The less heavily modded 3.5 the better. I am hopefully finally putting the 3.5IM on my car next weekend and getting rid of this USIM, and I want to run some cartests on gutted vs non-gutted 3.5IM. My car is pretty mild right now with just 3.5 swap w/ 3.0 timing components and 3.0 cams, ypipe, 3" exhaust, filter on a stick, and emanage controlling AFR.

So if anyone has a before and after of a gutted 3.5IM, I'd love to see it to run the tests.

 

NMexMax is the one to be expected to answer this. He has that dyno comparison SOMEWHERE on the dyno forum. I tried looking for it quickly on his "My dyno thread" thread to no luck for the actual comparison, but no luck

 

I saw his but a couple things bother me about his dyno for my application. 1) He's got lots of mods, way more than me, and 2) using his dyno indicates that the car will be actually be slower which is not the idea behind this mod so I'm looking for other data.

 

So I guess that's a big "no".

 

You will lose hp if you gut the 3.5IM and no supercharged/turbocharged. Between 5 & 10hp

 

Not at all. It depends really on what you want for your setup. For an all motor setup its great, but unfortunately (as it is the case with me), you get a surge of power right at 4k and its nuts from there on. Before that its quick not nothing spectacular (real world sensation).

While I was on boost however I did hate my SSIM. Because my turbo was sounding like it was spooling from around 3000rpm! yet because the gutted IM didn't flow good until 4000rpm, THAT was the area where I would see full boost. Which sucked because depending on the speed I was in, it would require me to downshift to be in the power band.

While on All Motor, If you have an extended redline, the SSIM is definitely your best friend, for obvious reasons- every shift lands you right back into the power band.

Thing is that even though the midrange would be great with a FULLY FUNCTIONAL 3.5VI, the top end would suffer. Its really a choice between the two to as far how you want your power band to be. It would be GREAT if we had the variability of the stock IM, with the better flowing characteristics of the gutted equivalent.

Just for reference, looking at my dynos, I didnt really loose much midrange. I lost just about 4 WTQ around 3500, and gained alot more after 4000 over the non-gutted IM.
Something important that should be thrown out here- I did not loose much midrange, because I never had a functional VI to start with. While it was stock, I never had a window switch wired up. In the midrange (where the power valve is meant to be closed) the power valve was on its default open position.

So to ME, going into SSIM, I did not loose any "butt-dyno noticeable" midrange power, but I definitely noticed the much improved top end.

To someone that does have a functional VI, then yes, THEY would compromise midrange power by gutting their IM.

Being as it may be, I can make a safe guess that about 97% of 3.5 swaps reported on the org do not have the window switch wired up, just like how that many 3.5 swaps are running (relatively) like crap because they have no tuning what so ever.... but that's another subject for another thread....

 

When I said "that's a big 'no'" I meant on the subject of before and after dynos that people could post. Not that I'd made any decision on whether or not to gut the IM. I appreciate the info though because I've never paid too much attention to some of the more in depth N/A only stuff since I've been boosted for years. I'm just looking to make my basic 3.5 swap as fast as it can be for right now and in order to do that I want to run some cartests on different setups, but if I can't get dynos to compare then I can't do the tests lol.

 

ah ok I understand now lol.

Well unfortunately, I dont have any of the actual runfiles from last year back (I didnt "upgrade" to having a thumb drive with me until maybe a year ago lol). But I do have the scans of the print outs from back then.

This one is from February 07, stock non-functional IM


This one is from April 07, SSIM all else constant


Dont mind the #s, as they are after all different Correction factors (SAE vs STD), but just note the overall shape of the curves. Notice also, that in stock non-functional form, the IM flows peak WHP right around 5250rpm. When gutted, that peak shifted over to about 5800rpm, which is also supported by this last dyno from my last NA dyno in November 07 (the red lines. Green is 9psi, Blue is best of my 3.0)...


Mind you that this higher point of peak airflow is also affected by the CAM TIMING that my intake cams are set to. On the 5.5gens and up, by 6000rpm, the intake cams are at their full retard position further helping breathing up top.

On my swap, Im using stephenmax's adapters clocked for his default position, which although do retard the int cams more than stock 3.0 timing, it is still far from the relative "full retard" position that the 3.5 cams would have with VCTCs. But of course, one can just ask him to clock the adapters for the int cams to have a "full retard" position. This would increase power in the low and top end, with a slight compromise in the mid.

This is the reason why for my build, although I already have the "wilder" Debuloz ebay cams that DandyMax and Jime have been using, I wont put them in until I have (among other things) new cam adapters to have them set to full retard. This way I can really exploit the top end for all its worth and REALLY find the limits of what the FWD 3.5 IM can do.

Make sense?

 

I've got about 25+ drf's, many of them are on a 6mt with headers, not really much of an exhaust (stock with custom pipe on each side of the resonator), an intake and udp. I did quite a bit of extensive testing of with and with out aarons spacers, with just ssim, and with and without port matched upper/lower/spacers/cutback & smoothedelbow, blah blah. I also have before and after ones off of that 3.0 with the '02vi on it which has just an intake, y, returnless & afpr, and an obx catback.

The far superior out of all of the combinations in terms of area under the curve, peak hp, (but NOT peak tq) was: Aarons spacer kit MINUS the large one between the upper/lower, port-mathced upper/lower & elbow, and v-notched elbow shelf. I'll also say this about the nwp spacer kit: It is absolutely fantastically silly at giving some HARDCORE consistency between pulls.

