hi.. im really in need of feedback from the My350z community.

last summer July 2011, I finally found a shop in my area ( montreal), that tuned with Uprev and had a Mustang Dyno in the shop.
I got the car tuned NA with Uprev.. and it was great.. car gained 25whp. for NA car ran so nice.. and definitely noticed the power gains.

ive been wanting to go SC with a Vortech setup for a long time. but could not bring myself to dish out the $$$ to do it..

then by chance just a few months after around Oct 2011.. I found a used Vortech tuner kit V2 in my area.. for non-rev, my car is 2005.
I calculated approx I would save $2000 in total when everything would be done. I was skeptical to by used, but was so enticed by the savings.. I went for it.

kit was missing some piping. inlet, outlet, downpipe, which we ordered.
at face value the blower looked healthy, smooth etc.. we did not open as it seemed to be in good shape.

the kit came with a different intercooler, Godspeed, but roughly same size as the one Vortech supplies..

I bought all the remaining parts.
gauges: A/F, Boost
DW 600cc injectors
Uprev GT Maf
colder plugs
walbro pump
kit came with 3.12 pulley

my tuner installed the kit all nice and good.

remaining aftermarket parts are:
Motordyne 5/16 Iso thermal plenum spacer
Berk HFC
Inchiba Y-pipe
Tanabe SMH exhaust
UR crank pulley ( underdrive) I know big mistake lol.

the first tuning session, the car was barely making 5lbs boost a WOT.?
so we knew something was wrong right away..?
when the 3.12 should make close to 10lbs.

I did a bunch of searchs here in the Vortech thread by Sentry.. and realized I still had the UR crank pulley..I bought it from a friend several years ago and did not remember it was the smaller underdrive pulley..

we were both releived.. that this was likley 99% reason why it was making only 5lbs..

it caused some delays cause crank bolt was seized.. but tuner got it off. put back the stock crank and got new belts etc..

now car is ready for tuning attempt #2.. this was yesterday afternoon.

to our surprise.. there was barely no difference..? it maybe barely reach 6lbs..? the stock crank is back in now.. so we were completely perplexed.?

all piping is sealed good.
BPV is functionning correct ( we checked it as a possible leak)
there is no belt slip

our only other areas to check would be a leak/issue with the intercooler.
or something with the blower. which he will remove and open up. possible chance impellers could be damaged on the inside..

but at face value, we dont think its either of those..but at this point we cant overlook it.

as well.. I checked the Teeth on the cog pulleys. and they are correct.
32T for the Jackshaft cog and 28teeth for SC cog.
as per my research here. this is the right cog setup for non-rev kit..

at this point we are both dumbfounded what the issue could be..?
this project has officially become money pit status..already wipping out the savings I would have made.

feedback would be greatly appreciated.!

thanks
Tony.

 

boost doesnt mean anything and can vary 100% between cars with exhaust/intake/ etc. what was your dyno?

You should been in the 350ish range on a mustang with that pulley

 

thanks for reply..

in both tuning attempts.. he did not give it any timing to make power.. when we noticed the boost was not right.. so I dont have any whp figures..

the Mustang does read low.. but Ive seen plenty of members with similar setups making close to 400whp on the mustang with the 3.12 and making the correct boost ranging from 8-10lbs with the 3.12..

yes.. in my research, ive read that different exhaust mods etc.. can effect back pressure.. but I dont think by that much.. im losing easily 3-4lbs of boost.. but again, ive read plenty of vortech threads.. with similar boltons with no issue regardin boost etc..

only 5-6lbs makes no sense..?

 

in terms of boost lose due to exhaust boltons..
I have my oem cats and y-pipe.. and im already running on the oem headers.

which would contribute to more boost loss..? HFC's or y-pipe...

or should I just swap both back in..?

but I still dont see how i can be losing 3-4lbs from that..?

in addition.. there was barely no change in boost from when the smaller underdrive crank pulley was in and when we swaped back in the oem crank pulley... its facted the smaller crank kills boost..

so with the oem crank back in.. the boost should have easily went up.. all else equal..

but it didnt..?

