TBI Mods:Snake oil or worthwhile??? Updated 5/19/12 AFPR and Pod Spacer!!!

[smier]

I'm honestly not sure what my gears are, I know they are stock, and I am currently running 31" tires on the stock suspension for now. Check out Thirdgen.org and go to their TBI section, lots of good info there. Quite a few guys drag racing TBI third generation camaros over there. I'll be updating this quite a bit and adding pictures, as well as keeping track of my fuel mileage to see if I gain or lose anything. It's going to take me a little bit of time, last week of class and working full time, all while finding time for the family. This truck is my way of keeping my sanity and having a little fun.

 

[shovelbill80]

actually the first thing i'm buying is the fuel psi adapter and gage so i have a base line on what i have to start with..

 

[ryoken]

you'll be amazed at how low the factory psi is...

the 2 best power gainers of all cfm tech's stuff for me where an AFPR and the salad bowl...

 

[shovelbill80]

Smier......it would be great if you can find out your gear ratio for reference and comparison. mine is 3.73 with 31's right now. when i swap to 33" tires it'll drive like a truck with 3.42's and i'm hoping get better economy on the highway than now. at this point all i get is 7 city 14.5 highway......power is fine for what i do. at this stage of my life i'm way past wanting 4000hp and 7000 ft pounds of torque . 200/300 at the wheels would be fantastic.

ok ryoken, thanks....i'll order the bowl at the same time as the regulator stuff......probably tonight or tomorrow.

looking forward to more pictures and detailed narrative!

 

[smier]

you'll be amazed at how low the factory psi is...

the 2 best power gainers of all cfm tech's stuff for me where an AFPR and the salad bowl...

I've read that GM spec for fuel PSI was between 9 and 13 PSI... That's a pretty big difference on a low pressure system!!! What did you end up setting yours at? I've read different things as to what the stock system performs best at.
I actually found CFM's site because I've suspected I have a fuel pressure issue so I was looking for a way to mount a guage, and before I knew it I had $263 worth of gear in my shopping cart... I'll probably be ordering the salad bowl in a few weeks, the more I look at the TBI setup, it looks like it would help. So next up is the guage install to get a baseline of where my fuel pressures at, and then I'll install the Adjustable fuel pressure regulator and pod spacer... I want to get a baseline pressure reading so I can isolate the pod spacer, I'm sure it might help things, but doubtful it will be noticable to my Buttcheek dyno...

 

[Col_Sanders]

Inside your glove box there is a sticker with a bunch of 3 digit codes. You can use that to figure out your gear ratio.

 

[smier]

Shovelbill80, I can relate, my 3 year old daughter ended my amateur drag racing dream for now... Thats why I have a bored and clearanced block and an unfinished collection of parts for a 383 sitting in my basement. I had to choose, Blazer or Camaro, well you can't fit 3 kids in the back of a Camaro!!! Now I get great enjoyment out of getting a brick to get reasonable fuel mileage... How quickly things change. I actually thought my blazer had 3.73's, I'll have to see if there's a sticker in my glove box like my '86 had with all the specs.

 

[AJMBLAZER]

A good decade ago www.TurboCity.com was the hot name in TBI tuning up.

There's also www.TBIChips.com . He knows how to tune them.

Your plans now sound very similar to mine a decade or so ago.
Crap, just realized I sold my '92 Blazer in '02.

 

[ryoken]

I've read that GM spec for fuel PSI was between 9 and 13 PSI... That's a pretty big difference on a low pressure system!!! What did you end up setting yours at? I've read different things as to what the stock system performs best at.
I actually found CFM's site because I've suspected I have a fuel pressure issue so I was looking for a way to mount a guage, and before I knew it I had $263 worth of gear in my shopping cart... I'll probably be ordering the salad bowl in a few weeks, the more I look at the TBI setup, it looks like it would help. So next up is the guage install to get a baseline of where my fuel pressures at, and then I'll install the Adjustable fuel pressure regulator and pod spacer... I want to get a baseline pressure reading so I can isolate the pod spacer, I'm sure it might help things, but doubtful it will be noticable to my Buttcheek dyno...

expect it to be under 10.. mine was around 8 or 9.... with a basically stock mill I bumped it up to about 13.5 and noticed a big improvement in power...

oh, and just a side opin ion, tho the gauge at the tbi is a necessity, I find it much more useful out on my cowl.... nice to see what it's doing under load.... out on the cowl is not for everyone, but it's a simple cheap mechanical solution.. obviously going with an isolator and in the cab is nice, but that's also a bit more coin...

you can see my old setup with the hood up.... next version is going under the cowlhood lip...

 

[Wyomingboy]

Just thought I would add my experiences with trying to make the TBI run better.
CFM Tech was the best bang for the buck with the spacer & ultimate TBI mods. My open exhaust didn't seem to make that much difference, nor did the K&N filter(although they have been very good on my other vehicles)
But it's possible they all added together?

I had a lot of trouble getting my Modded engine to run right with the "guy in North Carolina" chips. Very frustrating experience.

In retrospect I should have went with either a big block or a 6.0 with the fuel injection system and ECM that comes with it. There are a lot of companies that will build you a wiring harness to graft in a 6.0, then you would have a modern system and the aftermarket that supports it.

