OgreDave

iTrader: (1)

A friend of mine works for the gov (ack) .. and among other things, he designs turbos - albeit for airplanes. He told me he could design one for my max (since they dont exist) if i could get him some numbers, and a few other things would have to be trial by fire.. but anyways, he thinks itd be a fun project, and id love to have turbo..

Ive already asked Turbo95Max, and he's tryin to help.. I'm not sure who here is knowledgable or not, just curious who i could bug for information here other than Matthel.. he's gonna get tired of me real quick

Some stuff i got from Matthel..

==============
>Mass Flow rate of intake and exhaust
didnt check this
>Tube Diameter at installation points
2"
>Temperature of Exhaust gas
Max EGT is about 780C
>Allowable Boost (detonation)
I belive i detonated at about 9psi Intercooled. 92 Octane
Using a reprogramed ECU would help this
>Type of Boosting (Constant Boost/Absolute Pressure)
???
>Expected Performace (psi boost)
Depends on size of turbo.
==============

So i guess this is a check/poll to see whos willing/able to donate some emails to me.. this might be a solid idea, might be another shot in the dark.. dont know until i see how much data i can scrounge up .. would be cool to develop it and get a manufacturer to build it for us tho, wouldnt it?

Much thanks, hope it works out.

Turbo95Max

iTrader: (25)

hehehe

get sick of you fast?? no its koo. Anyways, i wrote a turbo article for Cheston's website under TECH if you wanna check it out. i hope you can get some answers there. Whatever else your wondering go ahead and ask me. Some of your questions i didnt understand fully. I think its too enginnery for me. Ask with smaller words and i can prolly help you out. I been doing turbos, motorswaps, custom mods and much more for over 5 years so ive got some pretty good knowledge about whats going on. Maybe i can learn a few things from your project as well.,.,..later

the fish

Try http://www.jimwolftechnology.com. They make a turbo setup for the Maxima.

OgreDave

iTrader: (1)

thats a fable. a bedtime story..

OgreDave

iTrader: (1)

Ill see if i can get him to reword his stuff in english.. that one euthomololololology one threw me too.

PiotrC70

I envy TurboMax for pursuing his fascination to get a turbo installed...
Maybe it would help if it's okay with him, to take some pictures of his setup, under the car, side...etc.. To see exactly how the turbo is hooked up so to speak.
If the turbo could be manufactured for the price of a SC then that would be better...
Here is my question for Turbomax... Is each turbo different for each car.. I mean, how it looks, as is designed.
Couldn't you just buy a T04 for example, and custom all the piping and such??? I'm just speaking thoughts here so sorry if I"m not making any sense..
My friend told me how this guy bought a turbo from the junkyard off a car and custom piped it to his CRX and it worked and it was quick...

Turbo95Max

iTrader: (25)

hehe, thanks for the compliment..Lots of people talk the talk but with me i actually walk the walk. I said before i was gonna go turbo and i did. Im not talkin bout anyone here, juss alot of people i know do that. Basically you can use any turbo you want but it may not be good for the car. Using too big or too small a turbo will greatly affect performance. Also if the flange isnt right then youll have to get the right flange. Some turbo's come with internal wastegates which i dont like. Im using an external Tial wastegate on my Turbo setup. In parts alone if you dont go with the expensive stuff you can get everything between $1800-$2500 but then all the custom fabrication adds up. i do have some pics of my car but not really anything from underneath. Lemme know if you wanna see any of them.

Black VQ

I remember you said how you ran your turbo off of both banks of engine cylinders. Would it be less expensive to run an asymmetrical setup(only one bank)? I remember reading about the Saab 9-5, and how it has the turbo only running off of one bank of cylinders. I forgot what the advantage was, other than simplicity.

I like turbos a lot, and if I could get a setup for less than an SC, I'd be one happy Max owner. I just want a relatively mild and simple system, maybe a T25(like on the 2nd gen Eclipse) and hopefully, not much extra fuel.

OgreDave

iTrader: (1)

Thats pretty much what i want .. a smaller turbo, just a lil bit of boost.. just nuff to walk on the edge, n such.

PiotrC70

It's okay to use a small turbo/supercharger, but once you start running too much boost.. lets say more than 9 psi, it increases the chance of predetonation or knocking, therefor, you have to lower the compression ratio by increasing displacement of the engine.. unless someone can correct me on that. One way would be to go internal and bore out the cylider's and getting new pistons and such.
I'm still looking into this because idealy, I would like to get a turbo or supercharger setup and be able to run 9-11 psi and not have to worry about if my engine is holding up.
From what I have learned, turbo engines already have a lower compression ratio to start with so increasing HP and boost isn't a problem.

