99-7.4 suburban 2500 engine upgrades

[Tom P]

Thanks for the tip Tom. I dropped the Burb at the mechanic today, and I did bring him a new FPR as well. You think I should specifically mention the vacuum hoses to him, or is this something he'd notice while workin' on it?

[my apologies for the thread jack!]

I would hope your mechanic would know to replace it since he's pulling the whole works out, but perhaps just ask him to replace it anyway for piece of mind. It may not look bad but you really don't want it cause issues in the future.

 

[BowtieBrody]

Just a heads up on injectors, go ahead and cough up the extra for FiveO motorsports Bosch injectors, and a lot of guys run a 5.7L FPR as it has a better bar rate than the 454 FPR,

 

[Supercharged111]

Just a heads up on injectors, go ahead and cough up the extra for FiveO motorsports Bosch injectors, and a lot of guys run a 5.7L FPR as it has a better bar rate than the 454 FPR,

Please elaborate, the 5.7 regulator is full inches longer than the 7.4 part and both run at 4 bar. I can attest to the tune and I haven't even done it yet. It was absolute night and day on my 5.7 and it's looking like I'll be adding about 10 degrees across the board to the main timing table at a glance and that doesn't count the additional I'll likely be adding at low RPM (the stuff that helps you hold OD up a hill with a trailer) and the torque management that needs to go if there's any in there. And making the shift points not suck.

 

[BowtieBrody]

Please elaborate, the 5.7 regulator is full inches longer than the 7.4 part and both run at 4 bar. I can attest to the tune and I haven't even done it yet. It was absolute night and day on my 5.7 and it's looking like I'll be adding about 10 degrees across the board to the main timing table at a glance and that doesn't count the additional I'll likely be adding at low RPM (the stuff that helps you hold OD up a hill with a trailer) and the torque management that needs to go if there's any in there. And making the shift points not suck.

I'm a little foggy on the details, but I read in that big ass thread for 454 owners on FSC I think it was that the 5.7L flowed at 4-bar, and the 7.4L FPR flowed at 3-bar; was I mislead on that?
On the topic of tuning, I'm really kicking around PM'ing Lextech or emailing him to get a 411 and a pinout sheet; I'd like to contact Black Bear and see what all they can do for the black box first though.

 

[Supercharged111]

I believe Blackbear uses EFILive which would limit his blackbox abilities to 98+. Both engines operate at 4 bar and having had both regulators in my hand I can tell you they are incompatible. Could have been an LS1 5.7 they were alluding to.

 

[my name is alex]

Just a heads up on injectors, go ahead and cough up the extra for FiveO motorsports Bosch injectors, and a lot of guys run a 5.7L FPR as it has a better bar rate than the 454 FPR,

I was always reading about the FiveO injectors here, so that's what I went with. There was a coupon code for 30% off mentioned in another thread, which I used. Wasn't happy with their communication, but hopefully the injectors are good.

I also remember reading about there being a better option for the FPR, but I couldn't track down any concrete info on it and so just went with the one that's made for the 7.4

 

[BowtieBrody]

I believe Blackbear uses EFILive which would limit his blackbox abilities to 98+. Both engines operate at 4 bar and having had both regulators in my hand I can tell you they are incompatible. Could have been an LS1 5.7 they were alluding to.

I figured Black Bear wouldn't be able to aid in tuning the 411; I thought about having my truck dyno-tuned if I went through with the upgraded PCM but I think something like that is beyond my budget.
I could always learn to do it myself though, is it a pain in the ass to tune vehicles? I've never really dug into it.

 

[df2x4]

I believe Blackbear uses EFILive which would limit his blackbox abilities to 98+. Both engines operate at 4 bar and having had both regulators in my hand I can tell you they are incompatible. Could have been an LS1 5.7 they were alluding to.

Just wanted to add that Black Bear can tune the '96-'97 black box PCMs, no problem. No idea how or what software they use, but they can do it. They tuned my red '97.

I figured Black Bear wouldn't be able to aid in tuning the 411; I thought about having my truck dyno-tuned if I went through with the upgraded PCM but I think something like that is beyond my budget.
I could always learn to do it myself though, is it a pain in the ass to tune vehicles? I've never really dug into it.

Pretty sure Black Bear actually can tune the 0411s. They can do GMT800 stuff so I don't see why they wouldn't be able to handle the 0411.

 

[Christian Steffen]

I figured Black Bear wouldn't be able to aid in tuning the 411; I thought about having my truck dyno-tuned if I went through with the upgraded PCM but I think something like that is beyond my budget.
I could always learn to do it myself though, is it a pain in the ass to tune vehicles? I've never really dug into it.

I wouldn't call it a pain in the ass, it does take time and patience but if you're thorough and do some research most of it really isn't that hard. Plus there are a few of us on here that can offer help / collaborate on the tunes. Between @Supercharged111 and myself we have the two big softwares covered. Probably the hardest thing I've encountered is getting cold starts to do what I want.

 

[Supercharged111]

Blackbear can absolutely tune the 411. I bought one from him preloaded with an Express van base tune and custom operating system for my 1500.