Need Advice: Two things I'm not happy with: Suspension and Driving at Altitude

mscot

New member
Hi All, I generally love the 4Runner but after about 12k miles there are two things I'm not happy with and I'm looking for some advice.

Truck is a TRD ORP w/KDSS. Toytec Boss Performance 2.5 w. JBA UCAs. No engine/exhaust mods.

The first is an issue that I created.

I'm really unhappy with how rough the ride is. Every bump and dip is teeth rattling and on a shitty freeway it takes more effort than I believe it should to keep it in the lane.
believe the Toytec suspension I have is just too stiff for the truck. It's the Boss 2.5 all around with just over 2" of lift.
Is there anything I can do short of pulling them off and having them rebuilt softer or replacing them?

The second is just the nature of the truck and where I live.
Driving to/in the mountains is a pain in the ass and we spend most of our winter back and forth from Denver to resorts (often quite tired).
You're constantly having to floor it to get the engine going when climbing hills and it is not a smooth acceleration at all.
Is there anything that can be done short of the supercharger? Would a new air intake or cat back exhaust help here?

I assume the answer to the first is either a rebuild or replace and the answer to the second is shit out of luck but I thought I'd throw it out there to see.
The drive home this weekend was really frustrating me.
 
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Can't offer much input concerning changes to existing suspension, but I've been happy with my Dobinson setup.

For the acceleration, a Pedal Commander or Sprint Booster device may help. I do not personally have one but people who I know say it does improve throttle response. Doesn't change horsepower, but does change the throttle response curve.
 
What is your spring rate? Can you adjust dampening? What is your tire pressure?

Those all play a role in comfort. I have the Trail with KDSS, equivalent to your ORP. I have King 3" lift set at 10 out of 21 (?) with a 650 spring and about 35-38 PSI on 265 KO2. Rides great, lo body roll, and smooth!

I visit CO often (sister lives in Boulder) and I understand about the climbing, I use a Pedal Commander on Sport mode and it helps with sluggishness. I have the TRD intake, and it really doesnt add HP, just makes it sound louder when high in the RPM's

HTH
 
Anytime I'm in the mountains here (Eastern Sierra) I just leave the transmission in S4. Helps a bit as 5th is just blah on slopes.

Suspension wise hmmm... I've heard a few folks with ToyTec bosses saying they are too stiff. What tire pressure are you running at?
 
Thanks fellas.

Altitude:
I do have a sprint booster. I'll try keeping it in 4th.
Sounds like CAI won't help?

Suspension:
The Toytecs are not adjustable on the fly. It would require a rebuild as far as I know.
The front springs are 650lbs - I have a C4 hybrid bumper with winch so that should be fine, right?
The rear sprints are Dobinsons for stock weight. I've thought about replacing them b/c they sit at 2.25" and I'd prefer they were at 1.5" and replacing rear springs is easy. But that's another $150.

I have p-rated 285/70 tires and since it was just at Toyota for the last free check up I imagine they are at Toyota's recommended pressure. I generally run them a bit lower than that. I'll check tonight.

Thanks for the help!
 
I saw significant gains in power and throttle response with my AFE Intake, TB Spacer and Borla Cat-Back exhaust. I added a URD MAF Calibrator to even out the shifts and throttle response, but my truck gets up and goes now
 
I've had quite a few guys in CO order the S&B intake from me and just with that they noticed a nice difference. Also, the Sprint Booster helps too, and Gibson also.

Burtman Industries S&B intake

sb_4runner_5th_gen.jpg


actual testing results on this intake and CFM airflow - Google Drive And yes, carb approval for CA has been submitted so if you're in ca this will be able to pass soon.

Also, on the sprint booster I've have people reporting about 1 more mpg. Again, this is after you start driving normal and not flooring every few min to test the upgrade :)


Burtman Industries Sprint Booster, you can send it back if you don't like it! - You can also call your order in or text with any questions, 717-319-2100

Gibson 5th gen Exhaust at Burtman Industries - YES, ON SALE

judd94-albums-all-picture53233-29cd019b-2154-4ca2-b76b-38b1183ed157.jpeg


There is also straight out the back option and choose of black or POLISHED tips.

