Morbid Intentions

if I push 9PSI out of the base basel S-trim with an intercooler and methanol injection and P&P up my heads real good I have a couple questions...

can I do this on stock internals?

where will I be compared to a STOCK 03-04 cobra (not that there are any)
and where will I be compared to a STOCK 98+ LS1 (again not that there are any)
and where will I be compared to a STOCK C5 base model and a C5 ZO6...

comparing to others to get a feel for how much power I will be at about

2000GT4.6

At this point you would be better off running a set of blower specific camshafts rather than having the heads ported. You see great gains with a set of cams on a blown car, plus you get the cam sound (a nice bonus).

You can easily run 9-10 PSI on the stock shortblock. All you want to do is keep it under 440~ whp (i prefer 420 or so to have a saftey net). Its all in the tune though, a good tune and your fine, bad tune and the engine will let go.

Assuming you install the cams, and you already have a full exhaust, this should put you somewhere around 400 to 420 WHP (the shorties are really gonna hurt ya though). At this point, you would eat a stock 03 cobra, stock 98 ls1, and a stock LS1 equipped vette for breakfast.

Honestly, I don't think I would have to much if any problem with a LS2 vette either. MM&FF tested that 400 horsepower LS2 and only got a 12.59 out of it, with good ole evan driving (re: great driver). Any 400+ WHP GT should be ticking off the quarter mile alot faster than that.

Morbid Intentions

thanks 2KGT
as always straight to the point and knowing your stuff

orangedrp007

why are the long tube headers better than the shorties? pros and cons?

2000GT4.6

The LTs simply outperform the shorties by a country mile.

The real problem is the shorties are not true equal length, so you have differen't length exhaust paths for each cylinder. This results in problems with scavagning.

Note that midlenghts that are equal length perform just as well as LTs. Its all in getting the exhaust to have the least restriction and the best timing, so it hits that crossover pipe and scavanges. What this basically means is that each exhaust "puff" (cyl fire) crosses the midpipe before the next, causing a small vacum which sucks the next one along quicker. This reduces resistance and increases exhaust speed in the pipes and increases horsepower.

Edit: people get shorties because they are cheaper, easier to install, and pass emmssions in certian states where LTs will not.

mikev08826

1. Yes
2. Beating them (w/ stickys)
3 Beating them (w/ stickys)
4. Beating them (w/ stickys)

mikev08826

If you have money comming out of your ***, or if you do nothing all day but sit around palying w/ your *****...

Get the LT's

Lots of labor on install & changing the clutch

2000GT4.6

?

You will see virtually NO gains on a boltons only N/A GT with shorties, compared to a 15-20 WHP difference on the LTs.

They are not that bad to install. It is a bitch to remove them for something like the trans/clutch, but thats why you install a new one when you install the LTs. If you wear thru your clutch fast enough to make it nessicarry to regularly change it, you need a better clutch.

LTs are far and above worth the effort and cost compared to shorties, espically in a blown car. On my car alone I would guess the LTs are making an easy 15+ horsepower MORE than a set of shorites, and its only gonna be a wider and wider gap with more horsepower.

mikev08826

This is true. But they are a BITCH to install. It's not like your add CAI.

2000GT4.6

Shorties are not gonna be any fun either.

If your gonna be under there fighting getting the mainfolds off and new ones on, get the ones that will make a difference, or save your money and buy something else.

This is of course unless you plan on going FI (shorties are better than nothing then) or you really want to replace the stock manifolds but still pass smog in cali etc.