"Best" Drum-to-Disc Approach? [Archive] - Chevelle Tech

: "Best" Drum-to-Disc Approach?


'70 Chevelle
Mar 15th, 03, 2:48 PM
Ok Guys,

I've read all of the archives - no luck.

I have a 1970 Chevelle Malibu currently undergoing a body-off-frame rebuild that has drums on all 4 corners. It's going to be a street/strip ride w/ a supercharged BB powerplant. I want to goto disc all the way around (or at least up front). Cost aside, what is the best way to go about this?

Option:
1) B-Body Tall Disc conversion (leave rear drums?).
2) Procure the original OEM '70 SS Disc brake components (spindles, backing plates, caliper branckets, etc.)
3) Aftermarket "stock" disc conversion (like Master Power, etc.)
4) Aftermarket Hi-Po conversion like Baer, Wilwood.

Now, I'm still contemplating dropping the front 1 or 2" for the sake of looks. How would that change your answer? I want to make sure whatever I do that I'm not sacraficing weight transfer abilities for racing.

PS. Anyone have any before/after 2" drop spindle conversion pics? That would be really helpful.

Thanks

Slo307
Mar 15th, 03, 3:02 PM
Tall spindle conversion is just a bad deal. If you want the best, go with a 4 wheel kit from Baer I have used a lot of parts from the aftermarket over the years and they did what they were susposed to do and were very afordable.

'70 Chevelle
Mar 15th, 03, 3:06 PM
Thanks for the response Slo307.

I have a Baer catalog coming through snail mail. Do you know if they offer a dropped spindle option for their disc conversion kits? Any known issues with geometery, bump steer, etc.

Slo307
Mar 15th, 03, 3:38 PM
I do not know about drop spindles from baer. I used the Edelbrock Eibach springs and shocks. The car sits about 1 3/4" lower and drives good.

82caballero
Mar 15th, 03, 3:46 PM
i have seen the tall spindle conversion posted all over the place, but lately i have seen a lot of negative posts on this procedure. i was just wondering why its sort of a bad idea nowadays?


thanks.

l. garcia :cool:

Chuck Constantine
Mar 16th, 03, 12:15 PM
I did the tall spindle conversion (B-body 12") 2 years ago and it was the best, affordable mod I ever made. I rip thru some of the local canyons that are fairly bumpy and have never had a problem. If I had big bucks to spend on a "Commercial" conversion kit, I probably would have done that. However, any conversion to disks is better than drums. Mine has paid for itself at least twice in LA traffic where things are moving 75+ down the freeways then suddenly stop. I know for a fact, the Elky would have been totaled cuz it would have never stopped in time.

http://home1.gte.net/res096qi/71Elky.htm

thor27
Mar 16th, 03, 2:46 PM
I've got a tall spindle conversion on one car with hotchkis uppers. They are HEAVY and fairly spendy when you factor all the parts in. I don't have any negative comments on their function, just that they weigh a lot more than the stockers.

Doing my other chevelle now and if your not in a hurry and can shop around some the stock stuff is readily available. I Just got a mint set of spindles, caliper brackets, backing plates and core calipers for $90.00. They are out there, but you can't be in a hurry.

cjlandry
Mar 16th, 03, 3:44 PM
Originally posted by Slo307:
Tall spindle conversion is just a bad deal. Really? Tell me what experience you have with it.

It's funny how people are knocking the tall spindle conversion all of a sudden. Seems like one person started all the negative talk about it and a few others have jumped on the bandwagon.

It's been the way to go for quite a while. If the bump-steer issue were so dangerous, Global West and Hotchkis would have been sued out of business long ago.

Originally posted by Slo307:
If you want the best, go with a 4 wheel kit from Baer I have used a lot of parts from the aftermarket over the years and they did what they were susposed to do and were very afordable. Baer affordable? Are you a millionaire or something? I'm sure their stuff is awesome, but affordable is a very subjective term.

I did the tall spindle conversion and fabricated my own tubular control arms to get the better caster and camber out of the swap.

