For those with both, what did you do? I have no chip burning equipment, nor does anyone around here. Is there anyway I can run a stock Speed Density tune and turbo? Here's my thoughts, please feel free to shoot them down if you have either tried or no for sure it won't work.

Okay for starters, this is what I have. 1991 rebuilt 305 TPi motor. Auto transmission and coated headers. That is it. I am wanting to do the RMT.

Okay, I know a few things about forced induction from my previous car, hence my screen name BigwhiteGTP:

Too much timing with less octane=bad.
Too much boost without proper precausions (ie, intercooler or alky) = bad
Not enough fuel = bad

Okay, here's how I plan to fight the stock tune to add more fuel.

1) I have a 350 Speed Density memcal. As you know it's programmed with 22lb injectors. So in my car it would run rich. If I swapped out to 22lb injectors, with the stock 305 memcal, it will run rich. So I need new injectors pretty soon and I was thinking of running the 350 memcal with either 24lb or 26lb injectors to keep things nice and rich.

2) Timing, I would simply reduce timing to either 4* or 2*.

3) Alky kit. I've seen one work and can put one together.

So maybe with all 3 of these to help fight detonation, would the stock Speed density tune freak out? Is there any way I can run a turbo with stock tune? MAF is more tolerant, and I might just go with that. Again, no access to chip burning.

No flames as this is just in the preliminary steps and I'm asking questions. I'm not the type to buy something and slap it on w/o doing some research of every step of the way.

Now if someone can recommend an aftermarket chip, that would be cool too.

 

I think your best bet would be 24# injectors, stock 305 chip, adjustible FMU, MSD BTM, booster fuel pump, fuel pressure gauge, boost gauge, and less than 6 psi of boost. Or do some research on the $58 syclone code and get some chip burning stuff on <u>DIY Fuel-Injection Tools:</u><br>Created by an EFI enthusiast for EFI enthusiasts like you! : Moates.Net

 

The only thing wrong with the stock 305 chip is the 110mph speed limiter. It sucks. With a turbo, I think I would want a bit more speed.

Now what about my alky/water injection idea to help with more than 6lbs boost? It works well for the non-intercooled GN and GTP guys. I know I am running stock compression and stock replacement pistons. Basically, this motor will be the driver motor while I build something else on the side in the meantime. The turbo is to give me some power for now, then with the built motor, really have fun.

 

There are other ways to do it but in my opinion none are as accurate as a properly tuned PROM and ECM designed/modified to run boosted engines. The Speed Density TPI 730 ECM is not meant to support a boosted application in stock form, but there are a few choices you have to make it happen. One of them involves modifying the 730 ECm or swapping in a 749 ECM, upgrading to 2 bar MAP sensor and re-tuning the PROM with different code. But since you said you weren't gonna go that route, don't even need to worry about that. The other way I've seen people do it is run external parts that compensate and work in conjunction with the stock 730 ECM. It usually involves controlling timing and fuel beyond what the stock ECM can do. Vortech Supercharger kits for our cars use the MSD 6BTM to control timing and Vortech FMU (Fuel Management Unit) and secondary pump to control fuel. You could do a similar setup, and with the right parts you should be OK for lower boost levels and stock 22# injectors. As already mentioned there are also other ways to do this, the MSD 6BTM and FMU way is only one choice. If you're thinking of running high boost, I'm not sure how much I would trust these setups, I would recommend going to a single engine management ECM thats designed to completely support a boosted application and can be re-tuned (be it modified OEM or aftermarket). Remember that these ECM's are what run the show, don't want to be putting your investment (engine) at risk because you decided to cut corners. You don't necessarily have to spent alot to protect your investment, just make sure you do it right.

 

I've heard of putting a toggle switch on the VSS from the tech articles to temporarily disable the speed limiter.

I'm probably not qualified to comment about the secondary injection, but it sounds like it might be a good idea. Then you just gotta watch your compression ratio with lots of boost.

