LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

242/250 112, stockish heads dyno

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Old Feb 7, 2009 | 05:07 PM
  #1  
Zigroid's Avatar
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From: Stroudsburg, PA
242/250 112, stockish heads dyno

I put my car on the mustang dyno at PSI motorsports to see what she puts down as a baseline. I ended up making 365 rwhp @ 6400 rpm and 355 rwtq @ 4500 rpm. I have a stock airbox still so I pulled that and dynoed it again. it put down 389 rwhp @ 6400 and 366 rwtq @ 4500 rpm. amazing the stock airbox is costing me 25 rwhp.

dyno vid: http://videos.streetfire.net/video/P...ird_634625.htm
(excuse the guy recording, he is one of a kind haha)

crappy cell phone pic of dyno graph:
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im just gonna quick copy and paste my mods list from my fquick site.

Performance:
Ed Curtis specced custom cam. 242/250 112 lsa, just under .600" lift
3 piece hardened pushrods
Comp cams pro magnum 1.6:1 roller rockers
7/16" rocker studs
PAC1518 valve springs
Trickflow guideplates
stock heads/valves, minor bowl work, good valve job
MrGasket .026" thick head gaskets
~11:1 compression ratio
BBK 58mm throttle body
meziere electric water pump
rebuilt stock bottom end with:
new main, rod and cam bearings
ARP rod bolts
hastings piston rings

Pacesetter long tube headers
Pacesetter Y-pipe with dual electric cutouts (not used on the dyno)
Hooker catback

Suspension/Chassis:
135,000 mile stock other than UMI tubular front K-member

Drivetrain:
Locally built 4L60E transmission
Yank Pro Thruster 4000 rpm stall torque converter
4.11s will go in to replace the stock 2.73s once its running

Electronics:
PCM tune by Ion @ madz28

overall I am VERY VERY pleased with how it runs. I was asked what I thought it was going to make before I dynoed it I said 300-310 rwhp. you can imagine the shock I was in when I was told i just laid down 365 rwhp.

and finally some pics of the fun:
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oh and I would like to say thank you to everyone who told me it was a mismatched combination, it would never idle, it would peak power too high, it wouldn't operate power brakes, it would be impossible to tune. you made my day even more enjoyable knowing I proved so many wrong. most of these people don't post regularly on this site, but they read it. thanks guys
Old Feb 7, 2009 | 05:15 PM
  #2  
slowride94z's Avatar
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if you would have lowered the head lights it would have been good for another 10 hp at least


good pulls
Old Feb 7, 2009 | 06:09 PM
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Good job man. I am trying to get close to 400rwhp on my stock 350 rebuild. Still trying to figure out the cam. Is that with the stock rear end.
Old Feb 7, 2009 | 06:50 PM
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Don 97 SS's Avatar
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Those are impressive numbers. I am sure you are pleased.
Old Feb 7, 2009 | 08:23 PM
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So is it streetable? ive been looking at a similar combo.... hows the brakes? any bucking or bogging in your bottom end? is the tune spot on? It sounds good
Old Feb 7, 2009 | 08:50 PM
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nice cam numbers. I cannot believe the stock airbox cost that kind of power either - incredible.
Old Feb 7, 2009 | 10:22 PM
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Zigroid's Avatar
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Originally Posted by BLKOUTZ28
Good job man. I am trying to get close to 400rwhp on my stock 350 rebuild. Still trying to figure out the cam. Is that with the stock rear end.
stock rear, 2.73s.
Originally Posted by Don 97 SS
Those are impressive numbers. I am sure you are pleased.
yes, very. I was guessing 300-310 rwhp. I haven't really been able to feel how quick it really is with the 2.73s. 1st gear just spins, 2nd gear lasts till ~120. hard to tell how it pulls when one gear lasts 60 mph lol.
Originally Posted by briggsbuilder
So is it streetable? ive been looking at a similar combo.... hows the brakes? any bucking or bogging in your bottom end? is the tune spot on? It sounds good
Its very streetable. it has a hint of bucking at 1500 rpm when the converter locks up. the brakes arent bad, if I pump them while coasting down at an idle they will start to fade away just a little. my bottom end is fine, it will go up a steep hill in 3rd at a little under 2000 rpm which is around 55 mph with ease. in OD at 1500 rpm it will start to act up if I keep giving it gas and eventually unlock the converter before it gets annoying.
the tune is good but I am running out of fuel on the top end. with the stock airbox on I saw a tad under 14:1 A/F. with the airbox off it hit 14.6 at the end of the pull slowly leaning out. I am running stock injectors and I am sure they are maxxed out. I figured stock injectors would be OK but I really was not anticipating making this much power.
Originally Posted by SS MPSTR
nice cam numbers. I cannot believe the stock airbox cost that kind of power either - incredible.
yes that was the shocker of the day, no one would have guessed until they got a real good look at just how restrictive the stock airbox looks.
Old Feb 8, 2009 | 08:31 AM
  #8  
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Very nice That torque curve looks strong for such a huge cam on a stockish-headed 350.
Are you considering ported heads, or are you happy with it as-is?
Old Feb 8, 2009 | 09:08 AM
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Now THAT is pretty damn cool. Makes me think I'm going to have to put a little more thought into what cam I'll try next. Good job!!
Old Feb 8, 2009 | 09:20 AM
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Originally Posted by James Montigny
Very nice That torque curve looks strong for such a huge cam on a stockish-headed 350.
Are you considering ported heads, or are you happy with it as-is?
My next build will be something pretty radical. I have wanted to do a solid roller 383 with converted SBC heads and a single plane intake for a while, similar to what fastfatboy is running. For the time being I am just going to fine tune this setup and save some cash for the next build. So long as it runs 11s at the track I will consider this setup a success.
Originally Posted by Z-RATED94
Now THAT is pretty damn cool. Makes me think I'm going to have to put a little more thought into what cam I'll try next. Good job!!
Dont get me wrong this setup runs great but if I had a set of ported heads I would not want a cam this big. the reason this performs so well up top is because it is over cammed. I am certain with ported heads it would push my peak hp up past 7000 rpm, the stock heads are restricting it enough that it doesnt go that high but still makes good power.
Old Feb 8, 2009 | 09:27 AM
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Kevin Blown 95 TA's Avatar
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Not sure I follow your logic. I would think you would go with more lift and less duration for stockish heads/lower rpm and avoid the low end reversion that all that duration gets you.
Old Feb 8, 2009 | 08:18 PM
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I wanted to shift the power peak as high as I could with no concern for driveability but without having to shift over 7000 rpm.
Old Feb 8, 2009 | 10:27 PM
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Zig, I understand your point about not going to big with a cam if you have some decent heads, and why you chose that cam for your application.
My car sees only 500 miles a year. It has some good heads and needs a cam that can make more power some day. Your results are nice to see and I'll have to seek some advice for a healthy size cam that is tweaked towards the nitrous a bit. LE has already made a suggestion that makes sense and wouldn't hurt the NA #s too much.
Old Feb 8, 2009 | 10:35 PM
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So, where is the original thread to this?

Also, seems to run quite well judging from the burnouts.
Old Feb 9, 2009 | 08:48 PM
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i said this on ls1tech, you need a LS lid/ FTRA or SSRA setup. think the 25rwhp gains proves that.

I am curious to see what your heads would flow. I saw the pics of them but after what amazing f ing power they put down it makew me want to know even more.

but again, nice setup.



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