Need help with 93 octane tune knowledge

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Dec 27, 2012 | 09:54 PM

Ptaylor459

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From: Keller/Lubbock TX

Need help with 93 octane tune knowledge

Hey guys, I'm new to the whole forum posting thing to start things off. I bought a 98 T/A last summer from a dad who wanted a weekend hotrod but got tired of it quick. The owner before him only left the dad with receipts of the work done before I got the car. Some of the mods: stage 2 phantom heads( polished and ported), custom Comp cam with a .590 lift, chromoly pushrods, eagle 1 forged pistons and crankshaft, stroked to 383 ci, stock Ls1 manifold and TB, stock Lid, 3.73 gears, 2700 stall, long tube headers with x pipe and dumped before rear axle. The dad I bought the car from told me it runs on 87 just fine and 93 fine as well. I always put 93 in the car, however. When I dynoed the car, I was running 93 octane and the car made 397 rwhp on it's best pull. I feel like this number is pretty low for the mods done to the car so my questions are:

- was it tuned on 87 octane?
-if it was, should I retune it on 93 at a reputable place and advance the timing?
- I also am interested in buying an Ls6 intake manifold to help the car breath a little better along with a new TB. Should I port the stock TB or which should I buy with my current mods?

Sorry this is so much information and so many questions, I've just been put in the dark with the car's mods. I really feel like it has the mods listed but just was tuned on 87 Octane and is missing that extra push

Thanks

Patrick( Fort Worth area )

Ptaylor459@gmail.com

Dec 28, 2012 | 01:01 PM

MUSTANGBRKR02

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Car should be making more power than that but I would do a tune up and get it retuned by a reputable tuner then go from there.

Dec 29, 2012 | 03:20 PM

06X6spdGTO

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Numbers sound low but the LS1 intake could be a MAJOR culprit for that...

Was this with the converter locked???

Id keep running 93octane if it was mine. Switch to a FAST 92 or at least and LS6 intake and bigger TB.. Maybe swap to a different cam if funds permit.. Kinda sucks when you pickup a car that you dont know the ins/outs of the heads and rotating assembly or block work..

As for intake... Id get a FAST 92mm and Nick Williams 90mm TB if it were mine.. Possible add a FTP 90mm Lid while I was there and a 85mm LS6 MAF..

Dec 29, 2012 | 04:19 PM

1998silverbird

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I would change the spark plugs to NGK TR6's and get a LS6 intake or better on that thing. That LS1 intake is not helping at all. I would then have the car tuned. I dont know how that guy you bought it from was running 87 octane. My 383 motor has a compression ratio of 11.4:1 and that is way to high for 87 octane and if it were to get tuned for 87 there would probably be no timing in the motor to compensate for detonation.

Dec 29, 2012 | 04:56 PM

Ptaylor459

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From: Keller/Lubbock TX

Ive looked at getting a FAST 92 Intake Manifold but the only thing holding me back now is the price. I can save up for it however and plan on getting it this summer after doing some research on its gains over an LS6 Intake Manifold. As for the throttle body, mine is stock. Could i simply port out the stock TB or is getting a new 92mm TB to match the FAST 92 manifold the best option? I also dont see how much i would really gain from buying a bigger MAF, correct me if I am wrong please because im new to modifying motors.

Dec 29, 2012 | 08:56 PM

1998silverbird

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It depends on what maf you have? The stock maf is good but if your getting a bigger intake and a bigger Lid the in between having a small maf it kinda defeats the purpose. An 85 mm maf is a great buy. They are easy to tune and can support 600 hp or more.

Price is what kept me away from a fast intake as of now as well. I just got a Typhoon style 96mm intake and 102mm TB that will be going on in a week. Got the whole setup TB/Intake/ Fuel Rail/ and 98mm Airlid for right around 600.00 brand new. If I dont see at least a 10 hp gain over what my car makes now I will bite the bullet and get a Fast 102 intake but I have a hard time shelling out 900.00 for a intake alone. You can port your stock TB but if you get a fast 92 you will have to get a LS2 style 4 bolt TB as the stock LS1/LS6 TB and intakes have a 3 bolt style TB.

Dec 30, 2012 | 06:42 PM

Ptaylor459

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From: Keller/Lubbock TX

I've been looking around and found a combo deal on Ebay

http://www.ebay.com/itm/FAST-LSXR-GM...c5d4de&vxp=mtr

Is that something i should look at? I know i'll be needing new few rails as well due to LS1 manifold not being able to support the fast 92 or 102 manifolds. Havent got a chance to glance at new MAF's that are larger than stock.