need help picking between 550bb vs 700bb

[DTRUONG9]

hi im new to the forum and now its time for some new turbos, i've been trying to search reviews on the jwt550bb and jwt700bb for awhile but haven't found anything that answers my question. I'm looking for 450-500rwhp as a daily drive so the boost needs to be around 14-17 psi for peace of mindr. can i do this with the 550s or is it pushing them too much,
and with the 700 do i have to get cams and ms manifolds or can i still make the power goals w/o them?
and ill be running on 93 octane

my current mod list
built short block
ported intake and exhaust
1mm OS valves
dual intake with selin trans
3inch dps and 3-2.5inch test pipes
740cc nismo inj
arp main and head bolts
greddy boost controller
jwt ecu

[marty1mc]

If 450-500 is your goal, you don't need the 700's. Fitment can be a real hassle and the 550's drop in pretty well. I would only go for the 700's if you feel you want more. I have the Sport 500's and I have more power than I can keep on the road. I am not sure what an extra 100 or so would do. I also have the Nismo 740cc injectors, dual pop, JWT ECU, Stillen SMIC (you should also look at upgrading IC's). The thing runs like a beast. At 17-18lbs, I can't keep traction.

Just my .02

[vulcanrush]

marty is one of the smarter people in the z-world...i have similiar mods to yours, sir, but also please keep in mind, the 700bb's are only 100 bucks more.

it does give you more flexibility later, and if you don't want the power, you can turn down the boost?

i went with the 550bb because i have a street car instead of a track car, and i just don't need all that power.

[BigTDogg (MA)]

700s will also have more lag than the 550s. But they will have more top end, if you plan to drag race the car for more than s*** and giggles.

550s are plenty for your goal, and will be a very responsive street turbo. You also need upgraded intercoolers and would benefit from the Selin Dual MAF kit. I would definitely get MSP manifolds with any turbo upgrade. Stock TT cams will be fine for your build, the head porting will definitely help your response.

[DTRUONG9]

thank you for the input, its tempting to get the 700s for 100 dollars more, but i need to keep in mind that its a street car more power equals more problems....lol.

what is the max psi on pump gas with the 550's some one has ran?

[marty1mc]

On my sport 500's, I have hit 19 on pump gas with no detonation. It will actually depend on your setup, the outside air temps and the motor.

[Rich@RDZ]

As a rule of thumb 18 psi on pump gas max, otherwise run race gas. Race Fuel is still cheaper then buying new motors, why risk it.

[marty1mc]

As a rule of thumb 18 psi on pump gas max, otherwise run race gas. Race Fuel is still cheaper then buying new motors, why risk it.

I agree on that. The 19 came when the temps at night fell significantly. I didn't know I hit it because I was listening to the motor as I boosted. Once I shifted and looked I saw it had peaked. My EBC actually needs a season setting to compliment the High/Low settings it has.