I sent a note to Pypes Exhaust asking about their 3"exhaust system, and what mufflers would be best with my combo.

Here's what I sent:

"Here's my combo:

Dart Big M 4.5X4" 509 ci, 10.14:1; custom Comp solid roller, RT series lobes: 250/250 net @0.05, 707/703" net lift working Jesel SS 1.75 rocker arms. AFR 315 CNC heads matched to a Holley Tall deck C950 EFI 2000cfm TB with wideband O2. Hooker Comp ceramic coated 2" primary headers. Engine is in a 79 Camaro Z28, backed by a beefed T56."

Here's their reply:

Hi,
We usually only recommend 3" stuff if you are at 500 HP or higher. Are you at that point?

Now I'm realy worried.... :eek:

John

If that combo doesn't make over 500 hp I'd start looking for disconnected plug wires!

Like 3 of them....

John, your combo is very similar to mine. A 502 at 10 to 1 with AFR 315's and a solid flat tappet of 258 @ .050 and .615 lift with a Vic Jr. and Holley 1000 HP. I made 615 on a very conservative East Coast dyno. You definitely have the horses there buddy.

Guess I should have mentioned I was going to run it on all eight cylinders ;) ;)

John

69ttop502, could u please post your dyno numbers at all RPM? Im curious to what the torque curve looked like on that combo.

69ttop502

Thanks for the info. Haven't got the engine to the dyno room yet, but I was hoping for 600-625hp and a very flat torque curve, hoping for a peak of 600 ft/lbs. I was tempted to step up the duration on the cam, but the car is mainly for the street, and I still have to pass the sniffer.

John

TD.... if a roller 509 dosent make 500hp somone needs to find another hobby

Makes you feel really good about the tech guy at Pypes, doesn't it? If you know anything about engines and you work in the industry, how could you even ask that question? Look at the Hardware! graemlins/clonk.gif

I agree completely. If I can't get this over 600hp, I really should be looking for another hobby redface.gif

I'll fire of another note to Pypes explaining what I expect from the motor, but it does question the technical ability of their staff.

John

Here is the dyno chart for mine.
Torque HP

4000 499 380
4100 507 396
4200 516 413
4300 527 431
4400 541 453
4500 552 473
4600 563 493
4700 569 509
4800 573 524
4900 576 538
5000 578 551
5100 579 563
5200 578 573
5300 576 581
5400 573 589
5500 568 595
5600 563 600
5700 556 603
5800 550 607
5900 544 611
6000 537 613
6100 528 614
6200 519 613

This chart was open exhaust with water pump and was with an unported Holley Strip Dominator and a 950 HP. I since have added a ported Vic JR and 1000 HP. I also have the charts with mufflers from 3500 rpm up if anyone is interested. I will chassis dyno this combo in a couple of months.

TD509, Your motor should easily make over 600 H.P. but if i were you i'd use 1.7 rockers and drop the lift a little for street driving as it won't affect the power much.

69ttop502,

Thanks for showing those dyno numbers. Please do show the dyno number with the mufflers. smile.gif

Harold,

I went with the 1.75 Jesel rockers to maximize the lift and take advantage of the excellent flow of the AFR 315 CNC heads. At the same time, I didn't want to increase the duration due to smog requirements. With that in mind, I used the RT series lobes to increase the area under the curve. The lobes have roughly 172 duration @ 0.200". I know the higher ratio will be tougher on the valvetrain, but that's why I went with the Jesel SS rockers system, the Manton 7/16" pushrods, and the Crower HIPPO lifters. smile.gif The springs on these heads are set for 240 seat and over 600 on the nose with this lift.

Of course, the downside is the increase in maintenance. :rolleyes: But I can live with that. I could be wrong, nut I felt the higher lift could be used to good advantage with these heads.

My biggest concern right now is my fuel injectors, they're rated at 42 lbs, but if I end up making nuch more hp, I mught have to change them out for 50 lb ones.

John

You should be good with 42's at 630 HP. You can always raise the fuel pressure to 50-60 as well.

