700+ rwhp 93 octane daily driver C6 Grand Sport build thread
10-16-2014, 10:26 AM
#25
Instructor
Member Since: Sep 2010
Location: Warner Robins, GA
Posts: 196
Likes: 0
Received 0 Likes
on
0 Posts
10-20-2014, 07:36 AM
#26
Instructor
Thread Starter
Cylinder head cooling. The early LS1 engine used to have a coolant crossover pipe underneath the intake manifold that connected the steam pockets from cylinders 1-2 and 7-8. When the Corvette went to the LS6 intake in 01, the crossover connection to the rear cylinders was eliminated because there was no space under the intake. The rear cylinders are the last to be cooled and number 7 is the very last. As a result, steam pockets develop on #7 and combustion temps can go super high, making detonation a very real & common phenomenon.
The solution is to get some cooling balance to the rear cylinders. Sure you could use the Trick Flow coolant crossover kit which opens up the steam passages on the rear of the cylinders and and connects them via rubber lines to the front 2 cylinders. I would do that with any LS engine as a minimum. But cylinder head guru Greg Good had a better idea for my Trick Flow heads. He installed 3/8" pipe to the water jackets on the back of the cylinder heads and has dual #6 stainless lines carrying coolant from #7 and #8 to the radiator hose up front. This is a much more generous way of moving coolant from the back of the heads than the steam pipes.
On the crankcase ventilation: It's well known that engines with boost build lots of crankcase pressure. This internal pressure has to be relieved somehow. The stock PCV system is not up to the task and the pressure usually finds its way out by blowing out the dip stick or worse, blowing out the rear main seal. My approach was to have a 3/4" line welded onto each valve cover and have the hoses extend to a remote catch can with a breather top mounted behind the right front headlight. This keeps most of the crankcase gasses from entering the cabin and enhances the 24/7 driving appeal of the car.
As an update, we added race fuel to the car and some methanol injection to cool the air charge in preparation for this week's Texas Mile. While still running the same 11-12 lbs of boost, our power increased to 801rwhp/735rwtq. The dyno sheet is below. This is really nice for a little Novi 1500 6 rib setup on a car with street manners as nice as stock. Still stock 6L80 trans and stock torque converter too.
10-20-2014, 12:41 PM
#28
Instructor
Member Since: Sep 2010
Location: Warner Robins, GA
Posts: 196
Likes: 0
Received 0 Likes
on
0 Posts
I'm fairly new to the LS3 so please excuse my lack of knowlege on some of the subjects. From what I have read, the ports are plugged in the back of the stock heads. Is that correct? If so, how hard are those plugs to remove?
10-20-2014, 10:32 PM
#30
Instructor
Thread Starter
With further tuning, we had our pump gas tune up to 747rwhp/709rwtq. Timing was in the 14-15 degree range on 93 octane. The latest race gas tune added 6 degrees of timing which brought it up to more like 20-21 degrees of timing. This coupled with some meth to cool the air charge brought the numbers up an additional 54rwhp to 801.
10-22-2014, 10:19 PM
#33
Instructor
Thread Starter
10-24-2014, 03:38 PM
#36
I can tell you about these mods, but I don't have photos to post today. It will be a few days before I can post some.
Cylinder head cooling. The early LS1 engine used to have a coolant crossover pipe underneath the intake manifold that connected the steam pockets from cylinders 1-2 and 7-8. When the Corvette went to the LS6 intake in 01, the crossover connection to the rear cylinders was eliminated because there was no space under the intake. The rear cylinders are the last to be cooled and number 7 is the very last. As a result, steam pockets develop on #7 and combustion temps can go super high, making detonation a very real & common phenomenon.
The solution is to get some cooling balance to the rear cylinders. Sure you could use the Trick Flow coolant crossover kit which opens up the steam passages on the rear of the cylinders and and connects them via rubber lines to the front 2 cylinders. I would do that with any LS engine as a minimum. But cylinder head guru Greg Good had a better idea for my Trick Flow heads. He installed 3/8" pipe to the water jackets on the back of the cylinder heads and has dual #6 stainless lines carrying coolant from #7 and #8 to the radiator hose up front. This is a much more generous way of moving coolant from the back of the heads than the steam pipes.