 

Belt slip is your issue. Tighten that sucker up. If that doesn't work check your couplers and bypass valve for leaks.

 

You need to answer this question and a dyno chart would be informational..

 

hi.. I appreciate the replies..

I will likely not have any hp figures soon.. cause the car is alreay off the dyno and my mechanic/tuner will be testing the the intercooler and removing the blower from mounting plate.. to open it up.. neither of us thinks its the blower.. but he is checking anyways at this point.

he is no rookie when it comes to FI setups.. he's worked with many Vortech kits for mustangs and vets.. and has branched out to the Vq's.

he rebuilds blowers.. so he will know if there is an issue when he opens it up..

regarding belt slip he has it at the right tension.. and says.. there is no slip.. and it was obvioulsy the first thought for low boost.. so it has been ruled out for the low boost..

we also tested the BPV, by closing it completely.. and still no change in boost.

continued feedback is still greatly appreciated..

 

Assuming the belt isn't slipping - does it peak at 6psi at redline or does it reach 6psi earlier? Earlier means the belt is slipping

with the supercharger, boost pressure varies according to how much airflow you have as well as elevation/air temp.

if you make 400whp with 6lbs of boost, who cares what the boost number is? You want hp right?

In the case of a supercharger, high air pressure just means the air can't get out quickly and will therefore stress the engine more


If it was a turbo with a wastegate and you weren't making x boost pressure, then something would be wrong because a turbo makes excess boost - that bleeds out the wastegate, hence why it exists.

The vortech has a finite amount of CFM it will generate and the revup kit is a little different than the non-revup in that the pulley is less aggressive to make up for the higher redline.

 

hi.. much appreciate feedback Sentry.. now i think we are getting somewhere..

the 6psi.. is barely reached by redline.... this is exactly how my tuner described it..
so given your description.. should mean no slip..

my car is the non-rev.. and the stock crank is back in..
and I counted the teeth for the cog configuation.. for non-rev..
it is correct with 32T for Jackshaft cog and 28T for SC cog..

as mentioned in previous replies.. my tuner has not given it any timing.. so we dont have whp figures.. in both tuning attempts, once we saw it was not making the right boost.. we stopped..

sure if it made near 400 whp at only 6psi.. I would be happy.. but somehow I dont think it will be the case..if he put it back on and did a full tune.

 

The only thing I can think of then is if there's an intake or exhaust leak somewhere or if the vortech unit itself is somehow damaged.

You'd need to know how steady the boost was climbing. If it was steady and the boost peaked at redline, then there's no belt slip. If it was wavering at all as it climbed, then it's slipping some. The gear you did the pull in can also impact belt slip because it changes how quickly you reach redline.

Bear in mind the 3.12 pulley only does around 10psi on a bone stock car with no aftermarket exhaust, cats, plenum, etc. Even still, I wouldn't expect the psi to be lower than 8 psi though in your case.

The tuner should be able to find out within a few dyno pulls what sort of ballpark power the car will be capable of making.

Bare in mind I don't really follow the forums much these days and haven't kept up with everything you have going on with your car or what condition the vortech kit you bought was in.

Assuming all other options have been ruled out like leaks, belt slip, etc, just diagnosing over the internet IMO you might have 2 choices that are each a gamble in spending money. 1 is you just start tuning the car and see what power you make. 2 is you get the blower rebuilt and see if that changes the boost.

 

Smoke test the beatch ... no leaks and FMIC is good then just tune it. If you have a free flowing exhaust mods then you will not reach 'expected' boost levels.

 

with the high flow cats, y-pipe, plenum spacer i wouldnt surprise me to see 6psi, i had HFC's, Nismo exhaust and DC Sports headers on my car and was only making 8psi and about 360 hp... but as everyone else said it would help to see some type of graph even its not the final tune, or even some of the logs so we could at lease see how the boost is building in relation to RPM.

