I have a 1986 Monte Carlo. It currently has the 4.3 TBI but i'm assembling a 388 for it(.060 over instead of .030). I've been a member of MontecarloSS.com for over a year now and have only talked to 1 person running a V8 W/TBI in a monte. Everyone else either has TPI or a carb.

Forgive the length but i think getting an accurate answer is largely dependent on complete info.

Parts i have

350 block .060 over
383 speed pro Hyper pistons and rings.
Scat crank 383 ext balance
Scat stroker rods
Cloyes Timing set
Scat flexplate
Clevite bearings
All ARP bolts
Weiand Stealth intake W/ TBI adapter
Dart 180 CC Iron eagle 72CC
TBI unit from a 1989 GMC 1500 5.7L
Computer from same truck
Distributor from same truck

I need to pick a cam still, but i'm leaning towards a comp cams Magnum 280 H
adv duration 280
.480 lift

Gonna set redline at 6500 RPM

My question relates to wether i can run TBI on that engine. Will the cam mess with the MAP sensor drastically? I'm not worried about emmisions or inspection.


Will a 454 TBi unit give the flow needed? Are the throttle linkages the same for a BBC and SBC tbi unit?

I understand that i may need to run higher pressure and i know a custom chip will be neccesary. I read all the posts that are sticky at the top of the forum. I am in the process of locating a laptop so i can log the sensors from the data port.

I understand tuning will be a horror but i'm determnied to be a little different.

I havent seen much info on the Monte board about custom tuning a TBI chip. You guys are very informative and i was hoping to get a little info specific to my application.

Thanks in advance
-Steve

I'm probably the other guy on MonteSS.com that is TBI'd. Here's some suggestions/answers to your questions.

It sounds like you have the mechanical side of things figured out. Your lucky, you already have the only G-body tank that has the proper baffling and pickup to run an intank pump. You will need to get your hands on a walbro pump, the stocker won't cut it. A walbro 190 will work with no problems, you may want to try to use a 255, some have reported that the stock TBI regulator can't bypass enough fuel at idle, some have ported the return passages and have had no problems.

You NEED the 454 TB and 90 PPH injectors that most of them have. The BB unit has a different throttle linkage than the SB TB. You may be able to swap the throttle shaft between the two TB's. You'll also need to up the fuel pressure, some where in the mid 20's would be a good starting point.

For tuning, you better be planning on doing the tuning yourself. Or saving up your pennies to pay some one local to do the hands on tuning. There is just no way to tune a combo like this through the mail. Some people pick up on it right away and learn fast, others take time. The BEST way to learn is on a completely stock motor like your 4.3. I suggest swaping in the truck ECM and get the hang of burning chips by tuning your stock motor. You'll be replacing it soon, so it won't matter if you lean on the motor a little while you learn. You'll find the best info on chip burning on the DIY Prom board right here on this sight. Start with the stickies there and then move to searching. After your thoroughly confused post up your questions and some one will be glad to help.

For the cam, you may want to look at a cam with a wider lobe seperation angle. Something with a 112 to 114 lobe sep will be much easier to tune for a newbie and give you a wider power band with a small sacrifice in peak power. Were talking less than 5-10 HP sacrafice, which will be well worth the ease of tuning.

You might look into a performer RPM intake. You have the room to run one, and it is THE intake to have for the street. You'll probably make the same peak power as the single plane you have picked out, but make more bottom and mid range power.

Your combo is completely doable with TBI, you'll be pushing the limits of what TBI is capable of, but others have done what your wanting to do. (TBI is fuel limited by the way, hence why you need the 90 pph injectors) Look up Ben73, he's running mid 12's on street tires. There are others as well.

It will be fine with those parts.
You will be better off with the 454TB and 90lb injectors as BMmonteSS said above.
I think you won't have to turn in much more than about 56-5800 rpm tho.. 6500 sounds a bit high for that combo to me.
I have a 110 LSA cam and it was suprisingly easy to tune.. Everyone says you must use 112-114 deg's, and for that reason, very few guys tried a narrower LSA. That being said, if you haven't bought the cam yet, and you are a newb to tuning, a 112 LSA cam would be a better idea.

I also don't believe that a dual plane manifold would be any better than a lo-rise single plane in a TBI application.. You are not reliant on strong signals for a carb, so it makes little difference..


