90 LeBaron V6 brake system w/rear discs on 89 Horizon/TBI or T1 engine swap?

[AngelesRunner]

I have both cars. I have GLH 5 lug knuckles and new KYB GR2 struts. I was thinking of SLH and have all of the parts but the Caravan calipers are huge and heavy. Since the 90 LeBaron has the unvented rear discs listed for SLH2 would it be okay to put the whole LeBaron system with smaller lighter 54 mm KH calipers, including the proportioning valve, under the 89 Horizon?

The 89 Horizon is in the early stages of rod knock with 135K on the odometer and leaks oil from the main and rear seals. If kept, it would need to be pulled and rebuilt. The Horizon is TBI with an automatic torque converter lock-up A413 automatic.

I have a complete 89 Turbo Voyager with 2.5L T1 and A413 automatic. I also have a 91 Caravan with the 2.5L TBI and A413. The Caravan's final drive ratio is higher. Neither van body is worth keeping so I was wondering what was the forums opinion of the best route for turning the 89 Horizon into a daily driver for a 30 mile 40 to 50 mph daily commute? If normally aspirated is better for a daily driver I also have a rusty 92 stock Acclaim with only 85K on a 2.5L TBI and A413 automatic. The Acclain has a lower final drive ratio better suited to highway driving than the Caravan.

Rebuild the 2.2 TBI? Transplant a healthy 2.5 TBI? Transplant the 2.5L T1 turbo engine?
You who have been through this please advise.

I was thinking of going to plain steel Chrysler 5 lug 14 inch wheels with 195/60R-14 or 65 profile tires. I also have a set of after market American Racing 15" aluminum wheels that I could use but which would require purchasing lower profile tires which are more expensive. What would you recommend?

88 Horizon on jack stands
89 Horizon
89 T1 Voyager
91 Caravan
91 Acclaim
92 Acclaim on jack stands
94 2.2L A413 Shadow

[raccoon]

id use the acclaim or horizon, with the turbo engine. seems you have more then enough stuff. horizon would be faster but the acclaim would be comfortable.

[turbovanman²]

Well, hmmmmmmmm, the turbo engine will require more work to get running but will give you more power, the TBI's are pretty sad so if you can handle the extra work, then go turbo.

As for brakes, you can't really swap over the car stuff to the front without machining the knuckles to fit the L body and slotting the mounting bolts to adjust the camber. If you just want a DD and the current brakes are ok, just leave them alone. So the simplest swap is Caravan calipers and the solid rear discs with the disc prop valve and matching 24mm M/C.

Best bet is too rebuild the 89 TBI trans to turbo specs and retain the LU.

[RoadWarrior222]

On a 40-50mph drive though, you might wanna put a lockup on a switch... it's ultrafrigging annoying having it come in and out at those speeds, and can I think frag it quickly.

---------- Post added at 04:49 PM ---------- Previous post was at 04:47 PM ----------

Oh btw, I think at 40-50mph the turbo motor is gonna be rolling in vacuum, probably low 2000s RPM, so might not be all that thirstier than TBI...

[supercrackerbox]

Oh btw, I think at 40-50mph the turbo motor is gonna be rolling in vacuum, probably low 2000s RPM, so might not be all that thirstier than TBI...

My Charger is decently modded, and I average 29.5mpg mixed driving and have a personal best of 34.1mpg on the highway. Granted, I have a 5 speed.

[cordes]

I've found that the turbo cars get better mileage than the TBI cars in general. Even more so with the potential for a custom cal that's just not supported with the TBI stuff.

[turbovanman²]

I've found that the turbo cars get better mileage than the TBI cars in general. Even more so with the potential for a custom cal that's just not supported with the TBI stuff.

That's why I said turbo motor, some of the MPG you guys are getting makes me cry, lol.

[supercrackerbox]

That's why I said turbo motor, some of the MPG you guys are getting makes me cry, lol.

Keep your boost gauge as deep into vacuum as possible when accelerating and cruising. Be willing to give up a little speed going up hill- you'll make it up going down the other side. Shift at the lowest RPMs you can without lugging the engine. Engine brake as much as possible to slow down without putting the car into neutral or hitting the brakes. Try to time stop lights so you can coast through them without actually stopping. Obviously don't be a danger to others while doing all of this.

Let me know if you see any improvements.

[turbovanman²]

Keep your boost gauge as deep into vacuum as possible when accelerating and cruising. Be willing to give up a little speed going up hill- you'll make it up going down the other side. Shift at the lowest RPMs you can without lugging the engine. Engine brake as much as possible to slow down without putting the car into neutral or hitting the brakes. Try to time stop lights so you can coast through them without actually stopping. Obviously don't be a danger to others while doing all of this.

Let me know if you see any improvements.

I do all of that but its extremely hard to keep it in vacuum but we'll see soon how my new setup does.

[supercrackerbox]

I do all of that but its extremely hard to keep it in vacuum but we'll see soon how my new setup does.

Yeah, I found it a lot easier on the Charger than the Daytona due to the quick spool of the Daytona's Mitsu turbo. Still, once I started trying all this, the Daytona's average mpg went from 26.5 to 30.

[tryingbe]

KH 54mm caliper is what stock on my GLH. I won't advise "upgrading" to them.

[AngelesRunner]

KH 54mm caliper is what stock on my GLH. I won't advise "upgrading" to them.

