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Carbuerated LS1 !??


Guest plainswolf

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Guest plainswolf

Guys... check this out..

 

Edelbrock has designed a new manifold for LS1 engines to actually convert them to a carbuerated setup!

 

go figure.. :?

 

" Performer RPM LS1 Carbureted Manifold

This powerful new manifold is designed for the popular Chevrolet LS1 (5.7L) small-block V8 originally used in 1996 and later Corvettes and 1997-02 Camaros and Firebirds. It also fits the Corvette ZO6 engine and any other Gen III engines including the LM7 (5.3L), LR4 (4.8L), and LQ4 (6.0L). The Performer RPM LS1 manifold allows the use of a carburetor on these originally computer-controlled engines, offering maximum power and a broad torque curve, providing optimum performance from 1500 to 6500 rpm. This manifold includes a unique electronic Timing Control Module made by MSD® which works with OE sensors to fire the “distributorless†ignition system and offers a choice of three timing curves. We have also included a special throttle and trans bracket that works with 700R-4 and Turbo 350 transmissions making the LS1 engine an easy retro-fit into any muscle car, street rod or marine application.

 

Performer RPM LS1 Manifold and Timing Control Module for GM Gen III engines..... #7118 "

 

http://www.edelbrock.com/automotive/autopartsphotos/manifolds/7118_pro_e.gif

 

It's under their "new for 2004" menu..

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im pretty sure it was the 1997+ Vettes and 1998+ F-bodys.

 

still about the topic its pretty cool, im not sure if i would do that if i had a LS1 but still.

 

mike

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Guest Z-rific

I actually heard an Edelbrock tech talking on one of the 30 min. car shows, don't remember which one. He said that Edelbrock's new intakes and carburetors now match injection systems in performance. I'm not sure if that;s just PR or what, but they are trying hard to keep carbs up with EFi technology.

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Guest plainswolf

This actually suprised me a great deal... the only thing I can think of as far as it's reason is to defeat most or all of the stock computer set-up?

 

It would greatly simplify the motor but at what cost in terms of engine durability/longevity?

 

To me, one of the finer points of the LS1 is it's precise engine management system, besides it's lightweight to power ration..

 

interesting concept though!

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I am sure they will sell them though.

Even if the full throttle performance matches EFI you still have a carbed motor to fire up when it is cold out etc...

I am still surprised at the number of knowledgeable older hot rodders who shrink away from EFI like dracula from garlic...

they will sell to guys who are afraid of wires and computers on their cars.

Perry

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I think getting rid of the stock LS1 computer controls would be great for hot rodders that want to put them in an old T bucket or something.

 

When you get an LS1 equipped car, can you tweak it so that the thermostat doesn't have to open at 245*, or is that not one of the things that you can mess with? That thermostat has got to hurt power (I know they did it for mpg), and decrease longevity of the engine, and that in and of itself might be a reason to swap out. I've always wondered how much room you have to play when you take a car to the track and it's cooling system starts to operate at 245. Seems like Vettes and Camaros would be really prone to overheating.

 

Pretending at advocating for mephistopholes...

 

Jon

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No one has mentioned the cost on one of these puppies. I would like to hear more on the thermostat issues. Wouldnt that just be something you could swap out with a colder thermostat? I think the ls1 would be a good candidate for a street performer with a carb minus the cold weather starting issues. However it would also be cool to add a plate nitrous setup :) for an extra 100 shot

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Guest plainswolf

True enough...

 

Many old and even young may greatly shy away from engines with sophisticated electronic engine management systems and the complications that arise when they try to swap the engine into a different vehicle, which is what I think this new manifold's greatest selling point--ease of swaps into other vehicles..

 

It would GREATLY simplify things as far as swaps... especially when you read about the guys in here who have done the ls1 swap into their Z.. The wiring sounds like it can be a tough one. So my hats off big-time to them that have!

 

sounds like with this setup one would never have to worry about a reprogramming when trying different mods on it or have a ton of electronics to worry about when swapping the motor into another type of vehicle..

 

As far as cost goes? I have no idea what they will sell for..

 

Personally I suppose I like the engine management system, but I can also see the merit of this new setupo as well..

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I'll chime in here. The wiring can be a challenge, but the wiring is like any other. Find out what the wire does and make sure it is connected to where is needs to be. My problems came from the computer not liking the way I tried to wire around the anti-theft system. Once I got the anit-theft programmed out of the computer, it started and ran beautifully. First time, no smoke, no stutter, no tuning required. :D

 

But, if you wanted to tune, you can do it on the dyno without swapping carb jets etc., just type in your changes. Economy, maintenance, etc. become much easier when the computer is doing it for you. I think that is well worth the time and few hundred bucks to get the computer straightened out! Just my opinion. 8)

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Firstly:

When you get an LS1 equipped car, can you tweak it so that the thermostat doesn't have to open at 245*

this is not so. The thermostat opens at about 180* on my LS1. Thermo is a plane old mechanical jobby mounted in the water pump - no computer controls involved. Now the fans are programmed from the factory to come on fairly late - I think it is 236 or something. This is an emissions dealio meant to keep the system hot. The shop that editted my ECU adjusted this down to 210.