You don't mention the exhaust, but all up it sounds like a nice street combo and TBI will have no trouble with it at all.. But it WILL take a bit of tuning, so if you wanna do that yourself, factor in the cost of the tools required to do it properly.. WBo2, Laptop, aldl cable and Ostrich recommended..

Ben.

I'll look for a LSA of 112. When the catalogs have a RPM range next to the cam how close it that to the real powerband? I realize that every engine is different. I dont want to spin the snot out of this motor. If i have good power right up to where i set the redline i'm happy. I dont want to shift/rev past 6,000. If i use a MSD module i'll put a 6500 chip in to prevent any mishaps.

Obvoisly i dont want to overcam the engine. I may also change the heads to a set of 200CC runnners but i dont want to hurt torque. If i need extra lift 1.6 roller rockers are no more expensive than 1.5 rockers.

I was actually refering to pickupman95 as the other TBI member. He was the only one i could think of off the top of my head.

As far as the intake is concerned i picked it up for cheap so i'll run it. If I come across a Performer RPM on the cheap i'll consider it.

I've been planning the swap for a while but just recently got my bottom end together. The furthest thing from my mind was tuning during the planning phase. I'm looking into cheap used laptops on ebay. What is the lowest i should look for?

I have the stock 4.3 TBI unit on the car and the TBI from the 5.7 truck so i'll snag the throttle shaft from one of them. I dont want to lay out a bunch of cash for a bored 454 TBI unit and screw it up when trying to swap the throttle shaft.

Tuning the car with the current setup is not possible cuz i dont drive it. I'm waiting to close on a house with a 2.5 car garage. We should be in by x-mas.

Thanks for the reply
-Steve

The cam doesn't match the heads well at all. It is too big for the 180 cc heads on a 383. Plus the 383 won't take too kindly to running 6,500 RPM for any extended time. The piston speed is too great. I would stick with a powerband of 1,800-5,800. That is an awesome powerband for the street. My brother has this cam in his 1995 4x4 Tahoes 350 TBI and it makes power to 6,000 RPM WITH STOCK SWIRL PORTS. Peak torque is at 3,500 RPM. With a 700R4 and a 2,800 RPM stall this thing gets it.

http://www.cranecams.com/?show=brows...tType=camshaft

I have the same cam in my closet for my 312 in my Van. It will prove to be a screamer, more so than the L82 cam that is currently in it.

The 180 CC heads i got by accident. They were supposed to be a set of 200CC heads. I bought them on Ebay and since paypals buyer protection program is worthless i'm stuck with them. I found that they were stamped wrong. 1 has a stmp that says 64 cc and the othe says 74 cc. I took them to a machine shop, had them CC'd and they both came out as 72.

I havent bought any valvetrain components yet so i'm open to suggestions.

Let me clear the RPM thing up. I dont want to run the motor to 6500RPM. Thats where i'm gonna set the rev limiter. I want power untill about 6000 RPM. If i have to give 200 RPM back in order to keep the motor alive longer i will.

Thanks
-Steve

I agree. I would steer away from any type of air gap manifold. TBI needs some heating of the plenum.

I based my performer RPM suggestion on runner length. At just over 6” it’s in the same ball park as the stealth ram and just slightly longer than a Victor Jr. I would assume, that a low rise single plane would have even shorter runners than a Victor Jr. Every dyno test I’ve seen has shown that an RPM intake makes more power to 6000 rpm and the vic makes more from 6000 on up. How much of this is due to signal strength to the carb, or runner length and cross section, I can’t really say. I have run both intakes and my butt dyno say the RPM pulls better down low, but my butt dyno hasn’t been calibrated in a while. I also second the suggestion to skip any type of air-gap intake, I’ve iced over my TB in cold weather and I have the exhaust crossover functional, I couldn’t imagine it with an air-gap intake.

In all reality intake selection is probably not worth 5 hp either way. Tuning will make the difference between making it out of the driveway or making all the power the engine is capable of, this is where you need to spend your brain power and money.

very happy with holley performer TBI manifold(rated 6000 rpms). stock GM linkage worked with minor adaptation as did the 7.4L TBI. my comp cam efi cam 114 lsa 224/230 (rated 5800 rpm)is about as big as i would ever go on a 350 yet i bet a perfect fit for your combo.

