Tbi chips(jet and Hypertech)

[Jaeden de boer]

just curios if any of you have had success and noticeable power increases from either jet or Hypertech chips for tbi systems, I searched formum and had no results found.

 

[Supercharged111]

I'd never give my money to either of those companies. I'm sure someone will be able to chime in with a reputable chip supplier, but avoid those 2 like the plague.

 

[88monteSS]

I'd never give my money to either of those companies. I'm sure someone will be able to chime in with a reputable chip supplier, but avoid those 2 like the plague.

Same. I'm actively avoiding doing too much on my tbi truck just so I won't have to deal with tuning it.

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[Supercharged111]

Same. I'm actively avoiding doing too much on my tbi truck just so I won't have to deal with tuning it.

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I'm not sure about the TBI, but on my Vortec the tune was the single most significant mod I did until the blower went on. You shouldn't be avoiding it, it was the very first thing that I did to my 98.

 

[df2x4]

I'm not sure about the TBI, but on my Vortec the tune was the single most significant mod I did until the blower went on. You shouldn't be avoiding it, it was the very first thing that I did to my 98.

I think he was probably referring more to the lack of people willing to tune the TBI era PCMS, not so much the significance of the tune. Seems like not many people are doing custom tunes for the older hardware, and the popular options like Harris Performance (TBIChips) aren't very reputable. Just seems like it's a pain in the ass compared to getting a mail order tune for a 96+ black box. This is just what I've read though, I've never owned a pre-'95 GMT400.

I want to say there are some guys over on gearhead-efi.com who will do custom mail order tunes for TBI era PCMs but I'm not positive...

 

[88monteSS]

I think he was probably referring more to the lack of people willing to tune the TBI era PCMS, not so much the significance of the tune. Seems like not many people are doing custom tunes for the older hardware, and the popular options like Harris Performance (TBIChips) aren't very reputable. Just seems like it's a pain in the ass compared to getting a mail order tune for a 96+ black box. This is just what I've read though, I've never owned a pre-'95 GMT400.

I want to say there are some guys over on gearhead-efi.com who will do custom mail order tunes for TBI era PCMs but I'm not positive...

Yep. I've heard too much about TBIChips to want to even try them. There's a guy near me that supposedly is decent, he primarily does LT1s (he goes by lt1 pcm tuning, I had to look it up when I got home), but he can do TBI. He offers a scan cable tune for TBI, but when I get to it I'll probably go do an in person since he's close enough. Either that or I'll go to an EBL flash & figure it out myself.

I'm not sure about the TBI, but on my Vortec the tune was the single most significant mod I did until the blower went on. You shouldn't be avoiding it, it was the very first thing that I did to my 98.

It's been a while since I screwed with anything TBI, but from what I remember for the basic TBI mods you could just bump the fuel pressure up to compensate. IIRC that truck just has tb spacer, shaved tb, pod spacer, salad bowl & AFPR. I need to swap it out for a vortec pump though, the afpr is wide open & it still needs a little more fuel at WOT...but first I gotta put a new motor in, it's been knocking for 5 years now lol. I also don't want to go too crazy with it b/c the hm290 has a case rated at 310 ft-lbs & the motor is rated at 300 stock. Makes perfect sense according to GM logic.

 

[Supercharged111]

You're still leaving other stuff on the table, I'm aware of the TBI mods. The thing that doesn't do for you is recurve the timing map, it's more stingy in some places than others. If it does that stupid PE timing thing like a Vortec then there's that too. Later 4L60 trucks can always benefit from some shift time tweaking and stuff like that, plus I heard but cannot confirm that the 95 trucks in particular had some TR/TM and there's no way to fake the computer out of that from the outside. I'm aware it can be tough to find someone to burn a good chip, but there are still people out there. Might be worth a trip over to 3rdgen.org for this too, I'd **** a chicken if there weren't a few guys over there who didn't know what they were doing with fellow members who could vouch for them. I highly encourage the OP and anyone else interested in it to download a stock tune and software, that much you can do for free and it'll give you an idea of what can be done to the stock computer. Start on moates.net for the software and tunes to see what the options are.

 

[884x4310ci]

I am in the same boat. I am getting a 94 with a 350 tbi. And would eventually like to get a chip. But it's getting harder to find.

 

[88monteSS]

You're still leaving other stuff on the table, I'm aware of the TBI mods. The thing that doesn't do for you is recurve the timing map, it's more stingy in some places than others. If it does that stupid PE timing thing like a Vortec then there's that too. Later 4L60 trucks can always benefit from some shift time tweaking and stuff like that, plus I heard but cannot confirm that the 95 trucks in particular had some TR/TM and there's no way to fake the computer out of that from the outside. I'm aware it can be tough to find someone to burn a good chip, but there are still people out there. Might be worth a trip over to 3rdgen.org for this too, I'd **** a chicken if there weren't a few guys over there who didn't know what they were doing with fellow members who could vouch for them. I highly encourage the OP and anyone else interested in it to download a stock tune and software, that much you can do for free and it'll give you an idea of what can be done to the stock computer. Start on moates.net for the software and tunes to see what the options are.

It'll get tuned eventually. I'll either go with an ebl flash unit & do it myself with help from some of the forums or I'll go see the guy I mentioned earlier & find out for myself if he's any good. But for the time being I don't want the truck making more power than it does now. At least not until I find a nv4500 to put in place of the hm290. I'd even settle for a later model nv3500 that's at least slightly easier to rebuild.
TBI does have PE mode, but idk how it compares to the vortec PE mode.

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[98 Nitro]

I think Sinister performance(gmtuners.com) does Tbi/Tpi tuning I would give them a call 1st.
Now there are a few posts on here in the Tbi chips sticky that said the Jet stage 2 chip worked ok.