Deciding on next upgrade

[robomatic12]

I've reached the point where I'm itching to upgrade something. I'm thinking that it's either going to be for engine performance or suspension. The thing is with my suspension I'm at about -2* camber up front and -2.5* at the rear currently. I'm deciding between:

1) Selin Dual MAF Translator w/maf + additional filter ~$600
2) 555/615cc Injectors + Early style fuel rail adapter kit (was going to go with JECs) ~$800
+ECU re-chip ~$100
3) Front and rear upper control arms (looking at the powertrix versions) ~$600

What I have currently is:

-Stock turbos and engine (fresh rebuilt, probably 6k on both)

Performance Mods:
Kakimoto Stage 2 ECU Chip
Kakimoto 2.5” Catback
2.5” Testpipes and H Pipe
Exedy Stage 1 Clutch
Z1 short shifter
CZP Intercoolers w/ silicone piping
AMS underdrive crank pulley + overdrive water pump pulley
Greddy Profec SpecB II Boost controller
JWT Pop charger intake (single)
Samco Silicone Boost hoses
CZP SS Clutch line

Suspension Mods:
JIC Race Coilovers
JIC adjustable tension rods
Polished Rear Strut Tower Bar
Aluminum subframe spacers
Polyurethane steering rack bushings
Powertrix Rear HICAS Delete Bar

[A Paratroopers 300zx]

Honestly, I would probably got with number 1 or 2. Suspension can wait lol. You would probably get the most power out of number 2 because with higher flow injectors and a re-flash... you would be able to turn up the boost safely!

[vulcanrush]

you can try to get nismo740cc's, might be even cheaper than nismo555-615cc's, and there's no downside.

but i would try to swap out your ams underpulleys...and the czp intercoolers, the ams underpulley causes a misalignment of your timing belts, and the czp intercoolers might be a bottleneck in your system.

[BigTDogg (MA)]

Where are you located?

How is your camber currently set and adjusted up front? You need solid bearing upper arms with solid tension rods, otherwise your bearings will be shot.

Addressing needs, you need the upper arms first if you have no front camber adjustment.

Then I would get an HI overdrive water pump pulley from importpartspro.com to spin your water pump at the proper speed. I would have never got the AMS pulley in the first place, but since you have it just leave it.

After getting the upper arms, I'd get the Selin, and used MAF from someone. That's an easy 20hp in 20minutes. Then get the injectors, that way you only need to get your ECU flashed once. You can run the Selin with a single POP ECU, but it's slightly better with a Dual POP. So when you get the injectors, get the 740s and get a Dual POP program. I'd also look to Specialty Z or Ztuner for an ECU, as I'm not too familiar with Kakimoto.

CZP intercoolers I assume are the AVS ICs? The CZP Bell ICs are great, but the AVS ones are OK. Fine for stockers, but anything bigger and you'll want to upgrade.

[robomatic12]

you can try to get nismo740cc's, might be even cheaper than nismo555-615cc's, and there's no downside.

but i would try to swap out your ams underpulleys...and the czp intercoolers, the ams underpulley causes a misalignment of your timing belts, and the czp intercoolers might be a bottleneck in your system.

The ams underdrive pulley has nothing to do with the timing belt lol. The supposed misalignment happens on the accessory belts, which I haven't seen as a problem yet. But thanks for your input!

Where are you located?

How is your camber currently set and adjusted up front? You need solid bearing upper arms with solid tension rods, otherwise your bearings will be shot.

Addressing needs, you need the upper arms first if you have no front camber adjustment.

Then I would get an HI overdrive water pump pulley from importpartspro.com to spin your water pump at the proper speed. I would have never got the AMS pulley in the first place, but since you have it just leave it.

After getting the upper arms, I'd get the Selin, and used MAF from someone. That's an easy 20hp in 20minutes. Then get the injectors, that way you only need to get your ECU flashed once. You can run the Selin with a single POP ECU, but it's slightly better with a Dual POP. So when you get the injectors, get the 740s and get a Dual POP program. I'd also look to Specialty Z or Ztuner for an ECU, as I'm not too familiar with Kakimoto.

CZP intercoolers I assume are the AVS ICs? The CZP Bell ICs are great, but the AVS ones are OK. Fine for stockers, but anything bigger and you'll want to upgrade.