Also, below are all the FORUM threads on all these parts if you want to see more people commenting on them besides me :)

S&B Intake - 5th Gen via Burtman

Gibson catback exhaust for 5th gen! Labor day special starting now! Video attached

Sprint Booster SALE for 5th gen 4Runner, Limited time...
 
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Thanks fellas.

Altitude:
I do have a sprint booster. I'll try keeping it in 4th.
Sounds like CAI won't help?

Suspension:
The Toytecs are not adjustable on the fly. It would require a rebuild as far as I know.
The front springs are 650lbs - I have a C4 hybrid bumper with winch so that should be fine, right?
The rear sprints are Dobinsons for stock weight. I've thought about replacing them b/c they sit at 2.25" and I'd prefer they were at 1.5" and replacing rear springs is easy. But that's another $150.

I have p-rated 285/70 tires and since it was just at Toyota for the last free check up I imagine they are at Toyota's recommended pressure. I generally run them a bit lower than that. I'll check tonight.

Thanks for the help!

To answer your question on spring rate @650lbs, that is just fine. It should cover that weight perfectly. 650lb springs is about right for a hybrid bumper and winch. I have noticed that most aftermarket suspensions do run toward the stiffer side, but nothing that is so uncomfortable as you are describing. When i first saw your concerns i was thinking your tires may be E rated, but thats not the case. I noticed a huge difference in ride going from E rated to C rated but with you runnin P that's definitely not it. Maybe you are right... and the toytecs are just too stiff and need revalving for your comfort level. I wouldn't go to that extreme if I were you... I would probably sell them and try another brand. Just my 2 cents!
 
I would do a chalk test on your tires at operating temps. It can play a pretty significant role in both comfort and wear. I have found every dealers over inflates any car I have owned.

When my wife bought a new Jeep JK I picked it up, drove off the lot ant it was insane, bouncing all over the place (33” tires). I anticipated this and brought my tire gauge, 58 psi! Pulled into a parking lot and took them down and it drove normal. Did a chalk test and found that they were ideal at a 34 psi running temp. Got about 45k out of those with even wear and no cupping.

People read the max pressure and think that is what they should be at.

Worth a shot, just your time and some kids driveway chalk
 
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Checked my pressure this morning it’s at ~36lb all around cold.
I don’t think pressure is the problem.
Guess it’s time to research how much I can sell the suspension with 7k miles on it. Ugh.


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Suspension
The Dobinson 302 front springs I’m running are 586 lbs/in. Rear 325 springs are 220 lb/in. See the thread in this forum. Very happy with them as ride really no harsher than OEM XREAS on my limited. When my XREAS went bad I wanted a lifted suspension but biggest concern was additional stiffness. For once i made a good decision. Lol. And I run my P rated tires at 36psi.
 
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In the hills of WV, I find myself in 4th a lot. Love the truck, love my setup, but I do wonder if the Tundra would do better for me (but I'm not seriously considering the Tundra - I like it too much). With my build and rubber, it's probably not that much more of a fuel hit...
 
Performance:

2/ A lightweight, good AT tire such as the new Firestone Destination XT can help a bit especially if you can shave 5-7lb off the wheels via a quality aftermarket wheel.

I have P-rated 285 wild peaks and aftermarket rims that are lighter than OEM. I'm pretty much breaking even over the OEM set up.



For ride quality,

0/ Before anything more complicated, what tires and pressures are you running? If you are running E-load tires, that's the place to start. If you are running Ps on 32-33, then it is not the tires.

36psi this morning cold - p rated tires.

1/ I have no idea what shocks Toytec uses in the rear. They never replied to my inquires about that. They look like modified 5160s but I don't know. I thought they were suspect. Is your ride worse in the back than in the front? What coils are you using in the back?

