TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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I have some funds saved up and i'm looking to build up the iroc this winter. I want the best bang for the buck. Need direction. Heres the specs of the motor and what shes currently got and does.
GM Special Performance 5.7L (pt# 12356644)
Supposed specs from the rap sheet
300hp @ 5000rpm
369 lb/ft @ 3500rpm
Comp Ratio: 9.1 : 1
Bore x Stroke: 4.00" x 3.48"
Max rpm: 5700rpm
700R4 trans, Stock TPI setup, 3;70 posi(third set of gears, second rear end), hooker shorties with del. cat and flowmaster.
Went to the track this year ran around 87mph @ 14.7 Car gets good rubber shifting into second. think it eats the rear gears up.
Now about the car, I'm looking to do something major to make her scoot. Roots blower? ls1 motor and trans? Different TPI setup? What is the best bang for the buck? id like to make HP and have a much higher top end.
I dont like all the wires and crap in the engine bay and its really dirty, think it would be cool to pull the motor and clean the bay out, and get a new setup in there that doesnt use the TPI mess and easier to work on and play with.
Thanks in advance
I just ran a 9.32 @ 75.59 with a 1.92s 60', in the 1/8 mile in a FULLSIZE VAN with a TPI 350 in it! Should I mention to you that it weighs 2,000 lbs more than your car, has taller overall gearing (3.08s and a 29" tall tire), and still has the STOCK Runners and Plenum on it. Its a Vortec 350 with 9:1 compression, ported heads, mild Reed custom grind roller cam, edelbrock 3817 TPI Vortec base, Doug Thorley Tri-Y van headers, dual 2.5" exhaust, and custom prom tuning by me. The converter in the 700r4 stalls around 2,200 rpm and the governor upshifts 1-2 @ 5,700 and 2-3 @ 5,500 rpm. The 350 sings all the way to the shift points despite the stock runners and small cam.
Just proving to you that while I don't have much money into the engine it will still haul ***! In a lighter, more aerodynamic 3rd gen, assuming it would hook decently, it could be in the low 13s or high 12s pretty easily. It is so much fun to drive on the street as well. Ever seen a van smoke the tires all the way through first gear and brake em loose on a 2-1 WOT downshift at 20 mph.
Headers detached - drivers side out, got all the spark plugs out. The plugs look like they have been singed/burned, even though they were replaced probably no more then 10k ago.. They seemed so much more of a hassle to get out then I last remember loll.
Drivers side head - Took all the bolts under the valve cover out, rockers off. Now the 8-10 bolts on the outer edge are loosened.. I took one all the way out and coolant started squirting out like mad haha
Anyways.. so i guess i just have to drain my coolant, then get the bolts off the passenger side and its all skin n bones..
Need some help getting a parts list together and some ideas for what to get myself for Christmas .....thinkin..
HSR
Heads
Cam
Long tubes or just dump under the car, I dont like the 2 flowmasters on one side.
Enter text here.Enter text here.
HSR
Heads
Cam
Long tubes or just dump under the car, I dont like the 2 flowmasters on one side.
Nice work so far.
It looks like your 350 may already be setup for the factory roller setup. If it is, I highly recomeend going with it over a flat-tappet hydraulice camshaft.
roller cams produce much better power than flat teppet cams.
it depens on how much you can spend..
hsr is kind of $$. heads and cam would do more good. all you need is some decent aluminum heads and cam.
what year TPI setup do you have?
i have a complet intake for a 85 i'am getting rid of. ive ported the upper plenum and lower maifold, and its got AS&M runners on it and a 58mm tb.
but if not you can eazily port you upper and lower intake, add that with a mild head and cam combo and there you go...
mine ran 14.1 with just gears and exhaust so with that you should get low 13s