I have a '89 firebird formula w/ the 305 tbi setup and the T5 trans. This was my senior project with my dad and we built up a '77 sb 350. I really want to keep the tbi setup and also keep it emissions legal. I have read the article on, http://www.goingfaster.com/spo/modthel03.html, several times and it looks like I will need to do 3 things: get a chip burned, buy a new tbi, and buy an intake manifold. I am guessing the engine will put out about 300 hp, and was originally planning on just slapping a carb on before I got smart. I put on protopline iron heads and I want to plan out a good setup. I want to go with the 2", and don't know the best way to go. My main concern is having the older style engine and being able to keep everything running right.

The two manifold options that I found were the holley tbi w/ the 2" or using the edelbrock preformer w/ egr and using the adaptor plate. First will the egr on the preformer be compatible w/ the egr system currently on the car? Second is there an adaptor so that the holley tbi manifold will fit on the older engine because I think it will only work on the newer engine? Third which is the better setup or is there another that is better?

Also any suggestions for the tbi? I saw that holley had several and also I could get a stock bb one.

Sorry about the length, any help is much appreciated.

 

The difference between the manifolds is the angle that the four center bolts are on. The newer style heads have the bolts angled more vertical and the old style have them in line with the other bolts. You can modify the bolt holes and use a wedge style spacer to mount one to the other, or just check and see which ones your heads have (in line) and get a manifold to match. Some guys have had luck with a low profile single plane since TBI doesn't rely on velocity to atomize fuel like a carb, with proper tuning you can get a single to make as much torque as a dual plane generaly speaking.

As for chip tuning, this will depend alot on the size cam you have. Post up some specs and we'll let you know, sounds like your going to need some extensive DIY tuning. Check out this thread for a more recent discussion https://www.thirdgen.org/techbb2/sho...hreadid=302105

 

What about the egr options?

 

as long the intake is setup for EGR your good to go I think there is one single plane that has egr provisions, you may want to make sure your pro-topline heads have provisions for EGR some aftermarket heads don't.

Do you have to do a sniffer? If not you can just bolt it on and disable it in the chip, that way it'll pass the visual test and not be functional.

 

I really don't know much about the tbi computer system, this is the first time I have worked with it. Are you saying that it can be disabled in the computer?

I looked through the other post and it was good. Does anyone know a company that makes the convertor plates for old style heads to new style manifolds? Here is the info:

Engine: 350 chevy sb bored .04 over to 357
Cam: Comp Cam Extreme Energy 262H (262/270, .462/.469, 110/110)
Heads: Protopline iron heads 64CC/220CC 2.02" intake & 1.6" exhaust valves (Item # JRK 223400020A21) [Accepts both center mount and outside flange mount valve covers]
http://www.protopline.com/223400020a.htm
-Under manifold it says
Manifold - Std Chev Victor Jnr #2975 - Dart Wilson

I am guessing that this is the older style.

1.6 ratio roller rockers
160 thermostat
High Pressure Oil pump

Intake manifold: Looking, taking suggestions

TBI: Looking, taking suggestions

Ignition: MSD 6A

Thanks in advance

 

There isn't really any adapter plate for the "old" vs "new" intakes. The only differ in the angle of the 4 center bolt holes that aren't really that different, you can just grind the intake to make it work. Besides your heads should be the old style.

As for the rest of your combo. That cam is big enough to require a good bit of chip tuning, and your heads are on the big end being 220 cc's Those heads will probably kill some bottom end, and could use a bigger cam to take full advantage of. I suggest something in the 180 to 200 range for a hot street engine, but if you already bought them they'll have to do.

Your going to be treading deep into what TBI is capable of. Which means your going to be needing lots of DIY chip tuning. Mail order isn't going to get it done. Start doing your research now, and start now while your car is still stock, or just switch to a carb if your not willing/able to do the DIY chip thing.

 

The Holley Projection intake will mount your TBI and is designed for the pre-86 engines/heads. You are by no means near the limit of the TBI injectors(think 90 lb/hr injectors at 32 psi). The factory intake shouldn't hold you back but the stock TBI will. Ultimate TBI mods would be good, the projection intake is also already equiped with 2.0" holes. A big block TBI or Holley 670 would be a good choice. The EGR on the projection intake is compatible with the stock carbed era EGR. You can use your solenoid but not the valve itself. Find out if yours is Negative or Positve backpressure and get the equivalent carbed one.

You are however over the limits of any factory chip. Chip tuning will be a must. Your cam is a little narrow on the lobe seperation so you may have some problems getting a clean idle. You will need a VAFPR as a minimum to enable you to change the fuel pressure as the engines load increases. That will give you the ability to get control over the injectors at low engine speeds and loads while not leaning out under higher speeds and loads. I have seen some VAFPRs worked into the chip to vary the BPW based on MAP readings. All you have to know is how much fuel pressure the regulator produces at a certain vacuum and it is simple calculations after that. I believe Dimented has that in his coding, IIRC.

 

Thanks for the input. I purchased the cam with an engine rebuild kit as a package and I still do not know very much about cams. If it is too much or too little, is there a better one to put in? I really want this engine to run well with the set of heads that I have and have a descent amount of power. If getting a milder or hotter cam does the trick it's worth the money. Also is the vaccuum ajustable fuel pressure regulator hard to install?

Another question you said, "You are by no means near the limit of the TBI injectors(think 90 lb/hr injectors at 32 psi). " and then also said, "but the stock TBI will (hold me back)".

