Vetal

iTrader: (3)

Guy here had 406whp from LQ4 (364ci) with CR 9.5:1 through an auto. Gained 40whp from cam
https://ls1tech.com/forums/dynamometer-results-comparisons/827220-hms-dyno-results-f13-cam-only-44rwhp.html

Paint_It_Black

iTrader: (1)

Yes a cam is going to gain you power, with the low compression ratio, you'll want a new cam to close the intake valve sooner than normal to increase dynamic compression, and longer duration than a 214. I don't have the computer with my spreadsheets on, so I can't give you a ballpark on a cam just now. I'll bookmark this and come back to it later.

Marc 85Z28

iTrader: (8)

That may be his case, but it won't be yours. That gain was comparing the larger cam vs a stock cam. You already have an aftermarket cam. Granted, it may be small, but it sure makes more power than a stock cam would. You might see half of what he did if the tuning is spot on. Which brings me to the BBK throttle body. Getting the tune right with one of those is difficult, and gets worse the more aggressive the engine gets.

Vetal

iTrader: (3)

Wow! Found this thread where Patrick G dynoed 347ci 9.2:1 motor at 425 and 449whp (DynoJet #'s, that would be like 385/410 on Mustang)
https://ls1tech.com/forums/dynamometer-results-comparisons/857261-ported-fast-90-vs-ls6-dyno-comparison.html#post8654072

Patrick G

iTrader: (14)

You couldn't be more wrong. You can make big power on low compression. Did you ever see a Busch Cup motor with 9.0:1 and 358 cubic inches make 650 hp? How'd they do it? Airflow, rpm, and proper cam selection. Lower compression demands that you work your valve events a little different. My last engine was a 9.2:1 346 with AFR 225 heads, a 224/230 113LSA cam, and FAST intake. It made in the 440-450 rwhp range on 87 octane. This 383 is just a cam swap away from a big power increase. Here's a dyno sheet of my 87 octane sipping 346 making 449 rwhp on the dyno. The lower numbers are with an LS6 intake.

quintenk

iTrader: (1)

Depending on what head gasket your running, going to a thinner head gasket can get you around half a point of compression. or if you have a thinner gasket in now, mill the haeds and jsut run the stock thickness head gasket when you do the turbo...
Just an idea.

Marc 85Z28

iTrader: (8)

Fine. I'll admit that I'm wrong when you spec the man a cam and you can prove me wrong. Until then, I'll chew on your horrendous comparison between an all out race engine with millions of hours of R&D to a street minded 383" LS1 built for boost. A 650HP Busch engine... yeah, it's just airflow, RPM, and proper cam selection

Vetal

iTrader: (3)

Thank you Patrick for clarifying this

N4cer

iTrader: (11)

Spray the ***** off it for now!

Patrick G

iTrader: (14)

The NSACAR reference was to illustrate that you don't need high compression to make big power. After that, I posted a real world dyno sheet of a 9.2:1 346 LS1 that made 449 rwhp sipping 87 octane. This was a budget motor and much more representative of what people on this board could build. Did you not see the dyno sheet?

The OP's cam selection was not right for his motor. A cam with proper valve events will make a huge difference. You will probably get lots more help on the board if you check your ego at the door and listen to people who are doing things that you say cannot be done.

Vetal

iTrader: (3)

Thanx once again, I'll do my reading and buy some used 232/238 or similar as a temp solution now. When turbo will be set up, I'll ask you to spec me the cam that will suit it the best
Thanx!

Marc 85Z28

iTrader: (8)

I saw that dyno graph. What did it do corrected to SAE? And was this the same dyno that you tested the 500rwhp combo on? You know, the one with the "malfunctioning" weather station

Of course his cam was all wrong. It was a blower build, not an aggressive naturally aspirated setup. So with the "right" cam in it and good tuning, what do you honestly think that engine would pick up? Mind you he's not running AFR 225 heads, nor a FAST intake here like your example.

Patrick G

iTrader: (14)

Not the same dyno as the one with the jacked up weather station. This one spits out repeatable numbers and corrects for conditions properly.

With the right cam and everything else that's wrong with his setup, he should be able to be in the 390-400 rwhp range on the same dyno with a new cam and a proper tune.

Vetal

iTrader: (3)

What else is wrong except cam and tune?

BYE RICE

iTrader: (2)

I saw your link in the Pat g "500 HP" thread.
I have a 383 also.Pat spec'd my cam..You say you're running 67 cc heads..What are the valve relief sizes on your pistons...My 383 came with -7 cc.
I'm running a 62 cc ported LR4 head.

Irocss85

iTrader: (1)

I say go with a used cam in the mid 230's also. you could go larger duration if your willing to put up with it daily driving. my little LT1 383 had 10.8 cr, and 233/239 cam. that cam was too docile for my taste. very tame to drive around. it performed well at the track (11.69) and its no stripper car either. anyways, long story short, your heads are far superior to my home ported LT1 castings. and the 1.2'ish compression difference isnt even close to making up the power diff. between an LS1 with good heads, and an LT1 with home ported heads. so if your car was in that ballpark, even with the low compression, you should be able to outperform my car. oh, my trap speeds were 113-114 but mines a stalled auto. if I had a t56 prolly would have been more like 117-118mph.

crzytown69

iTrader: (17)

cam is way to small that motor needs to breath

Vetal

iTrader: (3)

bye rice: I only know this about my pistons: "-0.155 dish"


thanks to everybody, I hope turbo will be installed soon, but I'm still thinking about changing to "larger" cam.
BTW, I finally took it to timed track, it made 13.0@109mph with ~30hp of nitrous

Irocss85

iTrader: (1)

what ws the 60ft? sticks are very hard to launch and will cost you ALOT in terms of E.T. but usually the mph is still high, indicating good HP. your mph is def. really low. most stock LS1's with headers, cai and exh. will do what your car did. your tune might be totally jacked up too. fear not, you got the major components to go really fast, you just need to make a decision to make it a better matching set. either way bigger cam for now, or just live with it and finish the turbo setup.

Vetal

iTrader: (3)

60ft was consistent in 2.05-2.1. Rwds did not get much better 60fts.
Well that's the problem, that I don't see a problem in my setup, except cam (and low-comp, of course). Tuning at WOT is pretty OK, 26 degrees, AFR is near 12.5:1
So it must be smth. in the hardware...