Honestly I wouldn't know how to tell the difference. It seems pretty stiff all around, however the rear doesn't feel like its being shifted over like it used to do with the oem suspension when you hit bumps. I have dobinsons in the back that are rated for stock set up (no additional weight)

2/ The front coilovers should be Radflo 2.5 and they should not feel too stiff. I almost bought the standard Radflo 2.5. They are normally valved the same for all 4Runners but that's for the Radflo branded ones. I am not sure if the Toytec ones are spec-ed a bit differently. You could make adjustments. What springs do they come with? If it is 650, go down to a 600lb spring. If it is 600, see if 550 King springs would work with the Radflo shocks. The shock is so powerful, it should work well even with a 550 spring, which is the standard rate for Kings.

They come with 650lb. I have a hybrid bumper and winch so I'm running at about 100lbs over stock. I probably could get away with a 600lb spring and that's what I'd do if I bought a new set up.

OR

3/ If you don't visit much the long dirt roads and easy trails of Utah, AZ, NV, or CA, you could sell the Toytec and get Eibach shocks with more reasonable front coils from Dobinsons so you don't run a nearly 3" lift on 265 tires. People here have been raving about Eibach ride quality.

This is probably what it will come down to... as the reality of life with a toddler and our lifestyle has hit me, I realize that what I really want is a great road trip vehicle that can go off road and do things like Webster Pass without blinking - but mostly drives really solid and comfortable on the road.
I just have to decide how big I want to go with a new suspension - adjustable kings so I never have this same complaint or an Eibach/Dobinsons set up and roll the dice with the ride again.
I'll definitely never buy a mid-range suspension again. Waste of money.
 
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I have P-rated 285 wild peaks and aftermarket rims that are lighter than OEM. I'm pretty much breaking even over the OEM set up.

Therein lies your problem "driving at altitude". It's not the altitude, it's the reduction in power from going with a 33" tire on the stock gearing coupled with the grades you're pulling on I70 west of town. It's a tradeoff you either have to deal with, or re-gear to correct the overall ratio and restore the factory power.
 
Therein lies your problem "driving at altitude". It's not the altitude, it's the reduction in power from going with a 33" tire on the stock gearing coupled with the grades you're pulling on I70 west of town. It's a tradeoff you either have to deal with, or re-gear to correct the overall ratio and restore the factory power.



I can see how the tire size is a contributor but it was the same experience with 265s. Maybe not as extreme.
Once I wear these out I’ll probably go down to 275s or do the 255/80
But that’s a ways off.


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Hey mscot,

I didn't read all the replies but wanted to chime it. I'm also in Denver and have the same ToyTec lift as you do. I started with K02's at the time of the lift and had the same crazy harsh ride you are referring to. I switched to the Ridge Grapplers and really wish I would have started there. The ride is literally half as rough as it was with the K02's. Night and day difference, IMO. Also, not sure if your running spacers but they will greatly increase the harshness as well. For driving at altitude, I can say the Sprint Booster is almost a must have for our rigs in the Mtns. It's made a HUGE difference for me both around town and in the high country. I do have a CAI and a high-flow exhaust as well, which I'm sure helps "some" . Good luck!
 
Therein lies your problem "driving at altitude". It's not the altitude, it's the reduction in power from going with a 33" tire on the stock gearing coupled with the grades you're pulling on I70 west of town. It's a tradeoff you either have to deal with, or re-gear to correct the overall ratio and restore the factory power.

So general question - with larger tire choices is it the weight or the diameter that really has an effect? Im running KO2 E 275/70/17 which claim to be 56 lbs each - I've been thinking of going to the P rated Falkens 285/70/17 which list as 51 lbs each - does the jump in diameter offset the drop in weight?
 
So general question - with larger tire choices is it the weight or the diameter that really has an effect? Im running KO2 E 275/70/17 which claim to be 56 lbs each - I've been thinking of going to the P rated Falkens 285/70/17 which list as 51 lbs each - does the jump in diameter offset the drop in weight?
the diameter will have more affect. it changes the overall gearing. it just slows the crank down too far, gets its below the necessary torque area.
 

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