Re: NHRA Expands Factory Stock Showdown
 

Sorry, Ed was buried in work today. :-) Just got loose. What Kyle ^ said.
People do it all the time.
Never needed to pull timing back to launch. Something wrong there.

Re: NHRA Expands Factory Stock Showdown
 

Ed , have you ever ran a 1000hp supercharged CJ ? if so and that track is bad you pull timing to get it off the line . I would agree with Kyle dot files work the same way with MSD . Nothing wrong with the cars just a lot of power

Re: NHRA Expands Factory Stock Showdown
 

Never had to deal with 1000 hp on 9" tires. LOL

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Actually, the MSD set up to adjust the timing events is far better than what the FI cars can do with the ECUs such as the FAST XFI. The MSD can adjust the timing at far more events like each gear for example.

Re: NHRA Expands Factory Stock Showdown
 

Still waiting for you to hit the powerball Ed!

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I know. Edwards was pulling 1/2 degree on each gear change. Enter how many RPM drop to pull timing, and how much. Can't wire them to the tranny or shifter, so they use RPM drop to identify shift points. I worked with that some a few years ago.

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I wish we could tune the fuel and timing by gear. Rumor is that the next generation of the FAST will allow this plus even more stuff if you are inclined to dig deeply.

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:-)

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So how was the race in N.J.?

Re: NHRA Expands Factory Stock Showdown
 

Looks like they really "show-cased" them yesterday. Today they are moving on to 11.50 Index Cars.

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Ed, I know they're different, however just like adjusting boost levels can extract hp from your engine, you can also go into an EFI computer controlled engine and adjust a variety of things to enhance the performance of the FI engines (Woodro Josey is/was an ace at doing it, and I wish I understood those Accel Calmaps half as much as he). They may not be the same, but getting hp from either combo is easier than trying to legally extract more hp from a carburetor. Note: Sorry for the late reply, but since my budget hasn't allowed me to race my car in my region earlier this year, I haven't been as motivated to keep up with the racing scene, however since I know you were referring to my April post, I have to reply back to this. I recall being at Bandimere Speedway during a divisional points race, and (although your comments of spark advance & air fuel ratio are good), I managed to pick-up .4 sec., just by spending 10 minutes on my computer (and I'm not the sharpest person out there with regards to these things by any means).

If there's no advantage to EFI's over carburetors, then how come small block EFI engines are the performance equal to carbureted big blocks? Moreover, how come all production vehicles come with computers and no longer carburetors? They're more efficient in extracting more power from the same (or less) amounts of fuel. My EFI '04 Colorado does a better job with only 5cyl's of towing my Cavalier around (on less fuel I might add), than my '77 half ton 350 V8 carbureted Chevy Full Sized truck did back in '99 (it also was rated 45hp more). I'm not going to challenge your mechanical knowledge, but EFI put carbs in production vehicles to RIP status, thus proving the merit of what I stated as well...

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EFI was implemented by the car makers to make it possible to achieve the emissions requirements imposed by the EPA. Simply put, the required feedback system (oxygen sensor measuring and reporting the mixture) is much more easily controlled by a PCM pulsing an injector than the limited range of a carburetor and the inconsistencies that come with it. Setting a bi-metal spring operated choke for all conditions is virtually impossible, just for one example. A PCM, if programmed properly can easily handle the task of good cold starts and drivability in Denver or that of a 100 degree day in Tulsa.

Power is about airflow and the amount of fuel and oxygen you can combine in the chamber. IMO, a properly tuned carburetor can handle the task just as well as injectors assuming the airflow is not compromised. I have not seen significant gains by replacing a GOOD carb with a throttle body and electronic injection as far as full throttle performance is concerned. Where the injector really has an advantage is that it allows for a wider range of intake manifold design and throttle placement. If you notice the fast small blocks you refer to have a lot of technology in the cylinder heads and intake manifold that compliment the injection system.

Tracy

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Plus, if you sell your soul then anything is possible.

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The first paragraph of your message Tracy had was true, but just like the evolvement of racing, people were always going to try to make what they had created produce more power, and it's recently proven to be more and more true even since the mid '80's when mass produced FI engines started the good by (to carbs) era. However, your last two sentences of your second paragraph proved my point too. If you're going to change the way fuel goes through the induction system, then all elements of it's transistion to the cylinders should change, not just the initial part. What once was carbs/manifolds/heads, is now FI, manifolds, heads. Just like an engine has to be made stronger to handle nitrous oxide, an engine that's going to produce cleaner emissions (and more power as well), has to have improvements made to all areas to make it work better. Thus what I said about getting more power out of less cubes, due to the enhanced fuel systems we have today.

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I remember reading some articles headlines. "The end of the Hot Rod era, Fuel injection." I remember reading about all the guys ripping off the EFI systems in 86 Mustangs to back to the tried and true Carb/manifolds and was making more power(in fact the 85 car was rated at 210hp and the 86 was 200). In fact there are still guys pulling EFI off their race cars to switch to carbs and are picking up ET.
The 86-88(except for the 88 California cars) were all speed density and couldn't compensate for agressive heads, cams and intakes. The mass air cars helped out and guys learning the "new" way of hot rodding started to catch on. This is really were metered FI injection really comes into its own. You can run more aggressive on things and not lose the street ability of a daily driver at idle and part throttle driving. Computers can advance/retard cams, change timing and fuel based on air mass and O2 readings, pull timing in cases of knock or detonation.

The intakes can be made in multiple configurations without having to be locked into a general design(although I've seen some mighty creative carb set ups). The new cars(talking street cars) are making a lot of power out of smaller displacement engines for a multiple of reasons. Such as better materials, better manufacturing abilities and being able to run at tighter tolerances. They can run more aggressive cam profiles, thinner ring packages, have computers to map all variables and not to mention all the hot rodders experience on how to build a better engine.

On the street EFI is king for superior drivability. On the race track everyone has their own preference. I personally prefer EFI.

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To answer one of your questions Gary, some of the reasons late EFI engines make more power than older engines are the cylinder heads. Improved air flow and improved detonation control allowing higher compression ratios on low octane fuel with out detonation.
The '96 / '00 Vortec trucks heads are so popular on older engines that Edelbrock makes a 4 bl carb intake manifold for them. The ports are high enough a regular carb intake doesn't even cover them. You understand what raised intake ports do, right? :-)
Those Vortec heads make more power than earlier (even "camel hump") heads.

The reason for EFI in late model vehicles is simply emissions and fuel economy.

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Hi Ed,
Our current EFI combo was first dynoed with the carb and intake off of our current carb combo. (750 q-jet and victor -E). After breaking it in we put the big stuff EFI system and related hardware on.....It lost 15 HP... The reason is the little throttle body that comes on our combo. If we were bracket racers and could change the throttle body , then the power would swing over to a plus for the EFI. But like you say ...Its all about airflow (and of course, compression ). Being able to manipulate all the fuel and spark management gives the engine's a wake up call, but how much varies widely from engine to engine depending how out in left field you were in the first place.

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Hi Jeff, I have seen that before. I would have mentioned this, but nobody would have believed me. The carb guys just know there is magic in that ECU. LOL