boostd4

I'm starting over with my head/cam combo. Right now I have Stage 3 GTP ported 5.3L heads and a 226/226 112lsa cam (AFAIK). It's got a nice lope at idle and I want something more stealthy that can get better fuel economy as well.

I plan to have PatG spec me a cam and here is where I ran into a slight issue. I'm also having my 5.3 heads re-done - new valve job, blending, bowlwork, etc. I read on here that the valve job/blending, etc, can very depending on what cam you plan to use - so I'd need to know my cam specs first...

Conversely, I need to fill out a sheet for PatG with my head's flow numbers at different lifts... for that, I'd need to have my head specs first...

So which do I do first?

SOMbitch

iTrader: (8)

Get your heads worked and flowed then contact PG. Matching your heads to your cam is back asswards......

fatmat80

^^^what he said altough i am not that big on the 5.3 heads..

Lopoetve

iTrader: (1)

Does that advice stand in general? I'm doing a 383 build and trying to figure out which was is normally done - pick the cam, and then find heads to match, or pick some heads that work well for your engine, and then match the cam to those...?

From what I've seen in the FAQ - heads are $$, cam is cheap, so switching cams isn't that big a deal...

boostd4

I'm not partial to them in particular, but they do REALLY well with my setup:

Stock LS1 shortblock
Stage 3 GTP 5.3L heads
TSP 225/225 112 LSA cam
Long tubes, catless 2.5" true duals
LS6 intake, ported stock TB, CAI

428whp, 410wtq. 350wtq from 3000-6300rpm. Not too shabby for a small cam.

fatmat80

They might do pretty well but im sure some stage 3 243s would do better.. Your numbers are respectable, and if i had those heads i would be satisfied with those numbers, its just here in my area people are not seing those numbers nor are they running good times at the track..

boostd4

The car has gone 11.6@123mph on this setup, though it dyno'd 415/390 the day before. That was on 19" street tires with a 1.85 sixty.

I'm happy with the speed and power, I'm not as happy with the drivability and lack of traction on the street.

To solve this, I'll be swapping cams to something more civil at idle/cruise, and I bought some 18x10" Enkei RPF1's (19lbs rear, 16lbs front) which will get 285/35/18 Nitto DRs.

Since I'd need a cage for faster than 11.50, that is my goal. I'd like to drop down in cam size, but step up in traction and low/midrange torque. That should sit me solidly around the 11.50 mark so I can have fun at the strip without being booted.

Then I'll throw a 100 shot on top of it and see if I can't break 10's <crossing fingers>

hammertime

iTrader: (1)

If your goal is to go roughly .1 faster, why take the heads off for further work? By adding a stickier tire, you should be able to reach your goal with the power you have now. Pat can spec a cam for you that is less rowdy and makes as much or more power.

RARON455

iTrader: (35)

I am kinda partial to them,,,,,,,,work well for me,

If I was in your shoes, I would decide what heads I was using, and then give Geoff Skinner a call at Engine Power Systems, He specced my cam out that I have, Super guy, and Very Very Very good, he will put you right where you need to be.
You will need to know your engine Info, compression, Head cc, etc. He may be able to help you with that if you are not sure.

Patrick G

iTrader: (14)

Definitely do the heads first and choose your cam and pushrods last.

matt510

iTrader: (9)

Yes Heads first then pick the cam.

boostd4

The car dropped a valve earlier in the year. I didn't take the heads off then and the dyno numbers and track numbers came after I fixed it. I'd still like to take everything apart for peace of mind, and I have a hook-up with Opel Engineering. Also, as part of my driveability quest, I'd like to have less valvetrain chatter. My lifters have 100k on them and are original '98 spec. I'm not sure if the bent pushrod (from the dropped valve) did any damage to that lifter but I'd like to change them all anyway. Plus doing all of this has a side benefit of not worrying about the lifters falling when I swap the cam.

I'm expecting to lose ~20whp by going to a cam that has stock like idle. I might gain 5-10whp from the valve job and headwork but I'll still be down at least 10whp. Adding the stickier tires should put me right where I want to be, if not a little faster.

It's not really about dollar-to-horsepower for me. The car is nearly perfect and it's about getting it to be that last 5% where I want it to be.

02*C5

iTrader: (1)

I have done all my cams through Ed Curtis and he always pics the cam and then does the heads to the cam specs maybe he is wrong but apparently he is very good at being wrong.

boostd4

That's where my confusion came from.

At any rate, I suppose if one KNOWS who will be spec'ing the cam, they should ask that person

SOMbitch

iTrader: (8)

Just get the best heads you can afford and match the rest for most satisfactory results.

I had a shot at some used ETP's and instead sold my LS6 IM and picked up a used FAST 90/90 and went with ARH headers instead of PS's. I guarantee I would be leaps and bounds ahead with the ETP's over My ported 5.3's had I just kept the original bolt ons and just spent that $$$ on the better heads ..... NO DOUBT IN MY MIND!!!! This is no knock on FAST or ARH but heads are just a much bigger factor in your power potential IMO......

boostd4

Point taken. The point of this thread wasn't whether or not I should get different heads. I never had any intention of changing them. I was only asking if I should have the headwork tailored to the cam, or the cam tailored to the headwork.

stoverz28

iTrader: (8)

What is it that you don't like about how your current cam drives?

I would think a 226/226 with a decent tune would drive great on the street and make plenty of midrange. Either way you can't go wrong with a Pat G cam.

99blancoSS

iTrader: (115)

You consider the whole combination together. You decide what your goals are and then budget for it as best you can. We can assist you with this, pm me if your interested.

boostd4

I'm a rattle/squeak/NVH ****. The car holds idle (900-950rpm) just fine, never stalls, etc, but I don't like the lope/stumble at idle. It's a very light car (2800lb RX7) so the mix of 112lsa/lope/stumble/higher compression makes the car shake pretty good. I'm going to spend a good 30-40 hours sound deadenning the whole car for a small stereo system this spring and I hate that loosey-goosey sounding interiors. I'd hate to have the cam rattle the stuff all loose again and my work was wasted (to some extent).

Not to mention it gets about 8mpg less than other stock-ish setups in the same chassis.

It was tuned by Jim Moran @ Speed Inc, before anyone says it's the tune... not to say he's not infallible, but it's definitely not a mail order or "hack" tune.

Nitroused383

iTrader: (10)

Raise the idle to 1000 or 1100 rpm that should smooth it out. I wouldn't think a 226/226 cam on a 112 would lope much at all. Unless you have a really loud free flowing muffler. There is quite a bit of tuning stuff you can do to smooth the lope out as much as possible.