Jumbo's custom turbo build

jumbosrule said:
Ray, final gearing isn't going to effect the lag. The motor's rpms don't change because of a gear in the differential. Since a turbo is powered by the motor's exhaust, transmission and differential gear ratios are not part of the equation.
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Yeah i understand.....can't seem to get that out of my mind.....still thinking each time of the gearing.
But what i thought was when having a shorter final gearing you would be sooner at the Rpm's at wich the turbo would start to spool. So same leg.....but you'll just be there sooner.
Nice vids....and indeed JC....very hard to imagine how such a thing runs in reality. Would like to here it from the outside any time. The turbo....wastegate....you know the deal.

And uhhhh do i detect a bit of carbon fiber on the steering wheel...:tonguey:

Great work buddy.....so with you being sort of finished.....i think i'll start my topic soon.....i'll call it Ray's Boost as a thumbs up for all your help an advise :tup:

Enjoy buddy..!! And keep sema in mind......i'm coming....!! :wub:
 
tchuck said:
Awesome. So did Powerfab give you final dyno numbers?
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We have been changing boost levels using the Osiris interface so the dyno gave us power levels at particular boost levels. I'm running at 12psi right now which should be right at 400whp. They went as high as 16psi, but at higher rpms, the turbo was starving for air.

Ray, good luck with your build thread! Looking forward to subscribing.

I really don't think the final gearing has any impact on lag. You are loading the motor differently but it is not enough of a change in rpms to effect spool time.

So far, I have been getting between 250 and 300 miles per tank. That is between 400 and 480 kilometers. With final gearing lower, I would expect that fuel efficiency to drop further - to between 225 - 275 miles per tank or 360 - 440 Km. If you can live with that, then go for the lower final drive. I hear great things from the Z community that does this mod about how it feels. In fact, it is something you could do to the car now since it doesn't depend on any modifications to the motor. You'd be able to enjoy the benefits for a while before adding forced induction.
 
I have a Euro spec 350Z pumpkin lying in the shop and ready to go. That one has LSD and a 3.5 Final gear in stead of my 3.3 RWD version. So i'll try that first anyway.
As you said this mod can be done outside the F/I conversion so i think i'll wait and see has the FX runs with that gearing and decide later if i would change it.

So boost levels done trough osiris...?? Why not trough the Haltech...?? And was the air for the turbo the issue to stay at that level or did the tranny give a hard time at that point already also....??
Can such an air issue be solved by using a bigger airfilter or changing the location of the air filter....??
 
A taller final drive ratio is good as far as staying in boost longer, (higher speed per gear). It will feel sluggish compared to a shorter FD.

Downside and realistically is the FX is a fat pig, same gear ratios and final drive as a 5AT G or Z but add the difference in overall tire diameter and it would be like a G or Z on a 2.85 FD.

Reverse is to have the same final drive at the wheel as a G or Z a FX would be somewhere around a 3.8.

Can't remember if I have a 3.7 or 3.9, but I wouldn't go back to a 3.3 for any reason. Off the line oomph is worth the little bt of fuel economy and having a top speed under 200mph. lol
 
rookie said:
A taller final drive ratio is good as far as staying in boost longer, (higher speed per gear). It will feel sluggish compared to a shorter FD.

Downside and realistically is the FX is a fat pig, same gear ratios and final drive as a 5AT G or Z but add the difference in overall tire diameter and it would be like a G or Z on a 2.85 FD.

Reverse is to have the same final drive at the wheel as a G or Z a FX would be somewhere around a 3.8.

Can't remember if I have a 3.7 or 3.9, but I wouldn't go back to a 3.3 for any reason. Off the line oomph is worth the little bt of fuel economy and having a top speed under 200mph. lol
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That sums it up great...
 
rookie said:
Can't remember if I have a 3.7 or 3.9, but I wouldn't go back to a 3.3 for any reason. Off the line oomph is worth the little bt of fuel economy and having a top speed under 200mph. lol
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I have done so many reading on the whole F/I and all the specs around it from you guys including yours rookie......lett me fresh up your mind a bit :laugh::

Old Set-up: 3.7

New Set-up: 3.9

:wink:

I wish i ever had the change to feel it before deciding, but i don't know anybody who has ever done that here to test it. Yeah a 350Z drift car wich has a 4.05 or something and that is extreme short for my liking, so i gues my end target would be somewhere at the 3.7 in the end.

