smikecq

My dad left me a 383 stroker with whipple charger out of his 94 chevy pickup. Does anyone think this would be a good idea to stuff into my 92 RS 305 TBI? can I use the stock harness? can someone burn a chip that would be compatable with this setup?
any help would be appreciated

BMmonteSS

Nope, no way. Your ecm can't see boost, and there is no possible way to tune around this with your current ecm. Some have had limited success with a FMU. Your best bet if you wanted to do it right, would be to go with a 749' ecm. Do some searches on the DIY prom board for what it takes to 1) get into chip tuning 2) run TBI with a 749' 3) what it takes to support that much power with TBI

No offence, but this is a huge project for a TBI newbie.

smikecq

No offence taken, I am new to F bodys and TBI, but not new to building cars to go fast. This combination I have was given to me when my dad passed on, there for it is free, and was also his.
The car has 40,000 original miles on it and is in excellent shape,
the problem it is not the 347 stroker mustang I just sold.Therfore I am willing to try just about anythingto make this car perform better with the equipment I have, so thanks for the info I will read up on it and let you know my progress.

Fast355

iTrader: (2)

Hey BM- Whipple made their kits work with the chipped 7747 or the like in trucks. They don't support boost either. What Whipple did is found out that boost stays more or less constant with the same vacuum and engine RPM. They were able to use the MAP attached to the TBI. Never even sensing boost. I have successfully used a Weiand smog legal TBI blower on a 305 TBI RS using a 299 ecm.

jimp2001

Can't you just use an MSD BTM to retard the timing with more boost? They sell blowers for 305/350 TPI systems and those ECM's can't see boost either. The vortech TPI setup includes a timing retard module.

BMmonteSS

I would think the only way to do it would be to go way rich and way retarded on the timing once you hit 100 KPA and then deal with the richness till you reached full boost. Not the most elegant way of doing it, but it might work. I would think an FMU would be a better way of doing it, and a boost sensing ECM the best way. Then it all comes back to TBI being fuel limited once you get over 400 HP, not trying to sound pesimistic, but you have to be on top of your game to do it.

Fast, care to elaborate on how you ran boost with TBI?

Edit: After reading your response again, I cought the part about hooking up the MAP sensor right below the TB where there is no boost. So by doing this they were able to correlate a certain RPM and vacume signal to a certain pound of boost? Sounds crazy, but it makes sense to me.....I guess that makes me crazy LOL! I wounder what the down side to this would be? Decreased resolution, because the engine has such a huge dynamic range? I dunno but it's got me thinking.

BMmonteSS

Sorry, I don't usually reply to a post right after I just replied. You got me thinking pretty hard. With the map sensor right below the TB, it's going to see vacuum just the same as if the blower wasn't there. A motor is nothing but an air pump, a blower is an air pump that feeds an air pump. So, in theory the ecm is just going to think that it has a very hungry engine under the throttle body. It won't really matter that the air is being forced into the motor, your VE curves will be reconfigured for the increased demand of the motor at whatever VE and RPM it's currently at. With a roots type blower the amount of boost you get should be very consistent with a particular RPM since it’s connected with a belt.

Now for the problems, like I mentioned earlier your going to end up with a huge dynamic operating range for your engine, and it’s going to be able exceed 100% VE pretty quickly, heck at 14.7 psi your going to be at 200% VE. This is where I think you’ll get into trouble. One the ECM won’t accept anything over 100% VE, you could fudge some numbers, but your going to end up with a very choppy VE curve that slopes out of this world once you start building boost. Our TBI ecm’s don’t have the greatest resolution any way, so you could end up with 5 or 10 % steps in the tables, which could leave you with AFR’s wondering +- ½ point or more. Second, our TBI injectors don’t have a huge dynamic range either. Some guys are doing the PW too short at idle and too long at high RPM shuffle with NA engines. Not good, now you see where a proper ECM that uses a 2-bar map sensor would be beneficial? I wonder if Rbob’s U-tbi code is going to have enough resolution to do this effectively with a 1-bar? This still leaves the problem with the injectors, well actually it’s the firing strategy used by the TBI ecm’s they fire the injectors twice as often as MPI setups, but for half the duration. This is where source code would be very handy. You could fire the injectors TBI style at low rpm to keep the fuel supply smooth, and then go MPI style at high rpm to get the dynamic range you need.

