spacer vs. cold air???

This may sound a little stupid but here we go. I am planning to put some mods on my '95 1500 silverado (350). I have decided to put on a flowmaster force II exhaust, and a S&B cold air intake. the problem is whether or not to put a 1in TBI spacer in. I have been reading about spacers and cold air intakes, some say they work together, some say work against each other. I am trying to decide whether to add a TBI spacer or not. Any suggestions or expeirence would be great.

I have an Airaid Cold Air intake and a TB Spacer from a local speed shop.  Paid $100 for both.  I've never tried it without the TB Spacer but I still noticed a gain on the acceleration at WOT but that was it.  When I tuned it, it made a bigger difference.  From what I understand, there is only so much you can do to the intake before it leans the engine out too much.  Most performance shops around here say that a cold air intake and tbs will lean the engine out too much.  An aftermarket MAF will REALLY lean out the engine.  A K&N filter only, or a K&N with a TB Spacer will be ok.  Otherwise you'll need a tune to richen up the air to fuel.  (You can also get away with using higher octane fuel, but the tune will give you more performance from the intake setup). 

The TB spacers are absolutely worthless on a Vortec engine. The vortec heads are designed to spin the air/fuel mixture like it already has a spacer on it.

how do you "tune" the air/fuel ratio? and I thought they didn't start using the vortec engines till '96?

And the S&B system I am trying mainly brings cold air into the engine, it lets a little bit more air flow than stock not not a ton more, at least that is what I have read from their wed site. would this still change the air/fuel ratio too much?

The only way to tell for sure would be a dyno or have someone time a few 0-60 times, a few with and a few without the intake modifications.  With my truck it was a slight knock coming off of idel and if you punched it and heard this knock it would accelerate like it was pulling a load.  The truck senses this knock and retards the timing, (in this case it was do to predetonation from a lean air to fuel mixture). 

Vortecs started in 94 or 95 didn't they?

S&B intake I'm not sure of.  You will prob be fine.  Mine is a 3.5" intake and made a considerable difference on its own.  After I removed the screen on the MAF, added the intake, the TB Spacer and removed the metal airbox base to allow more air in...it ran lean.  I know this because I had someone log the data from the PCM with their lap top and the A/F ratio was leaning out causing the engine to retard the timing.  Plus the knock I heard when accelerating.  (Keep in mind, I live in a pretty high elevation too meaning maybe the truck needed time to "learn" that there was much more air coming into the engine, I dunno). 

To "tune" it out you need tuning software or a Predator tuner.  Something that will allow you to modify Power Enrichment, fuel injector slope, timing, etc....  You can find someone to tune your truck online or even go to a performance shop and have them do it. (i'd wait until you were done doing everything you want to do to the engine berfore you tune).

TB Spacer are pretty weak on a Vortec engine, I had a better gain with TBI using a TB Spacer.  I have heard that the ones with the threads inside (torque curve style) do make a more noticable difference than normal spacers.  Hypertech will not promise prefect operation of your engine using their tunes if you have an aftermarket intake or TB Spacer or both.  So they have to change something enough to change the airflow.

Vortec heads are hard to beat on airflow, but getting the air into the intake quicker, with less turbulence helps, not by a landslide, but it helps.

How would I know if I have vortec heads on this engine?

I have been looking online at some programers for this make a model but all there is (at least what I have seen) are proformance chips. If all I can do is put a chip in how can I modify the chip that is already there? or do I have to get a proformance chip?

You have a 95 right?  It has an airbox an not a round air cleaner assembly right?  

The older non-vortec have chips that can be replaced.  I thought the Vortec motors could be programmed.  I might be confusing the years here or something.

There is an air box by the fender with a hose going to the a round filter housing on top of the TBI. On the inside cover my LMC catalog they give a time of what happen in each year, and they say that the vortec opition started being avalible in '96.

Ok in that case try TBIchips.com.  He does a good job with chips and they are only about $30.  Had him do my 91' GMC, made a very noticable difference.  I thought it was 95' and up that was Vortec (It would say right on the motor if it was).  Sorry, my bad.

Oh BTW, TB Spacer on TBI motors make a difference, I know first hand.  Get a smooth bore spacer for top end increase in power, or a helix, torque curve (the threaded one whatever its called) for low to mid power increase. Try AutoAnything.com, you can find a discount coupon code on CouponCreep.com for them as well and save a few bucks.

How do you program the new chip or does it do it on its own? and what kind of chip should I get i.e. stage 1, stage 2 ect.?

You need a stage 1, which will require higher octane.  Stage 2 is for modified engines, for example if you put a performance cam, lower temp thermostat and headers or something like that.  A lower temp thermostat will do wonders for that engine also (despite the chip).  Get a 160 if you live in a warm climate, 180 for a cold climate (otherwise your truck will never heat up enough to blow warm air into the cab on cold days).

The chip is a PROM, which is "read only".  I cannot be reprogrammed without special software/hardware built to rewrite these chips.  Thats what the guy sends you just a new chip with some modified parameters on it.  You keep your stock chip and can switch them back and forth as needed.  (Like if gas gets too high or you want stock setting for winter).

So the big question is will I need the chip with this setup? and how will I know?

Well I just got done talking with the guy from TBIchips.com and told me that I will not need a new chip unless I start changing cams or other internal engine stuff, but the chip he could send me would need a colder T-stat, but I could still use 87oct. what should the T-stat temp be normally? I have never seen the temp gauge get above 150.

Thats a sweet deal, mine needed 91+, but maybe because it was an older engine.  Your stat should be 190-195 or so stock.  If it is at 150 then you either have a aftermarket stat, a rad in need of a flush, or a faulty gauge.  Have you ever replaced the stat?

The T-stat is stock and I just did a coolant change, I should have changed the T-stat at the same time it just didn't cross my mind.

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ORIGINAL: jcbst12

Thats a sweet deal, mine needed 91+, but maybe because it was an older engine.  Your stat should be 190-195 or so stock.  If it is at 150 then you either have a aftermarket stat, a rad in need of a flush, or a faulty gauge.  Have you ever replaced the stat?

Could indicate a slight retard in the timing. Advance the timing and go back to 89 and see if it made a difference.

I know a few people that have run the TB spacer from cfm-tech.com, they designed this spacer just for the gm tbis. everybody i know that has used this spacer has loved it. and its the one i'll be installing on my truck when the 400 goes in. Another fairly cheap performance mod for the TBIs is an adjustable fuel pressure regulator. GMs stock specs are anywhere between 9-12psi is good. I know its been proven that even with a stock engine the tbis like to see at least 13psi (the stock pump with support up to 14.5 reliably) and with any kinda mods like exhaust and intake they really want that extra fuel pressure. IMHO if your gonna mod a tbi you should have an adjustable fuel pressure regulator.

I'd have to see someone with it first.