Opinions regarding this intake
Opinions regarding this intake
(OP)
This is an intake that is popular among the Neon owners... I dont believe that it is functional regarding performance gains. i have not personally personally performed this modification. I just wanted to see what kind of problems everyone saw with this setup. Please feel free to "Bash" it... I want all honest personal opinions.
thanks in advance, stephen
thanks in advance, stephen





RE: Opinions regarding this intake
http://forum.2gn.org/viewtopic.php?t=12037
RE: Opinions regarding this intake
It has to withstand turbo boost and under bonnet temperatures. ABS is not really strong enough nor temperature resistant, nor solvents resistant enough to do the job.
OEM plastic manifolds are normally made from Glass Filled Nylon 6.6 which is considerably more expensive and more difficult to process than ABS.
If ABS was suitable, OEM would use it and solve the problem of gluing the various components together.
Regards
eng-tips, by professional engineers for professional engineers
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RE: Opinions regarding this intake
RE: Opinions regarding this intake
Nylon is very difficult to glue.
The link says ABS, but you say PVC. These are different plastics with different properties. PVC is more common than ABS for pipe, but both are used and both respond well to solvent bonding to themselves, but not to nylon.
The manifold will be fragile and prone to cracks between the nylon and the PVC/ABS?
The different plastics will have very different reactions to temperature changes. ABS softens at about 100 to 110 deg C and PVC softens at about 90 deg C. under bonnet temperatures are more likely to peak at 130 or 140 deg C I would think.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Opinions regarding this intake
RE: Opinions regarding this intake
I would be very surprised if this owner gained much in the way of performance even at one specific rpm.
The intake runners entering the plenum are not radiused. Plus sticking the ends out into the prevailing airflow is not wise. T'would be better if they joined in a similar manner to the stock manifold.
RE: Opinions regarding this intake
But if you don't then I suspect the gains would be small, at best, and negative, typically.
Basic engine 101 says VE is good for economy, and torque, at a given rpm. OEMs like good economy, and performance, for no money. So, either the OEM engineers are thick as two short planks, or the VE has already been optimised. Most OEM engineers are only as thick as one short plank.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Opinions regarding this intake
Some of these make two short planks look like a computer!!
Ken
RE: Opinions regarding this intake
RE: Opinions regarding this intake
This intake design seemed so wrong in too many ways. I belive an all aluminum intake would be better for these kind of modifications.
Unfotunately I do not have any experience with welding aluminum, and do not wish to spend alot of money having someone else build an intake for me.
One of these days I will be able to fabricate what I need, but for the time being, I like to learn as much information as possible so that my "backyard" creations will add performance, rather than take it away.
Again, thanks everyone for the comments.
RE: Opinions regarding this intake
Individual throttle bodies are very difficult to fabricate unless you have considerable skills and equipment.
An easier way is a similar design to many OEM designs that have individual runners feeding from a plenum, with one big throttle body on the plenum. That way you just buy a suitable sized throttle body from the wreckers. This costs a fraction of response time, but actually can make more power as the throttle body is a restriction that creates some turbulent flow. The inlet to the plenum is a less sensitive area re turbulent flow than is the manifold runner near the port in the cylinder head. This is at least partly because the restriction in each runner disrupts both the inflow flow and the pulse back from the closing valve.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Opinions regarding this intake
This design has been used numerous times in OE form,,, but would there be better way to tune the butterfly time contrary to what the oem ecu is set to do? I know that rpm window switches (available in the aftermarket) can be used to control the motor that operates the inatke tract valves. Is there a formula used to calulate optimal dual plane intake manifold "actuation"? Or is it more or less just a trial and error on the dynomometer... -or cheaper- The butt dyno?
RE: Opinions regarding this intake
A cheap dyno is a stretch of steep uphill open road where relative speed can be checked against landmarks. A bit rough but can indicate reasonable size gains and losses with some measure of magnitude.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Opinions regarding this intake
WRT ITB's you can of course use suitably sized OEM ITB's or motorbike ITB's, but not with a stock computer...and it gets expensive.
Should you wish to get an article on tuning you can email me at rpmagazine@optusnet.com.au and I will email you a copy of an article from the current issue of Race Magazine. The material comes from a MoTeC engineer about his own car and his experiences with it. It might help a little with some aspects.
RE: Opinions regarding this intake
is a shot of our boroadband manifold. You can see the vacuum actuator, which turns 6 butterflies.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.