On the edge of the stock zxt turbo- Upgrade to T3/T04 hybrid turbo?

[Challenger]

Well Ive been doing alot of research for my turbo build and have a few questions. From what Ive read the stock T3 will poop out around 10-12 psi. Im hoping to be running ~10-12psi so Im going to be on the edge of the turbos efficiency. So my question is, should I look into upgrading to the T3/T04 hybrid turbo?

 

Plan as of now- stock ecu, f54, p90a with mechanical lifter swap, IC, manual boost controller, stock injectors, high pressure fuel pump, msa downpipe, 3 inch exhaust, blow off valve, ported intake manifold, edis... Not looking for a monster motor just a good efficient turbo motor.

 

Thanks

[thetremendoustim]

Well Ive been doing alot of research for my turbo build and have a few questions. From what Ive read the stock T3 will poop out around 10-12 psi. Im hoping to be running ~10-12psi so Im going to be on the edge of the turbos efficiency. So my question is, should I look into upgrading to the T3/T04 hybrid turbo?

 

Plan as of now- stock ecu, f54, p90a with mechanical lifter swap, IC, manual boost controller, stock injectors, high pressure fuel pump, msa downpipe, 3 inch exhaust, blow off valve, ported intake manifold, edis... Not looking for a monster motor just a good efficient turbo motor.

 

Thanks

 

how weird dude, i was just about to ask this question after reading a bunch of other turbo forums, such as that mustang forum and the other turbo stuff and that's exactly what 'im thinking! So far I figured I might as well be safe to go with T04E-50 ("50" trim) from this handy dandy site

 

http://www.atlanticz.ca/zclub/techtips/turbo/turbomaps/index.htm

 

So i can comfortably boost around 15 psi at 3250RPM (set at 20 psi for 6500) or 15 psi at 6000 (set at 16 psi for 6500)

 

it looks pretty straightforward, except for the cost of the turbo I checked and it's about 8 greens :. I'm running a 3" downpipe, 16 row intercooler, BOV, port/polish intake, 60mm throttle, and I have to still buy an Aftermarket fuel rail, but otherwise i'll be set. You have any advice for me?

[Challenger]

Couldnt give you much help, still learning myself... But from what Ive read the t3/tO4 is well liked and performs well at the psi you stated. But Im just wondering if it will be any better than the stock t3 at the 10-12 psi range.

[thetremendoustim]

just check the compressor map. here's what I know

 

at 10 psi setting you'll hit 10 psi at about 6500 RPM

 

at 16 psi you'll hit 10-12 at around 5000 RPM

a

and at 20 psi setting you'll hit 12 psi around 4500 RPM and still have 78% efficiency. With your intercooler and all upgrades, i'm guessing it'll be at least 300 flywheel HP. which is what I'm aiming for

[junglist]

I'm going to be getting a T3/T04E 57 trim w/ .63 a/r

with these specs:

 

flow: 53 lbs/min 678cfm

 

.60 A/R HOUSING

 

60 TRIM WHEEL

 

TURBINE SPECS:

 

.63 A/R HOUSING

 

STAGE 3 WHEEL

 

I don't think this will be too big. I'm shooting for decent low-end drivability and about 300hp peak to the wheels. With people running holsets and much bigger turbo's I would think that a .50 A/R would be pretty small to run on a Z. Most of the Honda guys that run on 1.6L and 1.8L motors use .48 and .50 a/r turbos.

[PanzerAce]

Where is a good place for me to read up on turbos and the different setups that they have?

[Challenger]

just check the compressor map. here's what I know

 

at 10 psi setting you'll hit 10 psi at about 6500 RPM

 

at 16 psi you'll hit 10-12 at around 5000 RPM

a

and at 20 psi setting you'll hit 12 psi around 4500 RPM and still have 78% efficiency. With your intercooler and all upgrades, i'm guessing it'll be at least 300 flywheel HP. which is what I'm aiming for

 

 

Well Im not wanting 300hp neccecarily. I was thinking more like 225ish. I saw the comparison of ever psi you increase will provide around 10-15 hp. I was thinking 10-12 psi so that comes out to 225-255 hp.

