Hello everyone! I have been doing some research trying to plan for some mods on my 2010 ZR1 but wanted to get some opinions on here before I officially pull the trigger. The car needs new cats and since gutting them with no tune will turn on the CEL and tuning it voids my warranty on it anyway, might as well do a few other things while I'm at it. After doing some research and reading many different threads on here my current list is:


1. Gut the cats
2. American Heritage Stage 3 LS9 Heads (I know the stock heads are usually fine on the LS9, but coming from 2 LS7s, one of which dropped a valve, I feel I need to do this for peace of mind)
3. ID1050 injectors and flex fuel kit
4. Flex tune for 91 and E85
5. Have intercooler bricks reinforced by Kong


On the heads I plan on upgrading to the PSI 1511ML Springs. I am still unsure of whether or not to upgrade to the Moldstar90 guides, I would love some opinions on this. The car will still have the stock cam. I also plan on having the rev limiter bumped up to 7000 unless there's some reason why that would be a bad idea.

I know there are far cheaper ways to make even more power on these cars, but the heads and bricks are being done for piece of mind and take up quite a bit of the budget. With that being said I was curious, what do you all think of this lineup and am I forgetting anything major that I should consider doing as well or instead? LPE 710 kit will be coming down the road but the budget is already getting close to maxed as is so that will have to wait.

Any and all advice is appreciated!

 

I wouldn't pull the heads unless you have a whole lot of miles on them. I haven't seen any history of LS9's dropping valves. I think you're trying to fix something that probably won't break.

If you're changing the valve springs, you're not far from a cam upgrade labor wise. You'll gain more power from a cam swap than you'll ever see from ported heads using the stock cam

Long tube headers would be on my short list of what needs to be done also. If you're in OK, you won't have any trouble at inspection time. That would be the ONLY reason I wouldn't add long tubes to the mix.

So, If you're dead set on pulling the heads, I'd add new LS7 lifters, have the heads ported and milled .010, and use a .040 Cometic MLS head gasket when going back together. That will up the static compression ratio to around 10:1. Pulley down a little to speed the blower up to get the power up a bit. Texas Speed will CNC port your heads, do a valve job, mill to spec, and set the valve springs up for $750. Deal of the day in my book. Have Pat G spec you a cam with these mods in mind.

You'll end up with a very nice increase in power without breaking the bank if you don't do the heads. If you do the heads, the price will go up, but the fun factor will too......as long as you upgrade the cam.

 

Having a blown LS3 with a similar blower don't spin it faster, you will just make more heat and get diminished returns
As said, headers, maybe a cam, and if not just throw a smaller pulley on to up the boost and get a tune. Headers, pulley and a tune should "wake it up" to say the least.

 

LS9 makes plenty of power in stock form to begin with on the ZR1

If you want more seat of the pants type feeling, then you can go into TM so it not hobbling so much power, but your going to blistering the tire more instead.


If your really want more HP (TVS-2300 has the torque pegged by 2.5K around 600lbs from the start that would just roast the tires if TM was not holding back power), then either e85 kit or meth kit to combat the extra heat from the blower, and change the TVS pulley to a smaller pulley and retune. Increasing the blower water coolers will help a touch, but the real problem on the TVS unit is the inner coolers in the blower instead. Due to this, something like a meth kit does a better job of cooling the internal air of the blower, plus helps with the increased octane rating that you will need when pushing more boost to the motor.

Hence stock oem LS-9 can take about 26lbs of boost without problems (so long as run e-85 or meth kit to combat the heat since the blower will tune into a heat pump at this much pressure), while the blower in stock form is only putting out about 10.5lbs of boost from the factory instead.


As for road coursing the ZR-1, since the TVS creates a huge amount of linear torque off idle to begin with, you will find that you will have faster lap times with the PTM set to 5. With PTM turned off, all your going to do is blister the tires out of every corner with the amount of torque that the engine as so low of RPMs isntead.

Truth is, for road course work, the LS7 motor is better. With that motor putting out about the same 620hp as the LS9, the torque increases with the Rpm, so your not having to PTM hobble the motor to keep the back tires sticking while powering out of the corner isntead. So really, the ZR7 carbon fiber edition with LS7, is the better car in most hands instead.

 

Call Kong and spend it there. Ported TB, ported blower, slight pulley decrease for a few pounds extra boost and a tune.

 

As stated, not of lot of mods needed on the ZR1 until is becomes dam near un-drivable on street tires due to the amount of torque that the LS9 makes so low to start with.
Hell, I can go in to remap the throttle and de-hobble the TM, and the car will blister the tire every time you breath heavy on the gas pedal.

As is, the car will pull 200mph with no problems, and most of the mods done to the higher horsepower cars, ends up with More hobbling of the TM to try to keep the super cup street tires sticking isntead.

Bottom line, give us the name of the high speed road coarse you are running, what your lap times are, and I will guarantee that adding more HP to the motor is not going to decrease your lap times. Hence your fastest lap time will be with the PTM set to 4 or 5 on the OEM power, and by adding more torque/ HP, your just going to end up adding in more PTM (down to 2 or 3) to maintain your lap times isntead.