I read a bunch of stuff about wide band O2 sensors. What are they, where can i get them, and what do i have to do to wire them into the ECM? Is it a matter of adding a 12v switched to power up the preheater?

I think i may have the cam
Crane 113801 2500-5000
114 LSA
.467/.494 w/ 1.5 rockers
278/290
222/234 @.050

I figure if i get the matching springs and such i'll be out a total of about $400

My brother is checking to see if he still has an old laptop lying around. What should i look for in case i have to buy one? I read that a 486 is good if i want to burn chips but a pentium 250 would be needed to datalog. Point me in the correct direction.

I got the throttle shaft out of my 350 TBI today. How much of a difference is there between the bored 50MM SBC TBI and a 454 BBC TBI? Can i just run the bored SBC one with the larger (454 90#) injectors? I saw someplace wanting to charge a $200 core on a $250 454 TBI. Now that i know that TBI is possible on my combo i feel a whole lot better about spending money on parts for it. I jsut dont want to buy stuff i dont need, cant use, or thats just not good enough.

Thanks for the very helpful advice and keep it comin.
-Steve

i have both winaldl and tunerprort. win does not require much as far as laptop. check rt for its requirements. the issue with a old one is the battery being insufficient to run laptop withiout dying. you may need a 12V convertor to cig lighter if you run a old one.

the Innovate is a good unit as is Zetronix(sp?). We and Innovate had a grpup purchase a while back(search). may be time for another???

my 7.4L was 2.00 inch so i think it is 50.8 cm? not much diff there. someone once said the 80 lb inj's are better than the 90's as far as quality? may wanna search on that.

WB O2 sensors are just a tuning aid, no way to really "wire" them into your ECM. A Wide Band O2 sensor is just that, it can sense a wide range of air/fuel ratio's, where your stock NB sensor can only see 14.7 to 1. A WB can be a *** send when it comes to tuning. Once you get to reading about DIY tuning it will become very evident how usefull they are. I second the Zietronix suggestion, mine has worked flawlessly, and the included logging software is a good way around our slow data rate that all TBI ecm's are saddled with.

You may also want to read about the new lockers board/ ultimate TBI code thats coming out. It will probably all sound greek to you now, but once you get the hang of things it will start making sense. Basically this hardware, software combo will fix every single problem with TBI along with a killer fast data rate, and graphical user interface for logging.

I read the whole thread about the lockers though i had no idea what they are. The computer i have is a 1227747.

Do you guys log thru the OBD port currently? I'll look into the lockers more completely before i lay out any cash for datalogging software/hardware.


Where would i place the WB02? Would i have to weld an seperate bung into my headers?

Sorry for all the newbie questions
-Steve

Yes the log comes from the serial port currently. The ground and the serial bus connection to be exact, just like a scan tool, just with WinAldl instead.

As far as the Wideband and a factory ECM, it is very possible. In fact I am now playing with only my wideband running my ECM. The signal is actually an output from the wideband controller. It outputs a 0-1 volt signal just like a standard 02. The only thing is that it is more accurate at a/f ratios other than 14.7:1. I could setup closed loop for a range of about 13-16:1 if I wanted too, although it is 14.7:1 for emissions now.

In your situation, I would definately go for the Blockers, the 160 Baud stinks. I barely have enough data to do anything on a 80-100 mile highway trip to do any good. The 160 baud is pathetic. The Blockers will put the 8192 Baud to shame as well.

Then on top of that the code that runs the engine is all new and made to run the engine much better than the stock code.

I currently log through the OBD (ALDL port) and it's very slow on TBI vehicles.

The Wideband needs a seperate bung in the exhaust, mine's right after the Y-pipe. For now, don't worry about wiring the Wideband into your ECM, you'll just confuse yourself more. The wideband will either come with a display of its own or you'll be able to record data on the Wideband controller itself and then upload that to your computer to analyze it. The good thing about wideband controllers is that they output data LOADS faster than the ALDL port and they usually can accept signals from other sensors on the car. On my wideband I inputted RPM, MAP, and TPS signals to it and now I can log all these at ~30 samples per second or something like that, which is priceless when you get into tuning. When I first got my wideband I held off on tuning for a month or two just because when you drive around looking at the wideband display you really learn what the car is doing and when it's doing it.

if you but a WB invest the $100 xtra for the inputs for rpm/map/tps. it give you a valuable reference to time events occur. b4 i had those inputs i had no idea as to why the log was all over the place on A/F. now i can relate to getting on xway from standing stop AE event, shift to second at 6000 rpms,(car gets a bit sideways), third gear(now i am over speed limit a bit), and see the PE A/F as AE is timed out. if i just drive down city streets i see the tps effect( volts convert to % of throttle opening and map inc as blades open) and can relate normal accell to AE event. all is logged that day and i look at on laptop at kitchen table. a neat tool.

