I had a kinda cool engine on the dyno this week

[Barry_R]

I can't remember the throttle size - I haveta go and look...

Those are 42 pound injectors. I remember that. We were on the cusp on the size if the motor got closet to 550 HP - but decided to "push" the 42s with more pressure if necessary so we could keep good idle speed control. We ended up plenty safe at 45 pounds pressure. And it idled really nicely.

As for the cost - 64 million is close. But just under 30 grand is closer. A big piece of that is the injector/intake/EFI concoction.

[Mohuska]

Barry,

Don't know if you are still around but I have a question. I have had a TWm setup on a built 460 (actually a 522) since 2002 and have never been able to get it right. TWM set me up with 60lb injectors at 60psi and it always seems to rich at idle, hesitates out of every gear and generally runs like cr*p.

I would appreciate any feedback.

Mike

[RICK LAKE]

Mohuska Mike Who's ECU are you using? What is the Max rpm you are pushing? 60 psi is too much pressure for a system at idle unless you are running turbos or blowers. 60 pound injectors are even high rating for a 522 motor. I run a 452 and then a 482 motor with 50 pound injectors. Idle fuel pressure with a vacuum controlled regulator for fuel is 42 psi at idle and 54 psi at WOT with 3-4 psi of vacuum. My duty cycle which is the amount of time the injector is no at 6,000 rpms is 64%. Max any injector should be on is 80-85%. You can go higher but this puts a harder use of the injector drivers in the ECU. Cooling of the ECU is important to a long life of the ECU.
Mike The issues at idle at to a degree normal unless you have a IAC motor and block to control the idle. Have you talked to Al T. about gett an IAC block for your motor. IMO again IMO TWM's are for making more torque and HP over a set of webers or olbergs if the ECU is setup and tuned to the max, This means matching parts to the system. The biggest problem I have found is that most motors are running the WRONG CAMSHAFTS. A carb camshaft doesn't work as good on a TWM, Weber, or OLBERG setup. LSA is too narrow for this setup. A 112 LSA has too much time for reversion in the intake and carb bodies. 114 -116 LSA is alot better. This is about the same numbers as blower or turbo camshaft numbers. The high the vacuum the better these throttle body and carbs work.
Mike, I am building a 498 motor with a 58mm TWM setup. I have talked to Al about running a IAC block on the motor. A custom camshaft is going into my motor. It's going to be a dual profile camshaft with a wide LSA.
Send me a P-M if you want to talk more on this. Rick L.

[Barry_R]

Still here....

I agree with most of Rick's commentary. I have the fortune of being near many good EFI guys - BS3 and DFI are both right in the neighborhood. Recommendations are to always "push" a smaller injector rather than have a big one act lazy. I ran 65 lb injectors in a 505 inch 712 horsepower engine at 45psi with capacity to spare. At 60 psi you'll be able to support well over 800 - but probably too big to idle well.


We did a few things to help idle. We made an isolator block to split the MAP and the IAC into seperate chambers- otherwise they "crosstalk" and can make the idle hunt - IAC opens, MAP sees that as a load increase due to the vac drop and richens the mix, which lowers the idle speed, and continuous loop....

Each chamber has a separate spiderweb of 1/8 vac feed hoses from each throttle body - we added those. It idles very clean and sounded good on the dyno. No way to check in car behavior yet - the engine is still not in the chassis - sctually a Dearborn Duece street rod that is still under construction.

I would try a smaller injector and lower pressures...

[Mohuska]

First, thanks guys for the response. Over all the years that I have suffered with a POS... I keep forgetting that there are a lot of guys with vast amounts of experience in these things.....

My TWM was one of the first on the 460. My motor is a 522 with a somewhat mild cam. TWM is the one who recommended the Bosch 60lb injectors at 60 psi. There are a lot of guys who recommend 60 psi or higher as it produces better atomization of the fuel. But the 60 lb injectors are running at 1-2% during idle. The idle is rock solid at 850 rpm....but stinks so bad it makes me physically sick. My clothes smell really bad after being in the car for even a few minutes.

Anyways, I use an electromotive ECU (TEC3r). It has many good features, but is a PITA to tune. I have spent countless hours and still not much further that I was in 2003.

Recently I noticed that I am running in closed loop and I was told that this could be partially responsible for the poor running and overheating. The overheating has been a real problem and the major reason I can never take the thing out even down to get gas it overheats and that is only a little over a mile.

I am taking the car back to engine builder next week. We are planning to put a more aggressive cam and rip out the Electromotive and go with a FAST system. Builder thinks there are a lot more people who know how to tune the FAST and it is not as tweaky.

I also have to contend with the heating issues. Is there a better fan set up ( say a 3000-35000 CFM fan) that will fit into my car (it is a West Coast).

I appreciate all the help.

Mike