 

hi.. thanks for the input..

im running on stock headers..

you had DC headers.. allowing way more flow.. with hfc and full nismo exhaust and you still made 8psi..

so doesnt make sense.. that;

my oem headers + hfc+ y-pipe+ exhaust would lose 2-3psi..?

I dont see how the plenum spacer would reduce boost.. if anything it should help by allowing more air and more inficiently flow into the intake..

once my tuner checks the intercooler and blower.. and if they turn out good.. we will do a full tune to see what the car makes and review the graphs etc..

but at this point.. im looking at min another week+ delay.. while he tries to get back to my car while he is working on other jobs..

he is a great guy.. but all this has been extremely frustrating for both of us.. after 2 times now.. and soon to be a 3rd attempt..

 

It does allow for imporved flow, but, now i'm just spit balling here and someone jump in if i'm wrong, it also means that you have to fill a larger volume with the same amount of air, thus a slight drop in pressue and slower more even filling of each of the cylinders

 

boost is the measure of air that DOES NOT get into the motor. easier flowing motors allow more air in, so less boost is seen on the gauge.

until you post a boost curve or dyno, we cannot help you any more than guessing.

 

ok.. great inputs from everyone thus far and greatly appreciated..

I thought the plenum spacer would help for FI as it helps for NA..thats why i did it when I was NA

but I see now and agree it makes sense that it would lower boost pressure..

I will ask my mechanic/tuner to remove it for next 3rd tuning attempt..

at this point I will just have to wait.. until he checks the intercooler and blower so we can at least rules those out...

and then get the car back on the Dyno without the plenum spacer and see what happens. but regardless this time around.. we will do full tune and see what the car makes..

I will post back to let you know what happens..probably within a week or so..

big thanks
Tony.

 

with HFC and oem headers you should see the 'normal' amount of boost - around 9psi (i had the same setup for about a year). all else being equal, if you had aftermarket headers and test pipes then i'd expect you to see lower boost / back pressure. anyway, sounds like a boost leak to me. in addition to re-tightening all couplers, double check that none of your vacuum lines has come loose. the few times my vacuum line has popped off, the car made 5-6 pounds of boost since the bpv wouldn't fully shut.

 

Drock, Do Not Waste Time and Money by having more Labor cost to remove the Plenum Spacer. It will make very little difference, if any..... As long as it's been installed correctly and does not leak, leave it....

I assume you are paying your tuner for the install ? I would say let him do his job and don't accept it in till you are Happy with it...

The Problems you are describing are Very Common with a new install. And it's the Installers job to get this worked out.....

Like people have said, we are all just guessing without hard Data.

I will repeat, the most common problems ( mechanically ) with a new install that are related to Boost are:

1. Belt Slip
2. Boost Leak

Questions

1. How are you reading Boost?
2. How do you know their is No Belt Slip?

Feel Free to PM me.

TimRod

 

Do you have the GTM pulley upgrade? Also try sand blasting the grooves of the 3.12 pulley. Here is a vid of when I was getting belt slip when I had my 3.12 and even the GTM pulley mod: http://www.youtube.com/watch?v=w3Z0fhUPvcU.

I realized that my 3.12 pulley was dirty and cleaned it and tightened the belt and then I got 11 psi. I later sand blasted my 2.87 pulley for extra traction. Here is a thread I made on sand blasting a pulley, check on page 2, post #24 for the pics: https://my350z.com/forum/forced-indu...pulleys-2.html

I also made a DIY on how to do a boost pressure test: https://my350z.com/forum/engine-driv...ml#post5989613

My guess is still belt slip or a boost leak. Just to give you an idea about if there was a leak in the intercooler. I had forgot to put one of the bolts on my vortech intercooler which allowed a 1/8" hole. I found this while doing a boost pressure test and figured that was why my boost was so low 5-6psi. When I put a bolt in it was still 5-6psi and the problem for me was in the end......belt slip.....even with the gtm pulley mod.

 

Sounds to me your losing boost from a leak or as stated previously the mods could be affecting it.
Can you list any other mods you have (if not in the first list) and other details like what octane gas your using, how much experience this shop has with Nissans, and if possible how many miles are on the SC.