NITROUS ROUNDTABLE
STEVIE “FAST” JACKSON
be completely honest, there just ain’t a lot of difference there. My whole
engine program right now is built around that zoomie and I spent a lot
of money changing to run the zoomie, so I don’t foresee me putting them
back on, but I’ll never say never. I love ‘em. I love the sound of ‘em and I
love the flames.
I could tell you this: if I had the bullhorns on the car when I went the .63,
I guarantee you at Virginia there’d be about 10 more cars with bullhorns
on ‘em. This whole racing deal is a monkey see, monkey do thing now.
Part of me hates taking the bullhorns off my car two years ago because
I spent some money to make the changes to run the zoomies, and being
dead-honest with you, I didn’t really find a whole lot. I just didn’t. We
put bullhorns back on this car and it runs dead-on what it runs with
zoomies. I can’t never say never. If I get a wild hair one day and want
to make some flames, we might put those things back on the car and
make some flames.
CB: It’s kind of a personal preference, but there are advantages to
zoomies. Zoomies create a better pattern of pressure, so therefore, down-
force. With that, we all use downforce.
For some basic numbers, when we went from bullhorns to zoomies, we
were able to take 20 pounds off the nose of the car. Whatever the downforce
number is, it allowed us to take 20 pounds off the nose of the car that we
did not have to replace. So if the car was heavy, we could now run the cars
at weight or 20 pounds closer to weight.
So do I see the bullhorns coming back? Prob-
ably not. I know there’s a lot of fans who really
like the flames. It’s neat looking – it’s as close
to Top Fuel as you’re going to get. But several
of us feel there’s a performance advantage for
the zoomies over the bullhorns.
PM: No, (bullhorns) are slower. They’re
cool though.
The reason why you have the flames, which I
don’t know if most people know why you have
the flames, but you have four pipes going into
a collector, so now you have everything mixing
up in the collector and it makes that big flame.
But the fact of the matter is the exhaust port
isn’t happy. It’s a way to clear the exhaust port
and clear the cylinder. We’re getting so much in
these things that you have to clear the cylinder.
It’s a big deal. What happens in the collector is
it reverts back, it goes back up in the manifold.
A lot of things happen and it’s not happy.
It looks good, but I don’t think you’ll see
them come back. You’ve got a couple stubborn
guys out there. I saw one guy – I think it was
Jeff Pierce – said we ought to make it a rule
that you have to have bullhorns for the show.
That’ll be a tough battle to fight. The zoomies
are probably here to stay.
BS: I would say it’s safe to assume bullhorns
aren’t coming back. Actually, sometimes the
engines will make better torque with bullhorns
on them than they will with zoomies. The big-
gest thing people miss on that is the zoomies
make their car happy, it’s not so much the en-
gine though.
Along with the biggest advancements – and a
lot of people probably don’t understand it – but
with the zoomies you’re dynamically adding
front-end weight to the car that you don’t have
to actually carry as physical weight. Now you
have a force pushing down on the front of the
car, keeping it off the wheelie bar, keeping it
from flipping over backwards, that doesn’t
actually equate to lead weight. It’s dynamic.
If you take a car and you run bullhorns on
it, then you run zoomies on it, it acts like you added 20 or 30 pounds to
the nose, yet the car doesn’t run 20 or 30 pounds slower. That’s pretty easy
to figure out because an engine always only fires one cylinder at a time.
Well, if you have X exhaust gas velocity coming out of a 4-inch tube or
that coming out of a 2.5-inch tube, you have four times the downforce. It’s
not so much an engine thing. It really has nothing to do with the engine.
In certain cases it can hurt and certain cases it can help. But if you’re
just looking for the highest power you can make, a bullhorn is probably
better because, on average, it’s going to make more torque than a zoomie
is going to, but only at very low nitrous levels. Once you start getting the
VE (volumetric efficiency) of the engine over 100 percent, it doesn’t really
care what header is on it. It just wants the exhaust gas out.
SJ: Well, that’s all open to opinion. I’ve ran both of them. Right now,
with the current engine that’s out, the zoomie is definitely superior.
For the fans’ sake, because I love big, honkin’ gorilla flames at night,
I hope we can bring the bullhorn back. If I ever come back Pro Nitrous
racing, I’ll see if we can develop maybe a new thought process on the
bullhorn. I remember that was a heated debate for a long time. It was
like a very taboo subject – you didn’t talk about the zoomie-bullhorn
deal for a while.
Right now, the exhaust ports on these cylinder heads are so big, I just
don’t think you can get it out fast enough with a collector. With that said,
DI DI DI
if I’ve learned anything in drag racing, it’s never, ever, ever say never.
DI DI DI DI
May 2019
DragIllustrated.com
| D r a g I l l u s t r a t e d DI | DI 99 DI