C6 Sequential Port Injection v C8 DI
Thread Starter
Intermediate
Joined: Jan 2013
Posts: 35
Likes: 3
From: Merced, CA
C6 Sequential Port Injection v C8 DI
Per YouTube videos Dual Injection or
Port Injection only are rendered obsolete
by modern Direct Injection.
To mitigate any carbon buildup to
intake valve I would change oil every 3,000 miles
with synthetic oil, avoid short trips especially during winter and an Italian Tuneup once a month.
Oil is cheap; engine and poor MPG are not.
https://youtu.be/qqu0V_iMBow?si=U523jvnIBKddgfH7
https://youtu.be/MIDItBqX3SQ?si=pBANCnJWe_llzAs3
Port Injection only are rendered obsolete
by modern Direct Injection.
To mitigate any carbon buildup to
intake valve I would change oil every 3,000 miles
with synthetic oil, avoid short trips especially during winter and an Italian Tuneup once a month.
Oil is cheap; engine and poor MPG are not.
https://youtu.be/qqu0V_iMBow?si=U523jvnIBKddgfH7
https://youtu.be/MIDItBqX3SQ?si=pBANCnJWe_llzAs3
Last edited by mikeflores2000; Jan 12, 2024 at 01:51 PM.
Pro
Joined: Aug 2022
Posts: 615
Likes: 441
From: Bay Area, CA
2025 C8 Stingray of the Year Finalist - Unmodified
Not all. I don't think I could trust Circle K or 7-11 gas.
https://www.toptiergas.com/gasoline-brands/
https://www.toptiergas.com/gasoline-brands/
Burning Brakes
Joined: Nov 2022
Posts: 1,054
Likes: 1,114
From: Western Mass
You can do it yourself in about 30 min or less. There are options for catch cans out there. I have a Mishimoto. If you check out Paragon's website you can find a video on how to install. Same with Mishimoto. Very easy and straight forward.
Drifting
Joined: Sep 2020
Posts: 1,453
Likes: 1,194
From: DFW
Per YouTube videos Dual Injection or
Port Injection only are rendered obsolete
by modern Direct Injection.
To mitigate any carbon buildup to
intake valve I would change oil every 3,000 miles
with synthetic oil, avoid short trips especially during winter and an Italian Tuneup once a month.
Oil is cheap; engine and poor MPG are not.
https://youtu.be/qqu0V_iMBow?si=U523jvnIBKddgfH7
https://youtu.be/MIDItBqX3SQ?si=pBANCnJWe_llzAs3
Port Injection only are rendered obsolete
by modern Direct Injection.
To mitigate any carbon buildup to
intake valve I would change oil every 3,000 miles
with synthetic oil, avoid short trips especially during winter and an Italian Tuneup once a month.
Oil is cheap; engine and poor MPG are not.
https://youtu.be/qqu0V_iMBow?si=U523jvnIBKddgfH7
https://youtu.be/MIDItBqX3SQ?si=pBANCnJWe_llzAs3
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Burning Brakes
Joined: Nov 2022
Posts: 1,054
Likes: 1,114
From: Western Mass
Race Director
Joined: Aug 2016
Posts: 12,763
Likes: 10,199
From: Garden Valley CA
There now a quarter million LT1/LT2 engined Corvettes on the road, some for over a decade with over 100K miles on them. I have yet to see someone post they had a problem attributed to coking or post pictures of intakes with excessive carbon buildup on a unmodified street driven car. You'd think if it was a problem there would be at least a few pictures posted by now.
Burning Brakes
Joined: Nov 2022
Posts: 1,054
Likes: 1,114
From: Western Mass
There now a quarter million LT1/LT2 engined Corvettes on the road, some for over a decade with over 100K miles on them. I have yet to see someone post they had a problem attributed to coking or post pictures of intakes with excessive carbon buildup on a unmodified street driven car. You'd think if it was a problem there would be at least a few pictures posted by now.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,943
Likes: 12,359
From: NE South Carolina
Per YouTube videos Dual Injection or
Port Injection only are rendered obsolete
by modern Direct Injection.
To mitigate any carbon buildup to
intake valve I would change oil every 3,000 miles
with synthetic oil, avoid short trips especially during winter and an Italian Tuneup once a month.
Oil is cheap; engine and poor MPG are not.
https://youtu.be/qqu0V_iMBow?si=U523jvnIBKddgfH7
https://youtu.be/MIDItBqX3SQ?si=pBANCnJWe_llzAs3
Port Injection only are rendered obsolete
by modern Direct Injection.
To mitigate any carbon buildup to
intake valve I would change oil every 3,000 miles
with synthetic oil, avoid short trips especially during winter and an Italian Tuneup once a month.
Oil is cheap; engine and poor MPG are not.
https://youtu.be/qqu0V_iMBow?si=U523jvnIBKddgfH7
https://youtu.be/MIDItBqX3SQ?si=pBANCnJWe_llzAs3
Like many, was concerned about Coking with my early 2014 C7, 1st high performance engine GM had used DI. On lower hp "grocery getters" DI s less likely and issue. BUT on a high hp, high performance engine the intake valve gets HOT. More likely to bake PCV stuff on the back of the intake valve. Before DI you would see ads from gasoline companies reminding the gasoline was NOT ENOUGH with port injection, carburetors etc to wash off PCV stuff! Had to use TOP Tier gas etc. Since zero gas passes over the back of hot intake valves it's useless with DI!
BMW and Ferrari had DI on high performance engines BEFORE GM and had ISSUES. Some BMWs used walnut blasting to eliminate backed on carbon, called Coking!"
So I added a Catch can to my 2014 C7 Z51 only street driven, often aggressively BUT not a high percentage with WOT. I collected ~1oz/1000 miles. That was 1 oz of PCV "stuff" (mostly oil and oil vapor" that could not bake on the back of the hot intake valves.) It may have helped. But as RKCRLR mentioned the C7/C8 have no reported issues in street driven cars. Perhaps some in cars that are frequently Tracked or Raced. But as Tadge Juechter said in 2014 it's mostly a cosmetic issue.
BUT then GM spent a lot of time and engineering to improve that "no problem" PCV system on my 2017 Grand Sport. I transferred my "Can" to the Grand Sport but did the research to assure "I was doing no harm." Even installed a pressure vacuum gauge to define where the fresh air was coming from that went into the Crankcase. It has very complex plumbing and I was collecting <1/2 oz per 1000 miles, not worth the effort. In addition, a tech article stated a small amount of oil does HELP lubricate the Intake valve guides! Removed it!
If you Track, perhaps there is a benefit at WOT- perhaps NOT! To each their own!
PS: That Italian Tune Up you referred to I often did with Carburetors or Port Injection. Could help as the rich gasoline mixture at WOT might have helped reduce coking of the intake valves and might reduce combustion chamber carbon. BUT WITH DI probably makes Coking on the back of the Intake Valves Worst as your just letting the intake valve operator hotter.
Last edited by JerryU; Jan 15, 2024 at 01:33 PM.