I get away with a peak of 14psi@5700rpm with 9.4:1, only because my wastegates are too small and it creaps pretty bad from a setting of 8-10 psi@3600rpm. The real fight (after tuning is correct) is against cylinder pressure which causes detonation. Increasing the boost increases volumetric efficiency, which increases cylinder pressure. At higher rpms, volumetric efficiency drops, cylinder pressure drops, so the boost can be increased a little.

 

The MSD 6BTM, I looked up a pic of it. Basically I have the dial inside my car and I can adjust it. But, how do I use it day to day? I mean, it seems that it doesn't adjust for me, I have to do that.

And the FMU, saw a pic of that, it basically a fuel pressure regulator under boost, correct?

Do I need a wideband o2 scanner?

 

you set the MSD BTM once, and leave it, unless you make a change.

that is exactly what the FMU is, it raises the pressure drastically to increase your fueling. the increase in pressure is why you NEED the booster pump inline.

Wideband O2 readings would help you tune an adjustable FMU, also with the secondary injection.

 

Just take the plunge and get some sort of other EFI setup. For the price of a BTM you can be cutting your own chips for your stock box or have a Megasquirt-II, and for another $100 on top the cost of an FMU you can have a wide band to tune it up with. That and upgrade the injectors to minimal of 30pph. It's expensive sure, but what's replacing that motor gonna cost?

 

You can take the 730 ECM and use the $5D hack to allow usage of a 2-bar map. Basically you are taking the programming for a Sy/Ty computer and running it on a 730 with a hack for a 2-bar. This will allow you to adjust for a boosted setup and it will be just like tuning a regular SD system. You can find more about it in the DYI Prom board.

 

There are two ways to go about the fuel/spark management.

1) All done through the ECM. Cheap, but STEEP learning curve
2) All done with mechanical add ons. Simple, but costs more

Doing the ECM route.
1) 730 ECM (used $50)
2) 2-Bar MAP sensor ($50)
3) $58 Syclone code (tune with TunerPro) Both Free
4) PROM burner (Xtronics $150, or Willem $60)
5) injectors, 30#/hr minimum for 305 TPI ($250)
or smaller with a adjustable fuel pressure regulator ($60)
Best route is EBay some used Ford 30#/hr sat. red tops (<$150 - $200)
This will give enough fuel and ability to tune fuel and spark (STEEP LEARNING curve)
Total: approx. $450 (and you can tune when you change parts later on and up the fuel pressure for more than 400 FWHP)

Doing the Mechanical route:
1) BEGI fuel regulator ($200 ???)
2) MSD or other spark management device ($250 ???)
Total approx. $450 (you are close to maxxing out the injectors with this setup and can't tune spark and AFR like you could with all ECM control.....but it will be fine)

 

Thanks. You said the mechanical is simpler but costs more, yet prices for both were $450. Did you forget to mention something?

Now here's a question. My mind is stuck on FMUs. So if an FMU is useless to me let me know, because I seem to have a one track mind. Isn't an FMU a fuel regulator? Couldn't I use that instead of a BEGI fuel regulator? Also, like I said above, I need new injectors anyway. So Couldn't I get a set of 24lb or 26lb with an FMU and avoid maxxing the iinjectors? I'm not being a smartass or not taking your advice as you know more than me. I'm just trying to understand the differences in parts and what works with what.

ThaANKS

 

I did forget. I forgot to add the injector cleaning for the mechanical setup so I was off there by $100 or so.

If you would like to use the FMU that is OK. Use what ever you feel most comfortable with. An stock type fuel regulator will raise fuel pressure 1PSI for 1PSI of boost. An FMU is adjustable to raise fuel pressure greater than 1PSI (typically 8PSI to 12PSI) for 1PSI of boost. I have heard good things about the BEGI brand FMU on multiple boards. If I were to use an FMU, that would be my choice. No facts to back up why I would choose it.....mainly just word of mouth.

