I just received a convertor from Abruzzi the other day and I'm curious if anybody is using a mech. diode convertor from Marco. I had him go with that style because I' not happy with the performance of the spragless one I have used this past year. The spragless is 2-3 hundreds slow and a couple mph over a previous sprag type unit. My car is a SBC @ 2500 lbs.

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Originally posted by DLR:
I just received a convertor from Abruzzi the other day and I'm curious if anybody is using a mech. diode convertor from Marco. I had him go with that style because I' not happy with the performance of the spragless one I have used this past year. The spragless is 2-3 hundreds slow and a couple mph over a previous sprag type unit. My car is a SBC @ 2500 lbs.

They usually are slower but less stuff to break

My experience with the mechanical diode is good. I have run several in several different cars, all with good results. I do not know of any reason it would be slow, should be faster than a spragless and equal to a sprag.

When one of my old converters broke I went back with a Hughes Spragless and could not any loss at all. That converter has been very good and consistent.

On the old one that broke the sprag I am not bothered too much by it I got my moneys worth out of it. Still it is one less thing to break and I did not lose any ET or MPH going spragless.

I run both from Marco, on mine if stall speed was the same the diode was a little quicker roughly .015 and .75 mph. I have the spragless in it now and it's 150 rpm looser than the diode was and is close ET wise. I have my diode converter ready to go back in after loosening it. It should stall 150-200 more than my current converter. If I sit on the 2 step a little long on my current converter it will flash an extra 100rpm and it pics up .01 or so. Thats why we loosened the other one even more.

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Originally posted by DLR: The spragless is 2-3 hundreds slow and a couple mph over a previous sprag type unit. My car is a SBC @ 2500 lbs.

curious… did both spragless and sprag type flash to same rpm at launch? What Flash RPM?

Mechanical Diode is the fastest available. Any fast stuff runs one. We use them in our 9" bolt togethers. Will not affect the flash or fall back. WILL pull off the fall back faster as that is where they normally pickup which also increases MPH. Also won't drag down as much when you rip the pedal at the stripe.

SL...

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Originally posted by DragRaceResults:
Mechanical Diode is the fastest available. Any fast stuff runs one. We use them in our 9" bolt togethers. Will not affect the flash or fall back. WILL pull off the fall back faster as that is where they normally pickup which also increases MPH. Also won't drag down as much when you rip the pedal at the stripe.

SL...

I call tell you with my combo that's 100% incorrect vs sgragless. I made the switch to reduce engine breaking when peddling at the stripe, I notice no difference. Performance, no difference with either et or mph. Add that into the pile of good ideas.



Every combo

Hmmm interesting. All I know is what my stuff does, and the feedback from multiple converter companies.

AL - who's stuff do you run?

I have a Neal Chance bolt together converter that came with a mech. diode and made it spragless car ran the same ET and mph in the 1/8. Havent run 1/4 with it being spragless

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Originally posted by DragRaceResults:
Hmmm interesting. All I know is what my stuff does, and the feedback from multiple converter companies.

AL - who's stuff do you run?

I work closely with Eddie at Select. I do feel the combo matters as with anything. Light cars/dragsters and good power are pretty numb to small changes. Eddie thought I may see some MPH increase but didn't. Since I tried the diode about 3 plus years ago, he has seen similar results that I saw.

To see MPH increase, you either need to put the motor in a better rpm range it likes through the lights, or decrease drag/increase efficiency. Not seeing how a diode, spag or no sprag would impact this.

To many focus on top end slip numbers, if the converter is correct for the combo, slipping 4% or 6% up top will change nothing on the time slip. It's all about wheel speed - this directly translates to the time slip. Converter slip is a direct function of its design and the load applied to it.

This message has been edited. Last edited by: TOP38,

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Originally posted by TOP38:
[QUOTE]Originally posted by DragRaceResults:
Mechanical Diode is the fastest available. Any fast stuff runs one. We use them in our 9" bolt togethers. Will not affect the flash or fall back. WILL pull off the fall back faster as that is where they normally pickup which also increases MPH. Also won't drag down as much when you rip the pedal at the stripe.

SL...

The proper diode/sprag converter will out run a proper spragless converter everytime. I personally sell and use spragless converters 99% time. But if im looking for rock star numbers im putting a converter in that has a sprag in it.

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Originally posted by 329L:

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Originally posted by TOP38:
[QUOTE]Originally posted by DragRaceResults:
Mechanical Diode is the fastest available. Any fast stuff runs one. We use them in our 9" bolt togethers. Will not affect the flash or fall back. WILL pull off the fall back faster as that is where they normally pickup which also increases MPH. Also won't drag down as much when you rip the pedal at the stripe.

SL...

The proper diode/sprag converter will out run a proper spragless converter everytime. I personally sell and use spragless converters 99% time. But if im looking for rock star numbers im putting a converter in that has a sprag in it.

Like I said, the combo matters,,, but for me a diode made no difference in performance, just cost more!