Sorry for the small novel, just thinking out loud. You see smikecq, there isn’t a simple part number to order for a chip that will work, it’s complicated. The simple answer to your question would be get into chip burning and get a good FMU. You’ll be able to make power no problem, it just won’t be the best it can be without considering the above novel.

smikecq

Thanks for all the good ideas, I will study all the information that is available and keep you posted on my progress, or lack of. If I have more questions I will post.

modifybywire

Did the computer still reside behind the glove box of that 1994 truck? The 16197427 is quite capable of being tuned for a 383. You can get a 2 BAR MAP sensor for a Syclone. Goto Moates.net and check out the downloads for a bin with TBI and Super/ turbo chargers. This ECM can be configured with 4,6 or 8 cylinders. There is a supercharger kit for the 1994-95 TBI. I would check at Jeg's and SummitRacing.com for more info. With the computer and a few parts, you should be running soon. The chip is also available from the kit manufacturer.

BMmonteSS

Just slapping a 2-bar map sensor on your ecm is not going to be pretty, and there aren't any turbo/super charger bins on moates.net because as far as I know no one has done it.....succesfully.

I would look and see what the manufacturer did to get it to run correctly. I remember one guy talking about an FMU that added more fuel once in boost. He said he ended up with over 50 PSI of fuel pressure.

Hopefully fast will respond back with how he did a SC on his truck/van/camaro.....errr whatever it is that he drives

modifybywire

I saw the thread at 60 degree V-6.com, not Moates.

Here is a great TBI Supercharger write up. It should give insight on boosted TBI theory.

http://home.alltel.net/mcfly/tuning_fuel.htm

Fast355

iTrader: (2)

BM-you got it! With the roots style blower the ECM really doesn't know that it isn't just feeding a normal much larger engine. It actually works better than I thought it would.

DISCLAIMER- this is for a roots style only. Centrifical and turbo applications present a completly unique situation in that boost is not linear with RPM and vacuum above the blower. The Roots won't boost creep and since it is positive displacement always pulls in the same volume (negating humidity and temperature).

Here was the setup on my buddies RS (6 spd now by the way).

Late model roller cam 305 block bored to 310 cubic inches displacement with dished hypereutetic pistons. Reworked 193 swirl port heads, 8.0:1 compression ratio, vortec roller camshaft, exhaust from the ports back. On top is a weiand 142 smog legal truck TBI blower. The air/fuel metering is handled by a 454 TBI with a VAFPR and 454 injectors. The VAFPR is connected below the blower to reference the fuel pressure to manifold pressure. I found this increased the range of the injector. The fuel pressure runs about 27 lbs @ 7 lbs boost. But it only runs at about 10 psi at idle when the intake is seeing vacuum. With no vacuum or boost the pressure is set to 20 PSI. When the blower starts boosting it adds pressure to the diaphram and raises fuel pressure 1 lb for every lb of boost. A more ideal situation would have been to use an aftermarket 2 or 3:1 rising regulator and a smaller injector.(9C1).

The engine has a very solid, smooth idle, great throttle response, huge off-idle torque, good manners, and a tendency to blow the tires off.

The timing was a simple fix. Most blower setups use ported vacuum advance from above the throttle plates/blower on the engine. The timing curve is also very widely documented. I just transfered that over to the main timing table and tweaked on it. Mostly it was dead on though. The 193s even with 8.0:1 compression and 7 psi wound not take over 30* advance @ WOT. They also like no more than 42* advance when cruising.

The reason the 299 ecm was choosen was for the combined VE table. The VE table was tuned using the BLM method as well as a wideband. The 299s single VE table only goes to 4,800 rpm though, which for this engine wasn't a problem. The vortec cam goes flat at 4,500 anyway, not to mention the blower is wound up pretty good then as well. The ratio is the stock 1.95:1 that is supplied with the weiand kit. This car is a torque monster.