The only problem is, I kinda seriously fawked up in 2 ways. Note to self: Keep notes while doing pulls for 3hr's !! I ended up getting very confused when I left as to what was what. The 2nd err on my part was the car initially had nasty vacuum leaks, and an exhaust alignment issue which turned into a full blown HORRID leak after about 3-4 runs, so I think that greatly affected my first few runs which had the basic ssim, so for that I'll probably post up the '02vi car's runs.

The good news is, starting on the 15th I'm renting out the dyno shop monthly and will be able to do pulls whenever, so I can re-dyno some **** and not only keep better notes, but not wait until the final combination is installed to tune the a/f, that was stupid as well.

 

I'll let ya'll enjoy my fun of trying to sort through this madness, but basically:

DRF's on vqbeatu.com

1249/50/51 ssim w/spacers.
1252/53/54 ssim w/spacers minus upper to lower spacer (Try to objectionably hold off on noting the fact that without big spacer not as much low gains as top losses, because this was where the a/f was REALLY screwey.
1255/56/57 stock manifold, not that it's hard to spot this one, for all intensive purposes majority gain of tq is WAY below the shift point in any racing auto or manual.
1258 non-a/f of the above mentioned combination listed above, except I left out something I also forget, it had the lower injector bumpstops removed.

 

Some of the after '02vi ones are 0058 or whatever onwards, the befores are also listed there as 1106, 09, 1126, 28 or something like that. However there will be one or two more quick runs on that car at some point to see what it's now putting down @ 50 psi with the a/f situated, when those runs were done, and especially the ones that I don't have after the fox-body with 1.8 rockers ran a few times (0059 got stuck in there accidentaly) It was very easy to see that the runs were heavily affected from the lack of oxygen just as much as my KILLER headache that I had for the rest of the night. I'll say this though, I gunned it on the way home and wasn't expecting the wheel to so violently get ripped out of my hand, it's been awhile since I had such un-anticipated tourqe steer and I hate to say it but I think in that case with the lack of oxygen the butt dyno pwned the rollers.

 

Neal, you still going to try the DEK manifold?

 

Neal, have you looking into the Kinetix's manifold?

 

Using a 3.0 intake manifold with 3.5 heads without mismatched ports one way or the other ain't happening w/out a custom LIM.

 

I'd still like to se ewhat would happen especially if you got a 13.6 out of the sucky USIM.

 

Me too. It won't be crazy fast - certainly not as fast as Dandy's car is for instance, but it'll be a pretty good representation of what can be done with a very basic 3.5 swap and a couple bolt ons into a 4th gen. We'll see if I can pull off the swap in one day. I've got one day and one day alone to do it. Saturday. We head to the track on sunday morning. I can tune on the way to the track if necessary, but I've at least got to get the thing driveable on saturday.

Kevin - no. As Nismology said - I severely underestimated the difference in the shapes of the two. Not only are the ports different shape (not the end of the world, I was planning on overcoming that) they are also offset totally differently - they aren't even close to lining up in any way shape or form. It'd take a ton of time to do the custom work to get that working. time I don't have and even if I did have it I doubt I'd be willing to put it into NA - I want to get my car turbo again not dink around trying to get a few HP out of NA.

 

Very good point Neal. Boost owns.

I hear you on underestimating, I just did that involving the 3.5 vs 3.0 cam sensor deal. But I'm confused what you mean by the offset, it should be the same as what I had to do to the '02vi on a 3.0 except what get's done to the heads is done to the intake and vice versa, yes it's totally off but it's also completely do-able and that new way oversized area where the heads meet isn't the end of the world. Regardless it sounds like someone somewhere at a later date will have to do this, preferably retaining a 3.5 tb as well. 1-day huh, damn, I geuss it depends how much you have done ahead of time, if you have to deal with the sensor/pan issues still, converting the dbw to cable, returnless, splicing the 3.5 rear harness and what not... Well i wish you luck and it will save you time if you get the ps and alternator and tranny/axles, y-pipe, x-member on ahead of time and lift it in.

 

I'm just talking about swapping my USIM for the 3.5IM on the 3.5 I already have in the car. Not an entire engine swap in one day.

The port mismatch I'm talking about is the mismatch between the 3.5LIM and the 00VI. Not the head to LIM mismatch.

 

Oh and KRRZ thanks for your comparison above, I'll have to look closely at it tomorrow night. Not in the mood to do a bunch of research tonight - long day. Thanks for it though.

 

wow i see....we'll it was a good thought though. hopefully someday some one will made a spacer/adapter for the 00vi - 3.5 setup and get some numbers. i see how it doesn't matter too much anyway since you will go boosted.

 

i see said the blind man peeing in the wind. Yeah THAT mismatch is bad, but if you hold the '00vi lower up to the heads it should be pretty close, but will still take a good 4+ hours to port match everything. The other option is, at the time I was comparing things I had a Z33 UIM gasket but no 00VI UIM gasket nearby, but from my memory they sure looked similiar, using a z33 LIM might really simplify things.

 

A spacer would make things way overcomplicated, it's really just a matter of someone not minding hogging the **** out of there 3.5 heads on the car and hoping it makes power, which it probably would, post 6k anyways. If I could get the 3.5 upper & lower's installed on a 3.0 and still see great numbers the reverse is entirely possible and would actually be MUCH easier in terms of rear valve cover/coil pack issues, there was a point during that swap where I had massive holes cut in the 3.0 valve cover along with a bastard child combination of de-k front coils with plug leads from the rear and I was still like "oh boy, it's NEVER going to work and I have a huge problem on my hands".

 

I noticed a big differance up top with my SSIM and a much smoother pull from down low..definatly worth it.