Upper Intake Manifold Mod

[matty61184]

I would like to get a new ported/polished upper intake manifold for my car. Was alos considering getting the lower, but I am concerned with the difficulty of installing it, as I don't feel I have the necessary tools to put the lower in, unless it's easier than I think. What kind of gains would I see with just the upper as well as with the combo. How long would it take me to put in the upper and what kind of mechanical experience is required (I would say I'm in the middle of the road experience-wise). Let me know. Thanks guys!

-Matt

[Redog]

Well first off, if you get the upper you minus well get the lower because it will benfit you more to have both done at the same time for HP increase, air flow, and only having to take apart the motor one time, which are all good reasons. Also if you have headers, those outlets are ported too.

Typcial gains are 11-13 for the upper and 12-14 with the lower, so your looking at least 23 more hp from this. If you add in a ported TB add another 5-8 hp. It actually pointless to only get a ported TB and not a manifold too.

As for doing it yourself, I'd say don't. The upper may be easy but the lower is a pain. You have all sort of pins and other goodies in there that you really don't want to mess with. I had my mech do it and as experienced as he is, it still took him a day and a half.

I have the P&P and TB all from RSM racing. The upper and lower are sold as a kit, (I think). They do not include the gaskets for the manifold but they do for the TB. Just get stock gaskets and port them yourself. After the core, the price is pretty reasonable.

[Insane75]

I gonna be changing my lower intake manifold gasket soon myself so I'll let ya know how it goes and how hard it is. (but from the looks of it it's not a job to be preformed out in the driveway w/o a wide aray of tools at your disposle)

[Naich]

its not as simple as adding up the horsepower from each one. You won't see 23 horsepower from the upper and lower, more like probably 15 for both, and 3-5 for only the top. Most local machine shops (if you have any) would do PNPs for you, and so would any hardcore performance shop.

[matty61184]

What kind of cost would be involved for installing the lower or upper separately and both. Also, after writing this post, I think I would be smart to go with a 62 mm ported throttle body as well. This would help. I already have a CAI w/ 5" K&N Cone and 8 mm racing wires w/ Bosch +4 plat plugs (dont really think the wires plugs helped much tho, CAI I can tell a noticeable difference, especially on the top end, also more growl). If I'm reading what you said correctly, it would be smartest to use both in conjunction and horsepower is more effectively obtained when you use a combination of mods. Let me know. Thanks guys!

[matty61184]

Originally posted by Naich@Feb 11 2004, 05:22 PM
its not as simple as adding up the horsepower from each one. You won't see 23 horsepower from the upper and lower, more like probably 15 for both, and 3-5 for only the top. Most local machine shops (if you have any) would do PNPs for you, and so would any hardcore performance shop.
Does this relate to the 23 hp gain at the flywheel, but only 15 hp output to the drive wheels?

[Naich]

well, every car reacts slightly different to modifications. Yes, using the upper and lower ported manifolds will be better than only doing the top, and yes, upgrading TBs will also greatly help. Also, I've heard some bad things about those Bosch plugs, you might want to do a search on them. I have yet to see dyno results for ported and polished manifolds on our cars, but some of the claims made by companies selling them (i.e. street arsenol) are completely bull. Our stock manifolds (from my understanding) flow pretty well stock anyway. In fact if it came down to it, I would do CAI and 62mm TB before the manifolds, because I suspect you'll get a better gain and have to do less engine work.

[matty61184]

Originally posted by Naich@Feb 11 2004, 06:32 PM
well, every car reacts slightly different to modifications. Yes, using the upper and lower ported manifolds will be better than only doing the top, and yes, upgrading TBs will also greatly help. Also, I've heard some bad things about those Bosch plugs, you might want to do a search on them. I have yet to see dyno results for ported and polished manifolds on our cars, but some of the claims made by companies selling them (i.e. street arsenol) are completely bull. Our stock manifolds (from my understanding) flow pretty well stock anyway. In fact if it came down to it, I would do CAI and 62mm TB before the manifolds, because I suspect you'll get a better gain and have to do less engine work.
Thanks Naich, I will try that first. I've found a few places for the 62 mm TB. Do you have any favorites or suggestions as to who is best? I have also heard some things about the +4s and to tell you the truth, my car has run less like "itself" since I installed these plugs back in May of 03'. I know NGK makes an Iridium plug, what do you think about that? Any good ones that you think make the cut?

[FormulaNERD]

i have the ngk iridium xl's, when i swapped them there were some bosch platinums (not the +4 though) and they looked fairly new... but i can tell the difference (not really 'performance' wise, but when starting and stuff) and when i got the NGK's they were pretty cheap (at orileys auto parts). i had never even heard of them, but the guy i usually go see there races too and he said they're the best out right now in his opinion... so i trusted his judgement and i'm completely satisfied... now i just need wires and an msd coil