how about now

 

FI cars are still affected by altitude. The wastegate is a differential pressure guage. 17 psi in the manifold is in referece to the ambient air. As ambient pressure drops (with altitude) so will the absolute pressure drop in the manifold. You are still in 'boost' though so it is not as pronounced.

Just a little FYI.

Although I think going up to the Antelope Valley will be no porblem, as the highest elevation on 14 up that way is like 3500 feet right? Maybe 3000? If you were going above 6 or 7 then I may be concerned, but the wastegate will still do it's job...

 

NOt sure about that. This is what I have read and heard:

If you have a boost controller that works off the intake manifold prssure readings, it will simply close the wastegates later. You will come up on your target boost later in the powerband - but it will achieve the target boost level (b/c out turbos are capable of much more than my target 7 psi). Now if oyu don't have a boost controller installed (and just work off your actuator spring pressure - which does in fact work on differential pressure) then yes, you will nto achive target boost!

This only applies to turbochargers.

Superchargers are another story - they ARE affected by altitude!

Clint, wanna weigh in?

 

Is cooling an issue at high altitude? I believe piston-engine airplanes have to run with beefier cooling systems at high altitudes, for example. There are not as many air molecules to carry away heat. Water boils at a lower temp. Would this effect cars, too?

'03 G35s 5AT, Garnet Fire/Willow
Staggered 18" SSR GT1/Bridgestone PP S03
Eibach Springs/Sways, Stillen 2-pc BBK
Stillen Intake & SS Cat-Back Dual Exhaust

 

don't think so. Again, i am not sure how this particular turbo will react.

Piston engine airplanes - unless they are turbocharged, do not experience cooling problems at hihg altitudes. Not only is the temperature lower up there but the engine (give nthe lower pressure) develops far less HP/heat and thus requires far less cooling.

When I fly, and I have an individual cylinder EGT and CHT readings, I always run at around peak EGT or thereabouts - to achieve a higher cht temperatures. I remember the cht's on my 58 J35 bonanza deeping as low as 300 at 9K+ feet. You want the cht to be around 350, hot enough to allow th elead scavengers to work, cool enough to prolong their life.

 

can't wait to see the numbers..

i always worry when companies shave down their welds smooth. did you happen to look on the interior of the piping to see if there was a good bead left? air pressure in those pipes under boost is pretty strong and could snap a weak weld with ease. obviously these aren't tig welded pipes because there is no need to smooth out tig welds.

install looks great, sorry to hear about your TC issues, this is your car's way of telling you to just do a manual conversion

 

Hey Dude,
Any luck with the TC dilemma? By the way I searching in my service manuals and that auxilary fan in front of the radiator is a dual speed thats why there is four wires. If oyur wanting to wire in an aftermarket fan let me know and I can scan the wiring diagram for yu and email it to you......Keep me posted


Infiniti Gearhead

 

Yep, you're right. Turbos are in effect adjustable pumps since they use exhaust flow where superchagers have a fixed rpm related to engine speed.

I had turbo on the brain for some reason in my example... :- )

 

Hey Vince

THe tranny is definitely jacked - and it was showing strong signs of this for a long time now. I brake torqued it today - very lightly - and the rpm needle traveled right through the rpm band with the car only moving a few dozen feet; it was like spinning tires - but not! I will swap in a fresh TC - and see what happens. Will keep you posted buddy. As far as the fan is concerned, it's funny, I do not even have a hint of overheating - according to the instrument cluster gauge - it sits in the exact position as it did before. So i am gonna ride it out for a while and fry the bigger fish for now! Thanks

Maxima,

I just wish the MT swap in was feasible cost-wise. It's just not.

On a general note - I, along with Clint stopped by Ted's place, and took the car for a drive. Between the 3 of us taking turns driving the car, the performance was very inconsistent - again the tranny being a highly suspect culprit. When Ted took the wheel, with 2 of us in the car and a trunkfull (~80-100lbs) of old car parts (headers, etc.), the car took off like a bat out of hell - it was incredible, and this is only at ~4.3 psi of boost. In the next 2 hours, clint and I experimented pretty extensively with different driving techniques, and could only get close to what we experienced on that run. THe performance varies depending on how you launch. I'll go into more detail later... and will reserve final judgement for now.

See you SoCal guys tomorrow at the Bova meet!

Gurgen

<P ID="edit"><FONT class="small"><EM>Edited by gurgenpb on 06/25/04 07:53 PM.</EM></FONT></P>

 

BTW

Those are tig-welded! At least that's what I am told by at least 4 people.

I do see that that one shot did not have the welding on the inside of ht emanifold - but that was deemed to be ok by Rich and Todashi, and given that i do not know anything about welding/welds and that they are the experts, we simply moved on. But todashi was vigilant about hte manifolds and one of the first things that he said to me, even before we picked up the kit, is that he is going to examine the manifolds at the time of the pickup. If the welds were deemed to be too thin, they would add more welds and refinish the manifold.

Gurgen

 

The manifolds are all tig welded, looks like hand done and very well done at that. I just worry about the welds on the piping, but it could be a mute point. Either way it looks like you have bigger problems to fix first.

Nissans/Infinitis surprising aren't that complex to doing auto/manual swaps. I know from experience since I swapped my auto for a 5-spd on my maxima. It wasn't EASY, but it was definitely do-able. Finding the parts is probably the hardest thing (like you mentioned).

jason

 

Jason

That's what I heard from someone else as well (about the tranny swap). Does it require an ECU swap? (It looks like I am hijacking my own thread!)

About the manifolds, believe me when I tell you that I almost drive with my fingers crossed. The do look "insufficiently" welded, but I am assured by experts that that is sufficient. They are SS after all, and are susceptible to cracking due to temp changes - and significant ones at that. Basically, if it is REALLY cold out, you have been really testing the car for a while, and come home and park it right away, the extreme temperature change would be bad. This is not as much of an issue (yet, I admit, an issue nontheless) when it's hot out, as is the case 5-6 months out of the year. What I would need to do I suppose is let them cool down gradually; that is, drive conservatively as you approach your destination. HOwever, even if you don't take care of them at all, they are likely to not crack for as long as 15 years (in reality, more like 5 +-2 i would say). That is ok by me, you need to make a compromise to get the best kit out there, and this is really the ONLY one that I can see (as long as you stay under 20lbs of boost).

Gurgen.

 

the manifolds look to be top notch, i wouldnt worry about them at all.. drastic temperature issues could crack a manifold, but its very unlikely to happen unless you are doing 24 le mans racing. i was just talking about the charge pipes and such..

and as far as the tranny swap, i actually ran an auto ecu on my car for awhile after the 5spd swap and had to deal with 3 check engine codes. realistically it shouldn't matter too much, however the g35 ecu may be a little bit more complex so it would be wiser to just use a manual ecu. it's really a hard thing to guess at, you just have to try it and see if it works. it will definitely through a P/N switch code, AT speed sensor code and possibly not let your reverse lights and cruise work without some rewiring.

i don't want to hijack your thread either, so if you want to pm about it id be more than happy to give any input i have... not sure how relevant it is to this car, but you just never know.

jason

 

Congrats on the new TTs.

I've heard turbos are good mufflers... Is your exhaust note more quiet after the TT installation?

'03 G35s 5AT, Garnet Fire/Willow
Staggered 18" SSR GT1/Bridgestone PP S03
Eibach Springs/Sways, Stillen 2-pc BBK
Stillen Intake & SS Cat-Back Dual Exhaust