[Hans Buijnink (72challeng]

Any opinions about fitting one of these on my 340 engine? See the specs of the 340 under the photo section

http://www.challenger440.pwp.blueyonder ... 1058206482

Only things different compared to the specs are it has a 4.30 rear, 3200rpm stall and 26" hoosiers right now. Ideas appreciated!

[Hans Buijnink (72challeng]

it's a manifold Dave... working range 4500-7500 (although for a SB Chubby, couldn't find one new for mopar) No, my carb is perfect, Demon 650dp rejetted to 78 right now, changing to 80-82 next week.

[Dave-R (Roppa440)]

OH! See how tired I am getting? I thought you were on about dominator carbs!

Silly me!

I shall delete my last post.

[Dave-R (Roppa440)]

I don't know what power range your cam is best at but unless you actually rev your engine up to 7000-7500 rpm I would find something that works at lower rpms.

[Hans Buijnink (72challeng]

Right now I'm running the edelbrock performer rpm which has a power range of 1500-6500rpm but as I leave the line with about 3200rpm of stall I thought maybe it perfoms better with a single plane manifold. Bettet at higher rpm's I meant.

The cam's power range is 2400-6900rpm if I remember right. With the existing dual plane I'm shifting at 600rpm, I was hoping to shift at 6500rpm with the single plane manifold. I was thinking about this as I'm able you use one for free...

Now don't say just try and if it ain't better go back to the existing one for the next race as we're only able to hit the track 3 events a year over here...

[Dave-R (Roppa440)]

I would say that as you are only at 6500rpm for a second it is not worth going to the other intake. Only testing will tell for sure!

[Christer (Christer)]

Wouldn´t a Holley street dominator manifold be a better choise?

[Dave-R (Roppa440)]

It still wouldn't be as good in the lower-to-mid rpm range as the performer rpm. In fact with a single plane manifold you might loose a little stall speed?

[Hans Buijnink (72challeng]

Christer, the street dominator has a power range from idle-5500rpm so the performer rpm is a better choice then. You got a point there Dave about the stall speed. Have yet still a couple of days to decide which I use on the strip. We'll see.

[Christer (Christer)]

I am sorry for that bad advice, Hans. Since I own a street dominator manifold myself, I should have known better !!! (a bit embarrassing....)
Since it is a single-plane intake (at least the b-block version is), I have been convinced (wrongly) that it is designed to work well on higher rpm´s (something about 1500 to 6500). It is quite obvious that I haven´t checked up the facts.

How about an Edelbrock torker manifold then, Hans? Isn´t it designed for the 2500-6500 rpm range? Isn´t this rpm range more suitable for a street/strip car?

[Dave-R (Roppa440)]

I don't know where Holley get their idle-5500rpm from because that is dual plane range and the single plane street dominator must be down on torque over a dual plane at anything under 4000rpm I would have thought?

Every now and again a magazine will try different intake manifolds on a test engine on a dyno. Finding such a test that used an engine similar to your own can be very difficult but not impossible.

However I think you would be very hard pressed to find a true street/strip manifold better than the Performer RPM at the sort of rpm and power levels you have. You might be able to squeeze a bit more peak power from a single plane but if it is offest by a loss of lower rpm power it is not going to make you faster unless you have gears that will keep you in the more narrow power band.

[Hans Buijnink (72challeng]

4.30 in the back Dave... But I decided to keep the performer rpm for now. I was only doubting because I can use the Holley for free. In fact, for my engine, the air gap edelbrock would be best I guess. Anyway, thanks for the input.

[Dave-R (Roppa440)]

Mmm. Yes. But if you leave the line at 3200rpm you will leave even slower with less low torque. In fact less low torque might drop your stall to 3000rpm. But only a dyno test will tell for sure.

Also you are using a three speed box. Shifting at 6500 your rpm will drop to 4000rpm at the start of 2nd and third. So if my thinking is correct (is it ever these days?) then really you want a power curve in that range and peaks about half way at around 5250rpm?

So if your peak power is higher you need to shift higher and then you have to start worrying about your con rods!

[Dave-R (Roppa440)]

Actually what I said just then is a simple generalisation.

Your ideal shift point is the rpm after peak power that has the same power level as the rpm your engine drops to when you engage the next gear. So if you have a narrow power band you need gears that are very close to each other.