Upgrades vs Amount of Boost

[FireRed04Vert]

I had a guy ask me a question last night I couldn't give a good answer to...but knew you guys (and gals...sorry Tracy) could. How much boost on a stock Eaton (unported) can you run without having to do any fuel or other mods? Can you go an additional 6 lbs (total of 14) without having to get into anything else? I know Ford claims you can bolt on their FRPP Whipple without even so much as a tune! But I don't know what kind of boost they're running on that either. But I told him he would definitely need a tune. I just wasn't sure about injectors, pumps, BAP, MAF, etc.

What do you think?

 

[postban]

2.93 on an unported eaton is ok with stock inj/maf/pumps

Porting will add more power and still not need any mods.

I have yet to hear of anyone putting on that FRPP package. Must have a 3.65 or bigger pulley to keep boost that low.

 

[SM0KE]

Yeah, I run a 2.76 pulley w/ a ported blower and don't have any fuel upgrades...Just a really good tune. However, I'm on the edge of my fuel system. I'm changing stuff around now, and I went w/ focus pumps, MAFia, and 60lb injectors for my new setup.

 

[CobraBob]

2.93 on an unported eaton is ok with stock inj/maf/pumps

Porting will add more power and still not need any mods.

I have yet to hear of anyone putting on that FRPP package. Must have a 3.65 or bigger pulley to keep boost that low.

Postban, that is not necessarily true. While the majority of people will probably be fine with the stock inj/MAF/pumps with a ported blower, it isn't so with everyone. I can tell you from personal experience. I had a 2.90 upper (stock lower) with an early Apten/Steigemeirer port making 504rwhp. At the 490 (approx.) level I maxxed out the MAF and at 495 (approx.) I maxxed out the pumps. This was confirmed by SCT who was up here doing tunes for our local club. I ended up going with a bored out Lightning meter from JDM and dual Focus pumps and my fuel issue was resolved. At this level though you are definitely correct that the stock injectors will work fine.
;-)

 

[FireRed04Vert]

Thanks guys. I think he's considering a 6 lb. lower only. That should be interesting how that works. My guess is it will be a torque monster...but down a bit on hp compared to an upper/lower combination producing the same amount of boost. Of course, going with just a lower should really help the belt slip issue too.

 

[sambandit]

His car wont put out any more TQ than a 2.76 upper alone would, which is about a 6 lb upper pulley. MOST cars dont need any fuel mods with a upper only and ported blower but every car is different. I would rather see him do the mods, then determine if he is running outta fuel, rather than spend money on fuel related items that he really dosen't need!

 

[CobraBob]

IMO why risk running out of fuel when we know what the consequences can be. Kaboom! I would highly recommend that anyone who is north of 475rwhp at least upgrade their pumps and meter. And by upgrading your injectors you're not only insuring you'll have plenty of fuel for now and the future, but your fuel system won't have to work as hard providing it.

 

[FireRed04Vert]

Good advice Bob...except I wouldn't do the injectors unless the duty cycle warranted the swap. Larger injectors are good for top end fuel needs, but can hurt the drivability when just cruising. They also can contribute to starting problems. I used to have an 89 LX with a very good 5.0 in it. The car was actually quicker than a stock Cobra. I upgraded to larger injectors and meter just because I felt I needed them. I was wrong. I had some drivability issues. I went back to the smaller injectors and recalibrated the meter to fit them and then raised the fuel pressure a tad. All drivability issues were gone and the car actually ran as good if not better on top. I think you've got to get pretty deep in the boost to warrant 60 lb injectors.