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- Oct 22, 2002
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Sweet! How big a tire can I run?
Not sure but 28" beadlocks would bring the bling.
Bolt on turbo kit (26 Viewers)
- Thread starter scottryana
- Start date
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Not sure but 28" beadlocks would bring the bling.
Well the car has flares and the stock shoes are 305 wide and the wheels are 20x11.
Mickey Thompson Baja MTZ P3 35x12.50R20LT!
mehbohdi
SILVER Star
HEY!!! How come you got TURBO stickers with yours. 
NLXTACY
Wits' End
HEY!!! How come you got TURBO stickers with yours.
Should be with your turbo kit. A couple didn’t have because I ran out but I sent out separately.
mehbohdi
SILVER Star
Found Wits-End sticker no TURBO 
Buy a $6K "Turbo" sticker, comes with actual turbo.
NLXTACY
Wits' End
Found Wits-End sticker no TURBO
boo, I may have missed yours. I’ll make a note to send out
For those who are running 35/37 inch tires. Once you install the turbo, is there still a need to re-gear?
NLXTACY
Wits' End
totally happy with 35s and stock gears. Perfect for frwy
Bludozer
SILVER Star
Thoughts on how stupid 35s/5.29s and a turbo would feel? Would I live my entire life in boost (not that I would really complain about that I guess)
I ran the math on the stock tires/gearing versus 37" tires/re-gearing. The stock tires are 275/70 R16's, which are 31.2" in diameter. The stock gearing is 4.10.
I am going to run 37 x 12.5 x 17" Milestar Patagonia tires. They measure 36.8" in diameter. The new tires are 17.9% larger in diameter / circumference (Pi*D=C)
To have the same RPM at any given vehicle speed, the gearing would need to be 17.9% lower. 4.10 * 1.179 = 4.84.
The rig I bought last year does not have factory lockers, so I had to put ARB's in anyway. I re-geared them to 4.88 at the same time. The rig will run at the same RPM on the freeway that it did with stock tires.
The math for 35" tires is not as convincing. If I were to run the Milestar 35 x 12.5 x17's, they measure 34.7" in diameter. This is 11.2% larger than the stock tires. Taking the stock 4.10 gearing lower by 11.2% would be 4.56 gears. So, 4.55's would get your right to the same RPM on the freeway that you had with stock tires. But the turbo motor is putting out more torque and that would compensate for the lost RPM with stock gears.
I concluded that if I were running 35's, I would stay with stock gears. I went with 37's and decided to re-gear with 4.88's.
Awesome, thanks Mike. I have KM3 37x12.5, which comes out to a true 35.5.
I was chatting with Christo about possibly doing 4.88’s while he has my rig. However I don’t want to spend all that money and be unsatisfied after I strap on a turbo.
- Thread starter
- #5,295
As I see it the turbo and gearing are separate arguments once you have a turbo.
With the turbo you will have enough power with 35's (maybe even 37's, I don't have them) that it is comfortable on the street. But gearing in my mind has always been about offroad control. Low gears give you the ability to use less momentum.
And please do remember that positive boost pressure is more a function of load than it is of RPM's. So just because you are changing your gearing it does not mean that you are always going to be in boost.
With the turbo you will have enough power with 35's (maybe even 37's, I don't have them) that it is comfortable on the street. But gearing in my mind has always been about offroad control. Low gears give you the ability to use less momentum.
And please do remember that positive boost pressure is more a function of load than it is of RPM's. So just because you are changing your gearing it does not mean that you are always going to be in boost.
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I would take the turbo out of the equation.
Would you want 5.29 and 35s in the real world? Probably not unless it's a wheeling/hunting rig only and wont be used on the highway. If you're looking for offroad gearing, a low range transfer case reduction would be the better bet and wouldn't compromise your ability to do highway speeds. 4.88 is the better choice for 35's. Or even high-range t-case reduction gears. Now if you're just waiting for your 35's to wear out so you can get 37+, then sure.
Having run with and without a turbo on 265's and 315's, I do think 4.88 gears would go great with the turbo kit. Totally not necessary, but I think it would be a good peppy combo.
This past summer, my brother and I installed 4.88s and I plan to leave them in with the turbo as well. I can report back once I get it installed. It might take me a second on the report though (yes, I am one of those shelvers that Joey warned about). I have to finish up a gazzzzzzillion other little things on the 80 first. Like my second hand trekboxx that had fire damage from a burnt up 100 series. To put it into perspective, I have boxes in the truck that I cannot remember whats in them....... most of those are Wits End boxes too!!!! 
Need to get better at prioritizing time for the land cruiser too! Cheers!
Need to get better at prioritizing time for the land cruiser too! Cheers!A couple of things that might help others from my turbo install this wekeend.
Replacing the small check valve under the upper intake manifold is far easier if you remove the throttle body. It does require you to drain the coolant down a bit, but it is very easy to replace from that direction. You then do not need to remove/loosen the intake support strut. This also makes replacing the plugs very easy also.
I removed the exhaust manifolds to replace the gaskets and clean some things up. It is very easy to assemble the peace pipe and sensor with all of that out of the way.
This will not apply to very many people. If you happen to have the front axle torn apart for a rebuild and have the front diff, steering linkage, sway bar, driveline, etc. all removed from the truck, the J pipe just slides right on in there from below. I did remove the rear exhaust manifold shield to make this even easier. My 13 year old held it in place from above as I tightened the nuts on the studs.
Overall, a very easy kit to install. Just need to get the welding done on the stock exhaust to downpipe and also hook up a boost sensor. Not to mention, reassembling the front axle and the transfer case, which is apart for a gear swap.
Replacing the small check valve under the upper intake manifold is far easier if you remove the throttle body. It does require you to drain the coolant down a bit, but it is very easy to replace from that direction. You then do not need to remove/loosen the intake support strut. This also makes replacing the plugs very easy also.
I removed the exhaust manifolds to replace the gaskets and clean some things up. It is very easy to assemble the peace pipe and sensor with all of that out of the way.
This will not apply to very many people. If you happen to have the front axle torn apart for a rebuild and have the front diff, steering linkage, sway bar, driveline, etc. all removed from the truck, the J pipe just slides right on in there from below. I did remove the rear exhaust manifold shield to make this even easier. My 13 year old held it in place from above as I tightened the nuts on the studs.
Overall, a very easy kit to install. Just need to get the welding done on the stock exhaust to downpipe and also hook up a boost sensor. Not to mention, reassembling the front axle and the transfer case, which is apart for a gear swap.
alia176
SILVER Star
I'm running 4.56s and 315s, which will be a sweet combo for the turbo at 5,000'+ elevation.
I will be running 37's, 5.29's and turbo whenever it shows up. I am sure it wont be any different on the highway than it is now. Cruising in the slow lane until that hill comes up then watch out!