Turbo95Max

iTrader: (25)

ok im gonna post twice or else itll get too long

Black VQ,

im not sure about running turbo off juss 1 bank. I can see this as causing some probs. much more turbo lag and other probs. Im sure SAAB has some sort of special design, ECU, or whatever that makes it run correctly from 1 bank of cylinders but i dont know much about this topic.

next post...smaller turbo..

Turbo95Max

iTrader: (25)

ok

Smaller turbo, in general a smaller turbo will run hotter then a larger turbo cause it has to spin faster to provide more airflow. I had a large debate with another forum member about small/large turbos. He had claimed 1 of the reasons for my overheating probs was due to my small Turbo. i disagree. My turbo isnt small compared to most turbos used in cars today. You could use a larger turbo but no benefit out of it. A too large turbo youll have lag till like 5500rpm by the time you hit full boost its time to shift. Useless on the street.

PiotrC70,

You can run an intercooler top prevent detonation.its useful for boost around 8psi and up. Alot of factory turbo motors already use low compression pistons 8:1, 8.5:1, 9:1. Im not sure what the Maxima uses. 10:1? 10.5:1? anyways, you can run low boost on higher compression pistons to retain some low end power but overall you cant get as much power from the motor unless you go lower compression pistons. We did a turbo system on a friend's Integra ran stock compression with a T4 turbo boosting only 6psi. Lots of lag, Full boost hit at maybe 4500-5000rpm but once above that it pulled hard. Ran low 13's on street tires..not bad

Black VQ

I guess it's both banks, then. But, at least I know I could run the boost pressure I want without too much(if any) trouble. I'm thinking around 9psi max.
I just want something for maybe another 30hp or so, like on the Volvo 850/S70 GLT. They use a 'light pressure' turbo setup(around 5 psi, I think) to go up from 168hp to 190. I'd be happy with that, and the tuning potential it has once I get more cash.

Y'know, I've said it before, but it'd be so sweet if one of us could get the turbo manifold from the tt version of the VQ offered in Japan.

PiotrC70

I second that...
Thanks TurboMax for the info..

OgreDave

iTrader: (1)

I guess its time to have fun. I'll see what there is to making a turbo.
I think i was not clear baout the exhaust temperature. 780C seems like a
valve temperature. I need the exhaust temperature after the header, becasue
that is where the expansion turbine will be. At 780C steels would have
problems, and i thought that most turbos were made of stainless steal.
Steels start to have problems at 830C, althought 50 C is a big margin Really
the coolest turbo would be a titanium 6-4 turbine, that would reduce your
rotational mass (second polar moment of inertia) to 1/3. This means that is
woudl spin up in one third the time as a steel one, but TI 6-4 is only good
to about 550 C.

Another problem i just thought of was back pressure, the turbo will
signifantly effect the back pressure. I'll see what can be done but a simple
bolt on turbo without header mods may not be possible.

The absolute pressure would be like 9 psi boost at sea level so 9+14.7
or 23.7 psi. This means that under all conditions the turbo would try to get
to 23.7 psi. Minus are you need an over sized turbo if you goto high
altitudes were the pressure is for example 14.0 psi this means the booster
must be 9.7. psi. This may sound trivial but it is not because the pressure
ratios is what drive the sizing. 23.7/14.7 vs 23.7/14.0 thats a 8%
difference.
-------------
A simple "bolt-on" turbo? Damn hes going nuts.

Jeff92se

iTrader: (82)

Unless your willing to rebuild your motor like turbo is, then you are restricted to the amount of boost. Let's say you wanna turbo a stock VE,VQ,VG etc.. You can look at any one of the restrictions. Injector size, fuel pressure, how much compression ratio the engine can stand, engine strength, air flow limitations, tunability restrictions. You can only boost to the weakest factor. Let's say the stock injectors will only allow 290 hp at the flywheel(like the sc'd VQ), well there's no point in getting turbo that will lag in the low end but flow enough to support 450hp now is there? Might as well match the hp to the turbo. Let's say you can't alter the ignition timing on the VQ, so it will start detonating at about 9 psi. Again why get a turbo that flows mega hp when the engine can't use it?
You have to look at the big picture and be realistic about the hp you want and how much you want to spend. You also don't want to run the the ignition/fuel systems right on their limit all the time. That's asking for a big time failure. Turbo seems to have his head on straight and learned big time the 1st time around. Good luck bro!

