Pulling Power from a Hemi

Decreasing Power from a Hemi

Hey guys! Finally bought a hemi for my Outlaw 10.5 car. Our main concern is obviously over powering the tires. So my question is what are some of the main things we will need to do to keep this thing around 1800-2000hp??? Kind of an unusual question for this site I know. Here's the motor specs: 526 Kb stage 10 w/ Brad fuel heads, SSI 1471 standard helix, Promag 44 (have a couple of 12's but i'm not gonna mess around w/ that, we will buy a 44) Would like an idea on how much to turn the blower down and the minimun I can run on timing...? Any help would be great!!

 

I don't personally think, considering your trying to tone down a motor, a 44amp mag would be useful to you. We run a 484kb now and we will be running a single mallory supermag IV. As for the blower i'd look at about 20-25% overdriven. Keep the fuel system and timing pretty much to what is recommended, don't want it leaning out too quickly and causing damage.

As for other ways to lose power, what trans have you got? If your using a clutch then let the trans slip more for the first gears. Higher rear-end gear also?

And by the way; You made a superb choice, hemis are great!

 

Yeah we're very excited about the switch, we were running a small block ford

As far as the trans, we're running a bruno/lenco 3 speed. I believe the way we have it set up now it has a 2.15 first gear. 4.10 rear end.

Leahy told me before w/ my small block, w/ 12:1 compression and over 20lbs of boost that there is no way i'd be able to burn all the fuel w/ a Promag 12. He ck'ed everything and said all of it was fine and that I really had no choice but to upgrade to atleast a 20. We were putting about 7gpm in the sbf.

 

How much power was your SBF making?

 

1400hp....ran 8.5@158 in a 3380lb steel car

 

Way too much 1st gear. Can't give you too much info since your a 10.5 competitor. 1.80 -1.60 1st would be much better. Control power with timing. I'd give you more info, but then I'd have to kill you.

 

Nice... Prior to your new Hemi acquisition we could have had some good match racing.

But now, I'll have to find some better cylinder heads.

-WJ

 

you will probley need the low gear in first if its 3300lbs you have a convertor dont you as far taking horsepower away you you can keep the motor fattened up that doesnt hurt parts 44 amp mag timing 25 to 30 degrees spin the blower about 40 over if you are using a high speed flip it over and dont ues it till you get a handle on it then turn it around and lean it out set it at about 65lbs depending on your fuel system take 65 out with the high speed agian depending on the fuel system it should be a 90 in the main at 1000ft of air thats corrected air you can always put a stop under the pedal that will work also good luck

 

i dont know much but...danny was heading you in the right direction and a good direction to go would be to visit north carolina and check out some of the incredible powerglide pro mods there. as he said timing is the key as in take timing out with a msd 8973 [may be 15 degree or more] and ramp it back in as tire, track can take it. your combo should be able to take 50 over and 35 degree total advance.

 

Is there a limit to how much timing you can pull from the motor w/out hurting it? ie-launching at 15*and ramping it to 25*???

 

Use the largest diameter distributor cap posible, and keep an eye on rotor/trigger phasing. If you start to pull out a *lot* of timing you run a greater risk of jumping to the next nearest terminal. Or, run distributorless ignition and pull as much timing as you want.

 

We dump 10 degrees min on the hit. Going to try even more to soften our wedge engine. TOL is correct,phasing is critical, esp on a mag-12 we found. I figure if it bangs and pops a little on the hit its better than when you have a full timing load/power. I phase my mag for full timing per Laehy.

 

Mike i'm surprised you were advised to run a 12, Leahy told me that wasn't enough on my sbf. He said a 20 minimum, but 44 would be the best. I think we're gonna switch just to eliminate a possible problem. What are you using to pull timing on the launch?

 

I am running a completely different set up but had similiar issues this year. Here is where I ended up. We ran Superquick (4.50 min dial in 1/8th) this year with 470 KB w/ Veney heads, 8.71 Std Littlefield, 110 Enderle, only hat nozzles, 44 MSD, Coan Mega Convertor, Lencodrive w/1.75, 4.10 gear. This was in an 1800 lb dragster with 34.5 tire. Our problem wasn't overpowering the tire like yours would be but detuning to run on a 4.50 dial.

We never got our 6-shooter to work but we did use the MSD retard box w/o the 6 shooter. It is going to Leahy in a couple of weeks.

12% over,
20deg timining
Left at 3200
1-2, 2-3 Shift at 6,000

Our 60' times were in the 1.115 range with this set-up.

Spend some time time with a fuel system and convertor guy on your initial set up. This will be very important. We caused ourselves problems this year trying to run 4.50. We didn't build the car to run this way but the races were close and gas isn't getting any cheaper.

Don Gerardot has several guys running big motored supercharged cars with his fuel systems that are running small tires or fast brackets. Give him a call on your fuel system. (260) 623-3048 www.gerardot.com

All the other suggestions given in this thread will also work. I need to check into on a couple myself.

Brad Hiatt