hi, i have a question for those of you with "Highly Modified" small blocks and a c4 trans. what stall are you running? what do you think is the best for the street and strip. my car will be street driven, but on weekends driven to the track, back tires swapped out for slicks, and raced. i currently have a built up c4 with a transgo shift kit with gear command. it also has all the other street strip bells and whistles. my only thing is, i got the wrong converter. i bought a 1800-2200 stall which i think is stock isnt it?. when i hammer it out of the hole, it stumbles then pulls slowly till around 3500 and screams like crazy and all it well. its just off the line where my issue is. everyting else is perfect. i was told to run a 2600-3000 stall by a racer buddy of mine. so id like to know what some people are running and what your result is. again i really only want to know from those of you with over 400hp and race you car as well as drive on the street.

i have a racing setup289. im currently running a 28 inch tall tire (not sure if ill go to a 26 or not), 3:55 gears, andmy cam is a .512 lift. if you need to know anything else just ask.

i got a 2800 in mine and it seems to do alright - i get about 2200-2300 before the backend wants to start creeping around on a launch, but then again i have bad clutches in the rear so i'm only launching on one tire, and with 3.73's it's ridiculous. - your 3.55's aren't too spectacular on the 3 speed but hey, whatever... and i think the cam could use a little more stall but i'd look elsewhere also for your low end prob.

just because you have a certain stall speed convert is not gonna be an actual stall speed, it largely depends on torque made from the motor. less torque will will have a lower stall speed more torque will raise it.

your torque converter choice will depend on your cam choice and your rear end gear ratio.

Stall speed is governed by the engine build.

What is the operating RPM of the motor you assembled?

well i plan on shifting @7500 while racing. i was told it will reach high 8k rpms. i havent ran the car at the trackyet, so thus far i have shifted at 5k on the street. and also i contacted my trans builder and he said that its a 2200-2500 stall not a 18-2200 (sorry, i was wrong lol) and it should be more then enought to make the car fry the tires off the rims if i wanted to. he said i should try bumpin my timiing and adj the carb more. so ill check into that was well. thanks, Nick

With only a 512 lift cam there is no possible reason to be turning over 6000 rpms. That sounds like a 292 Comp or comparable. Just an off the shelf cam. We need to what heads, compression, intake, carb, weight. Some people idea of a race steup and a street setup are many different ideas. A race setup would be above 10.1 compression. High flow head, alot larger cam, steeper gears, large stall.

The following is all stated with no mean nature intended.

If you have a motor that makes peak hp at 8k rpm you will need a heck of a lot more than a 2500 stall.

It is also important to point out the following:
3.55 gears at 1:1 with a 26 inch tall tire puts you crossing the line at 150-160 MPH at 8k rpm with a 26 inch tall tire ;) which you will not be doing.

As stated above you will most likely be out of gas at 6k and shifting around there. If you have a local club sign up for a dyno day and get 2-3 pulls on the cheap to have an actually grounded in reality HP/torque curve for you to plan shift points at.

no harm done dodgestang, its all good. but i never said id make peak HP at 8g's i said it will rev to 8K but i wasnt going to.my car was orig going to be a 5 speed with the restomod look, so thats why ibought the3:55's. i found out i got beat on a T5 i bought, so i trashed it and had my c4 built. i intend to drive this car on the street, most likely on nice weekends, but when i wana track it i can. once i heard my 289 run i deciced to make it a streetable race car. it has stock heads, but they are ported like crazy, and have alot of time and money into them. i bought my engine already assembled. its set up for racing. i really wish you could hear it run in person, b/c my vids on youtube do no justice. its 10.5:1 compression, and i was told a .512 is plenty. the carb is a 750 edelbrock. the intake is an edelbrock performer RPM the weight is basically stock. im told the car should be in the 11's and i can spray the piss out of it. the builder had a 289 in a falconrunning in the 9's with spray. unfortunatlyhe is no longer around. i will be honest, im only going by what i was told and what i can see/hear. i paint cars and do custom fabrication and body work. i only go by what im told and only take info on what to buy for my car from friends who race/build racing enginesand my local performance shop. so im sorry if my info may not sound accurate to you in any way. i dont want to make it sound like im b/s'n becasue im definatly not.

My opinion based on experiences with my own car...you might see 11s in the 1320...with a very large shot of N2O other than that people were talking to you about the 1/8 mile track ;)

The only way to ever know what a car runs is to run. Take it to the strip and report back your times. We can help make it faster still :)

Do you have a grind number or the full cam specs to share, this will help guide the stall. Stumbling/slowness out of the line can be a multitude of issues ranging from a blow power valve in the carb to a poor stall selection.

Can you share anymore specifics about the charateristics of the issue?
Is is there only a full throttle, do you have a stumble on the street when you leave a light like a granny? .
Does it still stumble will part throttle?
If you stumble, let up on the gas for an instant and then get back on it....does it 'restumble' or does it take off?
Are your plugs wet or do they show that you are running relatively clean?
What ignition is in the car (points or some form of electronic setup)?
What do you idle at in drive when sitting still?
If you increase your idle a tad does the stumble increase? decrease? stay the same?

