meccanoble

iTrader: (22)

just wondering if its needed when u r up to 9 psi or whatever psi is recommended to go with stock injectors, aftermarket fuel pump.

What are the losses if i go that high with no intercooler? I believe it charges the piping but just want to know if there's more to it...for future reference...

IceY2K1

iTrader: (3)

On pump gas, I'd say 4-5psi would be pushing it.

Bags

iTrader: (3)

I think 5 psi pushes it...

No intercooler means HOTTER air, never good. The colder/denser the air is the better it is on your motor.

jkklim

10char

densetsu

iTrader: (1)

no way you can run no intercooler at 9psi on stock injectors. the motor will already be on the brink of detonation and the added heat from the lack of an intercooler will further increase your chances of laying your motor to rest. believe me, i wish i could get away without one but sadly its just not possible at that level of boost on stock fuel injectors. now if you have upgraded injectors, the story changes in that you wont be risking detonation every time you turn on the car, but you will lose more and more power the higher boost you run without an intercooler.

meccanoble

iTrader: (22)

what power (i know it varies on a million things) would i be pushing at 5 psi? and what power u think is needed to be as fast as 11 psi SC w/ mevi? if i was to ever go turbo, just wondering what is needed to be just as fast as i was before....

densetsu

iTrader: (1)

nigel made like around 280 at 5psi when he first came out with his kit if i remember correctly. all you need to run at 5psi is a turbo, all associated piping, all associated oil lines and fittings, fmu, and a fuel pump. an intercooler would be optional but you would get the most power out of your setup if you had one. i believe thats all but i may have missed some minute things.

Max97Stick

ok how about a v2 sc with the 3.125 cartech fmu walbroo 255 pump safc2
daily driven will i need a intercooler?

meccanoble

iTrader: (22)

dam, ok with stock injectors and intercooler, whats highest boost u guys recommend me going to?

and whats closest boost to 11 psi SC w/ MEVI?

densetsu

iTrader: (1)

stock injectors and intercooled id stop at 9 to be safe but you should be able to run at 10 if you tune correctly. i really dont know anything about superchargers's so i cant help you on that.

meccanoble

iTrader: (22)

so what have u guys been paying for your intercooler? if i ever go turbo i want to be faster than SC 11 psi w/ mevi, thats it! Whatever will get me there. I dont need the heavy duty intercooler that can take 11+ psi or whatever cause i dont ever see myself going past 8...9 tops. What are some recommended intercoolers that can handle that type of power? best prices, etc.? whats flaw of going wit cheapo cooler vs the 700+ dollar ones?

stephenlc

iTrader: (1)

dude just get a $200-$300 intercooler off of ebay. I missed out on some company mistake. Everyone was buying them they sold like $450 dollar intercoolers for like $225 shipped. Doh

hlh0501

iTrader: (1)

this statement will change, gauranteed!

turbomax97

iTrader: (6)

yeah no kidding - boosted at 7.5 psi for a few days; then i got my boost controller in... each day i upped the boost like so 8, 9.5, 10.5, 11, 14,16 .... i'm currently running at 13 psi and tuning that... plenty of powa


Hal's right though, especially considering that a boost controller can turn ur pressure up via a **** - you'r egonna get greedy mecca

meccanoble

iTrader: (22)

u guys seem to forget i have the WORST LUCK EVER!!! I have more problems than half this board combined plus i cant even afford the recommended upgrades (injectors, Z32 MAF, emanage, etc.) so i dont even want to be at a boost level that will kill my car without the upgrades. I just want to be as fast as i was if not a little faster and i'll be content. Maybe down the line i'll want more but it wont be anytime soon, thats a guarantee, and when i'm ready, i'll definitely be upgrading before that **** gets touched.

But no one is answering my question . What boost should i go to so that i'm faster than 11 psi SC w/ mevi? or just as fast? i know it varies on tuning and setup and stuff but 5 psi sounds way too low, i figure 7 or 8 psi should be just about right but to get there, everyone is saying its best to run with intercooler....

Shadow

iTrader: (15)

Power depends on the turbo setup. ie, at 7 psi, I'm at 301 whp on my auto. W/ a 5 spd. I'd probably be closer to ~320whp. That's around where the 11 psi SC guys are. But I'm putting down 314 ft/lbs torque which is way more than the SC at that power level. I wish I could race an 11 psi SC'd max to find out, but all the ATL guys run turbos now.

meccanoble

iTrader: (22)

^^^^ very good point, i keep forgetting the torque difference.....

chris'smax

iTrader: (3)

mecca, you got rid of the supercharger?

matty

iTrader: (54)

He just wants to keep up with me

with my plans, itll be, mecca...lol

-matt

meccanoble

iTrader: (22)

^^^^ hahaha, my rival, i will catch you!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!

yea i sold the SC, money issues and had to do tranny swap....

