01-29-2021, 02:55 PM | #1 |
Drives: 2018 Camaro SS 1LE Join Date: Jul 2018
Location: Stuttgart, Germany
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Porting LT4 Blower/TB/Less Boost?
Greetings.
Have an interesting combination. I installed an LT4 blower on my LT1, but find a bit too much boost for the octane here in Germany. I end up using octane booster for those 'high stress' situations. I'd like to get away from that requirement - so shipped my 7000 mile OEM LT4 blower to have a 'larger' pulley (2.7) installed along with a full internal porting. Will also be adding a 103 MM throttle body to the mix. The hope is slightly less boost, but a reduction in restriction to make some of the power back. This likely won't be the last combination so an intermediate step at least for this upcoming season. Bad idea? Note: German restrictions for inspections and checkpoints dictate a stock appearing car... Thanks.
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Last edited by Tim M; 01-29-2021 at 02:57 PM. Reason: Images |
01-29-2021, 04:02 PM | #2 |
Drives: 2017 Camaro 2SS A8 Join Date: Aug 2018
Location: Petersham MA
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Nothing wrong with that approach at all. Very sensible.
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2017 Chevy Camaro 2SS A8 Whipple 3.0, Mast Black Label heads, Fore triple in-tank pumps, 112mm TB, LPE +52% injectors, LPE BB HPFP, 15” conversion 1059 WHP/944 WTQ, 9.48@150
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01-30-2021, 12:57 PM | #3 |
Drives: 2018 Camaro SS 1LE Join Date: Jul 2018
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Joshinator99: Good deal.
Bit tough to calculate the end boost. Currently, at ~11.5 psi. Going to a larger pulley along with the porting/TB (~+1.5 psi)...hopefully land at 10 or so.
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01-30-2021, 02:10 PM | #4 | |
Drives: 2017 Camaro 2SS A8 Join Date: Aug 2018
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Quote:
If your car must appear “stock” consider a 95mm TB. Looks like a factory piece because it is. And at your power level it’ll be great. A 103mm is great too obviously, but overkill for where you want to be and the 103/112 units definitely look more aftermarket.
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2017 Chevy Camaro 2SS A8 Whipple 3.0, Mast Black Label heads, Fore triple in-tank pumps, 112mm TB, LPE +52% injectors, LPE BB HPFP, 15” conversion 1059 WHP/944 WTQ, 9.48@150
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01-30-2021, 02:16 PM | #5 |
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11.5lbs of manifold pressure with stock LT4 pulleys?
Interesting. |
01-31-2021, 10:03 AM | #6 |
Drives: 2018 Camaro SS 1LE Join Date: Jul 2018
Location: Stuttgart, Germany
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Joshinator99: Europeans use different rating system although the commonly available 98 is similar to 93. They also offer 100 and 102...but at $8 a gallon...tough to swallow.
I considered the 95 mm, but I expect the combination to change again. Kong's porting opens up the TB boss to a 103 size. I will be going with the black anodized Nick Williams model...in hopes to minimize issues. gtfoxy: The logs show a solid 180 kpa on the top end - equates to 11.8 or so, no? Otherwise the car is OEM stock.
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01-31-2021, 10:47 AM | #7 |
Drives: 2017 Camaro 2SS A8 Join Date: Aug 2018
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No surprise on the boost level. My friend just put a ZO6 LT4 blower on his mostly stock SS and got similar boost levels. He ran into similar problems as we couldn’t give it any timing. So he’ll have to reduce the boost like Tim or add some E to raise effective octane level.
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2017 Chevy Camaro 2SS A8 Whipple 3.0, Mast Black Label heads, Fore triple in-tank pumps, 112mm TB, LPE +52% injectors, LPE BB HPFP, 15” conversion 1059 WHP/944 WTQ, 9.48@150
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02-02-2021, 08:45 AM | #8 | |
Dyno Show Queen LOL
Drives: 16 SS & 17 ZL1 Both Yellow Join Date: Jan 2014
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How about a restrictor plate between the TB and blower?
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Kong Ported 2650, Crawford Racing Port Injection, Weapon X 112mm Adapter, NW112mm TB, Livernois Ported LT4 Heads, Lingenfelter GT32 stealth cam, Haltech Elite, and Carbon by Trufiber |
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02-03-2021, 12:02 PM | #9 |
Drives: 2018 Camaro SS 1LE Join Date: Jul 2018
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:-)
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02-03-2021, 12:43 PM | #10 | |
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Quote:
I didn’t anticipate the heads/ manifolds being that much more restrictive either. |
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02-03-2021, 01:22 PM | #11 |
Drives: 2017 Camaro 2SS A8 Join Date: Aug 2018
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Hmmm...I wonder if the crank pulley size is the same between LT1 and LT4?
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2017 Chevy Camaro 2SS A8 Whipple 3.0, Mast Black Label heads, Fore triple in-tank pumps, 112mm TB, LPE +52% injectors, LPE BB HPFP, 15” conversion 1059 WHP/944 WTQ, 9.48@150
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02-03-2021, 01:50 PM | #12 | |
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Quote:
They are different part numbers. I see the LT4 is 8”, not sure on the SS. It’s a tough call, spend the $150 on a new LT4 crank pulley or more on an upper aftermarket pulley & have versatility later on. Or in my case $150 for an SS damper/ pulley or a lot more for an aftermarket damper & pulley for a couple lbs more boost. Crank seal ID should be the same? |
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02-03-2021, 02:43 PM | #13 |
Drives: 2018 Camaro SS 1LE Join Date: Jul 2018
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All the parts are LT4 including the drive system. LT1's lack the blower belt pulley altogether. It does use adapter plates for LT4 to LT1 cylinder head connections.
Believe the forum experts have said the LT1 cam and 11.5 CR contribute to the difference in boost readings. I think the tuning is very good, but just on the edge for using on a road courses for extended periods (cast pistons). It has too much power for my skills on the track...but it could use more for the autobahn. :-)
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02-03-2021, 02:56 PM | #14 | |
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Quote:
I’m not seeing how Cr changes anything. Well. Except for residual cylinder pressure at IVO, but that’s still tied to valve curtain. It would be cam timing or in the heads/ manifolds. |
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