Railroadjoe

The thing guys have to understand is this ain't a 1990 ford with a 3 or 4 speed and 28" tires stock( that we all put 33s and 35s on). The modern 6 speed keeps the rpms in you power range because the gear ratios are closer together. And the ecoboost makes power at low rpms. A programmer with adjustments for tire size will adjust the speedo and trans shift points for the new tire size and I'm sure the 60 hp and 100 lbs of torque will make up the power by far. Also seeing a lot of dealer built trucks running 35s with the 3.31 gears and actually drove one and didn't think it felt bad at all.( it only had a hyper tech calibrater on it). I think that you will be fine and very Happy with the 3.55

stanand23

I just don't know because I hear one thing and then hear another. I just don't want my truck to have transmission or turbo failure because of the lift and large tires and not having enough gearing. I understand a tune will help I just don't know if it's the right direction to go. I do appreciate all the help though.

AZTrail

Seems it could sway either way, but proof will be in the pudding. uzikaduzi's point is pure physics, & as an engineer I can certainly appreciate that. Railrodjoe too has a point. A smooth power band at low/mid RPM's with a tighter shift range should offer compensation. How much tho remains to be determined.

I also have a 5 Star Livewire; install planned the following weekend. I'll have driven stock for 4.5 weeks to get a baseline. Then lift on Tues, tuner next Sat. It's not a formal factorial DOE, but should provide enough empirical evidence to determine one way, the other, or no change. Also curious about MPG's. Fingers crossed. I dropped a wife-angering pile on all that stuff already, lol

stanand23

Just curious but how much did you pay for the lift and what tires are you going to run? And will you let me know what kind of power loss if any before tune? Then after tune if it either goes back to stock or better than stock?

uzikaduzi

it's a good point that these trucks aren't 90's f150's because comparing something that was severly lacking power and pretty heavy to these more modern trucks isn't fair... the first vehicle i lifted fits in this category which was an 86 bronco... the next isn't really in the same realm of trucks but my '99 jeep was next... the next 2 aren't too far off though. i lifted an 06 f150 with 5.4l (3.55's) and an 08 f150 with 4.6l (3.73) both tuned... they were both 4 speeds and had less overall power numbers to an eco boost which is relevant but going from a 30" diameter tire with 3.55's to a 35" tire is like changing from 3.55's to running 3.04 gears regardless of what engine you have plus i'm assuming those 35's are gonna be something aggressive like mt's which weigh double or more than the stock ones. it's certainly a subjective thing whether it 'drives fine' or not but driving it with stock tires and changing to 35's you will feel a significant power loss... with a tuner you can chase some of that back and firm up shift points but you're still turning the motor one half of a revolution less per tire revolution... if you think that's not significant, change your 3.55's to 4.10's and tell me you can't feel the difference.... there is also no question, your transmission will be put under more stress and your engine will work harder. that does not mean the eco can't handle it... it won't make it undrivable... but there is absolutely no doubt, you will feel the power loss.

Rcornine

I figure lift would be a tough post. I am looking for a home lift for raising and working on my truck. Has anyone bought a lift? What capacity? Brand, make. Model? Any horror stories?

stanand23

Really... Start your own thread please.

AZTrail

35's with 3.55's will be ~200 RPM less at 65MPH then the stock 32's. Stage 3's statement is based on the 6-speed tranny & EB power-band being fairly flat.

Bone stock, I'm getting crap gas millage at 14.2. MPG would normally slightly increase, but I predict it to remain unchanged or even slight decrease since going from stock 11" to 13.5" width. I also expect a slight power decrease more noticeable at lower RPM's.

Expecting the tuner to smooth some of this out. So overall, predicting negligible change, though I will have left some power on the table that I'll reclaim someday if I add shorter gears (4.10 or .56).

The BDS/Fox coilover, 35x13.5 Toyo RT, Fuel 20x10, & install will be $6 OTD.

stanand23

Yea I am going with just the fox shocks and bds system which fuel wheels you planning on?

uzikaduzi

something people forget when they change tire size, you're increasing your tire size by ~9%, if you don't correct your speedo obviously it will be showing you driving ~9% slower than you actually are and your odometer will show you driving ~9% less than you actually are traveling. so it will appear that you lost ~1.2 mpg that you actually haven't. I think, like you said, the tires being wider will have a negative affect... also the increased weight of the tires. but i don't think gas mileage is as bad as people make it out to be... around 1 mpg loss is what i've experienced after accounting for my incorrect speedos.