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Discussion Starter #1
I have a questions regarding what converter is best for my application. before I installed the fogger system on my car it ran the fastest with a converter that flashed to 6700 when the transbreak released and dropped from 7800 to 6600 on the shift.

Now I have installed a single fogger on my motor and would like to get a matching converter but have heard a number of different things on what way I should go.

I called and talked to 3 different, reputable converter companies and got 3 different answers on what I should put in the car.

First said that I should have a converter that when the nitrous was on matched my old converter.

Second said I needed one that flashed 1300 to 1600 rpm's less because the nitrous made alot more torque.

Third said I needed a converter that flashed to 4800 on motor and would flash to 6600 on the nitrous. This seems like a big jump for my set up, see below.

What has everybody found to be the best? I know all combos are different but what seems to be the concencess? One that is similar to my old one when on the juice or one that is tighter to let the torque work?

My combo is a 620" BBC with 18* big duke heads. 15:1 compression single 4 on a cast intake. Fogger has a 26/ 20 at 5.25 lbs.

This is in a 1900lb top dragster.

Thanks again for any input.
 

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If abruzzi wasn't on the list of the first three, he would be my next call. He builds converters, and runs top dragster, so guessing he has a handle on this.

What I'm seeing as I sneak past about 1400 hp total (and I think other guys have known this for awhile) is that an optimum converter for your combo, which I would guess at between 6200-6500 fallback on spray, may make it a real bitch to get off the starting line on the bottle.

My car is short and rigid, so longer and sprung will make that a little easier. I still see alot of guys, though, that are just driving through the converter on spray so that they can still 60' on motor. I don't think this is the only way, but they're going fast doing it, so I guess it works.
 

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I dont have a Top Dragster by anymeans, more like a beginner medium dragster. I am just looking for advice on my stuff because i believe there is more left. It is a 235" Swing Arm Dual Shock car. Car weighs 1900 with me in it. Hoosier 18700, 4.30 Rear, 1.80 Trans, 565 Chevy Tall Deck, Brodix -4 Heads, Bullet 808-748 (sorry dont have cam card on me) Terminator on Alky, 14.5 to 1. I only run 1/8 mile stuff, but on motor with a converter that would go 6400 it would run 4.75-4.78 at 142-143, On an .082n pill enrichening with Alky it would go 4.57-4.61 at 147-148 spraying from .3 to 3.8 seconds into the run. Found that the tranny pump had eaten itself up after 40 runs. Put new ATI pump and the ATI Wide band in the trans. The Converter now goes 5900-6000 on motor and about 6300 on the bottle. Car now runs 4.82-4.86 at 144-145 on motor, and 4.52 to 4.56 at 154-155 (still on the .082n)
This past weekend put a .088n jet in it pulled 2 extra degrees of timing. This was air that was 65 down to 50 degrees, humidity never got above 55% and the day started at 200 ft corrected altitude and finished at -50, and the track was good, but it is a rough track. But my question is, Are these reasonable times?

First Pass
60= 1.010
330=2.902
594=4.202
660=4.485
MPH=155.4

Second Pass: Shook hard and lifted

3rd Pass
1.002
2.895
4.214
4.512
143.11 (Had the other car treed)

4th Pass
.998
2.885
4.194
4.493
153.55

5th Pass
.996
2.882
4.196
4.491
152.48

6th Pass
1.13 (Huge Wheelstand 60 off rear tires)
2.885
4.192
4.495
151.98

7th Pass
1.008
2.895
4.205
4.497
153.01
 

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^^^^^HIJACK!!!!!^^^^^ :smt072 I agree with Vegaman. Sounds to me like all 3 gave you the same answer. Just pick a converter company you are comfortable with and tell them your combo and they will fix you up. Remember that you'll also need a nitrous cam if you spray anymore than what you are currently. Good Luck
 

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Discussion Starter #6
Thanks guys for the feedback. Abruzzi was one of the 3 I called. Maybe they were all telling me the same thing and just saying it in different ways, still trying to figure this thing out. I just want to get it close out of the gate and not need to pull the tranny and send the converter back a hunderd times before we get it right.
 

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Sorry to pull a D.A. Mistake on here in hijacking a thread. I was wanting to post my numbers in comparison to geise's. My car seems to be happiest when i am about 6300-6400 fall back. Any lower and it is a slug and any higher it wont run on the big end. Geise, what gear and tire combo do you have on your car?
 

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I know when i went from hoosier 33x16X15 to a hoosier 33.5x17x16 with my 522 i picked up a legit .03 off the bottle and .05 on the bottle. On the bottle my car would shake and kill 3 numbers with the small tires. Went to the 16" wheel and those problems went away with the 522. But now with the 565 its coming back a little, but i think there might be some ET in going to a 4.10 over the 4.30. On converters i have been thrown for a complete loop with them. Had a tranny issue that wasnt building enough Pump pressure which was allowing the converter to go about 400 RPM looser then it should. Which on motor it was awesome (6300-6400), but wouldnt pick up the ET i wanted to. So Had Trans Specialties build a converter that was about 400 RPM tighter. After putting it in we finally found the pump pressure issue after smoking the band. Put back together and the new converter would only go 5500 from the one i have now. So put my other one back in and now i am wherei want to be on the bottle, but about .10 off from where it can run on motor. Think i am either going to sell the new converter or send it back and have them loosen it up for motor. How many of you guys are running sprag-less converter?
 

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First said that I should have a converter that when the nitrous was on matched my old converter.

They are not the same
Your tune-up is adds about 200-hp. This will change stall speed 800 rpm.

So yes your converter needs changing to keep your engine at 66 to 6700.
On the motor it will stall about 58 to 5900
This is all providing that you keep the same tune-up.

#2 will drop you to about 6000 on spray
#3 will drop you to about 5600 on spray.

Your bracket racing right?

I know racers that keep 4-5 converters with them just to keep their stall speed with in 100 rpm either way.

Marco was probably #1
 

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Discussion Starter #17
Have not. Wont get to run the car again until Vegas divisional. I also made some other changes so we will see how it works.

From some of the info I have gotten off of here I am hearing that I want to have a converter built that when the nitrous is on makes the converter stall in the same RPM range as when we used to run the car naturally asperated? Around 6600-6700rpm's?

Sound accurate?
 

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For the most part a nitrous converter is about the same as a converter for a supercharged car. Leaving on nitrous is very hard on the stator because it is a shock load. Roller clutch setups even the best ones don't like it where a supercharger might be ok. To be safe on a nitrous car go spragless if possible. Even the Coan roller clutch setup has issues after a while over 800hp on a nitrous car where I have seen supercharged motors in that range last a very long time. Both setups need thick halves (balloon plates or billet cover) to keep them from balloooning under the pressure.
Alan
 

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i cant speak for some convertor companies but i will say one thing

lenny from ucc will be the only person your dealing with on the phone and it doesnt matter what time it is he will return your call

now ive not dealt with marco abruzzi -but ive heard the same thing about him :) very classful guys -not just looking for your money
 
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