Tuning a carb can be a pain.

man you said it...as bad as i wana run it right now, i unfortunatly have to wait till next spring to run it. its still not on the road yet. its only running, i still have quite a bit more to do yet before it can see the track. i dont have the specifics on the cam grind or anything, tho i wish i did. my car idles at 900 right now...in drive its around 550-600. if i put it in 1st and punch it, it stumbles, but yes if i get out of it (car will be moving a bit) and get back in it , it takes off with a very slight stumble then its great. if im rolling at i guess 20-25mph (speedo not hooked up yet)and punch it its fine. its just from a dead stop. if i take off normal and gradually lay into it its great, no issues. its only the initial hard step on theGO pedal! dodgestangill keep ya posted if u dont mind. you seem like you know quite a bit. i do have my other refrences, but you can never have too much, lol thanks , Nick

Accelerator pump, not the stall. As far as a stall, you need the right stall for the right build, and for racing you generally want a higher stall if you're going to be launching on sticky tires(it really depends on where the power is made). But your problem sounds like the carb. First of all even ported stock heads on a 289 with a little hydraulic cam aren't the greatest out there, given the lift of that cam it's safe to assume it;s not a huge cam, and with stock ported heads you're prolly only making about 300-325 at the crank. If it's a REALLY good build with REALLY good ported heads then maybe 350 honest flywheel horsepower. Peak power is prolly coming in somewhere around 6,000rpm, and you may be best shifting at around 6,500. What all this means is that the engine isn't moving anywhere near 750cfm, prolly more like 550 cfm at MOST when at peak rpm. And unless you have a custom built 750cfm you're going to run into problems. Most of the off the shelf type carbs are designed around general applications and aren't terribly expensive, so they don't meter as well as the uber expensive custom jobs(ie they don't use badass booster and emulsion packages). A typical Eddy 750 for instance is going to be set up for WAY more engine than you have, jetting will be wrong, accelerator pump will prolly be way off(reason for your stumble) and it most likely is costing you power throughout a LOT of the RPM range from ineffective metering. You at the very least need to dial the pump and jetting in, but in all reality you'll prolly find you'll go down the track faster with a smaller carb. You also have to have ignition set correctly. Right timing, right plug heat range, right plug gap. If ignition is off then the carb is off, like the old saying goes - 90% of carburetion problems are ignition problems. Carbureted applications can be VERY fickle, even if 1 thing is just slightly off it can be a real pain.

ORIGINAL: sixtysevenstang

hi, i have a question for those of you with "Highly Modified" small blocks and a c4 trans. what stall are you running? what do you think is the best for the street and strip. my car will be street driven, but on weekends driven to the track, back tires swapped out for slicks, and raced. i currently have a built up c4 with a transgo shift kit with gear command. it also has all the other street strip bells and whistles. my only thing is, i got the wrong converter. i bought a 1800-2200 stall which i think is stock isnt it?. when i hammer it out of the hole, it stumbles then pulls slowly till around 3500 and screams like crazy and all it well. its just off the line where my issue is. everyting else is perfect. i was told to run a 2600-3000 stall by a racer buddy of mine. so id like to know what some people are running and what your result is. again i really only want to know from those of you with over 400hp and race you car as well as drive on the street.

i have a racing setup289. im currently running a 28 inch tall tire (not sure if ill go to a 26 or not), 3:55 gears, andmy cam is a .512 lift. if you need to know anything else just ask.
A 289 is grossly overcarbed with a 750, you should use a 600 or 650 max.
The loss of vacumn from too big a carb is hard to overcome with the acc. pump shot.
Recurve the distributor for 10 deg advance = 20deg @ the crank.(all in by 2500 rpm)
Set base timing @18 deg. (for a grand total of 38 Deg adv).If she pings on you, use higher octane fuel, or retard base timing 2 Deg.
Accelerator pump linkage needs to be adjusted to have ZERO slop.
The smallest movement of the accelerator should have fuel squirting into the boosters.
True stall speed is rated with a transbrake. Not foot brake, so if your car doesn't have one, use a looser convertor.3500 stall should work for you.
Lose the 3.55's( you did say it was a racecar didn't you.)
With a 28" tall tire you should have at least a 4.10 gear(4.30 or 4.56 would be even better) if you don't street drive it much.
The only way the motor will pull to 8000 rpm is with a solid roller cam.
Don't forget a stock bottom end will come completely unglued @ that rpm level too!
6500 rpm sounds more useable to me.

local://upfiles/95778/8D6404DCEBE6436F85F1828AD0ABA2DB.jpg

750 edelbrock. There is one of your main problems. Get a Holley.

And just for input I turned my 1968 model block, crank and rods 8K rpms for over 10 years with 250HP of N2O on it. Now when it let go it broke two rods. But 6 are still usuable. I ran a solid roller, TFS heads. Cam was 688 lift on intake and 644 on exhaust. It ran 10.50's in the 1/4 @ 127.