New project, looking for build tips - 1996 Corvette Coupe LT4
09-25-2015, 06:27 PM
#21
Instructor
Thread Starter
Unless you're very concerned about (presumably) a small oil leak, I would put off that particular job until it was time to do the clutch also.
yes your car does have the J55 13 inch brakes on the front, which besides being larger in diameter are also thicker than the standard brake package. It's fairly cheap to replace the rotors (if needed) and upgrade the pads; aftermarket, even C5 brake conversions, are considerably more expensive. I'd hold off here until I felt I really needed a brake upgrade.
I had ZFdoc do a shifter mod on mine, and here's the best part, if you detach the entire shifter assembly, which isn't hard with the trans out of the car, he will rebuild the whole thing, (in addition to shortening the shifter). He did this to mine, and I can't say enough good things about how well it worked out.
If you want more power out of an LT4, start with cam and work out. The factory designed the LT4 Hot Cam to be a drop in for these engines, and the dyno tests from back in the day put LT4 engines so equipped well within the power levels you aspire to...and...this may or may not be an issue for you...but mine passed California smog without any problem.
rear spring delaminating; replaced it with a VBP spring, 480 inch pounds, they would only suggest a max of 500 inch pound for street driving; this was a significant increase over even a factory Z51 spring;
new tires (naturally);
new brake pads on the front;
all new U joints, six total;
key stuck in the ignition tumbler and the column was loose, replaced with a new OEM column;
new Opti...believe me someone got their money's worth, and mileage out of the old opti;
new water pump;
found some bad lifters in the rear of the engine, of course those cam lobes were trashed; hence the LT4 Hot Cam, new lifters, new timing chain and new seals for the timining chain cover.
bushings were original..read worn out...all new poly bushings for the rear end.
found the original MultiTech injectors to be leaking; replaced with new Bosch III injectors...this was mandatory;
But the real place to start, is as with any old car, is a complete filter (especially the fuel filter) and fluid change and a ignition tune up (at a minimum, rotor, rotor cap, ignition wires, spark plugs); clean the throttle plates and the idle air control valve; check all the vacumn lines, ESPECIALLY the ventilation harness for the opti (mine was cut and deteriorated) and the vacumn lines (mostly cruise control) in the vicinity of the battery.
yes your car does have the J55 13 inch brakes on the front, which besides being larger in diameter are also thicker than the standard brake package. It's fairly cheap to replace the rotors (if needed) and upgrade the pads; aftermarket, even C5 brake conversions, are considerably more expensive. I'd hold off here until I felt I really needed a brake upgrade.
I had ZFdoc do a shifter mod on mine, and here's the best part, if you detach the entire shifter assembly, which isn't hard with the trans out of the car, he will rebuild the whole thing, (in addition to shortening the shifter). He did this to mine, and I can't say enough good things about how well it worked out.
If you want more power out of an LT4, start with cam and work out. The factory designed the LT4 Hot Cam to be a drop in for these engines, and the dyno tests from back in the day put LT4 engines so equipped well within the power levels you aspire to...and...this may or may not be an issue for you...but mine passed California smog without any problem.
rear spring delaminating; replaced it with a VBP spring, 480 inch pounds, they would only suggest a max of 500 inch pound for street driving; this was a significant increase over even a factory Z51 spring;
new tires (naturally);
new brake pads on the front;
all new U joints, six total;
key stuck in the ignition tumbler and the column was loose, replaced with a new OEM column;
new Opti...believe me someone got their money's worth, and mileage out of the old opti;
new water pump;
found some bad lifters in the rear of the engine, of course those cam lobes were trashed; hence the LT4 Hot Cam, new lifters, new timing chain and new seals for the timining chain cover.
bushings were original..read worn out...all new poly bushings for the rear end.
found the original MultiTech injectors to be leaking; replaced with new Bosch III injectors...this was mandatory;
But the real place to start, is as with any old car, is a complete filter (especially the fuel filter) and fluid change and a ignition tune up (at a minimum, rotor, rotor cap, ignition wires, spark plugs); clean the throttle plates and the idle air control valve; check all the vacumn lines, ESPECIALLY the ventilation harness for the opti (mine was cut and deteriorated) and the vacumn lines (mostly cruise control) in the vicinity of the battery.