 

Secondly, I agree with many of the points here. But I wonder about the cost of this manifold + carb vs. the cost of a swapper's wiring harness such as the one Lonestar1 used. I didn't buy one because I am poor and so I had to go thru the stock harness and hook stuff up, which was time consuming. But with the swapper harness, from Speartech, GM, Painless, etc. - everything just connects up very simply.

 

Thirdly, I hate hate hate carburetors.

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I stand corrected. Don't they pretty much run 230* or more most of the time? I had heard that the thermostat opened really high, and a friend of mine with a newer Vette said that 245 was still in the middle of the gauge. It just always seemed like a bad idea to run that hot all the time. If not, then great. It's just something that's made me hesitate on the LS1 for a long time.

 

Jon

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Guest Z-rific

Maybe I'm in the tiny minority here, but I love wrenching on my car and tuning with screwdrivers and vacuum gauges.

 

And cold starting a carb isn't as God-awful as people make it out to be. I turn my engine over for about 2 seconds and stop. I turn it over for another 1 second and pump the pedal and it starts every time. When I had a Q-jet on, it cranked even faster. So, I've lost 3 seconds of my life sitting in my car listening to my baby wake up.

 

I for one, would jump at a carb fed LS1 happily avoiding the computer and wiring.

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Guest Z-rific

Check out this article...

 

http://www.popularhotrodding.com/enginemasters/articles/hardcore/0305em_holley/

 

Only thing that bothers me here, is that they put larger injectors in to help the EFI numbers, but didn't try larger jets or a bigger carb to help that out. Then they complian about taking 1/2 a day to change jets?!? yet have no problem swapping out injectors.

 

Anyway, the carb'ed version still puts out more torque, right out of the box.

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  • 2 weeks later...
Guest MegaShaft_2000
Check out this article...

 

http://www.popularhotrodding.com/enginemasters/articles/hardcore/0305em_holley/

 

Only thing that bothers me here' date=' is that they put larger injectors in to help the EFI numbers, but didn't try larger jets or a bigger carb to help that out. Then they complian about taking 1/2 a day to change jets?!? yet have no problem swapping out injectors.

 

Anyway, the carb'ed version still puts out more torque, right out of the box.[/quote']

 

I don't believe those results for one minute

 

How come they had to change the injectors? Unless the injectors they had in there were running at 100% duty cycle and making the mixture too lean, putting in bigger injectors won't do a damn thing. The computer controls the duty cycle of the injectors to maintain the optimum fuel/air mixture.

 

On my Z, putting in bigger injectors won't help me any, since my stock injectors aren't yet maxxed out... I could still pump more fuel into the engine if I wanted to.

 

In this example, they said the original injectors were 30 lb injectors.

 

If you do the math, you'd see that 30 lb injectors can support up to 430 hp without going over a safe 80% duty cycle. Or you can use a handy script like this one to do the math for you:

 

http://www.pontiacracing.net/js_injector_flow.htm

 

The original 30 lb injectors would have supported up to 430 hp at a normal 80% duty cycle, which is much more than the 367 hp that their engine was putting out. When they switched to larger 36 lb injectors, they picked up power due to better a/f ratios resulting from better tuning, not from the bigger injectors themselves (notice how they said they did some "reprogramming" after putting in the bigger injectors? That extra tuning is where the power came from). They could have done the same with the 30 lb injectors. At only 367 hp, the injectors were operating at a very lazy 68% duty cycle. The bigger 36 lb injectors can support up to 510 hp. Overkill and unnecessary for 365 hp. When they switched to the 36 lb injectors, the duty cycle to make 387 hp dropped down to 60%

 

For reference, my Z has 370 cc injectors, which is a little over 35 lbs/hr. Remember that I only have 6 of them since I have a V6. Since my car dyno'd at 339 rwhp, if I apply the calculation I see that my injectors are working at a 90% duty cycle. If they ran their 30 lb injectors at 90% duty, they'd be able to flow enough for 485 hp.

 

So I'm running a 90% duty cycle and not running out of fuel, yet they claimed that they had to switch to bigger injectors because they were using 68% duty cycle.

 

For God's sake, even their own website points this out on another page:

 

http://www.popularhotrodding.com/tech/0303PHR_Injection/index.html

 

Even according to their own calculations, they didn't need to put in larger injectors. The simple fact is that the original 30 lb injectors were easily capable of providing more fuel than the engine was able to use anyway, and the extra power they gained was solely due to the extra tuning they did after installing the bigger injectors, not the bigger injectors themselves.

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