Getting juice out of these TPI's
#1
Getting juice out of these TPI's
I'm a former LS1 guy looking to pick up an 87 Camaro with the 305 TPI and 5 speed manual. its rated at 215hp which is something I am looking to change. My question is, where do I find some after market parts for these cars (jegs and summit just arn't really cutting it, i could be looking in the wrong places.). My other question is how can I get more power out of these engines without a blower? I heard if you just let them breath they perform pretty well i.e exhaust, intake, heads and cam. True? any help will help ha thanks!
#2
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Car: 1988 GTA
Engine: LB9
Transmission: T5
Axle/Gears: 3.45
Re: Getting juice out of these TPI's
I'm a current LS1 6 speed guy as well as a 305 TPI 5 speed.
As you know, that 305 is weak at the top end compared to the LS1. But at most any other conditon under 4000 RPM, the 305 feels just as good.
If you want to spice up the 305 a little, you can smooth out the intake ports, go with a little more cam (don't overdo it) and some better flowing exhaust.
But it won't scream with delight at 6000 RPM.
As you know, that 305 is weak at the top end compared to the LS1. But at most any other conditon under 4000 RPM, the 305 feels just as good.
If you want to spice up the 305 a little, you can smooth out the intake ports, go with a little more cam (don't overdo it) and some better flowing exhaust.
But it won't scream with delight at 6000 RPM.
#3
Re: Getting juice out of these TPI's
ya im not expecting much, I was always a fan of the third generation camaro's. I had a 2.6 when I was a teenager. I wanna top out at about 300hp and way and I mean way down the road slap on a blower. so I was thinking full bolt-ons heads and a mild cam, what ya think?
#4
Supreme Member
Re: Getting juice out of these TPI's
Start with the exhaust. The manifolds and crossover pipe really choke these cars down. There is a solid 20 hp stuck in the exhaust on these cars. If not more.
1. Headers (everyone recommends Dyno Dons headers lately but I have not used them)
2. Cat-back (magna-flow just released a nice third gen system)
Next adjustable fuel pressure regulator. Holley makes the nicest one in my opinion for a TPI car. http://www.jegs.com/i/Holley/510/512...0002/-1?CT=999
Then the next big restriction on these cars is the TPI intake system itself. The lower intake is very restrictive and so are the runners. The plenum can be ported also.
1. Edelbrock base, and TPI runners by Edelbrock, SLP, or Arizona speed & marine, or TPIS will all be an upgrade.
2. Port the plenum.
3. Bigger throttle body (but generally the bigger TB is not needed until a cam is added)
You can also cut the bottom of the airboxs out for more airflow into the air cleaner and you should do a high performance tune up with plugs, wires, cap. I have had good results with adding an MSD 6A ignition system and matching ign. parts.
For a cam if you plan on keeping TPI I would go with the Crane 2032. Very computer friendly add's a nice bump in power without overworking the TPI setup.
You can also add a off the self TPI chip to the ECM. Many people will tell to try and burn our own but it is very hard to do and not needed in a mildly modified car. If you have a relatively stock application I would recommend a Fast chip by Ed wright.
http://www.fastchip.com/
1. Headers (everyone recommends Dyno Dons headers lately but I have not used them)
2. Cat-back (magna-flow just released a nice third gen system)
Next adjustable fuel pressure regulator. Holley makes the nicest one in my opinion for a TPI car. http://www.jegs.com/i/Holley/510/512...0002/-1?CT=999
Then the next big restriction on these cars is the TPI intake system itself. The lower intake is very restrictive and so are the runners. The plenum can be ported also.
1. Edelbrock base, and TPI runners by Edelbrock, SLP, or Arizona speed & marine, or TPIS will all be an upgrade.
2. Port the plenum.
3. Bigger throttle body (but generally the bigger TB is not needed until a cam is added)
You can also cut the bottom of the airboxs out for more airflow into the air cleaner and you should do a high performance tune up with plugs, wires, cap. I have had good results with adding an MSD 6A ignition system and matching ign. parts.
For a cam if you plan on keeping TPI I would go with the Crane 2032. Very computer friendly add's a nice bump in power without overworking the TPI setup.
You can also add a off the self TPI chip to the ECM. Many people will tell to try and burn our own but it is very hard to do and not needed in a mildly modified car. If you have a relatively stock application I would recommend a Fast chip by Ed wright.
http://www.fastchip.com/
Last edited by burnout88; 01-03-2011 at 08:16 AM.
#5
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Car: 1985 El Camino SS, 2004 Trailblazer
Engine: Hybrid 305, 91 SD TPI, lots of mods
Transmission: 200-4R
Axle/Gears: 3.42
Re: Getting juice out of these TPI's
I have an 85 305 in my El Camino with a 90 model Speed Density TPI and AXXB E-PROM. I am using EQ Vortec heads 1.940/1.5 valves, 1.6 Roller rockers, L31 350 roller camshaft, Ramjet springs, KB Super Stock Pistons, OEM TPI base is port matched top to bottom, plenum is port matched, Stock Runners have had the dings removed and the "Stretch" put on them with the steel ball treatment (9% flow increase), Edelbrock F body headers (modified), 2.5" full duals, Turbo mufflers, H Pipe, 19lb Gen3 Injectors, Stock HEI and some other stuff.
The heads, exhaust system and camshaft are the big restriction on a 305 F or G Body, way more than the TPI BASE and Throttle body. The stock heads are junk! The stock Throttle body will flow enough air for about 6000 RPM on a properly modified 305-310 engine and the stock TPI base will flow a little less. I would spend the money on the heads, camshaft and valve train. Port the TPI to match the heads, base, runners, plenum and Throttle body.
I would also make sure that the bottom end was in good shape and that the engine has good piston and ring fit. The stock bottom end is good for about 300 horsepower and no loss of reliability! I rebuilt mine with Sealed Power Rings, KB pistons, GM timing and camshaft components, Federal Mogul Bearings, Fel Pro gaskets and Melling Oil Pump. Nothing fancy, just premium components, precision machine work and meticulous assembly. More or less a Blueprinted engine. I did splurge on a balanced rotating assembly.
The heads, exhaust system and camshaft are the big restriction on a 305 F or G Body, way more than the TPI BASE and Throttle body. The stock heads are junk! The stock Throttle body will flow enough air for about 6000 RPM on a properly modified 305-310 engine and the stock TPI base will flow a little less. I would spend the money on the heads, camshaft and valve train. Port the TPI to match the heads, base, runners, plenum and Throttle body.
I would also make sure that the bottom end was in good shape and that the engine has good piston and ring fit. The stock bottom end is good for about 300 horsepower and no loss of reliability! I rebuilt mine with Sealed Power Rings, KB pistons, GM timing and camshaft components, Federal Mogul Bearings, Fel Pro gaskets and Melling Oil Pump. Nothing fancy, just premium components, precision machine work and meticulous assembly. More or less a Blueprinted engine. I did splurge on a balanced rotating assembly.
#6
Re: Getting juice out of these TPI's
Sweet, good info there. I can't decide if I wanna rebuild the whole motor or not...kinda short on funds at the moment :/. I've done heads and cam in my old 98 Trans AM it wasn't the biggest pain in the *** but i did have to pull the motor. looks like I have enough room in the engine bay to leave the motor in and work on it. thanks guys, keep the info coming!
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