Topic: 16mpg from a 22rte

[edeslaur]

I recently had the engine in my new-to-me truck rebuilt. They went 10 over, added a TEC turbo, and a stage 2 cam and 2.5" exhaust all the way out. Truck is otherwise stock down to 225s. Waiting to fix this before lifting, locking, and dual-casing.

Truck has an AT which works surprisingly well for the miles.  

I picked it up in Sacramento and drove it to San Diego, seeing about 20mpg (except over Grapevine) at around 80ish most of the way. This was bone stock, 212k, and a leaking exhaust gasket, AC off

this past week, I went from Houston to Galveston and back, again about 80ish, and saw 16mpg. AC on. The high has been 17, with the average being closer to 15/16.  

Power off the line is terrible and the truck doesn't want to go more than 80, and generally pushes 1/2 boost or more on the highway at anything over 65.

The cam has the same specs a TRD level 2 cam.
224/234 I/E duration at 0.50, .429/.442 I/E lift. Seems to be a Crane


What are the chances the cam is off a tooth? Any other suggestions?

[79coyotefrg]

you should pray the cam didnt jump a tooth.

much more likely is the ethanol content of the gasoline your buying.   Ethanol will cook that turbo in a hurry.
go to http://pure-gas.org/ and find some real gas and save your engine

my truck on 10% ethanol get 12 mpg  and on pure gas 87 octane 17 mpg  and on pure 93 octane 19 - 20 mpg

[edeslaur [OP]]

It's California, and CA isn't even listed. No surprise. :-)

Besides, plenty of turbos out there running on the junk they pump nowadays, and well over 6-7 psi I'm running.  

It got 20mpg on the same gas. Besides, I've only ever seen a 10% drop in mpg with Ethanol anyways.

I'm following several forum's "Post your gas mpg" threads, and mine is substantially lower than comparably equipped non-turbo trucks. Since it takes the same HP to push it down the road as theirs (maybe less, I have street tires on it at the moment), the fact I'm running effectively the same motor should mean I'd at least be close.

[edeslaur [OP]]

BTW, "dog off the line" means that I can floor the pedal in dirt and it won't leave tracks (remember it's an AT, stock gears, and 225s. But STILL!). How does this compare to anyone's 4 cylinder Toyota? Heck yes it's scary getting out into traffic!

Right now the rear driveshaft is out of it (I'm flat towing it places). And, get this - it won't leave tracks in FWD either. In DIRT.  It is S.L.O.W.

I spent about an hour scouring the web and I'm more and more convinced it's retarded by a tooth, but hoping to hear some corroboration before I pull it apart to check. It's 80% humidity out there and I'm not used to it!  

Let me check my knowledge here
 - cam advanced - more power higher up the powerband
 - cam retarded   - more power at the bottom end

But - what will each do to turbo boost?

Found a blurb that milling a head/block the equivalent of 1/8" is the same as being retarded one tooth on the cam. I have a new head, but don't know if the block got milled or how much. I doubt it's related, but tells me degreeing the cam could be a valuable step. I always wanted to learn how to do that anyways I guess...

[emsvitil]

Cam Advanced = more power at low rpm
Cam Retarded = mor power at high rpm

[edeslaur [OP]]

Thanks for that input.  I did find it on the web and was going to correct my post. 

[edeslaur [OP]]

Finally, after hours of searching, seem to have come up with the right words.

This guy has similar issues with his 2.3 turbo Ford Ranger.
http://www.turborangerforums.com/showpost.php?p=16422&postcount=1

What happens to a GNX when you retard the cam timing by a few degrees is also very similar
http://www.turbobuicks.com/forums/buick-v6-turbo-tech/20387-camshaft-retarding-experiment.html

Stand by for more details and, I hope, success!!

[BUDDERS]

Is your trans shifting through all the gears?  I worked on a early 4 cyl taco with a auto trans that was a total dog because it was stuck in a higher gear all the time.  It would stay in drive and eventually shift to overdrive if I remember correctly.  1st and second were gone.  A broken trans kick-down cable was the culprit.

[edeslaur [OP]]

The tranny actually works pretty well. In Power mode, it shifts earlier and holds the gear longer. I tend to run in Economy tho.

While it feels like I'm taking off in 2nd, it really is in first (revs to redline around 30s or 40s, then shifts into 2nd, then 3rd, then 4th, then convertor lockup, which I can unlock by touching the brake pedal).

[BUDDERS]

Good, sounds like the trans is fuctioning properly.  I can't really help you with turbo stuff since I don't have much experience with them. 

[bkubisht]

Degree the cam so you can stop doubting it.  And I would not have put anything beyond a stage 1 cam in a turbo motor, but that's not your power problem.

Maybe you're running lean?  You might try taking it to a test-only smog place and have them give you an air/fuel reading for it.

[edeslaur [OP]]

Yeah, that's the realization I've come to. Cam wasn't my choice, shop's supposed to know what they're doing, come extremely well recommended from many folks...