I have had my SVTF for about a month now and absolutely love the handling characteristics of the car. As far as power goes, this car is definatly lacking. Getting down to my question though. Has anyone ever experimented with a different intake manifold setup. The whole dual runner manifold seems like a waste of space and money. With all the problems I have read about and now encountered with the piece, it seems to be a piece of crap. I have read how everyone thinks it is great and how hp and torque will be lost if switching to a different manifold, but I am not sure this is true. If a aftermarket large plenum style manifold was made, couldn't the car be tuned to preform just as well or not better? I have no plans to turbo the car, so it will be a minimal gain if there is one. But i guess the whole purpose of this would be a escape away from this intake manifold that alot of people have problems with. Any thoughts?
11-06-2007 09:39 PM
FI would be the only reason for a new intake. All the custom intakes i have heard about or seen has always failed. There is nothing out there man. Sorry. As long as you keep an eye on your DSI clip and make sure your IMRC is working properly, i wouldnt worry about it. Aftermarket tunes can change when the runner changes. Do a search on these topics, they have been discussed quite a bit on here.
11-06-2007 09:45 PM
The issue with ditching the whole DSI is the fact of either loosing low end and gaining high end or loosing high to gain low...im sure you could make one that has a nice medium but you will then loose a little low and high. If staying NA then i dont really see a better option than a DSI manifold.
11-06-2007 09:46 PM
I have read many threads where people say forced induction is the only reason for a new manifold. I still dont believe that to be true though. You say you have seen many designs that have failed, but how far did they go through with the project. And yes i know that the engagement point of the runners can be changed by a tune, but i was referring to timing and fuel being adjusted to yield the same results or better with a aftermarket manifold compared to stock. I am not trying to come across as a jerk with this post, but Im just trying to see if anyone has ever tried or created an aftermarket manifold.
11-06-2007 09:53 PM
In response to losing high end hp or low end torque, I understand what you are saying. With that being said though, the use of aftermarket cams produces hp/tq gains and losses across the powerband depending on the grind, lift, and duration. It is all a give and take but people still choose to change the cams in their foci.
11-06-2007 10:09 PM
The fact that our manifold is made of two separate parts also eases the process of making a manifold. The flange side of the stock manifold could be retained lowering production costs. Then a larger plenum and runners could be mated to the stock flange using the stock intake manifold hoses. A bracket could support the new plenum to the block. It just seems to be a fairly inexpensive design that could be fairly easy to install after produced. Also by keeping the stock plastic flange, it could reduce intake temps from a metal flange by heat dissapation. I was just hoping one of the board sponsers such as c-f-m or focusport would jump in on this idea and create a manifold just for sole purpose of dyno improvements. Not only do i think it is possible to see hp and tq gains from this, but it would also be a nice dress up piece to the engine bay.
11-06-2007 10:51 PM
Heh, I certainly understand what you mean. The DSI manifold does seem like a bit of a mechanical hassle - although the only real problem consistently encountered is the clip breaking on the thing, which has been remedied by CFM with their billet aluminum clip. The thing is, just about everything that could possibly be done to suck an extra tenth of a horsepower or foot-pound out of these engines has been done, very completely, by at least a few owners, and those renovations that work tend to take off and gain popularity rather spectacularly, if they're in the least bit cost-efficient or helpful with the powerband. The fact that we keep running into, however, is that SVT did too damned good a job with most of the engine components to leave a lot of room for improvement with normal aspiration. The stock tune certainly sucks, but a great many of us have had that remedied by one of the fellas that has done everything that can be done to the SVTF and can provide tunes configured for every modification we have done individually. As SVT claims our engine to be the most sophisticated and complex one they've developed, it seems to be true considering what they've done to make the thing put out as much smog-legal and $$-friendly power it can. I guess the thing is that a lot of other mods would have to be done to the engine first to get to the point where the DSI manifold the restricting/problematic component. I'm as excited as anyone else, though, to hear of improvements that can be made - maybe someone's got a magic manifold hidden away under their hood that we still need to hear about :-D
11-06-2007 10:55 PM
Originally Posted by Slocusvt
I was just hoping one of the board sponsers such as c-f-m or focusport would jump in on this idea and create a manifold just for sole purpose of dyno improvements. Not only do i think it is possible to see hp and tq gains from this, but it would also be a nice dress up piece to the engine bay.
I think Focussport did make a prototype manifold and header and gave up on both as not being worth their efforts because the gains (if any were to be had) were so minimal.