Boosted Maxima

I run a stock 89 Maxima with a single turbo setup no intercooler. Everything STOCK will work. Injectors,fuel pump,regulator ect. I would not push it till you start up grading those areas but it'll take 7-8psi with a little timing adjustment and TPS adjusting to run 93oct. fuel.

Last week I put on Magnacore plug wires and a 225lr/hr pump. I'm currently searching for 370cc injectors, Aeromotive adj. fp Regluator and plan on having the stock GN tubo I use rebuilt.

If your going intercooled, You can use a stock GN intercooler (which I'm getting welded back up) it will support over 400hp. (effeciently cool) 75.00 -125.00 on www.turbobuick.com

When I install the intercooler,injectors,FPR my target boost for pump gas (like my GN stuff) is 14-16lbs. With tuning from the Romulator and Live edit. Might need to pick up a 300z maf at that point. If I hit my close to my target I should almost double my CID. (rule of thumb is for every 15lbs of boost you come close to doubleing the CID of the engine) or the way it acts anyway. So a little 3.8L buick acts like almost a 8L or a 3.0 Nissan acts like a 6.0. ect. It's not always a standard as there's alot of variables in tuning and engine effeciency. But it's a good goal to shoot for.

Moral of the story .. Used GN parts work great and are cheap. Nissan built one hell of a engine to go 194,000mi only to be boosted and modded and still live to tell the tail. Would not hesitate to do it again.. it's a blast to drive!
~Scott

meccanoble

iTrader: (22)

thansk for the input scott. Any pics of this intercooler? and u sure it would have same fitment on 4th gen?

densetsu

iTrader: (1)

i believe that piece on the back can be removed to make it thinner and you could probably get away with mounting it sideways in front of the raditor on the drivers side. that way you can even run shorter piping to it and fit it all through the space by the drivers side fender (instead of having to run one of the pipes over the intercooler like most people do) which is not only better for performance, but cheaper and cleaner too

i know that the old 944's had a similar design and could flow similar hp as well. saab, i believe, has this design on some of their intercoolers, but i dont recall which cars had them (sadly im not an avid saab enthusiast). a lot of stock audi intercoolers are the same shape and flow pretty big numbers (for stock intercoolers) but i dont think you would find any of those for cheap unless they were off an older model (i am not familiar with older audis so i cant vouch for the design or flow capacity).

Boosted Maxima

That's what a Stock GN IC looks like.. Thanks for the image help! What I did is cut off both inlet and outlets off flush with the top so all that was left is the core with square openings. Next I cut 45deg angles on both sides of the tanks (sides).

One side of that IC has a 2.5" opening and the other is just a 2". (see above image) We had done a different IC for a GN using 2 stock IC's welded together so I had a extra 2.5" kneck. If you rotate that kneck 180deg from where it's at now and lay it up against the 45 you just cut on the tank the oultet ends up being about flat with the top of the tank and pointed towards the headlamp areas on both sides of the car.
My routing is from in back of the headlamp on the drivers side... to the IC then from the outlet side of the IC around the pass. side headlamp then to the stock elbow that I modded (that was a real treat) whew. I have not found much drop in performance in more/less pipe. Plenty of cars with lots of pipe making more power than we are able to dream of. Too big of pipe might slow things down .. too small might be a restriction. Ideal size 2.25-2.5. Could get away with 2" inlet to IC and 2.5 after to Throttle body. I'm going to use 2.5" all the way.
The biggest restriction in the stock IC is that 90deg bend that's 2". The stock Cores are awsome and effecient. With the duel 2.5" inlet/outlet it's alot better flowing than stock. They got welded today so I'll get pic's to Mike Cook and you can check them out yourself.
Not sure about the 4gen. I've got 0 experience with them. Not saying it can't be done just have not owned one to know.
~Scott

densetsu

iTrader: (1)

i dont know much about intercooler mechanics so ill pose this simple question. is it possible to weld two cores together? i was thinking to take two cores and put 1-2" wide plates around the joint and weld one side of each core to the ends of it. cheap way to make a bigger intercooler witout having to buy a big *** core. will this work in terms of being able to flow more cfm or am i just wasting thinking power?

Boosted Maxima

We welded two stock GN intercoolers together and it worked better than the "Charged Air Systems" 1200.00 Intercooler. Run both cars and then tested inlet pipes with infared pointer. Two stock Ic's cooled some 30deg better.
Should have pic's tomorrow.