---------- Post added at 08:07 PM ---------- Previous post was at 10:11 AM ----------

So anyone who likes looking at the same movies a couple of time or reading to book twice might want to look at my battle when going F/I as well :laugh:

///12725
 
That's right, I had a 3.7 with an ATS diff. Had a bunch of whine so changed to a cusco diff and put in a 3.9.

As far as fuel economy, I have drive from Vancouver WA, (right on the border to Oregon) and made it Redding CA on a single tank of gas. That's over 400 miles.
 
jumbosrule said:
Me neither. 400? Rookie must have added a second fuel tank!

Viet - did you have alternate fuel maps available or was this on all a the same power tune?
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Haha i wanted to ask him if he had an additional race fuel tank in the trunk also :laugh: Wouldn't supprise me with his degree of
modding.....
 
No extra tank, no different fuel maps either, I just have the 1 tune. Mpg sucked with the piggy back originally installed.

All of my travels I've been able to keep same or better range than the G35s I go with, especially the Vortech guys. Their mpg in general blow.
 
Just wanted to keep everybody in the loop as to what's up with the car.

In the past three years of ownership I have had a lot of electrical work done. As part of the turbo build, I included an Optima yellow top to run all the extra gear & aftermarket audio. Since it was not plug & play, we modified the stock harness to mate up to the new battery, and also installed a battery kill switch. We ran the Haltech harness through the factory boot in the firewall.

More than a year ago before the turbo build began, the new audio wires were previously run through the factory rubber boot in the firewall. The shop that installed the audio is now gone - closed business a few months after I used them. They didn't seal the boot where the new wires passed through and during heavy rain, water would make it through the boot and drip down the wire harness... to the factory ECU.

I discovered this while vacuuming the inside of my car - the passenger footwell was wet. I dissasembled everything and let it air dry for three days before putting it all back together and sealing the offending boot with silicone. Everything worked normally EXCEPT I found what seemed to be a power hesitation or a stumble of some type through a very particular RPM range - no matter what gear or speed. At first I thought it was the transmission but ruled that out after several experiements. I learned how to drive around this glitch - never had to worry about it once I figured it out. But I could reproduce the "stumble" on command and the cause was bothering me. After installing the Haltech, the shop I have been working with was able to swap in a G35 ECU temporarily. The glitch dissapeared and the factory ECU was definitely the cause. The water had to be the issue.

Two weeks ago I had the Infiniti dealership install a brand new factory ECU and program my keys. The car has been perfect in every way since that day, but keep in mind the factory ECU is completely stock at this point and not Uprev tuned at all. Well it rained hard in Houston last week. The car wouldn't start. I had it towed to the shop where they discovered that when the dealership installed the new factory ECU, they yanked on the harness wires and broke the silicone seal on the boot. Water came in, ran down the wires and this time got to the Haltech.

Luckily, after dissasembly and mild heat lamps and fans, everything works as it should and the boot has been repaired once again. It seems that both the new factory ECU and the Haltech are playing together nicely. I worry about longevity. Some electronics are never the same again after exposure to water.

I'm sick about it because it's tough to blame the dealership. Up front they disclaim all work because of my aftermarket modifications. The guy didn't know he couldn't pull on the harness like he did and didn't know to check he had even done anything wrong. I guess I could have checked it myself and reapplied silicone. Lesson learned on this one. That boot at the back of the battery compartment against the firewall - make sure it seals!!!
 
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Damn man, that sucks. I have a big power cable running through that boot as well. I'm going to check it out today.

How was your Optima not plug and play? Did you get the D35?


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Can you guys post a photo of exactly where it is. Is there one on both sides of the car or just one side? After I get my audio stuff done, I want to double check it. Thanks for the update!
 
When I ran a wire through that boot, I sealed the little drain hole on the plastic panel above it. I also covered the boot with a plastic bag, since it is behind the battery...nobody will ever see it.
 
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