1967 GTO clone LT1
06-15-2013, 03:15 AM
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1967 GTO clone LT1 I recently started work on a 1967 gto clone... Running LT1 on a 3430lb car with no egr, no air, mid headers, ram air intake, with MAF, (soon to be) ported iron heads (caprice), corvette block, high flo cats, true duel exhaust, vented opti, currently tuned and can be re tuned at will.
Things I need,
1. Advice on a CAM for getting this thing to be able to drive well, primary interest is... MPG, I would like to be able to afford to drive the car. That is why I pulled the BBP motor out... with the side hopes of playful power.
2. How does the LT1 stock lower end motor hold with a shot of NO on it?
3. Any other things I have not though about... this is my first LT1.
Please dump all your vast collective knowledge on me... opinions too, with limits.
Things I need,
1. Advice on a CAM for getting this thing to be able to drive well, primary interest is... MPG, I would like to be able to afford to drive the car. That is why I pulled the BBP motor out... with the side hopes of playful power.
2. How does the LT1 stock lower end motor hold with a shot of NO on it?
3. Any other things I have not though about... this is my first LT1.
Please dump all your vast collective knowledge on me... opinions too, with limits.
06-15-2013, 05:55 AM
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I'd look at the Camshaft FAQ here (https://ls1tech.com/forums/lt1-lt4-m...ion-guide.html), and then talk to Advanced Inductions and Lloyd Elliot about getting a custom cam grind for you. That would be your best bet for what you want more than likely.
A stock block can hold a good shot of nitrous, just don't be dumb and throw a 200 shot at it. I've seen people running 150 shot on a stock short block easy.
A stock block can hold a good shot of nitrous, just don't be dumb and throw a 200 shot at it. I've seen people running 150 shot on a stock short block easy.
06-15-2013, 01:02 PM
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4l60e out of a 1993 Camaro, Stock stall, and I will open up the rear end and start counting teeth tomorrow night.
06-15-2013, 04:22 PM
#5
stock stall means stock cam period, if you think otherwise stop thinking about modding the car.
Also the 93 tranny is not "E".
If you want to cam the car start trying to wrap your head around the idea of 3000-3200rpm stall and at least 3.42 gears if not 3.73s. If you think that will decimate mileage again stop thinking about modding the car.
I know I am sounding very discouraging but I did a mild cam with stock gears and stock stall and it was a MISTAKE I would like to help you avoid.
the OD and lockup in a 4l60 mean 4.10s in that 4.10s are comparable to 3.08s in a car with an old three speed automatic and stall converters have come a LONG LONG ways.
Gears and stall are to be done BEFORE a cam or the cam will gain you almost nothing performance wise, even if you stay mild enough that it manages to drive fine.
Also the 93 tranny is not "E".
If you want to cam the car start trying to wrap your head around the idea of 3000-3200rpm stall and at least 3.42 gears if not 3.73s. If you think that will decimate mileage again stop thinking about modding the car.
I know I am sounding very discouraging but I did a mild cam with stock gears and stock stall and it was a MISTAKE I would like to help you avoid.
the OD and lockup in a 4l60 mean 4.10s in that 4.10s are comparable to 3.08s in a car with an old three speed automatic and stall converters have come a LONG LONG ways.
Gears and stall are to be done BEFORE a cam or the cam will gain you almost nothing performance wise, even if you stay mild enough that it manages to drive fine.
06-17-2013, 01:41 PM
#6
My best friend has a 69 GTO with an LT1 in it. He did for driveability and HP and to preserve the #s matching 400. The stock short-block has the GM HOT cam, ported aluminum heads, 58mm TB, cold air from behind the driver's headlight, Hedman long tubes, 2800 Vigilante stall in a 4L60E and 3.55 gears. He dynoed in the 370 range, I can't remember for sure. I don't know his MPG, but my Firebird with the the SAME exact combo, but with 3.23s would pull 16 MPG puttering around town. But I drive like a grandma. But then again my 94 weighs 300 pounds more at 3850 with me in it. The extra weight might hurt MPG a little.
Also, my stock short-block held a 150 shot of nitrous for 8 years of summer racing and never broke. Just have quality fuel, pump and I would pull LOTS of timing. But I ran it leaner than most at 13 to 1. Most people don't like to go leaner than 12.5 to 1. Just verify air/fuel after every jet change by checking the plugs. Run colder plugs too. I used the NGK BR7EF which is 2 steps colder than stock.
Also, my stock short-block held a 150 shot of nitrous for 8 years of summer racing and never broke. Just have quality fuel, pump and I would pull LOTS of timing. But I ran it leaner than most at 13 to 1. Most people don't like to go leaner than 12.5 to 1. Just verify air/fuel after every jet change by checking the plugs. Run colder plugs too. I used the NGK BR7EF which is 2 steps colder than stock.