 

What are the charactaristics of the stock turbo. From what Ive read it will make boost at 3000 rpm. Is that the peak 7 psi or is that when the boost starts to increase?

[thetremendoustim]

from what i understand, correct me if i'm wrong, but it's full boost (all 7) at 3000 RPM which makes it good because it puts out all the power early, but it's also bad because after about 4000 the power curve goes down (http://forums.hybridz.org/showthread.php?t=98461) (http://www.dynoperformance.com/dyno_details.php?make=datsun&dynorun_id=751&model=240z) <--different boost numbers but same stock turbo; so you don't have that much wiggle room, it's not too efficient. Check out the turbo maps and plot a line for 7 psi. it's not very hard, just check out that earlier site that i referenced too. 225 should be no problem and be really reliable with that setup you're running. When you get it all checked out, tell me how fast your 0-60 is would ya?

[jeffer949]

If all your wanting to run is 12 psi i would just stick with the stock t3 not saying there wouldnt be benifits from running a bigger turbo just that i dont believe the cost of upgrading is going to be worth the hassle. i was running my t3 at 12psi on the stock efi for 6 months and then at 14psi with MS&S for like 3 months. and it had no issues what so ever with the turbo. i did have a starion intercooler and a bov though. so i would just save your money and put it towards something more useful. Like a good 3 inch exhaust.

[Pyro]

I would keep the stock turbo and spend money upgrading your 25 year old efi system.

 

The stock turbo makes nice power even at 14 psi with a good intercooler. It can make 250hp at the wheels easily.

 

After you get your new efi going, then upgrade to a bigger turbo. It you use the stock cam then use a stock turbine. If you install a better flowing turbine then install a bigger cam.

[rvandivort]

Hi Challenger, Don`t quite what to say....but My instinct is go to Holsets. They have been on Ebay for relatively good prices. I got Mine for 326$w/shipping. They are on Dodge diesel trucks with twice the ci as a Z. You have seen all the posts here, so I don`t have to go on. Roger

[rvandivort]

Agree with Pyro. Get MS11, broadband o2.But 250 at the wheels--WOW!! Well, I didn`t have A t3 to begin with. Just a 81let w/o turbo so I`m biased. I thought You were limited to 12# if You had the 265 injectors.well I`m a newbie.

[rvandivort]

The cam issue is interesting with a turbo. I have been reading here for 1 year and the last thing I read was that the cam thing is somewhat irrelevant with a turbo. The early blogs said that You can go to 350hp with a 280let cam without any change. Has there been a difference here?

[rvandivort]

Hell, the original na cam is hot to begin with --276 duration! That`s a 3/4 race cam in the 60`s realm. I race a 305/295 .505 lift in My Street

Stock! 330 is as far as You can go!

[Pyro]

The stock NA cam is only around 248 degrees duration and the stock turbo cam is around 240.

 

The stock turbine makes boost very quickly but at the same time it is very restrictive which causes lots of exhaust manifold pressure. So, the turbo will not do well with any valve overlap due to the reversion into the intake from the high exhaust manifold pressure.

 

If you use a high flow turbine, the boost will come on later and the exhaust manifold pressure will be less. Therefore, a cam with more valve overlap can be used due to lower exhaust manifold pressures.

 

If you plan on staying with the stock cam, then the stock turbine works well. However, the stock compressor gets pretty hot after 12 to 14 psi of boost. It is worth the money to get the proper sized turbo. A T04E-50 trim is the right size for most L28et applications. Then modify the stock turbine if the cam will be changed. For example, use a NA cam with a stage 2 turbine modification or get a stage 3 mod turbine for a MSA stage 1 turbo cam.

