has anyone ever ported out their 5.5gen IM? if yes, what did you port out? how much did it cost? and did you feel any difference after the port job?

 

http://forums.maxima.org/showthread.php?t=225659

 

Based on that thread it does not look like anyone has done it. When I rebuilt a few engines (not Maximas) in the past, I sent the heads for P&P and it cost about $300 per head. The machine shop was set up with a flow bench. I did not dyno the gains. Some jobs you could feel the difference on some others you could not. The only time I would do it is if I had to tear the engine down for whatever reason as taking the heads off is not a fun job.

Some recent studies I read on the subject is that the P&P of the heads does not gain you anything and could potentially loose as the fuel does not get atomized properly when the ports are smooth but rather it drips through. On the other hand the same study suggests that polishing exhaust headers shows improvement as there may be burs left over from casting that are blocking the exhaust passages and creating turbulance (that is what some aftermarket headers use as improvement). I'll try to find the link to this study and will post it...

 

SR20 tried it but juding from all the "secretive" BS he must have failed.

 

I dont know about failed....263whp aint nothin to sneeze at

 

Not to mention his impressive N/A track times as well...

 

Does anyone know what he has done in P&P department? What parts did he P&P?

 

This would be the secret part

 

Hehe, I guess :-)

Would be nice if he shared... Not like I will race him anytime soon :-)

Has anyone opened a 5th gen engine? What do ports, exhaust manifold, etc look like? Any opportunities? I've seen the insides of engines where you can tell right away if it is worth doing some polishing or not and what sections. You can see on the exhaust headers if they are smooth or have burrs, etc...

 

Many have, look in the all motor forum.

 

Found some from 4th gen I think:
http://forums.maxima.org/showthread....hlight=porting

Not sure if the insides of 5th gen looks the same... Nevertheless, P&P may be something I may do on the first occassion I'll need to open the engine...

 

So did this thread get thrown a little OT or am I missing something ...since originally it was about the 5.5g IM ... And now igzy wants to try new things ... but has a 00vi, which is plastic and quite different.

 

My apologies if I sidetracked the thread. I thought we were talking about porting (and may be polishing) in general as the first link SEmy2K2go pointed was talking about that... Or am I missing something?

 

Yes we are, but I think you're more itnerseted in the heads .. rather than the IM, since that link was privided, and in all honesty, I don;t think port/polishing the IM would do any good, so even though you've side-tracked, it's probably for the better ...

 

I'm with that... IM polishing may be a bad idea and most likely would not gain you much if not loose...

 

Though there was one 4th gen owner who had it done, and it shifted his power curve ~500 rpms and he did pout down 190+ whp w/ ported USDM ... still not worth it.

Local shop here does for $450/550/750/head depending on the "stage" (smoothness)

It's a large job and not for faint of heart, even if you're not doing it yourself, not for the fain of heart pricewise either.

I think the stock ehads flow pretty well. Although, I'm wondering what they flow compared to the 04+ heads since those are the heads from the VQ40 (part #'s are the same)

You and I are still on different pages since I'm thinking of 5.5g and you're not.

 

Good point. Would a 04 head fit? If so, would there be any gains? They had to add 10 hp somewhere. I've been wondering if it was heads, ECU or exhaust. Doubt it's in the internals.

 

Just what exactly is it that I failed to do? Hit 300whp with the stock cams? Yeah you got me there, for now.

 

People assume that if you did something to get great power output that you would share it with the rest of us on the Org. They weren't paying attention to the threads where you posted your dyno numbers and track times. From what I gather about how secretive your mods are, the only thing that you "failed" to do is share the info about what exactly you did to your Maxima to get those results. Of course, what you say or don't say is your business, so nobody can really flame you for keeping it to yourself.

 

Secretive modS??? The ONLY thing I haven't shared is what I specifically did to the manifold. EVERYTHING else is posted, and yet many, not all, people still refuse to take my advice and pay attention posts where I attempt to guide them in the right direction and give out this info on a repetitive basis. Often times I wonder if I am speaking in Chinese or something.

