ittybittyfds

So i know that there are tons of Intake threads all over this forum and others. there in lies my problem. I did do research but because there is so much old threads its hard fro me to filter through them to see whats relevant.
I recently bought a 98 convertible Vette. I must say that I think she is beautiful and probably has not seen any weather elements. She was mint and only has 50,000 miles. The only aftermarket part I recognized was the Blackwing CAI. I didn't think it had any exhaust because of how quiet it was and I thought the wheels were stock. I was wrong on both. The wheels are from a 02 vette. a few days after i bought the car i took it to Corvette Carlisle and had the guys from B&B install a Bullet System and X-pipe. When they went to do the install They told me that the vet had a X-Pipe and a Z06 Titanium exhaust system. So i scratched the X-pipe but still went with the Bullet System. It was 2 quiet for me. Anyways I have a couple of questions i would like your feedback on.

1. Is there any way for me to determine if the Intake is the stock LS1 intake?
2. I am considering doing a Intake swap however I am confused about the Fast 90 or the Fast 92. If I understand correctly the number indicates the throttle body size? if the stock throttle body was 75 would a change to a 90mm or larger require a tune? or Would I be better off going with the BBK SSI with a 85MM TB?
3. What exactly is a SpinFast Fast intake and are they still obtainable? if I read the posts the Spinfast is just a ported Fast.
4. I plan on adding Long tubes as well to improve the low end torque at the same time of a intake swap. with the Headers and Intake, is the stock PCM smart enough to auto learn or is a tune required?

TPIS says that the Fast intake is meant for higher horsepower LS engines and i would loose low end torque but i would gain HP in the MID-Upper RPM range.

RedZMonte

LT headers will make the exhaust louder... BTW make sure you get thoes Ti Mufflers back, they are desirable and worth 300-400 bux and you might want to swap back someday (Alot of guys Do)

I would wait on the FAST intake and see if you have a 01+ LS1/LS6 intake. there should be a part number molded into the intake on the
side. that number is what will tell us if the intake is the new or old style. If you go with a FAST intake then alot of guys run LS2 (silver Blade) thottle bodies and harness adaptors and newer larger MAF's. You will need a tune if you go to a larger MAF.

Idealy after the mods you will want to do a Tune but the stock ecu will adjust itself a little to make it run normal, you wont make the power you could with a tune. A tune is HIGHLY recommended.

S

ittybittyfds

the number on Intake, passenger side under fuel rail is 12556333
after researching.... this is a LS1 intake

neutron82

I would save the money and skip the fast intake... unless you have a cam, ported heads, and longtubes it won't do you much good for how much it costs... your engine can only flow so much in stock form and no matter how much more air the intake brings in your engine will not flow any more on it's own unless it is forced in (turbo or supercharger)

ittybittyfds

Ok, thanks for your input. I was under the impression that the stock LS1 intake was not a good design and that a LS6 or Fast intake greatly improved the stock LS1.

is your comments based on Fast only or are you suggesting that until i get long tube any Intake swap would see minimal gains if any?

I am doing long tubes immediately for sure.

neutron82

the ls6 is a better upgrade for the moment and 1/3 the cost of the fast and no need to buy another tb... I did the ls6 intake swap on my trans am back in the day and it was a noticeable difference mainly on the top end just don't expect the gains to blow you away... longtubes, ls6 intake, and a tune would do pretty good for your car

Soul per4mance

On our 00 coup with ported heads and a cam upgrade. . It came with the ls1 intake... I later got the ls6 intake on a deal and it was a noticeable improvement midrange on up.....I later got a better deal on a fast 90 setup with 90 mm tb. Bolted it on..improvement over the ls6 on the upper end of the Rev range...but I would not have been happy paying full cost for that manifold unless my setup was already maxed out and every little hp counted.

RedZMonte

that does look to be a 1997-00 LS1 intake.
also know that 01+ LS1 intakes are the same as a LS6 intake. If you get one from anything other then a C5 make sure you plug the EGR passage, C5 didnt have EGR.

S

jp260z

Yup, your manifold is an early LS1.An LS6 manifold would give a much bigger "bang for the buck" compared to the FAST.Your stock 853 (or 241) heads and stock cam just won't keep up with a FAST. The LS6 CASTING #s to look for are: 12575372 (Corvette) OR 12561184 (Camero/Firebird) The F body manifold EGR is simple to block off.