 

But first, change the efi system if you can. The stock turbo can make good street power with little lag and lots of low rpm torque which is fun on the street.

[Clifton]

The difference between a stock turbo and the right turbo can be 250 rwhp (if you are lucky) at 14 psi compared to 350 rwhp at 15 psi with something a little bigger. If you are going to run a set amount of boost you may as well make more power while doing it.

[Pyro]

The difference between a stock turbo and the right turbo can be 250 rwhp (if you are lucky) at 14 psi compared to 350 rwhp at 15 psi with something a little bigger. If you are going to run a set amount of boost you may as well make more power while doing it.

 

I upgrade the stock turbo and cam on my car. sure it's faster but I do miss the low rpm torque of the stock turbo and cam when driving on the street. It was fun breaking the tires loose in 3rd gear at 3000 rpms. With the bigger cam and turbo, the engine now requires 4500 rpm to break the tire loose in 3rd. So, I find myself going way too fast on the street to get that pushed back in the seat feeling. If I had to do it all over again, I would had left the stock cam and turbo in place. Or maybe just upgrade the compressor.

[rztmartini]

hey pyro, what turbine did you upgrade to? do you think that if you kept the same size turbine as stock and used the bigger compressor it would have retained the low boost threshold? or would the cam not worked as well because of the restriction of the smaller A/R?

[Pyro]

I used a T04B-H3 compressor because I didn't want to add a turbine spacer since my exhaust was already in place. That was a mistake. I should had installed a T04E-50 and had a better compressor for the L28.

 

I used a MSA turbo stage 1 cam. It has wider lobe separation (114 degrees) but still has more overlap than a stock NA cam (3 or 4 degree more, I forget). I didn't try the msa cam with the stock turbine but guess it would have a little too much overlap for the stock turbine. (just my opinion)

 

I used a stage 3 turbine which makes max boost between 3500 and 3700. And the cam pulls to around 6800 rpms. I use 12 to 14 psi of boost and it starts to boost after 3000 rpms. It is much faster than the stock setup (at the same boost) but it does't feel like it. I know that sounds weird. I guess because the turbo hits much softer than the stock turbo and the power is in the upper rpms which I don't drive in as often. Plus the bigger cam and turbo requires downs shifts to accelerate where the stock turbo and cam didn't (lots of low rpm torque).

 

I'm glad I used the high flowing turbine because the T04B-H3 would surge if it made boost any lower in the rpms. This is not the case for the T04E-50 compressor.

 

If I had to do it over again, I would use a T04E-50 compressor, one stage up from stock on the turbine, and use a stock 75 to 79 NA cam for 8 more degrees on duration. I'm not looking for max power. I want a lot of torque at low rpms (fun street car), a good idle, and power to 6000. The stock turbo cam stops pulling too soon (5,000 to 5,500 rpms).

 

I'm also guessing a high flow down pipe could release some extra manifold pressure which could help the stock turbine handle a NA cam.

[cygnusx1]

Most people here like the T3/TO4E combo for the street. The stock turbo certainly works better at a lower power range and feels better between 2000 and 3000rpm's. I run a T3/TO4B "SuperV" trim which is close to a TO4E from what I've read. I lost some low end power compared to the stock unit, but the top end more than makes up for it. I run about 14-15psi and power is great from 3300 and up. The best part is that the faster you go, the harder it puts you into the seat. The feeling of being pressed into the seat at 70-80mph and climbing is priceless. One thing I did notice is that my new turbo makes more air than my engine can use from about 3500-4500rpms. The result is turbo surge at part throttle acceleration...damage to the compressor is prevented with the BOV venting like a wild goose.

 

Don't forget to raise your fuel pressure somehow with an FMU under boost or you will begin to go lean somewhere past 12psi. With the stock turbo you should be able to see around 240hp at the wheels with your plans. Raise the fuel pressure to about 65psi at full boost of 14psi and you will see 260-275hp with the stock injection.