# GA16DEt questions...



## Petrovich (May 13, 2005)

I'm on a quest of building the ultimate GA16DEt. Ultimate, as in, reliable, affordable, efficient, yet reasonably fast. 

Hence the question: how much power can I make using stock injectors at stock fuel pressure? Would the fuel pump be able to go that far, too?

Then, what's the highest RPM the engine can run at without encountering severe reliability/ problems? Assume stock or mostly stock configuration. If it's just harder valve springs I need, that's not a problem, but having to buy forged anything might be a bit too much.

Next question... How much air would it flow, given maxed out injectors? Assume 15-15.3 A/F ratio (yes, lean, that's what I have water injection for  ) I'm trying to pick the best turbo here, and looking at smaller Garrett GT series.

And last, but not least: can somebody let me in on the dark magic of intake runner length? How to calculate optimum length, is the curve a necessity or is it just for tight packaging, what are ITB's good for, etc. Intake manifold design, in other words.


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## psuLemon (Apr 23, 2003)

Petrovich said:


> I'm on a quest of building the ultimate GA16DEt. Ultimate, as in, reliable, affordable, efficient, yet reasonably fast.
> 
> Hence the question: how much power can I make using stock injectors at stock fuel pressure? Would the fuel pump be able to go that far, too?
> 
> ...


you can not run stock injectors on a our cars. they will max out around 150whp or less. If you want reliable, you need to make sure you have proper air fuels.. this being said, get the 370cc and get your ecu remapped


hell you really should upgarde to a 255 walbro fuel pump to help smooth out detenations. The valves should be fine as our head design is very good. lastly this really should be in FI section. ill get it moved


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## Petrovich (May 13, 2005)

psuLemon said:


> you can not run stock injectors on a our cars. they will max out around 150whp or less. If you want reliable, you need to make sure you have proper air fuels.. this being said, get the 370cc and get your ecu remapped
> 
> 
> hell you really should upgarde to a 255 walbro fuel pump to help smooth out detenations. The valves should be fine as our head design is very good. lastly this really should be in FI section. ill get it moved


Well, I'm actually going with Megasquirt II... The reason why I want stock injectors is to keep the costs down, and to preserve decent highway fuel economy.
In fact, 150-160hp would be plenty enough - I plan on raising compression slightly, so I won't be running much boost anyway. I'll have a 5th injector shooting water and/or water/alcohol mix.
And if stock injectors are really that bad, are there any others that would be of a comparable class, but slightly better? SE-R injectors?...


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## wes (Apr 30, 2002)

Petrovich said:


> Well, I'm actually going with Megasquirt II... The reason why I want stock injectors is to keep the costs down, and to preserve decent highway fuel economy.
> In fact, 150-160hp would be plenty enough - I plan on raising compression slightly, so I won't be running much boost anyway. I'll have a 5th injector shooting water and/or water/alcohol mix.
> And if stock injectors are really that bad, are there any others that would be of a comparable class, but slightly better? SE-R injectors?...


370 cc injectors can be had for $100 or less why are you trying to re-invent the wheel? Also I still get 28-30MPG on the highway even with my 50lb injectors, consumption is limited by your right foot... 

15.0 is too lean, even with water injection I forsee issues! Especially with raised compression. If you are looking to keep costs down why are you talking about intake runner lenght, are you doing all of the fabrication yourself? Also you talk cheap but yet mention GT series garrett turbo's? Not even worth it at 150 WHP. 

Megasquirt is fine as well and a great way to keep costs down. But if you really wanna be cheap. use a Standard T25, 370 cc injectors, 300z fuel pump, and fab the rest yourself.


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## myoung (Apr 15, 2002)

wes said:


> Megasquirt is fine as well and a great way to keep costs down. But if you really wanna be cheap. use a Standard T25, 370 cc injectors, 300z fuel pump, and fab the rest yourself.


For the HP he is going for the stock fuel pump will work fine..


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## wes (Apr 30, 2002)

myoung said:


> For the HP he is going for the stock fuel pump will work fine..


I agree, but with the setup I recommended he will be able to make more HP if he choses too.


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## Petrovich (May 13, 2005)

wes said:


> I agree, but with the setup I recommended he will be able to make more HP if he choses too.


Well, I can certainly see making easy 200hp, BUT... How am I going to put down all that power? 200hp in a FWD with open differential is calling for one tire burning to ashes and the other staying where it is, IMO  I would be able to afford a 1000$ differential... Only if anyone made one. Phantom grip is all I heard of and people have rather mixed opinions on it.
This is why I'm shooting for a low-pressure, quick spool setup with a broad torque curve. And I always have this thing for getting the best of the best if I can afford it  Hence GT's.


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## Petrovich (May 13, 2005)

BTW, where would you buy those <100$ 370cc injectors from?... I need them for my 931, which will be the guinea pig for Megasquirt.


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## wes (Apr 30, 2002)

Petrovich said:


> Well, I can certainly see making easy 200hp, BUT... How am I going to put down all that power? 200hp in a FWD with open differential is calling for one tire burning to ashes and the other staying where it is, IMO  I would be able to afford a 1000$ differential... Only if anyone made one. Phantom grip is all I heard of and people have rather mixed opinions on it.
> This is why I'm shooting for a low-pressure, quick spool setup with a broad torque curve. And I always have this thing for getting the best of the best if I can afford it  Hence GT's.


My car puts down good power, and guess what? With the PG it doesn't spin the tires in second gear, it just hooks and goes. First you have to modulate it a bit, but once your in second forget it.... It's gone. 

Oh yeah and I have a broad torque curve as well. Both my and Mike's car are exactly what your describing.....


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## wes (Apr 30, 2002)

Petrovich said:


> BTW, where would you buy those <100$ 370cc injectors from?... I need them for my 931, which will be the guinea pig for Megasquirt.


Here in the classifieds or on SR20forum.


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## Petrovich (May 13, 2005)

wes said:


> My car puts down good power, and guess what? With the PG it doesn't spin the tires in second gear, it just hooks and goes. First you have to modulate it a bit, but once your in second forget it.... It's gone.
> 
> Oh yeah and I have a broad torque curve as well. Both my and Mike's car are exactly what your describing.....


 :thumbup: 
SOLD to the man with phantom grip!
Ok, I'm convinced then, I'm building an asphalt eater. I'll do some research and will be back in a day or two... 
Speaking of 2nd gear, my tires are so bad now, they sqeak pretty bad in second, and god forbid I'm going into a curve when doing the shift...
I guess I've been spoiled by fat-tire AWD


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## psuLemon (Apr 23, 2003)

http://www.nissanperformancemag.com/july05/evil_twin/ that should be very helpful with youre tranny issues.


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