Mine is a daily driven street car that gets driven hard on the highway and around curves. And it's a well known fact that south Louisiana highways aren't always very smooth. I have yet to feel this bump-steer issue while driving hard. But I'm no SCCA racer either.

Several Team Chevelle contributors have run with the tall spindle conversion for quite a while, and I've yet to hear a complaint from someone who's done it.

I'm sorry, but if you're gonna post that "it's a bad deal", please give a reason. Yeah, we've seen the numbers. But that doesn't explain why everyone who's done it is so happy with it.

It reminds me of people who say you can't make a small-block run fast in a nearly 2-ton Chevelle. They have all the numbers, but real world experience proves differently.

'70 Chevelle, since you've stated that it's a street/strip ride, I'd say that you'll do fine with whichever braking system you decide on. I know for a fact, beyond any doubt, that the tall spindle conversion with 12" discs and drums in the back works awesome on the street. On the strip you won't have to worry about some idiot turning left in front of you (unless you're in the left lane and the other driver loses control).

And you have to remember that on the strip, you only have to slow it down once. So your brakes won't be heated up before you make your run. You sure don't need 13" brakes to pull you down from high speed one time.

I also agree with Thor, if you don't mind looking you can probably find an affordable original A-body disc brake setup.

'70 Chevelle
Mar 16th, 03, 6:36 PM
Thanks for the responses so far...

Let me elaborate some more too on what I was originally thinking.

- Global West GenII Uppers w/ Del-A-Lum
- Global West Lowers - coilover ready
- QA1 coilovers
- B-body Tall spindle conversion w/ 12" rotors off a 1LE Camaro
- stock drum rears

The whole front end of the car needs rebuilding regardless what I do. So the cost of the GW "D" kit is somewhat offset by the fact I'd need to buy a rebuld kit anyways. My only concern is all of bump steer talk I'm hearing on the tall spindle conversions. That's where I'm having a hard time deciding on the tall spindle... or just getting a "normal" disc brake conversion kit and just adding 2" dropped spindles.

Chuck Constantine
Mar 16th, 03, 11:48 PM
I didnt do as well as some but I think for what I spent for the complete front end wasnt bad.

1 set B-BODY SPINDLES & BRAKES $125.00
SUMMIT 1 set HSS-1155 LOWER BALL JOINTS $127.38
" 1 set HSS-1103 TUBULAR A-ARMS $409.95
HOEng. 2 set LG22S DURAGRAPH LOWER BUSHINGS $49.50
OPG 1 ea MPA1350 PORPORTIONING VALVE $65.00
AUTOZONE 1 ea DS749 CENTERLINK $31.99
" 2 ea ES406L TIE ROD ENDS $59.98
" 1 ea FA443 IDLER ARM $12.99
" 1 ea M1521 MASTER CYLINDER $34.99
" 2 ea ES427R TIE ROD ENDS $21.98
" 1 ea C110 DISK CALIPER $12.99
" 1 ea C111 DISK CALIPER $12.99
" 1 set SET5 INNER WHEEL BEARINGS $15.98
" 1 set SET3 OUTER WHEEL BEARINGS $12.98
" 1 pr 8871 BRAKE HOSES $31.98
" 1 set 522 PERF. Z-RATED BRAKE PADS $39.99
TOTAL $1069.17

69boo307
Mar 17th, 03, 7:44 AM
I'll be going with a Baer track 4-wheel kit when I get to that point in my suspension/brake rebuild. I know I could do 'stock' type conversion cheaper that would work just fine on the street, but I'm going for a little more 'aggressive' brake setup and I've heard nothing but good things about Baer. I guess it depends on what your goals for the car are.