[Edited by Jeff92se on 02-02-2001 at 04:07 PM]

OgreDave

iTrader: (1)

I agree, thats why i was lookin into smaller turbos. Im not looking for a huge gain, just a medium sized one. But, the turbo isnt really going to be the bulk of the cost, so large or small, it shouldnt make a huge difference. It may be a waste, but it also could be lookin ahead. A turbo that puts out say 450hp doesnt have to put it all out, you can run lower boost.. I'm not sure how efficient that would be, but thats why im feeling it out right now..

If my friend could somehow modify one to be a direct bolt on with just a few pipes, and no re-do'n the manifold.. ill $hit bricks..

But still, this is still research for a bit, until i fork out $$ for a turbo,tanks,wastegate,etc.. we'll see..

Turbo95Max

iTrader: (25)

i have an idea

run a low boost, 5-7psi, non intercooled turbo system. No intercooler would make the intake piping much much easier and less costly. Run inline fuel pump like Stillen's supercharger. You dont need to redo the manifolds. Use custom downpipe. Get a 6psi wastegate spring, dont need boost controller. Blow off valve as option. Lastly make it CARB approved and we can sell kits for about 2600-2800.

Thanks for the compliment Jeff92SE. that was a compliment rite?? hehe

PiotrC70

I guess I don't want 400 hp, although nice... I want to see low 13's, high 12's...
People on here have run low 13's... 13.3 if I can remember correctly and that is a goal I have for myself... I'm not talking just get a SC and throw the smallest pulley possible, I mean, reliable HP.. if that means I have to spend extra moolah on internals, then so be it.
Turbo, or anyone that can answer this question... When you go internal, (listen me through before you think) Are pistons just pistons... what I mean is, if I were to bore out professionally, would lightweight pistons and rods from an american manufacturer work, or is it a custom job.
I have a place that does custom work (nissan shop) and for a FULL headwork job I'd be looking at $1200-1600 with a good gain they say.(of course only way to tell is to dyno)
Now, is it THAT hard to lower the compression ratio or am I getting WAY above my head. I hate the it can't be done, or you're smoking on something answer....don't give me advice, (well you can) but give me realistic answers..
Thanks in advance =Þ

Jeff92se

iTrader: (82)

Turbo that was a compliment! Well I'm not turbo but I can answer this question pretty easy.

If you already own a 4-gen, I don't see why you see fit to re-engineer the wheel by trying to turbo your car. I know turbo has his own reasons but he has access to some pretty good resources also. I mean I think a sc'd maxima would be able to get into the 13's pretty easy, but getting into the 12's will require more than just power. I'm saying if you have the power (let's say 350 @flywheel) you still have to deal with the open differential tranny that the 4-gens have. If you have an auto, Don's VB mod is a must have and maybe more. Up to a certian point hp is great but at some time you have to start considering how your gonna get it to the ground ya know?

Now to answer the internals questions. Yeah you can go with a GOOD American company for rods(ie.. crower) had have full on bad *** custom rods made. They can make them any length w/ any size small and big end bearing dimensions. Cast, forged, exotic metals etc.....But be prepared for the bling bling! Same w/ pistons. I had some forged pistons from Arias in my L20b that featured a raised rod hole position. That lower the compression to about 7.5 to 1. Now that's just an example and not necessarily what you should be running. Every case it different. Like rods, you can have pistons made to whatever spec you want. 20 to 40 overbore, forged, cast, hi or low silicon content, dished or dome top, valve reliefed or not. Sky is the limit. Bling bling again! Now we haven't even touched the block, types of head work(or quality of head work from diff shops), pistons rings, cam timing, balancing, blueprinting, coatings, ignition, fuel issues, the rest of the driveline, mounts etc.. the list goes on. All of these things must be considered BEFORE you plunk down your hard earned cash. In addition to the above, there is a million combinations on the above too. More research again. What one shop says is the "best" is not what another shop says is "best". What is "best" anyway? Strongest? Lighest? Most expensive? Or maybe a selection of parts that work together the best? Engine work designed for a turbo is different than engine work for a na engine. You can't change your mind in the middle of a project w/o spending alot of cash to change everything. I'm sorry to write a dissertation but engine work is very difficult to get right and it's alot easier to get it WRONG that it is to get it right. Since I'm also from the NW, what is the name of the shop you are reffering to? I might know the guy. I know of a few guys that put me to shame in the engine knowledge thing.

Whitemax

is with a thicker head gasket. I was reading about the Lexus SC300 turbo on overboost.dom, and he lowered his compression by installing a thicker headgasket. Has anyone on here ever done that?

OgreDave

iTrader: (1)

Pretty much covered my idea there. As for carb approval.. i probably wont care about that.. I figured with lower boost i wouldnt have to f with too many things, being an auto and all.