New Idea for l98 Intake
Thread Starter
Intermediate
Joined: Oct 2002
Posts: 34
Likes: 0
From: north providence ri
New Idea for l98 Intake
Would like some opinions about modifing an l98 tpi intake.
Is it possible to bore a 1 inch hole in the top of each runner in the lower intake
(8 holes total) and 8 corresponding holes in the bottom of the plenum all in a row. Then put eight tubes running from the plenum to the lower base. Along with that put a single shaft in the plenum with 8 throttle plates covering the 8 tubes.
At about 4500 rpm rotate the shaft and open all 8 ports.
It would give the great low end from the long tubes and good top end from the short tubes.
What do you think, can it be done or is it more work then it's worth?
Is it possible to bore a 1 inch hole in the top of each runner in the lower intake
(8 holes total) and 8 corresponding holes in the bottom of the plenum all in a row. Then put eight tubes running from the plenum to the lower base. Along with that put a single shaft in the plenum with 8 throttle plates covering the 8 tubes.
At about 4500 rpm rotate the shaft and open all 8 ports.
It would give the great low end from the long tubes and good top end from the short tubes.
What do you think, can it be done or is it more work then it's worth?
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Re: New Idea for l98 Intake (MrNuke)
Sounds like more work than worth. Have you ever seen how the LT5 works? Its on the same premise. Under certain RPM/Throttle/Vacuum conditions the vacuum actuated secondaries open up the other 8 intake runners and start firing the secondary injecotors. Thats why you see 16 runners on the top of an LT5. When you turn the power key off the 2nd set of runners and injectors are completely disabled and cannot activate giving you nearly the same power as a stock L98.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: New Idea for l98 Intake (BLACKVET)
Great idea but it could potentially be a logistical nightmare. You would probably need to use an RPM window switch of sorts to open the "secondaries" Then you've got the question of controlling it. Is this something you would wan to go 100% open immediately or would you want to open it gradually?
Seems like a lot of work and a lot of money for not just a whole lot of gain.
Seems like a lot of work and a lot of money for not just a whole lot of gain.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: New Idea for l98 Intake (BLACKVET)
I had an idea similar to this that used two sets of runners for each cylinder, of different lengths.
above a certain rpm, butterflies in the plenum would redirect the flow stream.
Clearing the fuel rails would be the most difficult challenge.
Initially, I had a more elaborate design with two single bore throttle bodies, secondaries, and two seperate plenums supplying the alternating 'banks' of cylinders: 1,4,6,7 and 2,3,5,8 (Dividing them this way ensures alternating intake charges from each plenum.) The orientation of the seperate plenum make it fit easier, and makes it possible to have a bolt-on two stage intake possibly without needing more than a solenoid for the secondaries, and two single bore throttle bodies from a parts yard.
Oh well, I may be giving away good ideass, but it's nice to see other people scratching their heads too.
:seeya
above a certain rpm, butterflies in the plenum would redirect the flow stream.
Clearing the fuel rails would be the most difficult challenge.
Initially, I had a more elaborate design with two single bore throttle bodies, secondaries, and two seperate plenums supplying the alternating 'banks' of cylinders: 1,4,6,7 and 2,3,5,8 (Dividing them this way ensures alternating intake charges from each plenum.) The orientation of the seperate plenum make it fit easier, and makes it possible to have a bolt-on two stage intake possibly without needing more than a solenoid for the secondaries, and two single bore throttle bodies from a parts yard.
Oh well, I may be giving away good ideass, but it's nice to see other people scratching their heads too.
:seeya
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: New Idea for l98 Intake (BLACKVET)
I've done the siamese base mod and it provides two runners for each cylinder to breath through.
If you could put a movable diaphram separating the two tubes in the intake base you could essentially do what you propose. If you simply make the new functioun RPM dependent, you should be able to redo the fuel curve.
If you could put a movable diaphram separating the two tubes in the intake base you could essentially do what you propose. If you simply make the new functioun RPM dependent, you should be able to redo the fuel curve.
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Re: New Idea for l98 Intake (BLACKVET)
Sounds like Ferrari or maybe Lambo's new design....they have like telescoping runners that adjust with rpm to allow the perfect combo of low-end tq and high end hp....I would love to see it at work on a vette! :cool:
