ZL1 #140 starting mods

[Indpowr]

sexy

[sammyv]

Very nice!

[1st Gen Forever]

So here's some comparison between the stock LSA heads and the Mast medium bore LS3 heads. Mostly on the exhaust side.

Closeup of stock LSA exhaust port shape followed by angle shot of Mast exhaust ports




Horizontal diameter of stock LSA exhaust port on top and Mast on bottom




Vertical diameter of stock LSA exhaust port on top and Mast on bottom




Exhaust gasket alignment on Mast head followed by closeups of the inside of the exhaust and intake ports on the Mast head






I really like the craftsmanship in these heads!

[radz28]

Originally Posted by 1st Gen Forever

I'll get some better pics of those heads up tonight. Been at work today when they showed up.

I don't know if I'll stick with the 1900 long term. Figured I'd do what I can with it then maybe consider a Whipple later. I imagine KDi will release a Whipple kit sometime before too long...

Please - let me just say that I appreciate the way you are going. I've been wondering how far the 1900 can reasonably carry LSA. I know it's not too far, however, moreover, I'm looking to see if it's worth keeping. For example - I have a power goal in mind and had been considering pulleys and a little exhaust and intake mods' for several more pounds of boost. Now - with your project - I'm thinking it might be worth looking into better heads. I've been wanting to see some MAST stuff, and am very interested in these particular models and their splayed valve model. If I can go with something like these, and maybe a smaller upper, I might be able to keep the stealth factor and keep the smog police at bay. If I keep the boost lower, my IATs will be better, and I can just have a more efficient package.

Anyways - I love what you're doing!

Originally Posted by 1st Gen Forever

So here's some comparison between the stock LSA heads and the Mast medium bore LS3 heads. Mostly on the exhaust side.

Closeup of stock LSA exhaust port shape followed by angle shot of Mast exhaust ports




Horizontal diameter of stock LSA exhaust port on top and Mast on bottom




Vertical diameter of stock LSA exhaust port on top and Mast on bottom




Exhaust gasket alignment on Mast head followed by closeups of the inside of the exhaust and intake ports on the Mast head






I really like the craftsmanship in these heads!

That is all

[RoketRdr]

Originally Posted by radz28

Please - let me just say that I appreciate the way you are going. I've been wondering how far the 1900 can reasonably carry LSA. I know it's not too far, however, moreover, I'm looking to see if it's worth keeping. For example - I have a power goal in mind and had been considering pulleys and a little exhaust and intake mods' for several more pounds of boost. Now - with your project - I'm thinking it might be worth looking into better heads. I've been wanting to see some MAST stuff, and am very interested in these particular models and their splayed valve model. If I can go with something like these, and maybe a smaller upper, I might be able to keep the stealth factor and keep the smog police at bay. If I keep the boost lower, my IATs will be better, and I can just have a more efficient package.

The factory 1.9L blower is plenty capable as ADM, Hennessey, Livernois, Aspire Performance Tuning and others have already proven. Plenty of CTS-V owners that have been running 800hp on the stock blower for several years. Unless you're wanting well over that, or you're building a top speed queen, there's no need to change the stock blower. The fuel system should be more of a concern and focus than the blower.

[radz28]

Originally Posted by RoketRdr

The factory 1.9L blower is plenty capable as ADM, Hennessey, Livernois, Aspire Performance Tuning and others have already proven. Plenty of CTS-V owners that have been running 800hp on the stock blower for several years. Unless you're wanting well over that, or you're building a top speed queen, there's no need to change the stock blower. The fuel system should be more of a concern and focus than the blower.

Yeah - there are a lot of builds from those guys. I think I was thinking more along the lines of balancing boost with IATs. Would it be more worthwhile to go with a 2300 and run a few pounds less boost than increase the boost several pounds on the 1900 and have to get a new HE, pump, and reservoir? Now that I say that out loud, those three things will be less than a 2300 SC, lol. But... I'm trying to consider if a pulley and heads (shoot - even cheap CNC'd GMPP LS3 heads!) would be sufficient.

