Biggest tire you can put without regearing (91 Hdj81)

[Snipedoggy]

Hi, ik this is a silly question but what is the biggest size tire I can put on my truck ( 91 hdj81) without it being sluggish and having the need to regear. I have a lift and 35’s but the trucks too sluggish and don’t want to regear. I would go stock tires but I think it would look silly with the lift and small tires(last owner put the lift and 35’)

Thanks

 

[COYS]

Go back to stock height and alloys + <33s or stay with what you got and regear.

I’d rather roll a Prius than give up big tires so went with 35s + 4.88s.

Supercharging... I have a ‘97... don’t want to deal with the added heat mgmt and I’m perfectly fine driving 70mph max.

 

[IanB]

33's are fine with stock gearing, or you could add some more power and overcome the gearing deficiency that way while keeping the 35's.

 

[Douglas S]

You could make up for it with an upgraded turbo, upgraded valvebody, or t-case high range underdrive gears, or any combination of those items.

 

[Snipedoggy]

Adding more power in the future sounds fun haha, but I’m also worried about braking, because braking with 35’s isn’t the best, how are the 33’s with braking? Like original?

 

[Snipedoggy]

The big tires look sweet and i will be keeping them for winter and what not, but the braking and gutless ness uhhhh

 

[Tapage]

I've been running 315 on my HDJ80 for years now .. first with auto A442F and then swap to manual H150 .. breaking ..? well I guess everything can be broke.

when I was on the auto tranny, advance timing, more fuel and boost helped ..

 

[Snipedoggy]

Aha I mean like braking performance haha

 

[Douglas S]

If your HDJ81 is pre-93 is has the smaller brakes from the factory. You can upgrade to the 93+ brakes, the swap is well documented.

 

[SHREDwagon]

Install a 3” exhaust / rod profile with 35’s.
If you want more power after, add another $6k. Then look at gears.
Good luck

 

[Corbet]

There are underdrive transfer case gears for the petro trucks, I assume the t-case is the same in the HDJ but honestly don’t know. That could be an option easier/cheaper than regeared both diffs.

 

[BILT4ME]

Install 28" tires. You'll feel like you have a turbo. No problem holding speed, as long as it's not over 65.

 

[Tapage]

if you gonna stick on the auto tranny and plan to run at least 315 ( true 34" ) plus tires and living on the mountains, I'll go for 4.88 .. if living on flat ground, not towing and looking for HW performance 4.56

 

[Heckraiser]

If you're having trouble with braking, you need to address your braking system. Mine stops like a champ on 315's. Everything is stock and in decent shape (after much maintenance). Check hardware, make sure it's all still good, then bleed the heck out of the system (80's require 5x more brake bleeding than any vehicle I've worked on). Once you've done that, consider disabling your LSPV. Was a MAJOR improvement for me.

I would be looking at a turbo upgrade if I had an HDJ

 

[Lumpskie]

Stock axle gears with 315s and a Gturbo here. I have no problem with getting up hills. My rig isn't a race car but I never get bogged down on the highway. EGTs are my only limit, not power. I'm hoping to get an intercooler and cruise up all these small east coast mountains (hills) at 80 mph.

 

[Nay]

28’s.

 

[Snipedoggy]

Thanks for all your help guys, really appreciate it, I’m gunna go smaller tires and check the brakes/upgrade to 93 lc brakes. I will be keeping the 35” tires. I don’t have money to regear (I heard it’s pricey) and I may re gear in the future and run the 35”

 

[Snipedoggy]

The turbo is fine for now 15 psi, but hey maybe in the future I’ll like some more power hehe thanks again cheers

 

[jfmaillot]

are the brakes in the US different than the brakes in Europe? I don't get the braking problem. I'm rolling KM2 37" (with 4.88), I just have gold DBA rotors and EBC green pads and I can lock the 4 wheels without any problem at all here

 

[IanB]

are the brakes in the US different than the brakes in Europe? I don't get the braking problem. I'm rolling KM2 37" (with 4.88), I just have gold DBA rotors and EBC green pads and I can lock the 4 wheels without any problem at all here

'90-'92 had smaller brakes than '93-'97. If yours is a '96 you'll already have the larger brakes.