spyonu2007

Greetings from Central Illinois.

I recently went to have my car dyno tuned at a shop called Straighline Performance. They did an excellent job, but it would seem I have an issue with my cam being too small & my heads not flowing enough.

My heads are hogged out stockers. Ported and polished, but still using the stock valves. The bottom end is a zero decked forged 383ci, that seems to make good power all over up until the 4880, where power starts to roll off pretty fast.

The cam I have in there is a CC305, with a set of 1.6rr's.
I knew from the get go that this cam was probably going to be too small, but I was looking to cut some corners and costs so I ran with it. Im in a better spot now so changing the cam isnt that big of a deal, but Im not entirely sure of what I really should go with.

As it stands with the way the car runs now, I have a mountain of torque when ever I nail it. It makes somewhere around 350lb or torque at 2500rpms. Torque starts to roll off at 4000rpm, and really nose dives at 4880.
Hp climbs nice and steady from when he punches it up to about 4880 as well, where it really flatlines and falls off hard at 6200.

I read about how cam companies can get me a custom grind, and that some of the largest cams for a stock lt1 can be somewhat more tamed by additional cubes.

Compression is supposed to be 11.3:1.
I have hooker ceramic coated longtubes, a flowmaster exhaust, a walbro 255lbh pump, an aeromotive afpr, and 32lb injectors. Im running stock fuel pressure.

Currently my intake manifold is unported save for the holes being hogged out to accomidate the bbk twin 58mm throttle body.
Im running a stock maf, a morroso cold air intake etc.

The best numbers produced that day were 365whp and 389lb of torque through a mustang dyno. This is a manual transmission car.


Im not sure if just swapping out the cam will do it, but when my heads were done they were compared to a set of LE2, both in bowl work and porting.

Any guidance would be appreciated
Nice site btw.

Here is my preliminary dyno graph and then one with some fuel pulled out.

ABA383

iTrader: (1)

Well, who did the porting on the heads? This can be a tricky area where hogged out can be a problem...I love smaller cams even with 383s...I'm an A4 with an 11.2:1 383 with ported stock heads with 2.00/1.56 valves...I run a 226/234 cam considered very weenie by most and ran the times in my sig with a Vig 3600 and 4.10s (28" ET radial)...I agree that your cam is a bit small for your application, but I'm also concerned with who did the heads and how they were done...My heads were done in 1995 by Lingenfelter and re-ported in 2005 by Eric Bradby (E.B. Porting). FWIW I make 375 rwhp on a calibrated Mustang Dyno and my times/mph are in my sig...Remember that the Mustang Dyno will read less hp than a DynoJet...I think for your mods even with an M6 your about right...I'd look at a cam in the 220/230 range .570" lift...I went with a middle of the road 111 lsa, but you can tighten it up a hair...I also couldn't tell but it looks like your A/F was good, too...I run mine at a safe 12.8:1...

--Alan

spyonu2007

A local porting guru. He goes by the name of portholio, or "Porting by Dolan".
All the combustion chambers cc'd out within .01cc's. I can't provide you flow numbers, though they were flow benched before and after, I just don't have the results on this particular computer, but I can get that information tomorrow.

Thanks for the response, I could go with a big off the shelf cam, but Id prefer to get the best fit for what Iv got. Id love to break 400whp on a mustang dyno.

My timing is at 32 degrees. The tuner felt that was about as much as he was comfortable with on pump gas. It may very well be able to be ran leaner, but I havent dinked with it much. It runs pretty well, but I would prefer to see that hp line from 1000-4700 keep the same angle all the way up to 6500.

The torque feels good.