Sorry - I'm all turned around this morning. Thanks for the tip. It was my understanding from Magnuson that that 1900 was good to 700-800 FWHP when the TVS was being introduced

[RoketRdr]

Originally Posted by radz28

Yeah - there are a lot of builds from those guys. I think I was thinking more along the lines of balancing boost with IATs. Would it be more worthwhile to go with a 2300 and run a few pounds less boost than increase the boost several pounds on the 1900 and have to get a new HE, pump, and reservoir? Now that I say that out loud, those three things will be less than a 2300 SC, lol. But... I'm trying to consider if a pulley and heads (shoot - even cheap CNC'd GMPP LS3 heads!) would be sufficient.

Sorry - I'm all turned around this morning. Thanks for the tip. It was my understanding from Magnuson that that 1900 was good to 700-800 FWHP when the TVS was being introduced

Those are good points. It really comes down to the end result that you're looking for. I'm personally going to be running a combination chiller/heat exchanger set-up so I'm not worried about the increased temps that come with boost on the 1900. And don't forget about being able to port the stock 1.9 as well. But running a 2300 at lower boost to keep the temps down is definitely something worth looking at as well. I believe KDI has some experience in this area. Going with the heads will help but keep in mind that the factory LSA heads are no slouch either. They're very good right out of the box unless you're looking for monster hp. But you can clearly see the quality and flow increase in these MAST heads so even if you didn't make 800hp+ down the road they are worth the investment.

[radz28]

Originally Posted by RoketRdr

Those are good points. It really comes down to the end result that you're looking for. I'm personally going to be running a combination chiller/heat exchanger set-up so I'm not worried about the increased temps that come with boost on the 1900. And don't forget about being able to port the stock 1.9 as well. But running a 2300 at lower boost to keep the temps down is definitely something worth looking at as well. I believe KDI has some experience in this area. Going with the heads will help but keep in mind that the factory LSA heads are no slouch either. They're very good right out of the box unless you're looking for monster hp. But you can clearly see the quality and flow increase in these MAST heads so even if you didn't make 800hp+ down the road they are worth the investment.

OH - I hadn't noticed you're working on a project, too (ZL1?). If you choose to share, I'd be interested. I thought these FI OEM heads didn't flow too well because of the vains for the swirl GM wanted; I don't exactly recall flow numbers, but I thought I read they we're as good as LS3/L99/L76-type ports, even though they are very similar. I believe a 2300 is going be within a couple grand of a Maggie, KB, or Whipple, so I'm pretty apprehensive, especially considering there are probably CARB-numbers that might cover ZL1 for all three of those, while the 2300 from GMPP won't. I've been wondering which to go with, too, as far as chiller or HE, too. I was thinking maybe the chiller would be what I'd want if I'm going to spend more time on the strip whil the HE would be better for the rest. The two together would be outstanding, but I'm also really thinking about budget-conscience mods'.

I'm sorry for going a little off-topic. I just wanted to give a better idea where I was coming from. The more I think about it, though, the more heads appeal. I've been watching for MAST product reviews, so I can't wait to see how this turns out

[Andy@Livernois]

Originally Posted by radz28

OH - I hadn't noticed you're working on a project, too (ZL1?). If you choose to share, I'd be interested. I thought these FI OEM heads didn't flow too well because of the vains for the swirl GM wanted; I don't exactly recall flow numbers, but I thought I read they we're as good as LS3/L99/L76-type ports, even though they are very similar. I believe a 2300 is going be within a couple grand of a Maggie, KB, or Whipple, so I'm pretty apprehensive, especially considering there are probably CARB-numbers that might cover ZL1 for all three of those, while the 2300 from GMPP won't. I've been wondering which to go with, too, as far as chiller or HE, too. I was thinking maybe the chiller would be what I'd want if I'm going to spend more time on the strip whil the HE would be better for the rest. The two together would be outstanding, but I'm also really thinking about budget-conscience mods'.

I'm sorry for going a little off-topic. I just wanted to give a better idea where I was coming from. The more I think about it, though, the more heads appeal. I've been watching for MAST product reviews, so I can't wait to see how this turns out

Typically a stock LSA head is about 30 CFM down compared to a stock LS3 head. However, our CNC ported LSA head is within 2-3 CFM of our CNC ported LS3 head while providing a superior casting for FI builds.

