Moving past stock 1jz

[1jzQuest]

I was wondering what would be the correct order of things -ie stages to get my 1jz to 350-400+hp/ Motor stock- 2 1/2 intercooler piping-intercooler - bypass fuel line, walbro, 2 1/2 exhaust no cats, stock-y pipe.

Stage one would consists of? hp range?
Stage two ? Stage 3?

The reason why I ask is that I can get 440's cheap but would that be putting the cart infront of the horse due to not have the support mods to effectively run them ie- safc,wideband??

Thanks

 

[destrux]

There's no real "stages" to upgrading any engine... but things do kind of lump together.

If I had to lump 1JZ upgrades into stages I would probably put them like this...

Stage 1: Walbro fuel pump, 2.5" IC pipes, medium FMIC (sized for ~400hp), 3" turbo-back exhaust, boost gauge, 3" pre-turbo intake tube with pod filter. Estimated 12-14psi of boost (due to boost creep).
Stage 1 estimated crank HP: 330-350

Stage 2: Stage 1 mods, 440 (or larger) fuel injectors, SAFC (or some type of fuel control), electronic boost controller (set to 15psi), upgraded exhaust y-pipe. Estimated crank HP: 360-380

Stage 3: Stage 1&2 mods, 550 (or larger) fuel injectors, 3" intercooler piping, larger FMIC (sized for ~500hp), 3.5" exhaust, boost set to 16-18psi (walking on thin ice with stock twins here), aftermarket cams, race gas/E85 OR water/methanol injection probably required at this point to prevent detonation (especially with the small stock twins cranked this high). If you plan to stop here, a good option at this point is fitting up a set of USDM JZA80 twin turbo's. They require some work to fit, but flow more and heat the air up less. Estimated crank HP: 400-450.

Stage 4+: Single turbo... this can get crazy, so the supporting mods will depend on what turbo you choose.

This doesn't include supporting mods that should also be done to support an engine making more power such as an upgraded radiator, external oil cooler, an upgraded clutch, 12v fuel pump mod or upgraded brakes. Also... I didn't really write this as an ideal way to gradually upgrade a car. It's best to figure out where you want to end up and build for that goal... It would make more sense to skip right to a big FMIC, 3" IC piping and 3.5"/4" exhaust if you ever plan to go above 400hp. No point in buying things twice. It's not ideal to have an intercooler that's rated for 700hp and 3" IC piping if your car will only ever make 350hp though (both will increase lag and the bigger FMIC will block the radiator more), that's the only reason I did it like this. Similarly, there's no point in having a 4" exhaust on a 350hp car, you won't gain much power on a 350hp car by going from 3" to 4". Just more weight, noise, and cost and less ground clearance.

If I forgot anything or made any mistakes I'm sure someone will let me know....

 

[Dylan JZ]

well, I'm not really sure how to answer "stages," so.. but I'd recommend going to 440s regardless of what you're doing, as long as you have an AFC or whatever else.

 

[hvyman]

Really should have a 3pm exhaust already but I would put that at the top of the list.

 

[Dylan JZ]

so wait! what about a (gasp) 3am exhaust, what would happen?!

 

[te72]

so wait! what about a (gasp) 3am exhaust, what would happen?!

You'd probably be waking up a lot of neighbors, I'd say. :rofl:

For what it's worth, I'm laying down 320rwhp at 12psi with merely head work (porting/polishing, BC264 cams) and a 3" exhaust from the turbos back. Figure in a 20% drivetrain loss, and you're looking at 400hp crank. Not saying every car will be that way, but it works for me. Making power is the easy part, it's controlling it and putting it to the ground that's more important. Best place to start once you get the car running right would be to upgrade the brakes.

 

[Dylan JZ]

agreed^, well on the exhaust and the mods . I made 340 @ 16psi with stock head, but everything else outside standalone and injectors has been done. I've always figured 15% drivetrain loss, though 20% is probably more accurate.

 

[hvyman]

LOL. Damn iphone auto correct

 

[IBoughtASupra]

agreed^, well on the exhaust and the mods . I made 340 @ 16psi with stock head, but everything else outside standalone and injectors has been done. I've always figured 15% drivetrain loss, though 20% is probably more accurate.

My build thread is for my first 1JZ motor and you are saying you made 340 at 16PSI on a stock head? Was that with twins or a single? I have a ported and cammed head with a single, wonder what I would put down at 16PSI...

 

[Dylan JZ]

stock twins.. I expect around 450whp @ ~18psi when I go single.

my buddy did it with nearly the same mods when he still had his RB25, and I see no reason not to expect very similar results.

 

[1jzQuest]

Great posts - thanks for all the input and suggestions -

 

[te72]

agreed^, well on the exhaust and the mods . I made 340 @ 16psi with stock head, but everything else outside standalone and injectors has been done. I've always figured 15% drivetrain loss, though 20% is probably more accurate.

I figure once you throw some wide tires out back, you're looking at a decent amount of parasitic loss due to the additional unsprung weight of 2.5" of extra wheel width, 2" more tire width, and an extra 1" of wheel height... 20% seems fair for an older RWD to me, but I'm certainly not an engineer.

LOL. Damn iphone auto correct

Just gonna leave this here: damnyouautocorrect.com