Craig84Z

iTrader: (2)

Hello Everyone,

I have desktop dyno2000 that I have tailored for my car. It has worked pretty good. I was toying with the idea of changing over to retro hyd roller lifters and came across something.

By switching my current config from dual-plane to single-plane it said I would pick up 30hp @ 6000rpm.

I did some searching a few minutes ago and found that some don't like the Weiand X-celerator intake, some say the Edelbrock performer rpm is better, etc.

Does anyone have any actual dyno numbers after switching from an Edelbrock Performer RPM to a Weiand X-celerator?

My car is a 1984 L69 Z28:
355sbc non-smog obviously after you see specs below.
Holley 750 dp
Edelbrock Performer RPM
Comp 270 cam
hyd. flat tappet lifters
AFR 190 heads
1 5/8 headman headers
10.25:1 cr
331rwhp/331rwtq
T-5 tranny
stock 3.73 rear end
best 1/4: 13.029@109.76 with street tires

I'd like to get more top end power to dip into the 12's. It pulls well now to 6000rpm. I'd like it to pull harder at the top end. I like the price of the Weiand X-celerator but don't want to go through 2hrs of trouble if I'm not going to see good results.

Occasional strip time and road racing at O'Reilly Raceway Park (formerly Indianapolis Raceway Park)

Thanks,
Craig

zz4monte

The Performer RPM is a good intake for the street/strip with your cam.I would not change it. Your cam really isn't big enough for any huge gain.Maybe 5-10hp and you should lose some torque to.You might gain .1tenth in the 1/4 if that.What is your 60ft times? You have more than enough power to run 12s.With a 109mph trap you should be in the 12s.Do you have slicks and aftermarket suspension?
Sorry just saw the street tire remark. Slicks are going to help so much!!!!109mph in the 1/4 is fast for a 350 that is daily driveable and has no spray or forced induction.GET SLICKS!!!!!!!! I bet you will gain at least .3 tenths.

Damon

In general, DD2000 (at least my older version) has only 2 choices...... dual plane or single plane intake. I mean, aside from tunnel rams and such. That's an awful "generic" choice of intake designs to model an engine around.

My experience is that the "dual plane" choice is more like if you're going to use a standard Edlebrock Performer. The RPM is a different animal and I think DD2000 just doesn't model it well- it works more like a single plane, but with a little more torque in the low RPMs, maybe a smidge less up top.

It would be total guesswork, but I bet you have traction issues. Just a wild guess, right? It's POSSIBLE that a switch to a single plane MIGHT make you go quicker. It will soften the torque slightly in the low RPMs which might let you launch better and it will probably pull a little harder up top (with tuning)- where you DO have traction. MIGHT MIGHT MIGHT. I've had cars that this didn't work out very well in the real world. They hooked up better out of the hole but the better top end charge meant that all I did was break traction at the 60' mark when the motor was getting into it's new, higher powerband. End result- no better or even worse.

BTW- there are 2 different X-celerator manifolds. The one for use on the street is the 7546 (the 7547 is a completely different intake for an IMCA class of spec racing- not what you want on your street drving). The 7546 is kind of like Weiand's version of the really good Edelbrock Vic Jr. that's been around for a zillion years. I don't think it's as good as the Vic Jr, but it's a decent piece. It comes with a little plenum divider plate that they say you should use with any cam under 250* .050 duration. You can forget ever using that plate becuase I've always gone faster without it, even with cams WAY under 250*. Hey, maybe it works for you but it hasn't for me. I happen to have a 7546 in my garage right now and I've used it a couple times which is where this info is coming from.

Last, the 7546 will sit the carb about .150" higher than the Performer RPM. It's not much of a difference but if you're tight on hood clearance already this might put you over the edge. Smaller air cleaners to fit a taller intake under the hood almost always makes for a bad trade-off.

I'm not sure this is a project worth spending the time and money on, but who knows. Every engine is different. Wouldn't be the first time someone has made a change that shouldn't have done much but ended up helping out quite a lot. But, of course, you understand the flip side of that coin.

Craig84Z

iTrader: (2)

Thanks for the input guys!

My best 60' is 2.03 seconds. My DD just has the single plane/dual plane option too. I think I'll just stick with what I have for now. My friend knocks half a second off his 1/4 mile time when using dot slicks (12.7 to 12.2).

I'll start a new post on if anyone has done a retro-fit hyd roller lifter engine and what cam they switched from/to.

Thanks,
Craig

jbenge

iTrader: (2)

Hey Craig, its been awhile since I've talked to you. I'd stick with the Performer RPM unless you step up to a larger cam. I don't think you rev high enough to take advantage of a single plane design. I learned that from my first 383 build about 5 years ago. Heres the basics of the original combo: Dart Pro 1 215cc heads(no porting at the time), 10:1, Hyd/roller 225/230 .525/525, 750DP carb, hedman 1 5/8 headers, Vic. Jr., I was shifting at 5800-6000rpm's so I wasn't reving high enough to justify the single plane. I switched over to a RPM airgap and picked up some low end torque and had about the same top end......I was .2 faster with the dual plane.
If you want to change something I would change the cam and intake together for a well matched combo. I would think about going up in compression slightly, larger solid roller or hyd/roller cam and single plane together. I really like my current setup 11:1 with a large cam works great on pump gas and makes tons of power, there really wasn't much sacrifice in drivability either. Just depends on how radical you want to go and how much street driving you do. Or just stick with what you got and get some sticky tires for the drag strip and save your money for a 12 bolt. Sticky tires is the easiest way to get into the 12's. You can borrow my wheels sometime if you want to see what it will do with sticky tires...just let me know.