Okay – so the new tricks have been installed…

Much thanks to Derek (dsskyline) for the great deal and accommodating payment for JWT S2 cams (thanks brother!) – and thanks to Howard (and Rich) at Technosquare for the install and coming in below estimate! Also, Ben at JWT for the multiple questions & answers and Jim Wolf himself for being so gracious with his time checking the cams and discussing project with me. And SPECIAL thanks to Shawn Church at CAT for his generosity with tuning this thing! A few more tweaks need to be made, but I know Shawn is dedicated to get it right – some of the best customer service ever! Thanks a bunch Shawn!!!

So – The car already had Stillen intake, with thermal coated Z-Tube, TBS, MDE ½” iso-thermal spacer, DEO blueprinted machined upper & lower collector, Crawford HFC, Stillen cat-back exhaust, tuned with Osiris running 3.7 FD – it was a blast to drive and did respectable at the track and on the dyno… here are pre-cams & headers dyno vids – vid was taken to record sound pre and post headers (dyno sheet at bottom has pre and post trq & hp):

more for pre & post header sound comparison:


Never satisfied, I’m always on a quest to squeeze more power – I call it my Japanese Muscle Car! All the low hanging fruit was done, not much more left… I contemplated a full build, but wasn’t certain the time, effort and money would be worth it unless I was building an FI beast (which I couldn’t do satisfactorily for les than 15K closer to 20K)… I’m fascinated by making NA power – so I picked the brain of a few people, studied a bunch of stuff and decided to see if cams and headers would be worthwhile (a few very notable industry ppl thought it would be advantageous).

I wanted mild cams – because even though I don’t drive the car much, I want it to be a streetcar that performs well on the track… and my main concern was not losing low-end torque – so I chose JWT S2 cams. To help offset the minor bottom end loss, I chose Crawford headers (searched a bunch over the years and these are the longest tubes while still keeping cats that I know of – and they have reported good trq for others). Since I have 3.7 FD (in an AT), its hard to make it through ¼ mile in 3rd gear, I run out of rmp – so I needed to be able to redline at 7500 (my theory was also to take advantage of the cams up top)… in order to do this I researched what parts where a must to keep it safe – and chose JWT valve springs, rev-up rod bolts (stronger than non-revup DE) and rev-up oil pump (again, stronger components) – the revup parts do nothing for power – they are designed for higher revving engine and seemed to be a cost effective choice for my project.

Here are some pics of the headers – I wasn’t at the shop when internals went in (wish I could have got pics)… not many of us see our car with the heart taken out:





All was re-tuned with Osiris – I was really hoping to see 30 hp, 20 trq (just my personal wish)… and while there were gains, I didn’t get close to my wish. Peak HP gains was about 18 and peak trq 8-10… however, the trq gain is across the entire rmp range with a relatively flat curve… and hp gain is maintained well beyond previous 6500 (its 10 hp higher all the way to 7500) – so overall this should help with my goal for the track.

For the Dynapack haters, remember this is for gains, its futile to compare these numbers to others (than my own). The pre cams & header is the bottom thick green line (one week before install), the post cams & headers is thin green line on 91 pump gas and yellow on MS101 race gas (no difference in this case, which is unusual because previously I when I tune with race gas more timing advance can be made and a bit more power… it didn’t make a difference this time (previous was 105 though)… anyway, FWIW a few years ago I dyno’d 270 on this machine and 250 on Stillen’s dyno jet and 245 at Dyno Shop's Dyno Jet in SD – so I figure I’d be 270-275 on those machines (but it’s always different – there really is no point in comparing those numbers, but I know it will be a topic).


There are a few things still to be worked out… off idle to about 2500 is a total slug (really bad) then trq kicks in HUGE). This is a big problem, because it’s actually hard to predict in certain situations. Shawn has agreed to spend some time with it and we have some ideas that will fix. Also, I have (what I consider) excessive valve tap, more prominent when engine is up to normal operating temps (I’m still working on this one)… and one of the O2 sensors is acting up (this should be an easy fix, fingers crossed).

Here is a clip of the post install dyno


Sound clip post headers


Here’s one from inside the car – this is in a small garage so the sound is magnified – the car is not as menacing as it sounds in this clip… the end of the clip is pointless for this thread (I was trying to capture the valve tap for another thread – I have better clips of that if anyone is interested I’ll post the link to that thread)


So overall, I’m not horribly disappointed, nor extremely satisfied… I will say its not worth the expense – this is the only mod I have done that I would not recommend to most people – everything prior to this I would (and have) recommended to anyone looking for more performance. This project has satisfied my addiction for a while though (well not really, there are other things I’m doing, but that will never end).

I know it’s a long post – but figured I’d say it all at once for anyone that is interested.

10/29/08 UPDATE!!!
Yes, Yes, YES!!!!!

Saw Shawn Church this morning… added the recent UpRev Osiris release for ETC and played with cam timing down low – all the low end is back to its Ooomph! Thanks Shawn and UpRev – you guys RAWK!!!

 

D you plan on doing any other supporting mods?

 

such as?...

 

nice what did shawn say about the uprev tuned ETC control?

 

mabe som more head work, this set up would go well with a port/polish job that and some pistons would get you roughly around 300-305

 

I spoke to Jared before I read that in your thread and had sent Shawn an email about it... then when I saw you did it I sent him a link... he called me last night and said he had just downloaded that update - we are going to start with it, and tweak a bit from there... I'm think some cam tweaking might help too, but he knows best... going back next Wed.

 

I considered it, but honestly for the added time and expense, I wasn’t convinced it would be worth it... If I keep the car long enough, there might be a full build down the (distant) road.

 

Did the cams lean out your afr?

 

Nice Mike. Looks like its a blast up-top!

 

sounds great

 

nice hope all gets settled out will be fun to drive

 

Wow! That sounds fabulous. The gains above look pretty solid. I too would have expected a little more, but now you've got quite a bit more average power from 5500-7300rpms where your car will spend most of it's time accelerating. I don't see why those gains won't shed .2 seconds and add 1.5-2mph.

Unfortunately, I don't think there's going to be much you can do about that sluggish low rpm lag. Every cam dyno I've seen shows neutered power below 3000rpms. That quick ramp up in power is something all 5ATs seem to do from idle to 2800rpms. I think it's related the intake cam timing, specifically to control emissions. I'd imagine the cams, the exhaust, and the higher stall TC exacerbate this sluggishness even more and that's what you're feeling. Luckily you've got a higher stall TC and gears to get over this low rpm lag when you launch the car, but for daily driveability, I think you're pretty much screwed. You can't add better breathing cams without impacting lower rpm performance, unless you've got variable lift design with multiple lobs like on a Honda setup. Shawn can probably help restore a little life in the lower rpms, I would set your expectations low.

 

thanks for the comments guys... for those interested, there is a discussion on the Z forum - it helps put some things in perspective:
http://my350z.com/forum/na-builds/39...installed.html

http://my350z.com/forum/na-builds/383566-cams-3.html

 

Top end looks very nice....
Good Job taking the risk and doing this for all of us, since no one else has done this on N/A car (at least they haven't posted the results).

 

Mike, at the track, it should be anything but disappointing. Sure, its not a lot of HP for the money. But if you look at the graph, most of the power gains are at 5000RPM+...which is where you want it to be at the drag strip and/or road course.

Your average HP after redlining 1st gear are definitely good gains for the track.