Trying to Learn

[joe65]

OK I've done a lot of searching, but can't find anything relating to my question. I replaced my stock IHI with a DTS 64mm turbo. Also put on a AD 150, profab intake horn and got rid of my EGR and put in a federal pass up pipe and y-bridge. Already had ARE intake, 2-1/2" down pipe, 4" straight exhaust, and 90HP trans safe tune (my biggest) and built trans.

Question is, could the upgrades (more air) be causing me to run out of fuel with my current tuning? Lower gears are awesome, and the truck pulls way harder up to 75MPH, then it just seems to drop on its face at WOT. I checked rail pressure, and desired and actual are running good when it drops off. It will continue to gain speed, but has no pull.

Any input is greatly appreciated.

 

[blk smoke lb7]

OK I've done a lot of searching, but can't find anything relating to my question. I replaced my stock IHI with a DTS 64mm turbo. Also put on a AD 150, profab intake horn and got rid of my EGR and put in a federal pass up pipe and y-bridge. Already had ARE intake, 2-1/2" down pipe, 4" straight exhaust, and 90HP trans safe tune (my biggest) and built trans.

Question is, could the upgrades (more air) be causing me to run out of fuel with my current tuning? Lower gears are awesome, and the truck pulls way harder up to 75MPH, then it just seems to drop on its face at WOT. I checked rail pressure, and desired and actual are running good when it drops off. It will continue to gain speed, but has no pull.

Any input is greatly appreciated.

90 hose tune with a bigger turbo you need to be retuned you are for sure running out of fuel.A bigger turbo and a trans safe tune don't make sense.
Build your trans and throw the fuel at it.What are your egts doing bet its getting hot.JMO

 

[Hot COCOAL]

So, do you also have a ported fuel rail fitting on the drivers side rail?

I've never seen a 2 1/2" downpipe, other than stock? Is it stock?
Trans "is" built? I read that right, right?

Having more air available won't cause you to drop rail pressure...per se, it's tuning for the air without the fuel that would cause issues, typically more air, or having more air available than fuel is a "good" thing
Optimizing your tuning for the upgrades is always a good idea...
The 90hp tune, I'm guessing it's an edge or bully dog programmer???

If so, it's time for efi live:thumb:

 

[Big Block 88]

You have a built trans and a bigger huffer why are u wasteing time with a 90 hp tune?

It eating more air but there is no fuel for it to wash all that air down with

 

[joe65]

I will get bigger tuning as time and $$ allows. It is ATP EFI tuning that I have now.

I did not port the fuel rail, haven't heard of that mod before. I'll look into that.

Down pipe is an aftermarket no-name brand and it is 2-1/2" round.

Trans is built, so that's all set.

EGT's are not real high. They were running 1300+ at WOT before the upgrades, now seem to be in the 1200 range.

Forgot to mention I plugged the FPRV banjo bolt too while I had it apart.

Does it make sense that it's falling on its face at 75 at WOT because of the tuning? Never got any smoke at WOT even before the bigger turbo, so I know it can use more fuel, just not sure if that is what's causing it to run out of power.

Thanks for all the replies!!

 

[Dirtymaxx03]

it falling on its face because that tiny tune you are running is not getting on top of that turbo like it should.

Once the tuning is adjusted to something with about 120 more hp worth of fueling, you'll be golden

 

[joe65]

Cool. Thanks for the input. I thought that tiny tune was pretty awesome when I first got it, but now that I have a trans that will take more, it seems pretty lame. Fuel makes sense. I did notice it seems to be worse if I'm pulling a big hill, better on flat going. Guess I better get the tuning sooner than later.

Thanks again everyone!

 

[catman3126]

Yeah was gonna say 90 hp tune doesn not usually have a rail pressure issue in my experiences

 

[Hot COCOAL]

I still think you would benefit from a ported rail fitting...
It's a cheap, easy to install part that makes perfect sense for a tuned truck that requires more fuel than stock.

Personally, I'd try that first and see what happens.

You'll definitely need one if you purchase a built trans tune file

 

[Harbin_22]

I still think you would benefit from a ported rail fitting...
It's a cheap, easy to install part that makes perfect sense for a tuned truck that requires more fuel than stock.

Personally, I'd try that first and see what happens.

You'll definitely need one if you purchase a built trans tune file

Fleece did a test with the ported fittings a while back and I don't think they made any difference.

 

[Hot COCOAL]

Fleece did a test with the ported fittings a while back and I don't think they made any difference.

No chit

That is quite surprising actually, I find that kinda hard to believe considering how small the port is in stock form, and considering how much more fuel tuning demands...especially considering the passenger rail is fed from the drivers side.

Humph, well, wouldn't be the 1(00000th) time I've been wrong...:rofl:

 

[quadracer37]

No chit

That is quite surprising actually, I find that kinda hard to believe considering how small the port is in stock form, and considering how much more fuel tuning demands...especially considering the passenger rail is fed from the drivers side.

Humph, well, wouldn't be the 1(00000th) time I've been wrong...:rofl:[/QUOT



the lb7 rail fitting is already 1/8". The "ported rail fittings" are for lly and newer rails
HOWEVER the puck that sits behind the fitting is somewhere around .040", you can benefit some from drilling that out to 1/8", in this guys case though it won't effect a thing..

 

[Big Block 88]

I still think you would benefit from a ported rail fitting...
It's a cheap, easy to install part that makes perfect sense for a tuned truck that requires more fuel than stock.

Personally, I'd try that first and see what happens.

You'll definitely need one if you purchase a built trans tune file

Pretty sure i would invest in a tune before i would spend money on anything else

 

[Cknight199]

Ported rail fittings aren't with the hassle and do little to nothing imo