There is a limit though on raising fuel pressure. At a certain point injectors sometimes stop supplying fuel if the pressure is too high. It is injector type dependant. Using the stock injector size and FMU allows you not to have to tune the ECM (and not spend $$ on PROM equip.). It also means that you will be limited to how much HP you can run due to only being able to go so high on fuel pressure.
If you do use the 25 or 26 lb/hr, you can lower the base fuel pressure a bit so that it has a good AFR (stock) idle. Then you can adjust the FMU to get you the fuel you need under boost. I would do it that way before buying stock 22#/hr injectors. Ebay and classifieds usually have the mid-90's 24#/hr cheap. As in less than $100.

Don't let anyone tell you that you can't go fast with a stock ECM, FMU, and boost retard box. That is all you gain by using an aftermarket ECM or GM boost ECM. If the mechanical parts are tuned right then you can go just as fast.

The only advantage of using the boost ECM is getting into the fine details of fuel and spark and squeezing out a slight amount of drivibility and maybe a few percent HP at WOT (maybe). Keeping things simple and using the FMU & Timing box is a good method for tuning. It is quick and reliable.

Am I a fan of using ECMs for boost? Yes. That is how I control mine, but the mechanical way is just as good.

 

edit: I type too slow so read above.

FMUs are not recommended for much over 6-8psi of boost with injectors close to stock (like 19-26pph). In order to get the fuel needed for more than 6-8psi boost, the fuel pressure may need to go well over 100psi, where many injectors will stick shut from the pressure. Some people have done it though. If you get large injectors you will need a custom chip, then maybe an FMU with a lower pressure gain ratio to keep fuel pressure reasonable. Too big of injectors without a custom tune is a bad idea, I wouldn't go any bigger than an LT1 injector.

The injectors don't exactly max out when using an FMU because they open for the same amount of time as stock. Its the chip that determines how long injectors stay open. Increasing the fuel pressure forces additional fuel through the injector in the same amount of time. Bigger injectors are not good without a custom tune. Larger injectors stay open for the same amount of time as the stock injectors, and they flow so much fuel that the ECU cannot compensate (lean it out enough) and its undrivable at idle and cruise, but may actually run well in boost. If you get injectors just a little bigger than stock the ECU is able compensate for the extra fuel after a while.

Is an FMU useless for you? not for 6-8psi, but more boost than that will require additional modifications/$$$.

You will also need an inline booster fuel pump ($200-$300) to keep the fuel pressure high enough for use with an FMU. The in-tank pumps alone tend to max out around 70psi then drop off. Agian, some people have got away without one, but its highly not recommended.

If your goals for boost and hp are set on the low side, you could get away with an FMU. Anyone can tell you that once you boost your car, you're gonna want more, you can't help it. So I'd do it right the first time and ditch the FMU and BTM, unless you think your not capable of learning chip tuning, but then you could always have it tuned for you at a late model performance shop (big $$$).

I started at 6psi with LT1 injectors...then 8psi... then 38# injectors... then 10psi... now 14psi. The next step is a stronger bottom end. See how it works. I switch between the Holley Commander 950 and 7730w/$58. I think I would look into the MegaSquirt if I could start all over.

 

ttypecamaro makes I good point that I did not mention is that we are talking low boost here (4-8PSI range). Using the FMU will put you in the (43+8*8) = 109PSI fuel pressure range. If you went with 24#/hr injectors (mid-90's LT1) then they would look like 1.68 * 24 = 40#/hr injectors....good for 500 FWHP or so.

At that fuel pressure you need a very good fuel pump like he said. Remember volume decreases as pressure increases.

He is right. If you like the boost and want more then you will need to go to ECM control. If 500 FWHP will keep you happy and you want simple then go with the FMU and Timing box.

I went with ECM control and Ford 42 #/hr injectors because the 730 ECM was only $50 and the injectors were only $280 and I needed new ones anyway. Got the 2Bar MAP from GM direct for $50. I went this route because I knew that I wanted to fool around with the GM boost code and eventually go to higher boost. I already had the PROM equip.