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Originally posted by TOP38:

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Originally posted by 329L:

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Originally posted by TOP38:
[QUOTE]Originally posted by DragRaceResults:
Mechanical Diode is the fastest available. Any fast stuff runs one. We use them in our 9" bolt togethers. Will not affect the flash or fall back. WILL pull off the fall back faster as that is where they normally pickup which also increases MPH. Also won't drag down as much when you rip the pedal at the stripe.

SL...

The proper diode/sprag converter will out run a proper spragless converter everytime. I personally sell and use spragless converters 99% time. But if im looking for rock star numbers im putting a converter in that has a sprag in it.

Like I said, the combo matters,,, but for me a diode made no difference in performance, just cost more!

Curious, is that a boosted combo? Reason i ask, an engine that continues to make power the more you turn it, the less that a spragless converter will affect the engine. A spragless converter with an engine that starts running out of steam, will act like a brake and not allow the engine to accelerate like it should.

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Originally posted by 329L:

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Originally posted by TOP38:

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Originally posted by 329L:

quote:

Originally posted by TOP38:
[QUOTE]Originally posted by DragRaceResults:
Mechanical Diode is the fastest available. Any fast stuff runs one. We use them in our 9" bolt togethers. Will not affect the flash or fall back. WILL pull off the fall back faster as that is where they normally pickup which also increases MPH. Also won't drag down as much when you rip the pedal at the stripe.

SL...

The proper diode/sprag converter will out run a proper spragless converter everytime. I personally sell and use spragless converters 99% time. But if im looking for rock star numbers im putting a converter in that has a sprag in it.

Like I said, the combo matters,,, but for me a diode made no difference in performance, just cost more!

Curious, is that a boosted combo? Reason i ask, an engine that continues to make power the more you turn it, the less that a spragless converter will affect the engine. A spragless converter with an engine that starts running out of steam, will act like a brake and not allow the engine to accelerate like it should.

Nope, NA. 632 with Dart Pro 20 heads, single carb. Both the spragless and diode converter run the same.

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Originally posted by TOP38:

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Originally posted by 329L:

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Originally posted by TOP38:

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Originally posted by 329L:

quote:

Originally posted by TOP38:
[QUOTE]Originally posted by DragRaceResults:
Mechanical Diode is the fastest available. Any fast stuff runs one. We use them in our 9" bolt togethers. Will not affect the flash or fall back. WILL pull off the fall back faster as that is where they normally pickup which also increases MPH. Also won't drag down as much when you rip the pedal at the stripe.

SL...

The proper diode/sprag converter will out run a proper spragless converter everytime. I personally sell and use spragless converters 99% time. But if im looking for rock star numbers im putting a converter in that has a sprag in it.

Like I said, the combo matters,,, but for me a diode made no difference in performance, just cost more!

Curious, is that a boosted combo? Reason i ask, an engine that continues to make power the more you turn it, the less that a spragless converter will affect the engine. A spragless converter with an engine that starts running out of steam, will act like a brake and not allow the engine to accelerate like it should.

Nope, NA. 632 with Dart Pro 20 heads, single carb. Both the spragless and diode converter run the same.

Then it can be done, but MOST converter companies out there arent always capable of that.

AL refresh my memory. What's the fastest you've been and weight?

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Originally posted by DragRaceResults:
AL refresh my memory. What's the fastest you've been and weight?

1825 lbs RED w/a TD wing, C15 race gas
6.75 199.5 4.28 162 (650 DA)

Normal summer heat - 6.84 195 (4.36 159)

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Originally posted by 329L:

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Originally posted by TOP38:

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Originally posted by 329L:

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Originally posted by TOP38:

quote:

Originally posted by 329L:

quote:

Originally posted by TOP38:
[QUOTE]Originally posted by DragRaceResults:
Mechanical Diode is the fastest available. Any fast stuff runs one. We use them in our 9" bolt togethers. Will not affect the flash or fall back. WILL pull off the fall back faster as that is where they normally pickup which also increases MPH. Also won't drag down as much when you rip the pedal at the stripe.

SL...

The proper diode/sprag converter will out run a proper spragless converter everytime. I personally sell and use spragless converters 99% time. But if im looking for rock star numbers im putting a converter in that has a sprag in it.

Like I said, the combo matters,,, but for me a diode made no difference in performance, just cost more!

Curious, is that a boosted combo? Reason i ask, an engine that continues to make power the more you turn it, the less that a spragless converter will affect the engine. A spragless converter with an engine that starts running out of steam, will act like a brake and not allow the engine to accelerate like it should.

Nope, NA. 632 with Dart Pro 20 heads, single carb. Both the spragless and diode converter run the same.

Then it can be done, but MOST converter companies out there arent always capable of that.

I believe Marco told me that a small block is more apt to see differences compared to big block engines.

On my low power small block, switching to spragless ran about the same 1/8 mile, but it hurt the 1/4 mile about 3mph.