The only upgrade I did to my C6 to give me very reliable pedal was Castrol SRF fluid, stainless lines, DBA dimple slotted rotors, and Carbotech pads. I don't regret not paying the money for a BBK.
Good to know on ZFDoc, I've seen nothing but great feedback on his work, and it seems reasonable.
I know the Hot cam is a proven unit, but it's been around a long time - I like the proven factor, but wouldn't mind something a little more aggressive as long as street manners aren't entirely sacrificed. Emissions are not a consideration, car is registered in Tennessee and the County I'm in has no emissions whatsoever. Straight pipes baby... ok maybe not.
Impressions on the VBP? I had one response that indicated they weren't happy with it, but no indication why. I've had cars with almost solid engine mounts and very firm suspension - as a DD. My harshness threshold is pretty high, as long as the trade-off is for a reasonable increase in performance. That said, roads in Pittsburgh are pretty terrible haha. My initial thought was to go with that spring and the DRM valved Bilsteins.
On to your personal experiences:
The car has Conti DWS tires with less than 3k miles, brand new Opti, water pump, plugs, and wires. I'll check the other items first thing.
09-25-2015, 06:40 PM
#22
Team Owner
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The F45 shocks are totally impossible. Take them out, buy the resistors from MidAmerica, and install Bilsteins HD
That's a good, very good price. I guy wanted me to swap a new clutch, and I quoted him with that number, he bitched about it, and I told him to take it to the dealer. Two days later he called, and I did not answer.
09-25-2015, 06:52 PM
#23
Instructor
Thread Starter
There is no way in hell that the HOT Cam gets him to 400 wheel hp which is what the OP stated as a rough goal.
In general, with tuning and stock heads we all ran around 330hp at the wheels with the LT4 and the HOT Cam, less on the LT1 cars. With head work that bumps LT4 cars to 350-360hp at the wheels. With headers, big time ported heads, a bigger cam, a lot of tuning, and an aftermarket exhaust, the best I saw out of a stock bottom end was ~380hp.
That last 20 will come from a cam that's not enjoyable on the street or from cubes.
In general, with tuning and stock heads we all ran around 330hp at the wheels with the LT4 and the HOT Cam, less on the LT1 cars. With head work that bumps LT4 cars to 350-360hp at the wheels. With headers, big time ported heads, a bigger cam, a lot of tuning, and an aftermarket exhaust, the best I saw out of a stock bottom end was ~380hp.
That last 20 will come from a cam that's not enjoyable on the street or from cubes.
09-25-2015, 07:11 PM
#24
Melting Slicks
But, and if you have any concerns with these figures, please address them to SUPER CHEVY MAGAZINE and the September 24, 2013 issue, "Dyno Testing New Mods For The LT1 Motor (Part 2)".
Test #4, stock LT1 with nothing but stock LT1 rockers (1.5:1) and a LT4 Hot Cam, a gain of 60 horsepower, 415 hp max, 417.9 tq max;
Test 5 stock LT1 head with LT4 hot cam and lt4 1.6:1 rockers, 423.9 hp, 422.8 tq;
Test #7, ported LT1 heads (to better approximate LT4 heads) and LT4 hot cam and LT4 rockers, 471 hp, 432.6 tq.
