SouthFL.02.SS

Time to learn more stuff!

dug

iTrader: (10)

Yeah, I dunno. I have a feeling a high lift hydraulic is gonna cause a lot of headaches that can be avoided by going SR.

If those heads really flow that much the car is gonna make insane powah with over .600" lift cam.

Another thing, why not get a vette instead of a F-body? They handle way better with better brakes. Lighter too. Instead of blowing all your money on the motor, get a vette with a mild cam and headers.

SouthFL.02.SS

'98 LS1 Fbods are already around $7K. Totally within my parameters.

SouthFL.02.SS

Abother reason why the TRak intrigues me, is that the LSK lobes used on the intake supposedly come off the seat softer than XE-R lobes, as Patrick has pointed out in other posts, but surpass XE-R in the upper lift ranges in aggressiveness.

Again, does this provide sufficient reduction of valvetrain stress for sustained high rpm use? I don't know.

eamador11

Please post results. Everyone says 225s are too big for a 346...your head swap will confirm if it is. congrats..your the guinea pig!

z-ya

iTrader: (1)

I like it and think a set of morel lifters would be a good addition to that combo.Please
don't just port match the intake , split the ***** apart and address the issues inside also.Best of luck.

DavidNJ

What is the application? Drag racing? Road racing? Pink Slips? Show? Daily commute?

What is the service interval? 150k miles between oil changes? Valve springs once/year? Tear down after every race with new valves, springs, pistons, pins?

Does it have to pass an emissions test? Automatic or manual?

For a track day beater, too much emphasis on power.

SouthFL.02.SS

I've been told it's too much power over and over, and I guess I won't learn until I run off a threshold break zone into a wall because I can't stop in time, but damnit, this next project is about having fun, and experimenting with what's new out there.

Application is: car to have fun with, let's explore these new heads and cam options available. It will see a track day or two per year. It will cruise streets on weekends and see a 1/4 mile run every once in a blue moon.

Service interval: Valve springs about every 18 months (checked every 6 months max).
Tear down: none (until sh*t breaks).
Stock bottom end until it breaks.

M6, no emissions.

dolf

im interested to see how she does. i was thinking the same setup in my zo6 but with a g5x3 and 215 heads. good luck

LS1 BU

iTrader: (13)

Sound like a great setup. Should be a blast on the street as well as track duty.

777

iTrader: (21)

Well get to it. I'm ready to see what's going to happen.

DavidNJ

I guess what I'm saying is you want the smallest heads...the 215s from ET, or 205s from AFR or Dart. Then use the 78mm TB. Stock MAF. A good double spring.

The advantage from the LSK wouldn't be necessary. However, I would consider solid lifters for a maintenance reasons. And adjustable rockers. The street solid profile is between an XER and LSK in lift for a specified .050 duration. Then I would keep it small, maybe 218/224 (or even 224/230, which seat time comparable to a 210/216 hydralulic). Maybe a good header with merge collector.

What you want is controllablity, not power.

Another thing to keep in mind, track days are MUCH more expensive than drag racing or street driving. All sorts of things break. Tires, brakes (including rotors) wear out at an alarming pace. And the race versions are expensive.

Stresses are much higher and in four directions. Few drag cars maintain more than 1g acceleration for more than a few seconds. On a road course with race tires you will be under 1g braking and cornering all the time.

Plus the damage. Every now and then a drag car crashes. Some with serious or fatal injuries. However, road racing tracks eat cars with big damage all the time. And one person's spin can eat several cars. Having your car brought back from a track in Timbuktu can cost more than the cam.

Here's a question for Tony and Craig/Cary...who has the best throttle response at partial throttle openings? Different from all these flow bench comparions.

And a question for Patrick G...should this be an SD tune for throttle response?

MeentSS02

iTrader: (11)

I'll chime in on this part...running a big cam like he is thinking about, I'd recommend the SD tune to get the most out of it without the headaches of tuning for the MAF (reversion being the biggest problem - MAFs don't care which way the air blows through them).

With the way our PCMs work, SD is a good way to go on these cars for almost any setup (excluding those that have strict emissions standards).

SouthFL.02.SS

I'm aware of the alarming rate at which rotors, pads, tires wear. I expect to go through rotors and pads every outing/ every other outing.
As for run-offs, I saw at least a half dozen guys hit barriers at the race school I attended, so the threat of carnage is always there.
I won't overlook suspension, braking, cooling and safety items.

You are correct DavidNJ, fluid throttle response is something I have totally overlooked. Less aggressive lobes come on strong upper mid/high in the rev range, but then again, that's what most RR cams are ground on, so there's something to ponder. Hmm.

MeentSS02

iTrader: (11)

Oh, and to add to my SD comment above, I'd recommend steering towards a 99+ f-body. Tuning on a '98 is a PITA, and even the tuning companies really don't put much effort into software for the '98s partly due to the lack of demand, partly because of how GM made them.

That's something else to keep in mind.

DavidNJ

The less aggressive lobes...actually lower duration, not less aggressive, will give you more mid-range. More DCR from the smaller intake. Less overlap. Later opening on the exhaust. At higher speeds it will run out of breath.

My guess is you should shoot for a rev range between 3500-6200. This car could be faster (lower lap times) than than one with more duration, bigger ports, bigger TB.

The broad rev range with crisp and controllable throttle response will let you come out of the corners harder, control the yaw angle with the throttle, and stretch a gear at the end of a straight or stay in a higher gear going into some turns that will keep you concentrating on driving not shifting.

Shifting caused by having the wrong ratios in the first place (ideally, all of the ratios are picked to avoid unnecessary or inappropriate shifting.)

TroubledWine3

iTrader: (3)

Could you elaborate on that?

MeentSS02

iTrader: (11)

In their infinite wisdom, GM decided to make the '98 PCMs different than the later years. I'm not sure on the specifics, but it isn't as friendly to reverse engineer for tuning software. I think it is even limited in its capabilities in that aspect (which is why no one has produced a 2 or 3 bar MAP capability for these cars, but they are working on it). Basically, if you run an SD tune, you really don't want to be stuck with the lower resolution secondary VE table that 98, 99, and 00 PCMs have in them (running in SD means it will reference this table instead of the primary VE table).

With 99-00 PCMs, you can just change over to an 01-02 operating system, and your problem is solved. '01-'02 cars only have a primary VE table.

With the 98 PCM, you'd basically have to put a new PCM in because everything is wired differently in that one...you'd basically be rewiring your whole car (not really an option) just to run a later model year PCM.

FYI, in SD mode, the VE table becomes the primary reference table to figure out how much fuel to add under different driving conditions. Less resolution = less robust tune.

Cliffs notes: the 1998 F-body PCM is the red-headed, bastard, kicked to the curb step-child of the LS1 F-body PCMs. FWIW, I'm pretty sure the 1997-98 Vette PCMs are the same way.

SouthFL.02.SS

By the way, throttle respnonse is much crisper with 90mm TB's. The stock TB response is slush in comparison.

8banger

iTrader: (16)

That setup sounds incredible. Go for it!