I'm in BC, Canada. I currently have stock upper control arms, I always thought that you can have solid tension rods without upper control arms but not the other way around? Am I wrong lol?

I forgot to mention I already bought/installed the overdrive water pump pulley, forgot to add that to my list.

Yeah they are the AVS intercoolers, are they that much worse than the z1 intercoolers? I think I've seen that debate come up once or twice on the boards here.

Kakimoto ECU came in the car when it was shipped over from Japan, I've gotten their website translated and it looks "similar" to the things changed on the specialtyz chips. I've always been a little bit unsure of what it's doing...

[vulcanrush]

The ams underdrive pulley has nothing to do with the timing belt lol. The supposed misalignment happens on the accessory belts, which I haven't seen as a problem yet. But thanks for your input!

whoops, typo slip. http://www.twinturbo.net/nissan/300zx/f ... quest.html

i'll keep my opinions on ams to myself, opinions are like you-know-what, everybody has one, and it stinks,

[BigTDogg (MA)]

The ams underdrive pulley has nothing to do with the timing belt lol. The supposed misalignment happens on the accessory belts, which I haven't seen as a problem yet. But thanks for your input!

I'm in BC, Canada. I currently have stock upper control arms, I always thought that you can have solid tension rods without upper control arms but not the other way around? Am I wrong lol?

I forgot to mention I already bought/installed the overdrive water pump pulley, forgot to add that to my list.

Yeah they are the AVS intercoolers, are they that much worse than the z1 intercoolers? I think I've seen that debate come up once or twice on the boards here.

Kakimoto ECU came in the car when it was shipped over from Japan, I've gotten their website translated and it looks "similar" to the things changed on the specialtyz chips. I've always been a little bit unsure of what it's doing...

I was curious to your location because of the Kakimoto items. I kinda figured it was a JDM car.

The AMS pulley does place undue stress on your water pump, and is inferior to the HI pulley. They have since copied the HI pulley and called it their version two. I'd suggest one of two things; 1) sell your AMS pulley and buy an HI pulley, or 2) contact AMS and demand a version two pulley. They are a cancerous company however, and I would recommend against doing business with them in the future.

IMHO, you ICs are fine. I run Z1 ICs and they work great. The AVS units are similar, but having never seen them in person I cannot verify core density etc etc.

Your ECU, however, is not. I'd get that addressed ASAP as well, because if it's a JDM ECU, it expects a different type of fuel than you have in Canada. I'm assuming you use the RON+MON/2 method as the US does, so you have 91, 93 octane? Japan uses (IIRC) RON only to rate their fuel. An SZ tune will help your car out without a doubt.

The upper arm thing goes both ways. Soft bushings and hard bearings don't mix.

[robomatic12]

Yeah it was imported over from Japan.

So 2mm misalignment on the overdrive pulley will actually make that big of a difference? Do you know if anyone has proven anything lol? I'm just a little bit skeptical that difference is going to do anything. ( http://www.yugobernie.com/images/Pulley_Comparison/) I'm curious as to when they came out with the AMS v.2, I guess if I didn't see version 2 when I bought mine, I have the older one.

Yeah we use the same fuel calculation was the US, I am using a 94 octane gasoline. Just did a little bit more reading on Japanese octane ratings, it appears that because of the differences in the way the fuel is rated even the highest sold at a pump in Japan (100RON) is equalivient to our rating of 95 octant. I bolded the calculation.

In Europe 98-octane gasoline is common and in Japan even 100-octane is readily available at the pumps, but this octane nomenclature is misleading to Americans as foreign octane ratings are derived entirely differently from our own... So, like every other measurement system it seems that everyone else uses a different scale than we do, but unlike most other instances where we have had the good sense to create different units of measure in this case we all use the same name...
Japan and Europe use a system called RON or Research Octane Number to determine the octane rating of their gasoline, while stateside we use a system called AKI or Anti-Knock Index to determine gasoline's octane rating... Interestingly, to further complicate things it would seem that our own AKI system is actually derived from the average of the RON system and another more complicated system referred to as MON or Motor Octane Number... So, to recap our methodologies for measuring gasoline's octane rating are different, but share some common elements...
So, with the commonality of RON in mind a good rule of thumb is as follows, multiply the foreign RON Octane rating by 0.95 and you will have the US AKI equivalent.