Granted, these are dyno numbers, and they are maximum numbers, hey, we're bench racing here after all, but there's a lot of power to be made with an LT4, some even say the factory left a lot on the table so as not to "embarrass" their new LS engine
In any case, I do remember reading articles quoting actual rear wheel dyno tests that put LT4 engines, at or very near the RWHP figures that the OP aspires to...and if you want to compare apples, oranges and banana's, lots of folks on here will be happy to tell you all about their LT based 383's
09-25-2015, 07:19 PM
#25
Melting Slicks
09-25-2015, 07:22 PM
#26
Team Owner
Member Since: Aug 2005
Location: Riverside County Southern California
Posts: 34,988
Received 501 Likes
on
342 Posts
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20
I respect your opinion and I'm not gonna argue apples and oranges or rear wheel versus dyno power figures; you can apply whatever "correction factor" you want in an attempt to correlate rear wheel horsepower versus crank horsepower.
But, and if you have any concerns with these figures, please address them to SUPER CHEVY MAGAZINE and the September 24, 2013 issue, "Dyno Testing New Mods For The LT1 Motor (Part 2)".
Test #4, stock LT1 with nothing but stock LT1 rockers (1.5:1) and a LT4 Hot Cam, a gain of 60 horsepower, 415 hp max, 417.9 tq max;
Test 5 stock LT1 head with LT4 hot cam and lt4 1.6:1 rockers, 423.9 hp, 422.8 tq;
Test #7, ported LT1 heads (to better approximate LT4 heads) and LT4 hot cam and LT4 rockers, 471 hp, 432.6 tq.
Granted, these are dyno numbers, and they are maximum numbers, hey, we're bench racing here after all, but there's a lot of power to be made with an LT4, some even say the factory left a lot on the table so as not to "embarrass" their new LS engine
In any case, I do remember reading articles quoting actual rear wheel dyno tests that put LT4 engines, at or very near the RWHP figures that the OP aspires to...and if you want to compare apples, oranges and banana's, lots of folks on here will be happy to tell you all about their LT based 383's
But, and if you have any concerns with these figures, please address them to SUPER CHEVY MAGAZINE and the September 24, 2013 issue, "Dyno Testing New Mods For The LT1 Motor (Part 2)".
Test #4, stock LT1 with nothing but stock LT1 rockers (1.5:1) and a LT4 Hot Cam, a gain of 60 horsepower, 415 hp max, 417.9 tq max;
Test 5 stock LT1 head with LT4 hot cam and lt4 1.6:1 rockers, 423.9 hp, 422.8 tq;
Test #7, ported LT1 heads (to better approximate LT4 heads) and LT4 hot cam and LT4 rockers, 471 hp, 432.6 tq.
Granted, these are dyno numbers, and they are maximum numbers, hey, we're bench racing here after all, but there's a lot of power to be made with an LT4, some even say the factory left a lot on the table so as not to "embarrass" their new LS engine
In any case, I do remember reading articles quoting actual rear wheel dyno tests that put LT4 engines, at or very near the RWHP figures that the OP aspires to...and if you want to compare apples, oranges and banana's, lots of folks on here will be happy to tell you all about their LT based 383's
I guess if I take The Ghost to that dyno tune, he may score 500+ HP
The LT4 cam will not produce 60 horsepower on the LT engine. Thats LS talk
09-25-2015, 09:17 PM
#27
09-27-2015, 10:49 PM
#28
All the things I listed for 7500-8k? If I remember correctly, the LT4 build I referenced (Z07Josh) sold recently for 14k. Maybe I've been looking in the wrong places, but this was the cheapest LT4 I've ever seen that wasn't a basket case.
What cam are you running in yours?
What cam are you running in yours?
example of what you can not build for the parts this car has:
https://www.corvetteforum.com/forums...track-car.html
09-28-2015, 01:15 AM
#29
Instructor
Thread Starter
example of what you can not build for the parts this car has:
https://www.corvetteforum.com/forums...track-car.html
https://www.corvetteforum.com/forums...track-car.html
09-28-2015, 06:48 PM
#30
Tech Contributor
I respect your opinion and I'm not gonna argue apples and oranges or rear wheel versus dyno power figures; you can apply whatever "correction factor" you want in an attempt to correlate rear wheel horsepower versus crank horsepower.
But, and if you have any concerns with these figures, please address them to SUPER CHEVY MAGAZINE and the September 24, 2013 issue, "Dyno Testing New Mods For The LT1 Motor (Part 2)".
