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Hey all......New 2015 C7 Z51 (well not new, 8200 miles, but new enough). What mods does everyone recommend to help milk some more HP out of the car? Thanks in advance.
 

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Welcome to our forum Helirescue and congrats on your new C7! I am sure you will get some ideas from our members, but in the interim you can use our search tool to find existing posts regarding engine mods for increased hp.
 

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Here's what I've done.
1. Z06 grill. For extra cooling as my car is pretty much a dedicated track car
2. MGW short throw shifter. Missed shifts stopped when I installed this
3. Tow hook in the front (Track use if needed.)
4. Xpel over a large part of the car
5. 6 point racing harnesses both seats
6. Cray Spider wheels and Toyo R888R tires for track use during the summer
7. Racing compound brake pads for track use during the summer
 

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Hey all......New 2015 C7 Z51 (well not new, 8200 miles, but new enough). What mods does everyone recommend to help milk some more HP out of the car? Thanks in advance.
Welcome to the forum! We got our 2014 C-7 with 12,000 miles. The first thing I did was order a K&N filter to replace the stock AC filter (not the high dollar FIPK kit) The added airflow was amazing- at least an honest 12 to 15 HP. The other thing to replace are the plug wires. After 5 years, the resistance level on your Corvette's plug wires will be quite high. I ordered a set of MSD 8.5mm Super Conductor plug wires for the C-7 LT1. They have only 40 to 45 ohms of resistance per wire, and that is very good. The secret to these wires and for that matter any "magnetic suppression wire" is a thin copper wire winding around a carbon core inside a highly insulated wire. You get excellent low resistance spark and the coils do not have to work as hard to get the electricity to the plugs. If you get the MSD wires there is one thing you will have to do- on the spark plug end, bend the boot in the middle to create about a 30 to 45 degree angle. They do not explain this anywhere in the instructions. If you don't make the small bend and leave the boot straight, you will swear the wires are 1 inch too short. When I called MSD to complain, tech support told me about making the bend (30 degrees) and everything worked great. One other thing you may want to do as a matter of preventative maintenance is to take out the plugs and apply a very thin coating of anti seize compound to the plug threads. Wipe off any excess and be sure to torque the plugs to spec (I believe it is 15 lb ft). These plugs are AC iridium, and they will last a long time- a very long time depending on how many miles you drive in a year. The steel plug threads will seize to the aluminum threads in the cylinder heads as in dis-similar metal corrosion. If that happens you are in for a very expensive repair. Anti Seize compounds like "Nevr Seez" work very well. The air filter and plug wire change was all I needed to do, but the power increase was very noticeable and enjoyable. Hope this helps.
 

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Welcome to the forum! We got our 2014 C-7 with 12,000 miles. The first thing I did was order a K&N filter to replace the stock AC filter (not the high dollar FIPK kit) The added airflow was amazing- at least an honest 12 to 15 HP. The other thing to replace are the plug wires. After 5 years, the resistance level on your Corvette's plug wires will be quite high. I ordered a set of MSD 8.5mm Super Conductor plug wires for the C-7 LT1. They have only 40 to 45 ohms of resistance per wire, and that is very good. The secret to these wires and for that matter any "magnetic suppression wire" is a thin copper wire winding around a carbon core inside a highly insulated wire. You get excellent low resistance spark and the coils do not have to work as hard to get the electricity to the plugs. If you get the MSD wires there is one thing you will have to do- on the spark plug end, bend the boot in the middle to create about a 30 to 45 degree angle. They do not explain this anywhere in the instructions. If you don't make the small bend and leave the boot straight, you will swear the wires are 1 inch too short. When I called MSD to complain, tech support told me about making the bend (30 degrees) and everything worked great. One other thing you may want to do as a matter of preventative maintenance is to take out the plugs and apply a very thin coating of anti seize compound to the plug threads. Wipe off any excess and be sure to torque the plugs to spec (I believe it is 15 lb ft). These plugs are AC iridium, and they will last a long time- a very long time depending on how many miles you drive in a year. The steel plug threads will seize to the aluminum threads in the cylinder heads as in dis-similar metal corrosion. If that happens you are in for a very expensive repair. Anti Seize compounds like "Nevr Seez" work very well. The air filter and plug wire change was all I needed to do, but the power increase was very noticeable and enjoyable. Hope this helps.
So a couple questions:

1. How do you know you got any extra HP with the filter and/or wires? Did you dyno it before and after, or are you going by "feel"?

2. If a simple air filter change and/or different type of plug wires and/or plugs could create that much additional HP, then why wasn't it done at the factory. (I don't think these changes would make any appreciable change in EPA emission qualification requirements.)

Thanks
 

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Quite simply I went by feel. Our C-7 had 12,000 miles as stated in the original reply. I have had experience with K&N filters or the cotton gauze/ oil saturated filter media. The stock paper AC filter element is somewhat restrictive. Now having made that statement, I know that the K&N filter installed in the car made a very noticeable difference in part throttle and full throttle acceleration. The K&N engineers or marketing guys state that their OEM replacement filter yields 12 to 15 more horsepower based on their dyno tests. When you have 460 horsepower, an additional 12 HP might be hard to feel. However, regardless of what K&N or some marketing guy says, I do know that my 2014 Corvette was very responsive. My first thought was, "so that is what 12 HP feels like- how about that". nothing scientific, just a very definite improvement in response. It may also interest you to know that as I drove the Corvette more, the computer program integrator and block learn adapted to the greater air flow. The Corvette's ECM program evidently responded to greater filtered airflow. As far as the MSD wires are concerned, I cannot definitely say that they contributed to any additional horsepower, but there was far better response. When stock Delco wires are new, they seem to have around 100 to 110 ohms of resistance. The electricity produced in the individual coils are only what is needed to fire the spark plug. The electricity or Kilovolts (KV) required to fire the cylinder is based on the resistance in the plug wire and the spark plug as well as the spark plug gap. I used a Kilovolt Meter and found the stock wires needed 10 to 12 KV at idle. As RPM increases the KV settled down to around 8 KV under a no load condition. A snap throttle test saw a jump of 4 to 6 KV needed to overcome any resistance and fire off the fuel mixture. On our 2014 C-7 with 12,000 miles the stock wires had deteriorated to around 500 to 550 ohms in each wire. That resistance growth from 100 ohms when the Corvette was new to the 500 ohms after 4 years and 12,000 miles made a slight difference in throttle response when the new 40 ohm MSD wires were installed. Did those MSD wires make more horsepower? I really don't believe they did. All the new wires did was to restore the new car response yet it may be perceived as more horsepower. Combine the filter and wire change, and the motor is running better and responds very well. Oh yes, GM was against the use of K&N filters a few years ago. K&N took them to court and won. GM had claimed that the filter oil K&N called for would cause ECM problems and K&N's red filter oil would affect the mass airflow hot wire. This proved to be false. In fact, in the current Corvette accessory catalog for the C-7, GM is offering a new filter based on the K&N oil saturated gauze type/ style filter for somewhere north of $600. They buy this filter from a K&N competitor that uses blue colored oil.
 
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