IIRC, the numbers were around 300 RWHP @ 4,500 and 365 ft/lbs @ 3,000 and 7 psi of boost on a 4th gear pull..

Edit- Here are a few things I forgot to mention.

Once you surpass 100% VE or get close you have two options, increase the BPW constant or raise the fuel pressure. Given the low-rpm nature of the weiand street blower and the cam the 4,500 rpm peak is a blessing as far as injector sizing goes. I can make more HP at 4,500 out of an injecter than the same injector at 6,000 rpm. It is just the fact the TBI injector has to fire 2X as often. N/A this engine was using less than 1/2 the available pulsewidth/fuel that the 454 injectors can deliver at 20 PSI. Raise the pressure to 27 psi and it would use even less. I am still using less than 2/3 the available fuel. I could feed this engine to 5,500-5,800 RPM with the available fuel now, but with this punny cam their is no reason. The boosted fuel pressure when it goes into boost also helps keep the VE table smoother. The 299 has a better VE table than your standard 8746 or 7747 as well. One final thing is even though the MAP sensor is seeing vacuum at part-part throttle, the truth is this engine is starting to build boost at 65-70 MAP and builds smoothly up to 100 map. The MAP under full load typically sits at 95 KPA though because the air filter and TBI slightly restricts things.

BMmonteSS

Hmmmmm.....did some one say U-tbi code? Didn't Rbob mention that he started with the much bigger all in one code from the 299 ecm then expanded that? The U-tbi code might give you enough resolution to run mild blower setups. Your still going to be limited by fueling with TBI, you can never make that go away, but by keeping your power low like Fast did it's doable. It doesn't look like a 450 rwhp 6000 rpm beast is going to be fed by a system like this, but a mild street blower is feasible......I woulda called if you hadn't explained it as completely as you did. I guess I can now say that one person has successfully run boost on TBI with a stock TBI ecm.

Fast355

iTrader: (2)

BM-these blowers will only move enough fuel for 480-500 HP anyway. They say to limit the max speed of the blower to 12,000-14,000 rpm. With the stock 1.95:1 drive ratio that is about 6,000 rpm. My new 383 with Dart Iron eagles, that is being built, is getting built with a Weiand 142 in mind. I might even dig out the I6 injectors to help me out some as well. Here are the DD2000# for my project. The blower will make an estimated 5.7 lbs of boost at 5,500.

RPM-----------HP------------TQ-----------Boost------Fuel Press.
2000---------183-----------479-------------1.6--------19.4
2500---------246-----------517-------------2.3--------22.2
3000---------306-----------536-------------2.9--------24.6
3500---------363-----------544-------------3.5--------27.0
4000---------417-----------547-------------4.0--------29.0
4500---------464-----------542-------------4.6--------31.4
5000---------499-----------524-------------5.1--------33.4
5500---------518-----------495-------------5.7--------35.8

Here are the numbers sans the blower with a dual plane intake.

RPM-----------HP-----------TQ
2000---------140----------368
2500---------185----------388
3000---------234----------409
3500---------275----------413
4000---------311----------408
4500---------337----------394
5000---------348----------365
5500---------342----------327
6000---------318----------278

NA I would only need 454 injectors at about 15 psi to feed it pretty well. It will be using an aftermarket FMU with a rising rate but that rate may be 4:1. I am looking to give maybe 13 psi at idle and about 4 x 5.7 or 22.8 additional at peak boost. Total fuel pressure under load and peak boost will be around 36 PSI. That will give me in theory enough fuel to make 560 HP with 454 90 lb/hr injectors @ 80% duty cycle.

I will be stepping up to the newer PCM and a 4L80E transmission. I happen to have the tranny and wiring in a blown up 454 G30. The max shift speed on a 4L80E is about 5,300 rpm so spinning real high is out of the question anyway. Not to mention I am going with a long stroke and a torque cam. Once again everything is biased to lower RPM operation as it is easier to feed TBI the slower it is turning.

You could make a 500 RWHP TBI easier out of a 540 than you could a 454. The 540 would be spinning slower to make the same power and the injectors would have longer to fire.

