People running 238/100s or 250/100s......

mikeeg02 · Jun 24, 2016

Did some searching, didnt find exactly what I wanted.

What can you squeeze out for MPG when you are empty?

And to qualify, what turbo are you running? Who's tunes?

I ordered a set of 238/80s and 100s are what showed up. I can send them back and get the 80s if I want, but I was planning on starting installation of them and valve springs, head studs etc this weekend.

Basically the only thing I have any concern about with them over 80s is empty fuel mileage possibilities on trips. So lets see some real world results. :ford:

joe d · Jun 24, 2016

Honestly if i fill up at an exit and get right on the freeway run 72-74 1900-1950 rpm i can fill back up and get anywhere from 20-23 i have 238-100 a t4 billet s366 315-75-16 duratracks and 3.55 gears and gh tunes and i get great economy. Its a crew cab long bed with a heavey ass bumper and a very full tool box along with a full size spare tire. And on every trip i also have the dog the wife the kid and the gear. Ive had 100+ honest trips above 20 mpg. Runs around 625 cruising. Hope this helps

mikeeg02 · Jun 24, 2016

Good info, currently I have stock injectors and a stock a 38R, 235/85 tires. I get 17-18 highway. Seems to do better at 70 than 65, and I think its ICP related (its a bit higher at 70). But I could be full of it. I have 3.73s and DRW, so Im not expecting to have it not use any fuel. I just had a concern with the 100 nozzles, and basically the only concern with them! Keep em coming!

joe d · Jun 24, 2016

The thing is you lose econmy as soon as you do injectors... Your right foot seems heavy all of a sudden all the time..

mikeeg02 · Jun 24, 2016

Haha I have had a truck with injectors before, though one had AC's and the other 175/146s. And this was several years ago. Nozzle size I am unfamiliar with how they end up doing, when you do keep your foot out of it!

joe d · Jun 24, 2016

238-100 should spool that 38r instantly.

mikeeg02 · Jun 24, 2016

Which is what I want with a 6 speed. Though I fear a t4 is to come.

joe d · Jun 24, 2016

Yea im about a day away from ordering a 369 i keep hearing great **** about it.

mikeeg02 · Jun 24, 2016

I believe thats the one the injector builder said pairs nicely.

David N · Jun 24, 2016

Hell, I run 350/200's with a 38r and it works awesome. Not sure on power or track times but I've ran 8.3's back when I had 250/200's and stock oil.

ghohouston · Jun 24, 2016

i had 238/100's, 38r, and matts tunes in a 2002 Extended cab long bed 4x4, and if it was all highway miles, i could get 16 mpg. 14 mpg around town. this was with a pretty heavy right foot too.

TyCorr · Jun 25, 2016

David N said:
Hell, I run 350/200's with a 38r and it works awesome. Not sure on power or track times but I've ran 8.3's back when I had 250/200's and stock oil.

My man! 38r gang for life!

mandkole · Jun 25, 2016

I can get 16-17 on the interstate if I keep it at/below 70. With the 42R, they're kind of an engine saver with bottom end control, yet still make some decent power.

mikeeg02 · Jun 25, 2016

mandkole said:
I can get 16-17 on the interstate if I keep it at/below 70. With the 42R, they're kind of an engine saver with bottom end control, yet still make some decent power.

About what rpm does that start to spool ? What exhaust housing are you running on it ?

With a 6 speed, I would like it to come up on the charger kinda quickly.

njjeep · Jun 25, 2016

18-19 I got with stock injectors. 250/200's mpg's went down to 14-15 sometimes 16 if I baby it.

Sent from my iPhone using Tapatalk

mandkole · Jun 26, 2016

mikeeg02 said:
About what rpm does that start to spool ? What exhaust housing are you running on it ?

With a 6 speed, I would like it to come up on the charger kinda quickly.

It starts to come up good by 1700, but it needs lots of drive motivation that's only available unloaded. From there, its light switch and can be at 40# by ~2000. For a 6 spd DRW, its not a good choice. For your truck , Id stick with the responsive 300 frame chargers. 1.15 housing.

jbolen323 · Jun 27, 2016

TyCorr said:
My man! 38r gang for life!

i dont see how thats possible my 38r was on its knees with 250/200s

TyCorr · Jun 27, 2016

jbolen323 said:
i dont see how thats possible my 38r was on its knees with 250/200s

Ive had guys who couldnt tune stock trucks before too. Ill leave them nameless. People rip on php for being low on power but ill take the drivability over the headaches of some of the others.

And my 38r with billet wheel and 250/200s works great. No issues other than it won't clean them up up top.

I have personally seen some trucks with dinky injectors with 100% nozzles that the 38r didn't work well but it was usually because the tuning was poorly devised in terms of long pw.

Davids truck has been more public and it runs real good in the videos he has posted over the years. I can relate to his results as mine are very similar. Same setup down to the wheels and tires lol

mikeeg02 · Jun 27, 2016

Its sounding like the 238/100s are as likely as any other injector on the mileage end, it all comes down to right foot control. Its just a little easier to use more fuel with a 100% nozzle than an 80% thus lowering the average you want to achieve. Or so it seems. Though its interesting to me that people are advancing tuning on 200%'s down far enough to also make them do well on fuel for trip purposes. I guess 100% nozzles were just talked down enough to me to make me wonder if it was a poor choice to keep them.

Ty- I'm assuming you have the dual plane version of the billet wheel (6x6?) on your 38R then?

From what I was also told, the first version single plane 11 blade billet wheel was better for the big end, and took a little more rpm to get started. By someone who ran both.

TyCorr · Jun 27, 2016

mikeeg02 said:
Its sounding like the 238/100s are as likely as any other injector on the mileage end, it all comes down to right foot control. Its just a little easier to use more fuel with a 100% nozzle than an 80% thus lowering the average you want to achieve. Or so it seems. Though its interesting to me that people are advancing tuning on 200%'s down far enough to also make them do well on fuel for trip purposes. I guess 100% nozzles were just talked down enough to me to make me wonder if it was a poor choice to keep them.

Ty- I'm assuming you have the dual plane version of the billet wheel (6x6?) on your 38R then?

From what I was also told, the first version single plane 11 blade billet wheel was better for the big end, and took a little more rpm to get started. By someone who ran both.

No. I have the single plane. THE 6X6 may be better for trucks that have larger tires and cruise at lower rpms though. I have the stock wheel here on the shelf. I was chasing an egt issue a year or two ago. Im not sure what fixed it but I got new injectors, hpop, boots& clamps, and riffraff billet plenums.

I think a portion of it was the wheel. I was falling into a spot that was a combination of near impossible scenarios. Id hit od and it'd creep up to 1000-1200 deg cruising. 37s, 3.73s, and that wheel that loves rpms may have all come together to create a perfect storm.

Couple guys daily driving really like those 6x6 wheels which I believe is just a billet recreation of the stocker.

Mines been used so little lately that Ill probably leave it as is and change things if I see fit.