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Can a good carb shop add horsepower to a motor with mods, if so how much out of a single carb without any further motor work ?
 

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Just my .02. Out of the box a carb is set up in a will work ok for most condition. It is not set up to optimize a highly modified engine. Given sufficient engine details and how you are using it, a carb tuner or custom builder can provide an improvement. Exact numbers are hard to determine without side by side dyno pulls with each carb on the same engine. In some instances improvments of 5% or so can be had. I am not sure if it is because the custom carb is that good or the original carb was that bad. It will be interesting to hear more from others on this one.
 

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Baseline/homework....

You would need a solid baseline to work from. Unless you have unlimited access to a dyno, you're going to have to do a lot of "homework" collecting data from the "out of the box" version of the carb, vs the re worked version.... First and foremost, you would need to know what the current air/fuel ratio is. There are several EGT systems out there that are very valuable tuning aids, and allow for spot on a/f ratios in various locations... Once all that is established and you have a performance baseline to work from, it is possible a carb "guru" could find a little more, but if you've done your part to gain every bit you could, the amount of improvement will be minimal... As mentioned, a percentage of gain will be based on how far off it was to begin with.... On a side note, if you need to go up, or down, more than 4 jet sizes to get it better, chances are it's the wrong carb for your application....
Ray
 

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The WOT mix on a lot of the newer carbs is really good out of the box. The carbs with the adj. air bleeds and billet blocks (Holley, Quick Fuel, Pro Form, ect.) are really really close. I just finished a 410W at Westech with a box stock 750HP Holley. Never touched it. 491HP worth of air. Strapped on the 3310-10 (end use) and ended up with stock metering plate and up 2 sizes on the primary, the cruise was a little lean (14.4) for my application. 486HP. Both WOTs were 12.4-12.6. The only way to know, is the AFR gauge as mentioned before. If it pulls more rpm with your combo, stop there. Between myself, Steve Brule' and my dad Ken Crocie, I dont think the 750HP holley was going to get much better. Also at the end, ran an older (09' ish) Mighty Demon 850 with stock jets. Didnt touch it. 489HP. WOT AFRs were all nearly the same. If you are running Comp Eliminator or something, send it to a "guru". Then dyno it. And you might find some power.
 

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Speaking in terms of WOT... Once the carb is tuned for the day, whacha got is whacha got.

Any additional horse power is going to show up through mods that INCREASE AIRFLOW through the carb.

Who knows what milling the airhorn and other mods may net? It could be zilch on one engine and "oh wow" on another.

If you're not racing, IMHO... don't sweat it. If you're talking about NASCAR... I think those guys would pay more than a comfortable mans salary for 1/25 HP gain.

If you do not know how to properly tune a carb, money spent having it done by someone who does WILL pay off. Just getting it tuned correctly.

Good Luck!
-Seth-
 

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Discussion Starter #9
Good Input

I just got my carb back and it was jetted on a dyno, hope to see the gains i had lost due to years of use. I was told by a motor builder that a good carb guy can really do things up. He told me they did a dyno test and a carb builder brought in a carb and added 25 H.P. just bolting on his carb. I thought i would try to get some input before i flap my gums around people that could tell me i don't know shit. I do know if you can't process what a carb is dumping then you are either gonna suffer or gain nothing.
 

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Can a good carb shop add horsepower to a motor with mods, if so how much out of a single carb without any further motor work ?

Call C & J Engineering and ask for Johnny!!!! The best money you`ll ever spend!!! His son is on here as Piston maker I think??? Sorry my phone took a flight and I havent put their number back in yet....Tom
 

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