Hey ive seen dyno's and heard ppl say that the SSIM mod u loose bottom to mid range hp and it evens out and gains after like 5k+ rpm's...
and i was figuring that was with stock parts... if u had an ECU and tune, Headers, full exhaust mandrel bent (really good breathing car) with an intake and a leightweight flywheel as your mods would u have a descent midrange with the SSIM and maybe start loosing only like under 4ish or w.e? ive tried searching for an exact answer like this but i wanted to make sure it was under the same scenario so thanks guys in advance - cory d

 

It causes a loss of volumetric efficiency in a specific RPM range so it will never completely go away.

 

yeah i understand that but is it a major loss even with those mods or is it barely noticeable but will feel the top end diff.

 

Oops, beat me to it.

 

There will always be a lull in acceleration in that range. The most you can do is try to bump timing there but it will always be noticeable. You can't have your cake and eat it too. Most, if not every non-VI intake manifold sacrifices one portion of the powerband NOTICEABLY.


With that said, it's a worthwhile modification if you value top-end power.

 

How is MPG effected by this?

 

I'm pretty sure that has been discussed before. Any reason I shouldn't lock this?

 

Hey Nismo,

In my case I don't have the VI or VTC hooked up so I can feel the power loss below 4k, but after that it pulls very well.

Here is the question... if I do the SSIM, will the lull in power before 4k be even worse than now(non-working VI), or about the same? Cuz if its relatively the same, I would like to have the extra top end.

What do you say?

PS: I have an RPM switch waiting for install. Should I just do that instead of SSIM? I wonder which will give better 1/4 times.

 

http://forums.maxima.org/showthread....614&highlight=

 

Thanks for the link, I've actually had it bookmarked since 2006.

Its a tough call. 20hp/tq gain below 4k with RPM switch or 20hp/tq gain above 5.5K with SSIM.

The RPM switch seems like a good idea for daily driving, but the SSIM is probably best for the drag stip.

I'm going crazy trying to figure out which is better! They seem like they are both nearly even.

Linear power curve vs. sloped w/ more net power.


Please excuse the dead horse beatings

I think that the rpm range you are in when banging through the gears means that you would only be under 4K for 500rpms. So for racing purposes SSIM would be better because you would net more power.

But I still feel like the VI would be just as close even without the SSIM top end power.

Someone check my logic here...

 

What I really want to know is:
If I do SSIM will there will be a significant power loss greater than what is shown on the dyno graph below 4k with the VI constantly open(no rpm switch)

I've driven the car like this (red graph) for 2 years and its fine for daily use. If I can squeeze 20 more ponies out w/ssim for highway thrills I might concider doing that over the rpm switch.

Green: VI Closed
Red: VI Open
Blue: Old VQ30DE days

 

http://forums.maxima.org/showthread.php?t=557307

#31 down

TQ gets you off the line
HP keeps you going

You pick...

 

Well, I found a thread that answered my question:

http://forums.maxima.org/showthread.php?t=552190
If you are interested check it out!


POST #11:
95BLKMAX
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Join Date: Jun 2003
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No need to post my dynos, but as far as "midrange loss" when gutting the IM is concerned...

If like 90% of 3.5 swaps, your VI is currently not working, you will NOT loose any midrange power. The "loss" is already there from not having the VI functioning. So if you do the SSIM, really you have NOTHING to loose, and ALL to gain, mainly after 4500, thats where my powerband kicks in like woah.

Pre-SSIM I was ~180-185whp at redline, Post-SSIM I went up to 210whp. Added catback and 3" MAF took it up to 230whp. Add cutout and I dont remember what I gained at redline but it was ubber, lol. If you add some adapters clocked to have the Int cams in their "fully retarded" position, that redline would be insane with this mod on an A32

 

Yaup, that's another thing that convinced me.

 

Your VIAS system (2 stage) and CVTC (Z33) mapping make your comparisons invalid against oTranscendental's.