Q-ship
Mar 18th, 03, 2:21 AM
I'm here to say I have done the "Great Tall spindle Conversion", don't do it, it is not a poor mans disc brake conversion after factoring in the upper control arms require, and CJLandry how many hours do you have in building your own arms? That is not free your time is worth something, at least mine is. I have done it in the 80's when it first appeared in Car Craft mag, at first using the stock upper control arms, didn't work too many shimed needed to align the car. In the years latter tried again this time using the GW upper arms (very expensive), still not right, we did a bump steering check and found 1/4" toe out, very bad from a handling stand point, don't believe me ask anyone who drives a real race car. We knew that bump steer can be corrected with ALOT of work relocating the tierod end up. I also noticed funny turning scrubbing of the front tires, and I do SCCA race, and knew I had another problem that was traced to steering ackermann. So here are the problems that have NOT just came up, they been there. How many of you out there have compared a stock spindle disc brake with a good set up (not 30 year old worn out) to the "Great Tall Spindles", I have. If you are serious about brake there are alot a good quality brake kits out there, I agree Baer is the possibly the best on the market today, and yes expensive, but you get what you pay for. If your going to Drag race the car I wouldn't use the tall 12" brakes stuff very heavy!, the stock stuff is better but still a little heavy, Baer or Wilwood would be alot lighter and better for weight transfer, along with lower unsprung weight which will help handling. I am not to sure about the Wilwood stuff it may still be for off road use, single seal in the calipers which can let water in the hydralic system, Baers are a street dual seal system, but I could be wrong about the Wilwoods. smile.gif

cjlandry
Mar 18th, 03, 11:04 AM
I have 12-15 hours in the arms, and I enjoyed every minute of it. Those aren't hours that would have otherwise been spent making money, so I still consider it "free labor".

I understand that you do race SCCA, so suspension specs have to be much more precise for what you do. In that respect, I agree with you 100%. The bump-steer issue is a much larger factor for you.

I also agree that original disc brake setups are better if you can find one.

And I agree once again that the Baer brakes are probably some of the best on the planet. The price reflects this.

All I'm saying is that there are many ways to stop a Chevelle, and the tall spindle conversion is just one of many. It ultimately depends on what you have available (money and materials) and what you plan to use the car for.

As far as the Wilwoods are concerned, if they say they're for strip use only, believe them. They wouldn't say that if they didn't have to cover their asses. That probably means they're designed to be lightweight and they're not designed to handle the rigors of getting heated up in stop and go traffic.

'70 Chevelle
Mar 18th, 03, 8:05 PM
I didn't realize the tall spindle setup weighed that much. That's good information to know - and probably a good reason to look elsewhere for my needs.

OK, so let's assume I either go w/ a Baer kit or stock... Any geometery, bump steer or other performance problems if I also added a set of 2" dropped spindles (like those from Classic Performance Products)?

Oh, Oh!!! And then add a set of "normal" GW uppers and lowers. :D Anyone have some money I can borrow? :(

Palkojj
Mar 18th, 03, 10:58 PM
70 Chevelle, I am in the process of converting my 67 to tubular uppers and F body spindles. I have heard rave reviews on the handling and braking from many folks here and on other sites.

I am going with Powerslot 11 inch rotors. They are galvanized and the slots help out quite a bit with braking. Plus, no problems fitting my 15 inch wheels! Some folks say I will go through pads quicker, but for the better stops, no problem. Disc brake pads have to be the easiest thing to change on a car next to the air cleaner! :D

I will let you know how it all works when I am done. Good luck! graemlins/beers.gif

Q-ship
Mar 19th, 03, 1:38 AM
70 chevelle: I believe the 2" drop spindles use the brakes off the s10 and 78 - 87 g-body, these brakes are a joke, ask any grand national owner. The rotors are way to thin for a 3400 pound car it would be disasterious on a 3900 to 4000 pound chevelle. The baer kit uses stock spindles so there is no issues with steering geometry. I personally would never use the drop spindles due to the poor brakes.

Theo
Mar 19th, 03, 2:21 PM
After reading all this, I decided to skip the tall spindle conversion for my just purchased everyday ride (yeah!!!) :cool: .

I will go with the MP Brakes rear disc setup (http://www.mpbrakes.com/reardiscspecial.htm) and ECI brakes (new) front disc setup (http://www.ecihotrodbrakes.com/disc-brake-kit-with-drum-brake-spindles_ec-723ack.html). Total cost will be $1600. This includes the whole brake system except the metal brake lines.

Any opinions on the new ECI front brake kit?

Thanks a lot. This forum is great!!!

Theo