Fast355

iTrader: (2)

Several companies have already used boost with a custom chip. Weiand, Whipple, and Vortech have all done supercharged TBI engines keeping the stock GM ECM with a custom chip.

va454ss

iTrader: (1)

Some use auxilliary injectors though.

Fast355

iTrader: (2)

That would be vortech. To my knowledge B&M, Weiand and Whipple do without bigger injectors. They use a FMU and a chip.

va454ss

iTrader: (1)

Man knows his stuff

Fast355

iTrader: (2)

Found a recalibration kit for the Vortech FMUs too. If you have one you can change it to 4:1, 6:1, 8:1, 10:1, or 12:1 pretty inexpensively. The kit looks to include all of them.

http://store.summitracing.com/defaul...1&autoview=sku

modifybywire

I knew I had this somewhere. Some 1990-1992 F bodies might use this.
How to Convert 1990-1992 F bodies to a I 227749(Syclone) ECM
By Clint Buckalew
First let’s start with the question, why would want to do this? Easy because you’re running forced induction on your third generation F- body and want to control and tune with the computer under boost conditions.

Now let’s get a list together of all the stuff we will need to get this project going.

• • Equipment to read and burn chips (read Traxions article on this)
• • A 1227749 ECM from a 87-90 turbo sunbird, 88 quad 4 car, or 91-93 syclone/typhoon
• • Now for the MAP sensor 2 Bar: GM #16009886. or if you are running a 3 bar calibration 3 Bar: GM #16040749 (requires special modded bin from STG to run the 3 bar calibration.)
• • And a set of injectors to match

That should be everything you need to get you started. I left little things out like runner to plenum gaskets rn sure you can figure that stuff out as you go.
Now that we have all of the equipment we need, it’s time to repin our factory ECM connectors. This is what I did for my 91 Z28 5speed car and may not be the best for an automatic car.
 730 ECM 749 ECM
 A8 connect to A9 (ALDL data) not necessary
 Cl connect to B12 (VSS for cruise)
 CII connect to C12 (Injectors 1,3,5,7)
 C12 connect to CII (Injectors 2.4,6,8)
 D6 connect to C13 (Injector ground)
 E3 connect to E4 (IAC coil A high)
 E4 connect to E3 (IAC coil A low)
 E5 connect to E6 (IAC coil B high)
 E6 connect to E5 (IAC coil B low)
 Fl connect to F4 (shift light) for manual trans
 F2 connect to disconnect (AIR pump solenoid)
 F6 connect to F4 (TCC) for automatic trans

Next you will have to modify the MAP sensor connector on your wiring harness to accept the 2 (or 3) bar map sensor. I used a dremel tool with a thin gnnding disk and grooved the connector fingers so they would plug into the 2 bar map sensor.
Install your larger injectors (sized by using an injector sizing formula) in place of the factory injectors. Any manual made for 3rd generation F bodies should tell you what steps you need to do to change out the injectors.

Now you can remove your FMU or whatever you were using to meter extra fuel into your engine under boost conditions.

Ok we are done with the hardware, so let’s start with the software. You will have to reuse your stock memcal, and get a bin file from a syclone or typhoon and set it to 8 cylinders and modify it to get your motor running well. I used BBZB 1580 as my base file, since it is the latest .bin that GM released for the sydone and typhoon. On my car which still has the stock 305 tpi motor with a DiSC stage II procharger I ran very rich with the factory BBZB programming set to 8 cylinder. I’m sure a 350 tpi motor will be much closer to the factory BBZB VE tables. Now what did you just accomplish by doing all this stuff? You can manipulate your fuel and timing while under boost and data logging programs can now record your runs and give you a complete picture of what your engine is doing. Also you will notice that your cruise control and factory gauges work.

BMmonteSS

You can also run the sy/ty code in the 730, only downside is that the 730 won't drive TBI injectors, a 749 will. This is the way to go if you want to do it right, you can expect excellent drivability with alot less of the tuning hassles found with a FMU and making stock TBI code work with boost.

modifybywire

Hope my last post may help ya with your quest smikecq.