Z32 experts! really need help with boost level

[Z32TT_maniac]

hi guys! im new to this forum and a Z32 twin turbo maniac..im gona buy one in a couple of months...u see i wana run 16psi with factory turbos and stock engine..before i boost it up..i plan to add big intercooler,air intake,555cc injectors,new ECU,full exhaust and a boost controller...with all of these mods,do you think the car can handle 16psi without doing anything to the engine? thanx alot:help

[freakonaleash1187]

16 psi is a lot of stress on the engine. me, personally, i wouldn't run higher than 10-12 psi on stock internals. i have heard that the vg can handle up to 500 hp on stock internals, but i wouldn't probably put that much onto the engine.

[boomstriker]

I've got 180k on mine and have been running 14-16 psi nearly it's entire life. I run the sh1t out of it almost every day. I replaced the rod bearings at 120k showing a little wear, but everything else internally is stock. These engines are very strong and with good maintainence will run a very long time.

The bigger intercoolers and exhaust are great as well as plenty of fuel, but I don't think your going to get that much boost out of stock turbos.They're sized to peak around 4.5k, so they may make 14psi there, but will drop off up to redline.My sport turbos don't kick in till 3800-4k, so there's some pretty serious lag, but they will hold 16 psi to 7500 with a big exhaust and lots of fuel.Trying to get little turbos to make that much boost just causes more heat in the charge that the intercooler has to take out. A bigger turbo can produce the same boost pressure without heating up the air as much, so it feels like a colder day and you get more HP at the same psi. It will hold boost levels higher in the rev band, but the downside is waiting a little longer for the boost to build. Small turbos don't last very long anyway and pushng them past their limit just wears them out quicker.

With all the other mods you can get a good controller to hold 12 psi in the summer, 14 in the winter, with a max of maybe 10-12 at redline, but don't expect more than 90-100k miles out of the turbos.

Kirk

[Z32TT_maniac]

freakonaleash! ur baby is a non turbo rite? i've done some research on this baby and they say dat non turbo 300zx with manual transmission can hit 0-60 in 7 seconds and 5.1 seconds for the 2 seater twin turbo...

boomstriker! u run 16psi with stock engine or modified engine?

Goos93! just say the engine condition is excellent...u think its safe to run 16psi? or do i have to drop to 14-15psi?

[Z32TT_maniac]

thanx man..in dat case...i think i better run 15psi...dont wana stuff up the engine and turbos

[Z32TT_maniac]

i gotta say Z32TT is one of the best jap super cars...it got the stylish killer look plus blistering performance...cant wait to own one...my friend drive a stock 1992 model...damn! all i can say is the car is awesome..the performance is just breath taking..proud to be a member of the Z32 clan...cheers

[boomstriker]

The engine itself- rods, crank, heads, pistons and valves are stock.The rest is very modified.You can up the boost to 10-12 for a big increase over stock without doing any mods, but your engine will thank you if you do the mods first. What ever you do, don't go over 12 psi on a stock car.Big exhaust, intake and coolers are a start- some kind of supplimental fuel if you go past 14psi. Then when the turbos wear-out, get bigger ones, add more boost, more fuel and 103 octane will net very large HP numbers.Goos- the last time I had it on the dyno, the difference between 14 and 16 psi was about 35 HP. Another 2 psi with 103 octane gained another 35 horse for a total of 468 at the flywheel.On a cold day, it will break-loose the 275/35's in 3rd at 70-80 mph getting very squirrely all the way to red-line. My buddies call it 'scarry fast'.

[Z32TT_maniac]

boomstriker! with all the mods dat i've mention,u think its safe to run 15psi?

[boomstriker]

Sure, just be careful where you get your ECU done.I got one of the early HKS units and it hasn't past emissions since failing both CO2 and hydros by a long shot.Replacing all the injectors with higher volume ones gets very expensive and not really necessary if you don't plan on going to bigger turbos. You will need a way to control them- either a stand-alone, a piggy-back system or perhaps new ECU mapping, which doesn't leave room for tuning later. Another cheaper sollution is an aftermarket pressure regulator along with the high volume pump to increase the fuel-rail pressure at higher boost levels.I did a turbo system on a Miata a while back and it required near 90 psi on the rail for correct mix at full boost, but it worked great.

Kirk

[Wakkolio]

16 psi would be ok for the car, max is 18psi. However don't go driving like you stole the car, you will get some detonations. As for the ecu get the ashspec ecu from z1 motorsports and get a fuel controller to tune it one a dyno.

[aaacomp]

I'm running 555 Nismo injectors, ported lower intake, Upgrade turbos, custom ECU, ported exhaust manifold. Gutted cats, 2.5 mid pipes, x pipe, ss mufflers with 4" tip, Profec B boost controller, Under drive pulley, Koyo radaitor, Dual Pop intake, Kevlar timing belt, stock auto trans, and some more that I can't think of . Point is I run it at 12.5 boost in lo settings and 15 on high. with stock internals. burns the tires off from a roll at 12.5 .. There's many many Z owners running 16 and up with the same setup. And the only thing you have to do to get 500 + hp is put in some forged pistons cause the crank and rods are already forged, I have done nothing to the body expect put the Jpec side markers on it .. Running MDR M sport 18" whls with Nitto extreme tires. I bought the car with a blown eng (bad rod) BTY no need to change fuel pumps unless your above 500 hp.

[Wakkolio]

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[KaZ (VaBch)]

I was running 16/17psi all day long on stock internals, stock injectors... With 555cc injectors, the stock turbos max out at 19psi... they're more or less useless beyond that. With larger T28 based turbos, you can run 20-22psi on stock internals on 93 Octane with the right parts to back it up (555cc injectors, upgraded intercoolers, yadda yadda). I've heard of people running over 26psi on Race fuel. Also seen guys drag stock internal/stock turbo Zs at 19psi on race fuel...

At 16 psi my Z dyno'd 335hp/361tq at the wheels before I pulled the engine apart (overheated when I drove it back from ZCon 2002 in San Antonio, TX to VA). Had head gasket issues from then on out, but still would dyno 335hp/360tq... just did so at slightly higher temps... =(