On the crankcase ventilation: It's well known that engines with boost build lots of crankcase pressure. This internal pressure has to be relieved somehow. The stock PCV system is not up to the task and the pressure usually finds its way out by blowing out the dip stick or worse, blowing out the rear main seal. My approach was to have a 3/4" line welded onto each valve cover and have the hoses extend to a remote catch can with a breather top mounted behind the right front headlight. This keeps most of the crankcase gasses from entering the cabin and enhances the 24/7 driving appeal of the car.
As an update, we added race fuel to the car and some methanol injection to cool the air charge in preparation for this week's Texas Mile. While still running the same 11-12 lbs of boost, our power increased to 801rwhp/735rwtq. The dyno sheet is below. This is really nice for a little Novi 1500 6 rib setup on a car with street manners as nice as stock. Still stock 6L80 trans and stock torque converter too.
Cylinder head cooling. The early LS1 engine used to have a coolant crossover pipe underneath the intake manifold that connected the steam pockets from cylinders 1-2 and 7-8. When the Corvette went to the LS6 intake in 01, the crossover connection to the rear cylinders was eliminated because there was no space under the intake. The rear cylinders are the last to be cooled and number 7 is the very last. As a result, steam pockets develop on #7 and combustion temps can go super high, making detonation a very real & common phenomenon.
The solution is to get some cooling balance to the rear cylinders. Sure you could use the Trick Flow coolant crossover kit which opens up the steam passages on the rear of the cylinders and and connects them via rubber lines to the front 2 cylinders. I would do that with any LS engine as a minimum. But cylinder head guru Greg Good had a better idea for my Trick Flow heads. He installed 3/8" pipe to the water jackets on the back of the cylinder heads and has dual #6 stainless lines carrying coolant from #7 and #8 to the radiator hose up front. This is a much more generous way of moving coolant from the back of the heads than the steam pipes.
On the crankcase ventilation: It's well known that engines with boost build lots of crankcase pressure. This internal pressure has to be relieved somehow. The stock PCV system is not up to the task and the pressure usually finds its way out by blowing out the dip stick or worse, blowing out the rear main seal. My approach was to have a 3/4" line welded onto each valve cover and have the hoses extend to a remote catch can with a breather top mounted behind the right front headlight. This keeps most of the crankcase gasses from entering the cabin and enhances the 24/7 driving appeal of the car.
As an update, we added race fuel to the car and some methanol injection to cool the air charge in preparation for this week's Texas Mile. While still running the same 11-12 lbs of boost, our power increased to 801rwhp/735rwtq. The dyno sheet is below. This is really nice for a little Novi 1500 6 rib setup on a car with street manners as nice as stock. Still stock 6L80 trans and stock torque converter too.
How much timing did that gulf 116 and meth allow at 11-12 psi?
10-24-2014, 09:14 PM
#37
Drifting
Fantastic. Thanks for sharing that.
It is only a car like yours, which could allow me to imagine not driving my SuperCharged C5.
Hope you'll let us know how it performs in the Texas mile event.
Don
It is only a car like yours, which could allow me to imagine not driving my SuperCharged C5.
Hope you'll let us know how it performs in the Texas mile event.
Don
10-27-2014, 06:52 PM
#38
Instructor
Thread Starter
We were able to run 21-22 degrees of timing which is about 6-7 more than on pump gas. The additional timing gave us 54more rwhp compared to 93 octane and no meth. I'm going to keep meth on the car (with smaller jets for the street) so my 93 octane meth tune will likely be closer to 760-770rwhp.
The Texas Mile was a blast. My wife told me before the event that I'd have to sell my car if I broke 200 mph so I did some of the best top-end bracket racing of my life. I ran 199.8mph, not once, but twice, LOL. For what it's worth, the 1/2 mile mph was a little more indicative of our power with 169.7mph trap speeds. Had I run it out completely, the car would have been closer to 201-202mph. Since I don't have a roll bar or the required safety equipment, I didn't want to get booted from the 3 days of racing for going over 200mph either. To me going 201 then blipping the throttle for a 199.8mph finish is just as exciting and I still got to continue making rounds. Kept the wife happy and kept the Texas Mile race director happy too. 
10-27-2014, 09:33 PM
#39
Nice results Pat. I have no doubt 205 would be there with that 1/2 trap.