69ttop502, Thanks for the dyno curve. Those torque numbers are very impressive. Over 500 from 4000 to well past 6200. Gotta love those numbers! graemlins/hurray.gif

Doug F, thanks for the reasurrance. I've ran this combo on a few different dyno sims, they were all showing over 700hp. Found it hard to believe I'd miscalculated that much on the combo. With those numbers, I'm sure 50lb injectors would be in order. Nice to know I'm not going to be out another $400-500 on injectors. Can't believe how much I've spent already graemlins/clonk.gif

John

What are you using for an ECU? Do you have wideband O2?

Hi Doug,

I'm using Holleys C950 with Pro software and a wideband O2. Not sure about the O2 driver hardware, either the Tech Edge kit or buy the Innovate Technologies unit. Any preference?

John

I prefer a unit with the NTK sensor myself.

Doug,

I gues we're getting a little of the topic, but why the NTK sensor? It was my understanding that the Bosch LSU 4.2 had nearly the same response time and was just as rugged as the NTK. Is there something in their respective characteristics that I've overlooked? Haven't puchased the sensor or the hardware; do you have a recommendation or preference for the supporting electronics?

Thanks!

John

From what I know, the LSU does not really like lead whereas the NTK is much happier.

Look at what all of the measurement equipment use, the NTK.

The LSU should work ok, I just think the NTK is a lot more robust.

I would look at the FJO unit or the Holley unit (FJOracing.com).

The cost a bit more, but I think they are worth it.

You don't need a seperate datalogger that comes with some wideband units since you ECU already has that.

Doug,

Wow! What a site, and located right here in Winterpeg Canada. Looks like a very good price for a good controller. Will have to check what they want for the sensor. seems to me the NTK runs around $150 US the last time I checked.

Thanks for the site, I'll look into it!

John

That is a top notch controller. FJO makes an excellent product. Yes, the NTK runs around 150-200 US.

I made 671hp@5900 with a smaller 468 canfield 310cc enginge. Similar cam, 2000cfm TB etc.

Made my 3200lb car 9.96 ;)

godsend,

Thanks for the info. The dyno results you have, and from others that have a similar combo, makes me wonder if the 42lb injectors will be enough. The EA Pro software showed 714 hp, a couple of the other dyno softwares showed similar results. But I felt they were all too optimistic on HP/TQ. When I decided on all the parts for the build, I figured around 615 to 640hp. Now I'm not so sure.

godsnd could you post your results on the board?

Is there anyone else with a similar combo ( carbed or efi) or with enough BBC experience care to comment?

Thanks,
John

I only have Peak HP and TQ for that pull.

Without EFI/Alu heads i had full info.

Dropped TQ from 665ft/lbs to 650. Gained HP from 645 to 671.

Made 671hp @ 5900 and with carb 645 @6100rpm.

I saw alot perfomance gains. Better MPG, Alot better response, better 60:ier, lower ET, Higher traps.

42 seams to small. My 64lbs did it with small margin.

Some math,

Assuming 90% duty cycle
42 pph injector
.4 BSFC - 756 HP
.45 BSFC - 672 HP
.5 BSFC - 605 HP

42 pph injector at 60 psi = 49 pph

I think you can make it, but it might be close depending on real hp and real BSFC.

I'm running 50's on my new 491 and am hoping for 625 HP and room for 125 HP of dry nitrous. Will fine out!

Hey Doug,

How is the 496 EFI comming along? Heck, if you get yours finished before mine, I'll be able to use your fuel curves as a starting point! smile.gif

John

TD509EFI, we have a few things in common, we are both running tall deck EFI fat motors in a 79 camaro :cool: . I'm running a 540 with a F2 Procharger and 160 lb injectors. FWIW, I choose the Accel DFI and their wide band. Also running AFR 357's and Lemmon's headers, (2 1/4"-2 3/8" stepped tubes with 4 1/2" collector). I'm curious how you mounted the motor, header choice, and what you did to the steering linkage,(if anything)?

Rob

John,
Just have a few more parts to get. Time is in short supply and things are over budget of course :(

Realistically and hopefully it will be running by June. Have to see what I'm going to do for a rear. Right now Strange 60, more budget breaking...

Good to hear Doug, and I fully sympathize about the budget ( or lack thereof). Funny, I was starting to lean toward the Dana 60 as well.....budget...what budget? redface.gif Tried to email a reply to your mindspring account....returned "unknown recipient"

66rat, replied to your e-mail, but your antispam software sent it to "suspect mail"

John