But I have a Plymouth Horizon with tiny unvented rotors and narrow 200 mm drums in the back. The reviews from the past all said that the GLH had excellent brakes. Have you ridden in a stock Omni or Horizon with factory brakes and can you make a comparison with the stock system to that of your GLH's brakes?

I'm looking for a decent daily driver and I have to do something with the brake system soon.

Thanks if you have time to reply.

If anyone previously replying could look at the questions from my original post I would greatly appreciate your answers.

---------- Post added at 08:43 AM ---------- Previous post was at 08:38 AM ----------

I have GLH 5 lug knuckles and the larger brake horns. They go right into the KYB GR2 struts. 88 and 89 Caravan rotors and calipers slide right on. The 54 mm piston calipers form the LeBaron should go right on as well if I go that route. I'm thinking that lighter, less unsprung weight, is better if the road is not perfectly smooth.
What do you think? If it can stop a LeBaron which weighs 500 pounds more will it be outstanding on a Horizon?

[cordes]

GLH brakes will make a big difference in stopping power vs. the non vented stuff. I doubt you will notice a difference between those and the stock ones when it comes to ride or gas mileage etc.

[tryingbe]

Sorry, never drive another Omni other than my GLH.

To me, there is no overkill for stopping power.

[cordes]

Sorry, never drive another Omni other than my GLH.

To me, there is no overkill for stopping power.

I agree with that. I need to get a different prop valve for mine and the 11" brakes in the front to match the rear. It'll stop like no tomorrow, but you have to be careful in the rain.

[RoadWarrior222]

Just a FYI, minivan brakes with a light loaded van (~3500lb) will overwhelm 195 tires... but with 215s on they are very hard to get to lock on "sharp" blacktop (i.e. not wet, greasy, dusty) and bring it to a halt like you threw an anchor out the back... well this is cold, having some margin for if I get them hot would be nicer..... but I'm just saying, in a lighter car, you probably don't wanna go "too" good on the brakes if you wanna keep stock tire sizes, because they'll just lock up with not a lot of pedal. Whereas with 215s or even 225s on, the biggest brakes you can get on there will stop it like a brick wall.

[AngelesRunner]

So we are talking about a baseline of a factory stock GLH which is about 2,200 pounds and could have 4 pax for a total load of 3,000 pounds. I don't have a GLH to read the door sticker but an Omni or Horizon factory sticker says 2 pax front seat, 3 pax rear seat and 115 pounds luggage OR a TOTAL load of 865 pounds.

Omni/Horizon and GLH both use a 21 mm master cylinder and the same brake pedal so require the same foot pressure and produce the same line pressure to the proportioning valve.

The Omni/Horizon use 200 mm x 61 mm rear drums while the GLH uses 220 x 68 rear drums. Both use the same 5/8" diameter wheel cylinder. With the same line pressure to the rear, the increased braking force of the GLH is generated by the braking surface being an additional 10 mm from the axis of rotation (220 mm drum vs. 200). The 7 mm increased width of the GLH shoes and drums should make brake wear about the same in both systems by increased contact surface for heat dissipation.

The GLH uses 260 mm rotors vs. 232 mm rotors on an Omni/GLH so the clamping force is applied further from the axis of rotation and therefore the same clamping force would produce greater force tending to stop the wheels rotation. The same line pressure would produce greater clamping force if the calipers piston were larger but I don't know what the diameter of the stock Omni/Horizon piston is relative to the 54 mm diameter of the GLH's piston. I can't find an old caliper in the garage to measure it. The ventilated disc on the GLH would have increased ability to dissipate heat relative to the unventilated rotor on an Omni/Horizon.

So the Omni/Horizon system gets by for mild driving but the engineers who presumably knew what the car was all about gave the GLH 54 mm caliper pistons and 260 mm ventilated rotors for the front and 220 mm x 68 mm drums for the rear. They compromised for the best combination of stopping ability, fade resistance, lightest unsprung weight, long life and brake sensitivity and feel using 195/50R-15 tires.

Alterations we make beyond the factory GLH setup compromise some part of the balance the engineers accepted. Which ways have the community pushed the balance? Why? and what were the results? Anyone?

[tryingbe]

Alterations we make beyond the factory GLH setup compromise some part of the balance the engineers accepted. Which ways have the community pushed the balance? Why? and what were the results? Anyone?

You forgot the accountant part. COST

[AngelesRunner]

So very true, MONEY TALKS, and it's a wonder why they developed a smaller rotors and calipers and drums for the L-bodies when for the GLH they used existing parts that were designed for the larger cars that weighed 500 pounds more. I would guess that 1) They did save money over the entire production run of the Omni/Horizon fleet by using smaller, lighter, cheaper pieces even after paying development and tooling, 2) Unsprung weight may have been a problem when using correspondingly cheap struts, or 3) They may have needed smaller parts to go inside the 13 inch rims.

So what about it? has anyone out there switched a GLH over to 60 mm calipers from a minivan either retaining the stock GLH 220 mm rear drums or gone to the unventilated rear discs like SLH2? If so what was it like compared to stock GLH? In the rain, braking in a turn, panic stops, anything anyone can contribute?

Anyone used minivan calipers on a Shadow/Sundance or Spirit/Acclaim?

[RoadWarrior222]

Well the L-bodies came first by a few years, and the rest of the stable was ancient platform RWDs at the time, so it was new brakes for the new baby... then when the money was there, the K cars came and needed something bigger.