Test #4, stock LT1 with nothing but stock LT1 rockers (1.5:1) and a LT4 Hot Cam, a gain of 60 horsepower, 415 hp max, 417.9 tq max;
Test 5 stock LT1 head with LT4 hot cam and lt4 1.6:1 rockers, 423.9 hp, 422.8 tq;
Test #7, ported LT1 heads (to better approximate LT4 heads) and LT4 hot cam and LT4 rockers, 471 hp, 432.6 tq.
Granted, these are dyno numbers, and they are maximum numbers, hey, we're bench racing here after all, but there's a lot of power to be made with an LT4, some even say the factory left a lot on the table so as not to "embarrass" their new LS engine
In any case, I do remember reading articles quoting actual rear wheel dyno tests that put LT4 engines, at or very near the RWHP figures that the OP aspires to...and if you want to compare apples, oranges and banana's, lots of folks on here will be happy to tell you all about their LT based 383's
But, and if you have any concerns with these figures, please address them to SUPER CHEVY MAGAZINE and the September 24, 2013 issue, "Dyno Testing New Mods For The LT1 Motor (Part 2)".
Test #4, stock LT1 with nothing but stock LT1 rockers (1.5:1) and a LT4 Hot Cam, a gain of 60 horsepower, 415 hp max, 417.9 tq max;
Test 5 stock LT1 head with LT4 hot cam and lt4 1.6:1 rockers, 423.9 hp, 422.8 tq;
Test #7, ported LT1 heads (to better approximate LT4 heads) and LT4 hot cam and LT4 rockers, 471 hp, 432.6 tq.
Granted, these are dyno numbers, and they are maximum numbers, hey, we're bench racing here after all, but there's a lot of power to be made with an LT4, some even say the factory left a lot on the table so as not to "embarrass" their new LS engine
In any case, I do remember reading articles quoting actual rear wheel dyno tests that put LT4 engines, at or very near the RWHP figures that the OP aspires to...and if you want to compare apples, oranges and banana's, lots of folks on here will be happy to tell you all about their LT based 383's
When you tell him that 400hp is achievable, you are misleading him, albeit I'm sure unintentionally since you are quoting crankshaft hp and he is asking about Wheel hp
10-05-2015, 03:41 PM
#31
Instructor
Thread Starter
While horsepower is more fun to talk about, I gotta address the suspension first. I'm currently faced with two main questions, which are:
1. New monospring and DRM shocks, or coilovers? I'd love to save the money and stick with shocks/monospring, but the ease of ride height adjustability with coilovers is a big plus. Pittsburgh roads are terrible. I love the DRM shocks that are currently on my C6, but it is not lowered.
2. Ball Joints - I was quoted $850 labor to do upper/lower ball joints AND control arm bushings. Corvette Recycling has NOS complete upper/lower control arm assembly package for $999.99 (which I'd be comfortable tackling install myself). Are the OEM ball joints and bushings good enough, or should I nut up and pay the extra for labor plus parts?
1. New monospring and DRM shocks, or coilovers? I'd love to save the money and stick with shocks/monospring, but the ease of ride height adjustability with coilovers is a big plus. Pittsburgh roads are terrible. I love the DRM shocks that are currently on my C6, but it is not lowered.
2. Ball Joints - I was quoted $850 labor to do upper/lower ball joints AND control arm bushings. Corvette Recycling has NOS complete upper/lower control arm assembly package for $999.99 (which I'd be comfortable tackling install myself). Are the OEM ball joints and bushings good enough, or should I nut up and pay the extra for labor plus parts?
10-05-2015, 03:51 PM
#32
Instructor
Thread Starter
I'm trying to find build info on The Ghost - found your build thread but all the image links are broken. Can you point me to a quick and dirty list if it's floating around here somewhere? I'm registered in TN, so longtube is all good. Not sure how much of a difference that makes power-wise, I'm sure I've read it somewhere but can't remember.