nskyline34

iTrader: (2)

Car made 487 yesterday and I was really aiming for 500 - any ideas on how to get there and where I went wrong?? (NA no spray, that's later lol)

Callaway intake
100mm MAF
NW 102
Fast 102 - port matched to the heads

56# injectors

OE rotating assy
OE compression

PRC stage 2.5 heads
TR55's

288/291 .605/.610 111LSA cam
Johnson short travels @ .025" to .030" preload
Yella Terra Roller rockers
3/8" pushrods

1-3/4" LT's
high flow catted X
Borla stingers

Under drive pulley


graph was basically done at 6900-7000

Can anyone help me with why I didnt get pushed over the top?

Engine was at 25* total timing too

At basically sealevel on a 50* day in a shop/shaded dyno bay

shadowfirep

you could try two things: slightly higher compression pistons might help some, or you could take it to another dyno. Most dynos are different and will spit out different numbers. You could always shop around until you find the graph you want. What really matters is how the car feels and performs on the street/strip

427zm

iTrader: (9)

Mill your heads, replace the SS valves that come PRC 2.5's with some turned down LS3 valves and you'll be there IMO. Also, there no mention of what clutch you're running. Lighter clutch and flywheel will make a difference in what power you push through the tires.

00SlvrSS

1 7/8 inch longtubes. You'd be surprised what an 1/8" can do and bumping up the compression. Only thing is you could've had that make with some flat tops and a little more rigid bottom end to handle it a little better. Along with a colder plug and a bump in timing you got it. Nice numbers though.

427zm

iTrader: (9)

Didn't notice the 13/4 headers, yes move to 17/8 and that'll get you a few more across the entire curve.

nskyline34

iTrader: (2)

I'm not opposed to the valves - but why do you think that'd do it?

Wonder if the roller rockers hurt it too?

Clutch is a 18lb flywheel and the clutch is a 9" unit. Overall clutch/pressure plate setup weighs the same as stock but the small diameter helps the moment of inertia by about 20%, then add the lighter FW.

nskyline34

iTrader: (2)

I would bump compression but I can't without PTV getting too snug.

I'm going to do a forged rotating assy in a bit (once I get it to run right lol) and I will bump compression to about 11.5 or so and I can turn it to 7200+

I was worried that 1-7/8 might make a diff... Wonder if I can just get the LTs and have them bolt upto my current X-pipe...?

nskyline34

iTrader: (2)

I just don't understand how those who spend less and do less get 510 or even 520 unless they Dyno is looser than a $2 ***** lol

Bummed/bitter

427zm

iTrader: (9)

Lightening the value train on the top side is always a good thing... More stability, easier on parts, and allows you to spin it higher, along with longer peak torque carry. All these things equate to power. Yes, the yellow Terra's aren't doing you any favors as the stock rockers are about the lightest most durable rocker still to this day on the market. Add a trunnion kit to the stickers and you're set.

427zm

iTrader: (9)

Not sure who's spending less and NA getting 500rw out of an LS1. Truthfully, this is the highest number I've seen with PRC 2.5's! They aren't the best head out for the 346 or 364. Now, bang for the buck, the PRC as cast 225's with light valves, or the TFS as cast 220's put down the power while still being cost effective. I by no means am knocking PRC's work on stock heads... As I'm running stock LS7's ported by PRC on their 265 program and they flat out perform!

LLLosingit

iTrader: (4)

Couple bags of ice on the intake might have pushed you there lol. Not sure why people are so stuck on dyno numbers when how it goes down the road is what really matters. Peak dyno HP doesn't mean diddly just bragging rights compared to real world performance.

nskyline34

iTrader: (2)

Thank you, definitely the highest number I've seen on a 'stock casting' but I mean with spending $1k on short travel lifters, engineering to remove pushrod flex, and then the roller rockers was a trade off - weight for the lower friction on the valve stem - and stability for road racing events too.

nskyline34

iTrader: (2)

Motor will be good on the street as its about 370ft-lb - 420ft-lb from 3500-6500 rpm it's def pretty flat. But at the end of the day - coming onto the straight stretch, HP wins! Lol

BUT I understand what you're getting at, I focused on a number in my last build and ruined it. This one was 500hp AND drivable (in the opposite order tho)

thunderstruck507

iTrader: (18)

Not sure what those cam specs come out to at .050" but I'm surprised you made as much as you did with those heads, that compression, and the smaller headers.

I'm assuming the PRC heads are the 243 castings?

nskyline34

iTrader: (2)

Yes they are the 243 heads

Cam is 236/241 @ .050 IIRC

Forged bottom end is coming in fall so I will raise compression then on it. Was trying hard to hit it with OE short block and just ported heads by watching the details....

thunderstruck507

iTrader: (18)

I would be pretty happy if I were you. A lot of aftermarket casting head cars don't get where you are.

nskyline34

iTrader: (2)

Don't get me wrong I'm definitely stoked about it for that reason - just curious as to what I could e done better. I didn't just toss parts together to get to this, but I did come up short of the goal. I figured I would ask if anyone knows what I could've done better... Sounds like rockers and headers are the consensus

North*power

iTrader: (1)

Easiest way to get closer without totally ripping into the car again would be 1 7/8 Headers and an electric waterpump. What kind of gas are you running? 93 I'm guessing. Did you degree the cam when it was installed? Turned down LS3 valves will help to lighten the top end and give more valve stability, especially if you're going to road race, but as for actual HP gains it's negligible. I've also heard that turning them down a lot can weaken the valve too much.
Very impressive numbers none the less. Do you have a graph you could post?

john stewart

1 7/8s would help and why only 25*? would try 28*-29*

thunderstruck507

iTrader: (18)

electric water pump is another good idea

my car made fastest passes with 27.5* timing on 91 no ethanol at 12.8 afr