafs, then I can fine tune it with a block up to an inch if I desire for the stance I want. It seems to be the best compromise and since my goal is an 18x10 wheel I may not be able to run that low without a minitub anyway. I've cut quite a bit off my quarter and rolling the rest in the area of potential contact when I installed the new quarters and outer wheelhouses so I'd probably be okay, but I won't know until they are on the car going down the road with a load for sure!

[whytry]

I love my car being low, I am running QA1 coilover up front with 750 lb spring rate, cut 1/2 coil, it sits really low and the only downside is the collectors scrape and so do my Caltracs bars, but its worth it to me. I am leaning towards airbags on it again now...

[shmoov69]

Mine is pretty low. The only part that rubs (usually) is the exhaust. When I had long tubes, it rubbed all the time. Then I got a set of intermediated length headers and it helped a ton! The front spoiler will drag occasionally pulling into a parking lot or something. And as you know, speed bumps very slow and at an angle. I don't think that I have ever rubbed much of anything else except when doing something stupid!

[CarlC]

Regardless of spring rate, best handling will be achieved when the center of the sphere in the lower ball joint is approx. 1/2" lower than the center of the front lower A-arm bolt when the car is at full weight and on the ground. For most cars this means a 9 - 9.5" distance from the ground to the center of said bolt with the car on the ground. This does not typically yield the full-on slammed appearance, but the associated handling and practicality ills are greatly reduced.

[vcho455]

Xxx

[vcho455]

Having an exhaust installed that is tucked up as tight as possible will make living with your lowered ride much more enjoyable. Unfortunately most exhaust shops only care about how fast they can get you out of the door. If you can DO IT YOURSELF. Some tricks to help with low headers are to shim the rear tranny mount up. This will raise the collectors, just keep in mind your front u-joint clearance and angle. Get rid of the collector flanges. I use the stainless truck muffler band clamps. They are about 3" wide and work great. As with anything some are better than others, go for the ones with the formed metal blocks, (Nelson makes good ones) not the ones with the banding wraped around some flat bar stock. You can use them in front of the rear axle and get easy access to your tranny. (I've had lots of bad tranny luck over the years) You can also make spacer plates for your motor mounts (not as simple as it sounds) to get a little, but on an early bird your hood to carb clearance is not that great so measure often and think hard. You can live with 2 to 3 inches of clearance between the front wheels but you need 4 inches min. halfway between the front and rear wheels. My Javelin is set up like this and after 19000 miles, I've only hit once on the header, over some extremly grooved pavement. The tar looked like a semi truck had run over 5 gallons of playdough.

[Josh69]

Thanks for the info guys. I went with the conservative approach for now and got the 2" drop leafs and 2" drop big block springs from DSE ordered on Friday. I figured I can lower the rear more with a block if necessary. I can cut the front, or get other springs if I'm not happy. I needed to get the car on the ground, square, and finish it.

I got two differing sets of info from Hotchkis, one is the spring rates differ, the other is the free length differs. I went with the BBC springs since they are either stiffer, or longer, and according to most of the women I've known, it's better to be stiffer or longer, than too soft or too short..... ;)

This won't be the first car I've swapped out the springs on if I'm unhappy, and probably won't be the last!

[jerome]

Regardless of spring rate, best handling will be achieved when the center of the sphere in the lower ball joint is approx. 1/2" lower than the center of the front lower A-arm bolt when the car is at full weight and on the ground. For most cars this means a 9 - 9.5" distance from the ground to the center of said bolt with the car on the ground. This does not typically yield the full-on slammed appearance, but the associated handling and practicality ills are greatly reduced.

Why don't want the lower ball joint slightly higher than the center of the front lower A-arm bolt? That way the suspension would go directly into negative bump.

The way you have it, the suspension make positive camber, zero camber, then finally negative camber in bump. What is the advantage of this? I thought you wanted negative camber in bump

Not saying you are wrong, I just had a different understanding of this concept.

EDIT: I did a little more thinking, and I realized I was wrong about the positive camber stuff. Having the ball joint lower than the pickup points would actually help create MORE negative camber for small amounts of bump, so in the end it would be better to have the ball joint lower than the mounting point. You were right, I was wrong.

Jerome

[CarlC]

Keeping the ball joint slightly lower also helps average out bump-steer problems. Get the front end too low and it will dart under braking and make for a not-so-fun ride.