( RON Octane Rating x 0.95 = AKI Octane Rating )
98 RON Octane x 0.95 = 93.1 AKI Octane (US measure)
100 RON Octane x 0.95 = 95 AKI Octane (US measure)

So, as you can see the 93 or 94 octane fuel we are all paying an arm and a leg for is actually quite comparable to the higher octane fuels found in Europe and Japan. The people whom have to worry about low octane rating are our friends out west in places like California that are subjected to substandard 91 octane.
91 AKI Octane (US measure) = 95.5 RON Octane

[vulcanrush]

2mm+ is 10%+, a pretty considerable amount. it's your car, but for sure, nismo740cc's, no downside to them.

and before getting the selin, i'd upgrade the intercoolers which can support more/higher boost later.

[robomatic12]

I already bought upgraded intercoolers... they are the same as Z1 intercoolers... just copied by CZP

[vulcanrush]

I already bought upgraded intercoolers... they are the same as Z1 intercoolers... just copied by CZP

do you have any numbers to verify that? efficiency, face-charge numbers, etc.?

[BigTDogg (MA)]

So 2mm misalignment on the overdrive pulley will actually make that big of a difference? Do you know if anyone has proven anything lol? I'm just a little bit skeptical that difference is going to do anything. ( http://www.yugobernie.com/images/Pulley_Comparison/) I'm curious as to when they came out with the AMS v.2, I guess if I didn't see version 2 when I bought mine, I have the older one.

2mm puts the belt tension further out on the water pump shaft. This increases the moment on the water pump bearings. This will lead to premature failure, compared to a properly fitting pulley. If you bank on 60k miles for a water pump, you may have an unpleasant surprise after 50k miles. I would ignore whatever Vuk says, because he doesn't understand physics, nor is he an engineer; he's a slimy salesman, nothing more. They copied the HI pulley only recently, released about 3 weeks ago.

The ICs are copied by AVS, however they may not be exactly the same. The only way to tell if they're the same is to test pressure loss, delta T and CFM flow rate at a given pressure. Otherwise all you can do is measure dimensions, which will get you in the ball park. IC core design plays a significant role in IC performance. Vulcanrush and I differ here slightly, though I respect his opinion. The ICs you have are good enough for stock turbos, they're better than stock ICs. However there are better (albeit more expensive) options available.

[robomatic12]

Thanks for the info about the overdrive pulley, guess I wasted $80! I appreciate your opinion and knowledge!

I realize I saved a bit of penny buying a copied design but I just found it unfair to hear that after shelling out $500 for upgraded intercoolers I should be buying something else lol. I'm pretty happy with the power capacity of stock turbos on the street, also they fit within my budget. So the AVS IC's are going to stay for now.

I'm thinking that my first thing to purchase would be the HI overdrive pulley and front+rear upper control arms. It seems like powertrix is liked for their suspension products.

[BigTDogg (MA)]

I'm thinking that my first thing to purchase would be the HI overdrive pulley and front+rear upper control arms. It seems like powertrix is liked for their suspension products.

Powertrix makes good stuff, and Charles is a stand-up guy. I have their rear upper arms and traction rods (I have an NA rear end).

You can get the HI pulley from importpartspro.com. Sell the AMS pulley to someone for $50 to off set the cost and it won't seem so bad

[vulcanrush]

Thanks for the info about the overdrive pulley, guess I wasted $80! I appreciate your opinion and knowledge!

I realize I saved a bit of penny buying a copied design but I just found it unfair to hear that after shelling out $500 for upgraded intercoolers I should be buying something else lol. I'm pretty happy with the power capacity of stock turbos on the street, also they fit within my budget. So the AVS IC's are going to stay for now.

I'm thinking that my first thing to purchase would be the HI overdrive pulley and front+rear upper control arms. It seems like powertrix is liked for their suspension products.

i apologize, i didn't know they cost that much...in that case, yes, please keep them. and stock turbo's are plenty.
it seems everybody has an 800rwhp+ car. not sure what the point is.
powertrix is cool, spl is cool too.

[robomatic12]

No worries vulcan, I probably freaked out a little bit too much at the thought of having to upgrade my IC's yet again! Hahaha

Thanks for the input guys, now I know whats going on my shopping list