If you get the zeitronix unit, you don't need to buy extra modules for the extra inputs.

Well my brother cam thru with a laptop for me. It needed a BOIS battery so i went to rite aid and grabbed the correct size which was a 2025 and soldered the leads from the old battery onto the new one. Booted right up. Looks like a Pentium II 300 MGhz. Not sure how much ram. I need to find a CD drive for it and relaod windows cuz it give a bunch of errors for missing files in SYS.INI. Not bad for free. Should i just leave the thing plugged in overnight to charge the battery and see if its good?

Where do the units you guys are talking about plug into? Do they go between the ECM and the harness or do you have to make a seperate harness? Gonna do a search now cuz a picture is worth a thousand words.


Thanks again
-Steve

Wideband = Not connected to ECM

It's a completely standalone system, you can run them on carbed cars if you'd like. You can input things FROM the ECM into the Wideband, but don't worry about inputting the wideband into the ECM, it's not necessary.

look at the Innovate LM-1 website. it offers a whole lot on info.

Ordered a Lunati Cam w/ LSA of 114. Grind ## 00011 Duration of 285 lift of .455. Plan on running the 1.6 rockers to make up for any lost lift. Gonna pick up their valvetrain kit ##65002 with the matched springs, retainers and such.

I've read about the Moates ostritch in a few threads and wanted to ask if anyone has used any of his other product. His chip burner is only $85 and is USB so i can burn without needing a socket. Heres a link to the one i'm talking about.

http://www.moates.net/product_info.p...products_id=48

Is that what i need?

Thanks
-Steve

Thats a good burner, Mr. Moates is the go to guy for anything DIY prom related. As you have read the ostrich is a real time emulator, which means you can change things on the fly while the engine is running. Which is great, but you can get yourself in trouble fast if your not carefull and deliberate. Moates also has the autoprom, which is basically the ostrich and the flash and burn all in one. Very cool, and a bargain at 325$.

The only hitch with either of his tools is that they don't actually burn our stock 24 pin 2732 chips. You can read them, but not burn them. You need to get his adapter that lets you use a larger 28 pin chip. You just burn to the last "slot" in the chip and your good to go. The other advantage to these chips is that you can get electronically erasable chips, which take just seconds to erase right in your burner. Our stock chips take a UV eraser that is a major pain in the but to use, plus stock 2732 chips are flaky, you usually only get about 75% of them to work.

The last hurdle you have to overcome is the socket in your ECM. The stock socket is not like most chip sockets, it requires the plastic thingy that your stock chip comes with to work properly. I have gotten moates' adapter to work by just pluging it into the stock socket, but it's easily knocked out, which isn't good while your running down the road. Your best bet is to unsolder the stock socket and solder in a good socket. Moates has those too, or you can have him solder one in for ya for small fee.

I'm gonna be buying a ECM from a 91 RS with that adapter soldering in already and a flashable chip installed along with the Moates burner from a member here. I figure its a start. I after i get the hang of burning a few chips i'll start looking into Datalogging eqipment. My main concern is getting my motor built and broken in. Once i get that done i can get in the ballpark then fine tune it from there. I'm not expecting this to happen overnight. Ive tried to build cars all at once and have normally had poor results. This time im getting one peice at a time so i have time to research them and make sure they will work together.

I'll let you know when i confuse myself even more.
-Steve

Datalogging equipment is 5$ worth of electronics from radioshack. Check out Winaldl, it's a free datalogger and what most if not all TBI'ers use, there is also a schematic on their website that shows how to make the cable. You can also get a cable off of ebay for around 50$. Tunerpro also has a datalogger feature, and is free as well. Isn't DIY tuning great