 

[buefchris]

A good decade ago www.TurboCity.com was the hot name in TBI tuning up.


Your plans now sound very similar to mine a decade or so ago.
Crap, just realized I sold my '92 Blazer in '02.

Turbo City came to thier senses and got out of the TBI biz and is no longer offering performance mods to an antquated system.

 

[munepit]

I installed CFM Technologies throttle body spacer kit yesterday. This is one item I thought for sure would be a waste of $83... Was I wrong!!! Holy crap what a difference!!! It took a bit for the ECM to get used to it, but definately a noticable difference in throttle response and low end power. I really had a hard time spending the money on this one, I've read reviews of other spacers and really thought it wouldn't help. What sold me was their design, they've machined the center out to allow the motor to draw incoming air and fuel from both throttle bores instead of just one side. The kit came with all necessary gaskets and longer bolts for mounting the throttle body.

I bought this awhile ago, And its been sitting in a cabinet. I need to install it. Im glad it works! What is the salad bowl? Is it this? http://marine-performance-parts.com/hypertechpowerchargerforfullsizetruckgmtbi5057.aspx

 

[smier]

Yes, that's what we're calling a salad bowl. I almost bought it, but I felt like my bill was too high already for messing around... Now I'm wishing I had bought it, what was another $45?

 

[smier]

Turbo City came to thier senses and got out of the TBI biz and is no longer offering performance mods to an antquated system.

Actually their website looks like they're still selling the TBI stuff. It may be an antiquated system, but it's a well functioning system on an antique of a truck... and I can get parts off the shelf at any crappy autozone in any town in the USA!!! Up until 5 years ago, I was still playing with carbs and swore I'd never work on a computer controlled car... This is high tech sh** for me, hahahaha

 

[pmpski_1]

Yes, that's what we're calling a salad bowl. I almost bought it, but I felt like my bill was too high already for messing around... Now I'm wishing I had bought it, what was another $45?

Is this just the metal funnel or the entire air cleaner assembly? I'm assuming the former, but seeing as how I need to replace the entire air cleaner assembly, if it was the whole thing I'd be stoked.

 

[pmpski_1]

It may be an antiquated system, but it's a well functioning system on an antique of a truck... and I can get parts off the shelf at any crappy autozone in any town in the USA!!! Up until 5 years ago, I was still playing with carbs and swore I'd never work on a computer controlled car... This is high tech sh** for me, hahahaha

Slightly OT - I've been messing with carbs for the last couple years and I'm having a hard time troubleshooting due to inexperience. I work in the software industry and whenever I need more information from badly behaving software I hook it up to a debugger to find out what is going wrong. Many times I've wished I could do the same thing with the old truck.

Now I've found out that with the 91, I can hook it up to a debugger! I promised myself I would just drive this thing and not work on it too much, but the more I learn about what I can do, the less I can resist messing with it.

 

[smier]

Yes, it is nice to be able to pull the fault codes on these systems, the problem with the early On Board Diagnostics (OBD I) is it's very limited as to what it can tell you. It's still a huge help, but sometimes one bad sensor will throw multiple codes. For example a bad oxygen sensor can trigger other sensors to operate out of their range, thus triggering a false code. That's why it's not always good to throw parts at these systems, but when you get them running right, I think it's a great setup.

 

[smier]

Is this just the metal funnel or the entire air cleaner assembly? I'm assuming the former, but seeing as how I need to replace the entire air cleaner assembly, if it was the whole thing I'd be stoked.

I think it's just the "power charger", But I believe every TBI used used the same air cleaner assembly. I'm thinking any TBI camaro, firebird, or caprice would have the same housing, not sure about the vans though, they may be different due to lack of space... Worth a shot to check it out. It's been pretty well proven that the factory snorkel air cleaner assembly is capable of flowing plenty of air for even a somewhat hot motor, and it is technically a cold air intake system.

 

[AJMBLAZER]

Every 87-95 Chevy small block powered truck should have the right cleaner for ya. The lids might change a bit but that can be worked around.

 

[smier]

Quick update on the Throttle body spacer: I've had it installed for about a week, and so far I'm thrilled!!! Even after a week, I can still notice the improvement in low end power and throttle response. I've even noticed another surprise benefit... Easier startup!!! I'm not sure why, but my motor now fires up almost as soon as I turn the key. It used to take 2 or 3 revolutions befored it would fire up. I'm set up for an all out fuel mileage test this week, I have a set route that I follow to try and do a direct comparison. My best ever so far was 17.3 mpg. In the last week I averaged 16.88 mpg running errands around town, and a 20 mile shot down the interstate at about 75 mph hauling a load of material for a church community service project on Saturday. I'm pretty confident I'm going to see an improvement in my fuel mileage if I can keep my foot out of it... Adjustable fuel Pressure Regulator, Fuel Pressure Guage, and Pod Spacer are set to go in after I get the mpg results... The plan is to set the fuel pressure to whatever it is with the stock regulator to check out the pod spacer, then in a week or so play around with bumping up the fuel pressure. Then I may play with the timing again, right now I'm back at the stock timing settings. More updates to come, I got my photobucket account working again!