 

I was talking about the airflow through the throttle body. The stock TBI is about 480 CFM @ 3.0 in/hg pressure drop. The holley flows 670 cfm and the 454 unit is right up there too. The injectors themself are not the limiting factor. You can make 275rwhp with the stock intake and TBI.

 

Correct, your cam doesn’t match your heads IMO. I’d definitely go bigger on the camshaft side of things (and of course I wouldn’t sacrifice what choices I made on my cam because of possible tuning issues).

Listen to this post and take it to heart. You need to make this decision soon I’d say. If you are not willing to do a lot of DIY chip tuning or spend a lot of money on somebody else dyno tuning this thing, your best option is a carb. Think down-to-earth, are you going to be able to make this car reach its full potential with your tuning skills?

Oh, your current cam is plenty mild. That’s ok though, but keep in mind, with those good heads a relatively inexpensive camshaft is holding you back from making a bigger HP number (providing of course you have a good tune and exhaust system). This is my old cam I ran in a 355, I loved it. From 3000 RPMs up it was awesome. Here's a good cam too. It depends on what you want and your driving style. And mainly it depends on how you are going to tune it.


Not trying to be insulting, but it seems like you want to have a somewhat hot combo (as far as DD street action is concerned) but you don’t have any tuning skills. That’s going to be hard to do with TBI and DIY tuning. It’s all in the tuning man…

 

Thanks for the help and the clarification. Now I am also planning on swapping the cam while the engine is still on the stand. Out of those two cams that you suggested which would be the better, and how did you determine that (I don not know much about matching cams to heads)? This is my first project car (and I am 19), so yes I do not know very much about the DIY tuning, and I willl never know unlesss I try it out, it's just about the money. I actually am not planning the engine swap until next summer, but I want to have it all planned out and get everything ready this summer (full time student). I don't want to just slap a carb on there because that just doesn't seem like the right thing to do.

 

I'd pick the smaller of the two cams I suggested if I were you. However, you need to get some advice from people that are good at DIY tuning. They might tell you something like, "Wow that's going to be impossible to tune!!!" I don't know, I have never done DIY tuning (well I have, but it was on a carb).

A lot of people on here are going to suggest a pretty mild camshaft. That might be awesome for tuning it, and therefore it might be better for you. But tuning issues aside (and therefore this comment is theoretical in your case), you have a V8, you have a light car (compared to a lot of cars out there running SBCs), and you want performance. With those things in mind, IMO, there is no reason to want more torque at 2000 RPMs then a Cummins Turbo Diesel....

 

As for chip tuning, I have the 4x4 cam version of the cam thats in your motor now, and I have LOTS of chip tuning invested in making it run the way I like. By lots, I mean over 500 chips, I know this sounds like alot, but you can do 10 or more an hour if your just making small changes. The amount of overlap makes alot of difference in how difficult it's going to be to tune your idle. 112 or 114 will be much easier compared to say 110 or 108 sep angle.

Your heads are huge, by street standards. What thats going to do is kill velocity at low engine speeds, but in turn make big power up top. The cam thats in your car now will make good power between 2500 and 5500. I shift around 5800. The heads on the other hand are probably 3000 to 7000+ rpm heads. Either of the cams that brody suggested would better suit the heads you have.

With regards to the power band, TBI is not the best choice and here's why. Fuel is injected every time the ecm recieves a pulse from the disy. As the pulses get faster (rpm's increase) you have less and less time to inject the needed amount of fuel. At 6000 rpm you only have 5 ms to inject the needed fuel. If you stick with the accepted 80% duty cycle that means keeping your PW under 4 ms. When you get to 7000 rpm you only have around 3.7 ms (check math) to inject all the fuel you need. This is why I think you will be pushing the limits of TBI. It's not just the HP your making, it's the RPM that your making that HP. Ben is making over 400 hp and running mid 12's, but this is with a low rpm 383 not a high winding 350. I think he shifts around 5500 rpm. This makes a BIG difference.

These are things you will be dealing with if you decide to keep TBI and do the required chip tuning. I'm not trying to scare you off or anything, I just want you to be informed of what your going to be getting into when you build a 400 plus HP TBI engine.

 

I have a couple of questions that weren't addressed:

Can the egr be turned off with a DIY tuner?

Is there any options besides the $300 tuner, possibly one htat attaches to a laptop?

Also I sent my engine info to comp cam for them to match it, and they suggested the CS XE256H-12, here, any reason why they would suggest this one and not the two you suggested?

Thanks again

 

Yes.
I believe it does attach to a laptop. And I doubt there are any options out there for less money (for tuning TBI).
That cam is too small, no doubt about it in my mind…

 

Moates sells an 85$ dollar burner, with his 30 converter that lest you use flash erasable chips instead of the UV erasable chips your in buisness. The 300 autoprom allows you to do real time tuning without stoping to reburn chips. This is NICE!, but I would put my money into a wide band sensor before I'd get this.

Go check out the stickies at the top of the DIY prom board, they should get you started and give you an idea of what it will take on your part to get started.

If you told them you wanted to go with FI then thats why they suggested that cam, it's the only way to get the motor to even idle without chip tuning.

 

OSTRICH $175.00

These are cool and plug in to a USB port.


http://www.moates.net/product_info.p...ts_id=57<br />



And as BM said the Moates burner is cool too. Son in law has one.

DM

 

Emulators are real cool...
But I think for someone who is a novice at tuning they can be a bit dangerous. There could be a real temptation to make too many changes at one time, and if you make a mistake, you'll have no idea what you did wrong.

 

Hello,

I think that I will have to go with the carb because of the rpm limit described by BMmonteSS. Thanks for all your help. Are there any articles about changing from the tbi to a carb? And if not any suggestions?