Also, my time isn't free, is yours? The little bit of money I make doing these Maxima side jobs helps me to do more R&D and uncover more of the hidden HP. Which in MOST cases I turn around and share.

 

Hey SR20 has anyone attempted to port the 00 or 01 manifold ? Never heard of it thought you might know?

 

I found out that if you remove the power valve on that manifold it will make some extra peak power but you lose some low end.

Tilley beat me to the punch, took that a step further and gutted part of it, but I don't know how much more there was to be had in the thing. Untill someone brings me a '01 5spd to experiment with I won't know.

 

I said it already. I'm not trying to flame you, and I don't think anybody else should flame you just because you don't churn out a highly detailed write up and post it to the Org every time you ****. I also acknowledged that you HAVE posted threads with dyno results and track times from your various mods, but many people don't pay attention to those threads, so they usually miss out on it when you DO share info about your car.

 

Kool thanks, cause i was wondering if porting it would be difficult, cause it is plastic but with good tools you can cut plastic too just gotta be carefull as hell, did he have cams on the car he took the power valve of off, cause i was wondering if you did that but ran the 3.5 cams in the 3.0 would you still have that loss on the low end?

 

that maxima he is speaking had and still has stock cams.

 

I first did this (remove the power valve) on Nathans car (mad2kmax?) when I discovered the broken power valve issue. His car does have the stock cams in it but he doesn't have conclusive back to back dyno runs to prove the actuall gain. From the charts he does have it appears to be about a 10whp gain at certain high rpms and IIRC a pretty big delta from 6k to redline.


You'd have to ask Tilley on what cam combos he's tried when he modified his '00 manifold.

 

If you don't mind, could you post your performance mods? I read a thread awhile back that you were having someone possibly manufacture a new IM, how did that go? Also I think you were working on some type of juice for our engines, I could be wrong. I read the last 2 posts with your track times but as you can see it went in totally different direction.

 

i read both threads that were link, both of which half of the thread is people flamming one another, but contain some useful info,

but alot about porting and polishing the heads, some have answered my original question... so its not good to port the IM out?,

what can we do to get better performance then from the IM?, if I'm not wrong, from earlier threads and post, isn't the IM what is causing us to loose some power in the top end?

 

ICULookN, if you dont mind, could you look for the threads in which he has posted his mods? There are many. One good place to look is the dyno forum. Another would be the drag racing forum. Good luck.

It would be good but its not worth it ($/hp or tq), in terms of P&P. Kinetix currently has an IM for the altima 3.5 in teh works. It should bolt right up to ours. All it depends upon is hood clearance. I am not sure how well the room under the hood compares between the maxima and the altima. They begin testing in early september I beleive.

 

But the Kinetix is $$$ 500+, and we are still not sure what type of gains can be had if any ...

 

http://forums.maxima.org/showthread.php?t=377044

Gotta love the search function....

 

Thanks for the link.

 

here's a good site..

http://www.sa-motorsports.com/diyport.shtm

 

No problemo...

 

Nice site! If you were to port would we need different gaskets

 

if i could get this done for under $300, do you guys think its worth porting the IM out a lil?, like gasket matching the ports

 

Just a tip;
I used to work @ a machine shop that ported and polished heads on a 5 axis cnc and there is a big difference over doinig it by hand w/ a die grinder. in a machine each cylinder will the same. There is more gains as well which is proven on a flow bench and later on the dyno.
IMO, I would not pay the $$ to have some one do it by hand.

http://www.m2race.com/logo_page.shtml

 

You're willing to pay someone upto $300 for a little bit of unproven porting?

 

We arent running chevys here guys....PnP would provide minimal gains at best.

 

Since everyone wants too know the 00vi gutted on a 3.5 has NO LOW END i dynoed and had peak hp at 6800 or so. I tested it on my boosted 99 with a 3.0 and damn it felt really weak when it wasnt boosting.