I think the mechanical route is great in terms of reliability, quickness to build, and smallest learning curve, and a good value money wise. If you are staying under roughly 500 RWHP then I think it is a good way to build it. Besides, the BEGI is a quality unit and can either be sold later or used in conjunction with ECM control if you want more HP later on.

It all comes down to learning how to tune an ECM takes quite some time to figure out. With the MSD & BEGI you can tune it in a minute or less without fumbling with files and which ECM table to edit.

 

Okay, now I feel I am getting some footing here. I don't plan on more than 500hp for now. Hell, to me 350hp sounded awesome. I also plan to build a motor to handle boost. That alone will take some time. So basically this is something to get me by and have fun for a couple years.

And yes PROM tuning is out of my league in terms of fun and time. It's no fun and takes up time. I can test and tune to some degree, but the mechanical way is the best way for me at this time. That is not to say I will never learn PROM burning. That will come later.

Now you guys are saying that 24lb LT1 injectors with the L98 memcal, FMU, and a booster fuel pump would be pretty much all I need? Obviously besides the turbo stuff.

 

I'll throw my $.02 in here as one who has used with some success various mechanical add-ons to run turbo engines. Here is a rundown of my two cars using these devices:

'89 TT L98 IROC
1) junkyard turbos, intercoolers, etc., lots of used eBay stuff
2)Tuning:
Vortech SFMU
Vortech T-Rex Booster pump
MSD 6AL and BTM
Ford SVO 24# Injectors
Base fuel pressure lowered to improve off-boost AFR
Stock ECM and chip (MAF)
Base timing set to stock +6°
3) Results at 6psi of boost: 12.46 at 117MPH on 18" street tires

Remote Mount Turboed '89 Z24
1)Junkyard 3400 engine from '02 Venture Minivan, bone stock
2)T3/T4 Hybrid turbo built with spare parts
3)No intercooler
4)Homemade Alky injection engages at 6+psi
5)Tuning:
Cartech/BEGI FMU (the best out there IMO)
Holley 255LPH F-body in-tank pump
Accell 19# injectors
STOCK 2.8 ECM, PROM, and MAP sensor
No timing de-tune (premium fuel a must!)
120PSI fuel pressure at max boost!
6) Results at 10psi of boost: 12.59 at 114.7MPH on BFG drag radials
328HP/352TQ to the front wheels
7)Quite reliable 12 second daily driver that has A/C and gets over 25MPG
8)Its fun killing Mustangs and other 'fast' cars with a 200k mile Cavalier

I think I like my Cavalier better than my Camaro . They both work well with zero ECM tuning. HOWEVER, both have ECM tuning in their future, especially if I want to go faster. The IROC is out of fuel at only 6psi, so it will need more injector and complementing ECM tuning to get more from it.

Good luck with your project, let me know if you need help on the RMT system. I have over 20k miles on the RMT in my Z24, so I may be able to answer a question or two for you should the need arise!

-Kenton

 

Thanks Kenton.

Another area that is boggling me is the Alky kit. I am under the impression that in order to come on at a certain psi, in your Z24 it's 6lbs, I would need a 2 bar MAP so it could read boost levels. Now how would/could I overcome this. I am under the influence that I would need to "tune" to have the computer read a 2-bar map, or am I wrong on this as well? I planned on an alky-kit from the get go because it is inexpensive and small.

 

The alky spray is activated through a relay by a small, adjustable pressure switch. I got my switch off eBay for around $15 and I can adjust the turn-on point from 0 to 6psi. I made the rest of the system with parts from a local hardware store and a universal washer tank. All the parts totalled around $150. Provided a dyno proven 20HP/22LB-FT to the wheels at the peaks. Easy as eating pie.

 

89JYturbo,
What did you use for the nozzle/jet at the throttle body? Is it a hardware store piece or something you got else where?

Thanks,
J