_ink

iTrader: (2)

I've been thinking about this Jonny, and the only thing you have different is the GTM pulley which must be the cause. You should be able to swap this out to the standard one and start it on idle to see if it fixes the problem.

_ink

iTrader: (2)

cdoxp800

iTrader: (12)

Looks good. I like the catch Can.

_ink

iTrader: (2)

Thanks! Had to do some custom work for that.

ITOzann

iTrader: (30)

Quick update guys. I'm pretty sure I have idle surge or a bad bpv. I haven't check my car in detail, but I just found out the bando belt I'm using is too long. My mechanic try to tension it but it would still be too long. What belts are you guys using along with the 85mm? I have belt squealing at start ups. I change the ac belt and it's good, the small s/c belt is tight enough as well, but the long s/c is loose fml. I order that from Sam 2 months ago after he recommended that one

Also, Last time I dyno my car I only reached 8.x psi with the stock crank pulleys, crawford plenum, test pipes.

I'll be ordering a new belt for sure and maybe a hks racing bpv.

cdoxp800

iTrader: (12)

On my 85mm Pulley I am using the Bando 1060. Zero issue. Now you can also look at getting a Dayco 5070410. It's about .75in smaller or 1040mm

MR RIZK

iTrader: (7)

Why cut the radiator shroud?

cdoxp800

iTrader: (12)

Makes it easier to get the Idler pulley on.

ITOzann

iTrader: (30)

+1k

_ink

iTrader: (2)

Without cutting the shroud, it also makes it near impossible to tighten the bolts on the pulley.

MR RIZK

iTrader: (7)

i know it is tight but still can be done. Did it on mine previously with no cutting required.

BTW the catch can and wire covering look pretty cool..

IanP

iTrader: (2)

+ a million.

Was a horrible job to do, but I've got a 54mm radiator so was even tighter

I don't think I have anything left of my shrod at all now. i might look into some slimline fans next year though.

jonnylaw

iTrader: (3)

I originally did not have the radiator shroud cut, but it w as done after the idler pulley snapped off while driving (bolts were later upgraded)--thinking the beltsseized--possibly the belts were too tight. But this was a catch 22, b/c it seems the smaller GTM pulley setup is prone to slipping.

It seems those with GTM custom SC pulleys are eventually having problems with belt slip/idle surge/etc. I know I am and it is killing my boost and power. I should not be only making ~7.7 psi and 360/360 on a Stage 5 kit! I will post up dryno graphs soon, but I am not happy. I should not have to overspin the blower by 20,000 rpms to get at ~400whp, but if that's the car, it sucks, I do not want to overspin the blower by 18%--and do not plan going back to my old setup. I want to eliminate the belt slip, rectify the idle surge and be making the power/boost I should..

I will be talking to Sam hopefully early next week about how to solve boost/power/belt slip issues.

I am thinking I will be going back to a larger primary (crank) pulley and putting back on the stock SC pulley to help curtail the belt slip.

I find it interesting that on Marble Stage 5 build thread--where he made 394/353 on an automatic with a hearty powerband that does not nosedive--it shows pictures of his car having the stock HKS SC pulley--NOT the GTM smaller pulley that comes with stage2+ kits! He never had idle surge or belt slip issues.

https://my350z.com/forum/shop-builds...automatic.html

If the car was delivered and really made those numbes w/out belt slip/idle surge on the standard HKS SC pulley, me thinks the GTM pulley might not be the best to have on the car...but I will await judgment until I speak with Sam and make another pulley change and redyno (but can't get an appt. with my shop until at least the end of the month if not later )

edit: marble's build thread show some pictures with the stock SC pulley and others with the GTM pulley--I can't tell which pulley is on in the picture where his car is on the dyno...

IanP

iTrader: (2)

Mine is still on stock pulley aswell

I've got the 90mm pulley sat in my garage, but I doubt I will fit it

jonnylaw

iTrader: (3)

Right, you are running the stock pulley and are making just about the same psi and power levels as me and I am running the smaller GTM pulley--Only difference I see in our setups besides pulley is that I have a revup and you are running test pipes, while I have HFC's.

So why did I get a more expensive, higher stage GTM kit, that does not benefit from a smaller SC pulley because of belt slip and inefficiency, and also may promote idle surge due to belt issues

not happy that I am having to keep throwing money at a setup to try to get things rights (power was originally good but waaaay overspinning with the setup as delivered)--1.5 years later, I research and catch the overspinning, attempt to correct with by going to stock crank pulley and my power/boost takes a nosedive and having belt slip issues with the GTM pulley.

with all the money I have spent on parts/install/tunes (at least $20k), I could have probably had a built motor and a tt setup. And I still don't have a proper running setup

ITOzann

iTrader: (30)

Jonnylaw, I feel the same way as you do having a stage 5 kit without the fcon and supposedly marble's kit. I did all my dyno's on a mustang dyno and I never got close to marble's result. Maybe he reached all those numbers since he had a stroked engine(4.0L) and dyno'ed on a dynojet. I somewhere found that he only reached somewhere around 350whp on the stage5 but then at the end i found higher; This was when I was researching for info about the hks s/c . Please keep us posted with the results you get and what Sam has to say about all this.

I have scheduled a dyno session for this week with a different shop that has a dynojet. I'll compare the results with gtm's result and make a conclusion based on it before I go ahead and replace stuff or try new things.

jonnylaw

iTrader: (3)

Do you guys notice an occasional slight "bird call" type sound at idle with the HKS SC?

ITOzann

iTrader: (30)

Do you guys think I'll loose power if my crank belt is not tension good enough? I'm about to order a belt replacement pretty soon.

The belts I'm using are:
Bando PK1700
Bando PK1060

aren't those kind of sounds related with issues with the blower/bearings?

jonnylaw

iTrader: (3)

yes, your belts need to be of a proper tension and not slipping to make the power you should. There are instructions on belt tension in the manual. When my kit was first installed I made decent power. Then the belts were tightened down more and I gained 2 psi and more power, so belt tension makes a difference.


I don't believe so. It is not the dreaded vortech metal grinding sound nor is it a whine. I've been told it's normal for Rotrex style blowers but am unsure. With your car on and the hood up, put your ear close to the blower and see if u can hear what I am referring to. thx.

IanP

iTrader: (2)

My boost dropped to about 6psi & tailled off after 4k rpm because my crank belt wasnt tight enough