Turbo or Nitrous?

[ghost_masterCL]

I've done pretty much every realistic NA mod to my engine, and am now looking for more power. I'm trying to decide on turbo or nitrous. Obviously the nitrous is going to cost a lot less.

This is for a J30A1 engine. Current performance mods include: CAI,headers, axleback exhaust, UR underdrive crank and alternator pullies, CL-S cams, thermoblok spacers, helix throttle body spacer, MSD SCI ignition, MSD blaster SS coil, NGK wires and iridium IX plugs, VAFC2 tuned by myself. and some supsension mods.

If I went nitrous I would probably just do a 75 wet shot from a ZEX kit.

If I went turbo I'd probably be boosting between 6 and 10 psi.

If I were to go turbo I would have to either get an additional injector, or bigger injectors all around. Either way I would have to get a bigger fuel pump as the stock pump is rubbish.

here are my questions:
-which setup would be "safer" for my engine: turbo or nitrous?
-if I get a bigger pump will I have to get an aftermarket FPR either way? (stock pump is 190 lph, would proabbly get a walbro 255lph pump)
-which setup can be tuned with my VAFC2? Would the VAFC2 be able to handle the turbo tuning, or would I be better off getting a piggyback like the emanage or something?
-would you be able to tap the block and oil pan for the oil feed/drain, and do what is necesarry to tap the coolant for a GT30R oil/water cooled?
-what would it cost to tune the nitrous?
-what would it cost to tune the turbo setup?

-have I asked too many questions?

[john]

What car does the j30a1 come in? I'm guessing that it's a honda motor?

If it were me, I'd go nitrous, at least initially. You can always use the nitrous kit in tandem w/a turbo kit if you go that direction.

If you were to go as big as a gt30, and the longblock is still built to be N/A, you'll have to go inside and replace a decent amount of the guts (at least pistons/rings/rods). And running a gt30 @ 9psi would be a HUGE waste of turbocharger - go for something small which has quick spooling characteristics. Something like a t25 from a 2nd gen DSM might do you well.

[Deceptakhan]

And its cheaper

[ghost_masterCL]

The J30A1 is the honda accord V6 motor in the 98-02 honda accords, and 97-99 Acura 3.0CL. 3.0L SOHC V6, 9.5:1 CR, 86x86mm bore x stroke, 6000 rpm redline

The reason I would get the GT30 is becuase someone turbo'd his J32A2 CL Type S motor with a GT35R and got 419 whp at 6 psi :eek:, and I spent some time looking at compressor maps, and one of the GT30R maps puts almost the entire operating range in the middle of the map at 9 psi.

[john]

The gt30 starts getting happy around 20psi AFAIK. Which map(s) are you looking at?

Being that the motor is a 3 litre, it may have enough flow to spool up a 'big' turbo like the gt30. Which is one of the turbos on the shortlist for my 2.5litre legacygt.

[ghost_masterCL]

I think it was the GT3076R. I dunno if saying "it starts getting happy around 20 psi" is the right thing to say, as it's not really the psi that you would be looking at ont he compressor maps, it's the flow rate and pressure ratio.

as an example it woudl take like 5 psi on a 5.0 litre engine at 5000 rpms to equal 40 lb/min (just a total random number, it's just an example) where it would take 10 psi at 5000 rpms on a 2.5 litre engine to equal 40 lb/min (again, just an example, probably way off). Engine size plays a big role in which turbo to choose.

here's the turbo I was talking about: http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT30/GT3076R_700382_12.htm

at 9 psi at 6000 rpms it puts it at a pressure ratio of 1.8, and a LBM of 28.5 which is damn near right in the middle. 12 psi @ 6000 rpm would put it at 2.05 PR and 31.5 LMB which is smack dab in the middle.

on a side note, what kind of volumetric efficiency should I have, and what BSFC should I put in my calulations? those are the only ones you can't really calculate, and I'm not sure if my guesses were close or not.

[HONDA GHANDI]

What transmission does your car have?

[ghost_masterCL]

M7XA 4 speed auto, pretty mucht eh same thing as the 98-02 accord V6 transmissions on the inside, BUT I have a performance rebuild capable of holding 450 whp standing by. Has upgraded tq convertor, LSD, carbon-kevlar clutch packs, reworked fluid flow, pretty much redesigned fromt the inside out.

there's a guy with an accord V6 in the 12's who's been pushing 380 whp with a supercharger for a couple years now with no problems.

[HONDA GHANDI]

You will need the upgraded tranny if you do either one of the setups you want. Basically it is up to you and your budget. I cant decide which one is better for you.

[ghost_masterCL]

will I need colder plugs for the 75 shot of nitrous? And Is either more stressful on the engine than the other?

[HONDA GHANDI]

You should have them. Need them? probably not.

[inigo]

will I need colder plugs for the 75 shot of nitrous? And Is either more stressful on the engine than the other?

Ghost master from Acura cl dot com ? yes .....you should get colder plugs even for 75. Safer is better. As for your tranny made of glass*(hehe) you'll need a tranny cooler to get by. Remember FastvtecCL ? He was on his stock unit with a tranny cooler for some time on 125 shot.

[ghost_masterCL]

Ghost master from Acura cl dot com ? yes .....you should get colder plugs even for 75. Safer is better. As for your tranny made of glass*(hehe) you'll need a tranny cooler to get by. Remember FastvtecCL ? He was on his stock unit with a tranny cooler for some time on 125 shot.
yep that's me. I'm not worried about the trans. just the engine.

[john]

The general rule of thumb on colder plugs is once you add 50 hp, go one stage colder. I added 400+ hp to the 320 hp supra and ran 1 range colder, but I tuned it fat vs trying to get max power due to it being my daily driver.

The gt30r is one of the turbos I'm considering for my legacy gt. I believe that I should be able to make 300-350 pump gas awhp and still be close to, if not on the top of the efficiency island.

Regarding the VE of your motor, if someone else out there is running a similar setup, perhaps they can share VE info? VE is a moving target, so utterly dependant on the state of your mods (valves, porting, VVT, forced induction, etc).

[HONDA GHANDI]

You basically want to run as hot a plug as you can get away with without detonation and preignition. Every motor will have different characteristics for this. The best way to find out is with a couple of different heat ranges and some dyno pulls.

[ghost_masterCL]

Sounds good tobi. I'll probably grab some colder plugs and bring it in for a tune when I get it installed.

I'm just gonna go with the 75 wet shot of nitrous for now, and if that doesn't satisfy me I'll either up the shot (to maybe 125 like some other guys are doing since the trany isn't an issue for me) or I'll start peicing together that turbo setup .

[HONDA GHANDI]

Cool.