Jeff92se

iTrader: (82)

How come Ian can run over 300 fwhp on his sc w/o an IC? Are the charge temps THAT different inbetween sc and turbo?? If you keep running smaller sc pullies and compress the charge to up the psi, it will generate more heat.

vortechpower

iTrader: (1)

yes more boost makes more heat except that a turbo makes more heat than a sc. Exhuast driven versus belt driven

IceY2K1

iTrader: (3)

I'd say it's not really the additional heat of the TC, especially since most are more efficient at adiabatic compression then SCs now.

It's because of the nature of the SC producing peak power at redline vs. TC producing a HUGE dynamic compression ratio before/by the torque peak where timing is critical.

IMHO...anybody pushing more then 4-5psi non-intercooled is prematurely killing the engine. Even additional heat from perfect adiabatic compression, ie 100%, is not good. SC'd or TC'd *SHOULD* have an IC. My .02, is that the trade-off performance wise on the impeller speed limited SC is counter productive, however for engine life, it's a good choice.

Boosted Maxima

I'd have to agree with Ice on the importance of Intercooling not only for performance but longivity of the engine. The reason I am not going to run more than 8lbs right now is I have stock injectors and programing. Once I make a pass through the gears the inlet pipe from the turbo is not hot. At 8psi it's not compressing the air enough. Now if I'd turn in my actuator and make 15psi (if I could turn the timing down enough&supply fuel) I bet the oulet temps would raise ALOT. I'm sure someone smarter than me has made all the calculations for ever 1PSI boost raised the oulet temp from the turbo X degrees.
Anyway.. back to making 300hp with no IC. Supercharging is far less effecent than turbocharging. The only way he's making that power is by programming and having enough fuel supplied.
~Scott.

IceY2K1

iTrader: (3)

Just for reference.....

Assuming atmospheric pressure = 14.7, ambient 70*F, only 0.5psi drop across hte filter/compressor inlet piping, ignoring inlet air/compressor discharge air heating from underhood temps, and a 100% PERFECTLY efficient compressor:

At 5psi(manifold):
The 70*F intake air would exit the compressor at 190*F.
At 8psi(manifold):
The 70*F intake air would exit the compressor at 214*F.
At 10psi(manifold):
The 70*F intake air would exit the compressor at 228*F.


So, now lets take a 72% efficient V2 SC and a 79% efficient GT35R compressor:

At 5psi(manifold):
The 70*F intake air would exit the compressor at 222*F for TC.
The 70*F intake air would exit the compressor at 236*F for SC.
At 8psi(manifold):
The 70*F intake air would exit the compressor at 252*F for TC.
The 70*F intake air would exit the compressor at 270*F for SC.
At 10psi(manifold):
The 70*F intake air would exit the compressor at 270*F for TC.
The 70*F intake air would exit the compressor at 289*F for SC.


Now, say we use an 80% efficient intercooler with ZERO pressure drop:
At 5psi(manifold):
TC compressor discharge at 222*F drop to 100*F.
SC compressor discharge at 236*F drop to 103*F.
At 8psi(manifold):
TC compressor discharge at 252*F drop to 106*F.
SC compressor discharge at 270*F drop to 110*F.
At 10psi(manifold):
TC compressor discharge at 270*F drop to 110*F.
SC compressor discharge at 289*F drop to 114*F.

Notice that even though the SC vs. TC compressor efficiencies are 72% vs. 79%, once it goes through the intercooler that 7% difference only makes a 3-4 degree difference. However, on the non-intercooled it makes a ~14/18/19 degree difference.

So, would you rather have your engine injesting 222-289*F or 100-114*F air? Imagine if you live in the 100*F desert like myself vs. 70*F used in this example? Add in 10*F at least for underhood heating.

Finally, think about how much timing you must pull or additional fuel you must use that could be making *MORE* power just to ward off detonation from the 100+ degree higher intake charge temps.

Good reading incase you haven't:
http://www.stealth316.com/2-adiabat1.htm

Boosted Maxima

I told you someone smarter than me would have all the numbers for ya!
Anyway, My El Cheapo intercooler is done and the throttle body elbo is done too. I'm sending the pic's to Mtcookson right now. He's been hosting my pic's for me. I'll install the IC and TB elbow this week and let you know how much PSI I loose through the IC (if any) and what the inlet temps are after a pass.
~scott

Supermax95

iTrader: (2)

colder = more efficient, and safer.....the colder the more power, thats why people use cold air intakes...= ]

Jeff92se

iTrader: (82)

Or water injection?

JeffesonM

iTrader: (5)

Remember too that if you don't get an intercooler in the beginning, if you decide to up the boost later on you'll need to redo some piping.