(Cliff notes at bottom, Just read the first 2 paragraphs then look at cliff notes)

Well as you may recal, my car caught on fire on christmas day and turned my carburetor into charcol. It was a 600 cfm Holley double pumper. Before that the car went 8.8 in the 1/8th with the 600 cfm carb.

So I bought a new 570 cfm holley street avenger vaccum secondary. Which I thought would make my car 2 tenths slower due to the vaccum secondary.

The entire time with my new carb I was thinking it was slow and not as powerful. I even raced a STOCK '94 GT (from a 60 roll) and lost. And my friend (one I raced) knew I went that quick and now thinks his car is faster than mine due to the change and also in 30* weather (imo bad for my carburetor too cold)

So I bring my car to the 1/8th tonight to see how much "slower" my car is with the smaller carb.

I set my bald street tire (right rear, one tire fire) to 28psi and bump up my fronts to 45.

First pass of the night yields a 9.06 with a 2.5 60ft (i spin sooo bad)
Second pass yields a 9.25 with a 2.4 60 ft
Third pass yields a 9.0 again with a 2.5 60 ft

Now before I shock you guys with the last run, I couldn't get my car to hook at all. It was 75* when these 3 passes went down so a little loose the track was. But I tried with my launches at 2 grand rpm dump the brake and mash on the gas and WOT through the tire spin= BAD

Then I try when it spins get out of the throttle and then get back on it again= SLOW

So bracket racing just started, on my 3rd runand I won my first racein my 9.0-10 second bracket

I was kind ofmad since I KNEW my car had a sub 8 second pass in it traction permitted, so I lower my pressure down to 24 psi and the weather was now in the 50's so I knew the track tightened up a bit so my hopes were high.

At this point I could care less if I break up and I decide to not let up on this run.

I launch at 1500 rpm and go full throttle to my best 2.3 60ft and make my way to an 8.86!!!

I caught DECENT traction but still spun quite a bit (obviously) and wouldn't you know just as fast as my previous best.

Ok now my friend with that STOCK '94 GT thinks he can go 8.5-8.7 because he "beat" me. He doesn't realize going from a dig is a lot harder than just flooring it. PLUS my car felt like it pulled the hardest it ever has. the stock 3.00 gears is killing me, one tire fire is killing me! And at the highway, his stock 3.27 helped ALOT froma 60 roll.

Someone tell me if he runs an 8.6 in the 1/8th he has to have gears or something done to it that he doesn't know. I have seen under his hood and it's stock to the paper filter.

-CLIFF NOTES-
First pass 9.0
Second pass 9.2
Third pass 9.0
Fourth pass 8.8!!

What were your trap speeds? Times sound pretty good for your 60' and mods.

One wheel peel FTL you need a limited slip my friend;)

What trans do you have?

At that track they don't show trap speeds (which PISSES me off). I have a C4 auto, and yea I am working on the locker as we speak haha with 3.73 gears! So then i'll be down to possibly 8.3-8.5. with a sticky tire...

a stock Five liter fox runs ~9.5 stock, and IIRC stock 5 liter SN95s are slower, so if hes stock, hes teh boned

Sounds like you have the little relic moving pretty good.[sm=smiley20.gif]

ORIGINAL: bluebeastsrt

Sounds like you have the little relic moving pretty good.[sm=smiley20.gif]


Haha! Thanks man I appreciate it. She pulls pretty good till 5 grand anything after that I can feel it fall straight on its face. But last night I was seriously moving, fastest it's felt since the new carb.

I ran a car that went 6.0, he smoked me.
I beat a foxbody with a built rear end, exhaust.
I beat a dodge caronet with a 440 (that was when I broke out, but i still beat him to the line..)
I lost to another 6.9 second car

I'm running the 570 SA on my 302 as well, it's a pretty decent little street carb for the money. I'm ALWAYS telling people that they'd be much better off with smaller carbs, firstly because a carb's job is to meter and atomise fuel, not get air into the engine(in that regard smaller carbs have an advantage over larger carbs). Secondaly, most engines are actually pumping FAR less cfm than most people think. The extra 5-10 peak hp gained from a slightly less restrictive carb is NOT worth all the average power that's lost from worse metering. And I actually calculated the true cfm my engine was pumping at 6,500rpm, and it came out to around just under 500cfm of real airflow, which means on a 570cfm carb(rated at 1.5" Hg) I'm prolly only pulling 1-1.1" Hg intake vacuum at 6,500rpm. Granted though, power produced also depends on the design of the carburetor as well.

I noticed with this carb, the SA, that I was MUCH quicker off the line and didn't bog down at all, AT ALL! There was power from the tree, not once it bog down like with my Double Pumper i had on it. It's better I think across he board except top end (60-110) Better accel, doesn't bog, more power throughout RPMs...

Vacuum secondary carbs are a lot more forgiving too, and with a double pumper you really have to have the pumps tuned right. It does leave the line nicely though.

I'm starting to realize all of that haha. I thought it would be significantly slower but it's just as fast (i proved that) but may be quicker with a little cooler temps like low 50's, it was 60* when I ran my 8.8 i just checked yesterday.

Have you got it dialed in yet, or are you just running the out of the box settings?

Oh i've tuned it, maybe not to it's "full" potential, but it's my DD and idles fine, and under throttle- no hickups.

But the jets are stock, I think wiht bigger ones they might help a bit.

I had to jet the crap out of mine. It's 54/65 stock, I'm at 59/67. They jetted the primaries lean because they set it up for stockish mileage applications I think. I guess they want to sell the 670 to everyone instead. But it is pretty lean for a performance app from the factory.

Yea I'll see if I can find some bigger jets and throw them in there, just nothing TOO big. I remember I had 70 sometihngs in my double pumper in the back. and 60 in the front, I THINK, and that was too much, but good for top end.

Thanks.

Check your plugs, that'll tell you where you need jetting.

The first time i pulled them they were very gassy, wayy rich. Idk now the car seems to be fine but we'll see about that ha...