[RoketRdr]

Originally Posted by radz28

OH - I hadn't noticed you're working on a project, too (ZL1?). If you choose to share, I'd be interested. I thought these FI OEM heads didn't flow too well because of the vains for the swirl GM wanted; I don't exactly recall flow numbers, but I thought I read they we're as good as LS3/L99/L76-type ports, even though they are very similar. I believe a 2300 is going be within a couple grand of a Maggie, KB, or Whipple, so I'm pretty apprehensive, especially considering there are probably CARB-numbers that might cover ZL1 for all three of those, while the 2300 from GMPP won't. I've been wondering which to go with, too, as far as chiller or HE, too. I was thinking maybe the chiller would be what I'd want if I'm going to spend more time on the strip whil the HE would be better for the rest. The two together would be outstanding, but I'm also really thinking about budget-conscience mods'.

I'm sorry for going a little off-topic. I just wanted to give a better idea where I was coming from. The more I think about it, though, the more heads appeal. I've been watching for MAST product reviews, so I can't wait to see how this turns out

Its gonna take some time but I will be posting results of my findings. I'm a road racer and drag race just for fun so my focus is to have the chiller working 100% of the time and the HEX set-up for emergency back-up and WOT. I will be keeping the stock 1.9L blower and just add porting and 102mm TB. Going to stay with the factory heads initially but if I run into any issues then I will look at another set of heads like the MAST units.

[RoketRdr]

Originally Posted by Andy@Livernois

Typically a stock LSA head is about 30 CFM down compared to a stock LS3 head. However, our CNC ported LSA head is within 2-3 CFM of our CNC ported LS3 head while providing a superior casting for FI builds.

Andy, did you guys port the 1.9L on the 9 second car? Can't recall reading that you did but just assuming so.

[radz28]

Originally Posted by RoketRdr

Its gonna take some time but I will be posting results of my findings. I'm a road racer and drag race just for fun so my focus is to have the chiller working 100% of the time and the HEX set-up for emergency back-up and WOT. I will be keeping the stock 1.9L blower and just add porting and 102mm TB. Going to stay with the factory heads initially but if I run into any issues then I will look at another set of heads like the MAST units.

I'll be watching

Originally Posted by Andy@Livernois

Typically a stock LSA head is about 30 CFM down compared to a stock LS3 head. However, our CNC ported LSA head is within 2-3 CFM of our CNC ported LS3 head while providing a superior casting for FI builds.

Is there more than the vain the is a flow obstruction?

I do like the MASTS run 12* valve angles.

[Andy@Livernois]

Originally Posted by RoketRdr

Andy, did you guys port the 1.9L on the 9 second car? Can't recall reading that you did but just assuming so.

Actually no, unmodified blower, and unmodified blower snout, just a 90mm TB, cai, and our stage 2 heads were the only airflow improvements

Originally Posted by radz28

I'll be watching



Is there more than the vain the is a flow obstruction?

I do like the MASTS run 12* valve angles.

Typically a 15* head is actually better for this type of build since the rotated valve angle makes the head favor the intake port even more so then it already does. Don't get me wrong better flow is better flow, but it usually hurts the exhaust rotating the angle over, and since it's a blower it needs more help on the exhaust side then the intake anyways. Again, the intake improvement is always beneficial.

It will be interesting to see the results.

[1st Gen Forever]

I like the discussion guys!

Rad, I'm not experienced in this like the shops that have been doing it a while but from my research, if I were looking for a stealth solution, I would do the following at a high level:
-Port the stock heads
-Port the supercharger
-Go with a mild step up in cam/springs
-Change the lower pulley only (9.55 maybe)
-Larger fuel injectors
-Better heat exchanger
-Tune

Beyond the above, leaving the stock exhaust and intake would offer the best stealth look but you'll be limiting flow. If you add exhaust and a CAI with the above you should be looking at a solid 600 to 640HP to the wheels, not spend a whole lot, (maybe $8k) and look mostly stock under the hood.