Cruz headers

jay dcpt

Active Member
Anybody use them? Thinking about picking up a set of his race headers with a T5 flange and egt bungs. Looks like a nice set and definitely cheaper than having a set made. Just looking for some feedback.
 

TType85

Well-Known Member
I have the stock style set with the T4 flange and external gate. The headers seem to be really well done, the v-band connections sealed up really well. I did have to tweak the downpipe a bit but all in all I would recommend them.
 

TIMINATOR

Active Member
I have done a LOT of research on headers, and went with the T/A race headers.
They don't have as pretty of a finish, not shiney, but that only lasts until you fire it up and flog them. Then they look the same, purple, then brown.
From the design of the flow standpoint, the T/A race header has it all over the cruz units. Better port tube length, much better transitions from the port tubes into the main tubes, and less turbulence causing intersection between the passenger front tube and the external wastegate port. That alone was a deal breaker for me. I have spent the last 45+ years of my life porting heads and living on my flowbench, and I over analyze everything!
IMHO, the cruz headers are a prettier alternative to the STREET REPLACEMENT T/A headers, very close in design, but at a higher price. The T/A race headers are a much superior HP, flow, and designed header, again IMHO.
P.S. the T/A race headers are v band at the crossover connection, and can be ordered with 3 or 4 bolt turbo flange.
TIMINATOR
 

Mr.Spool

Well-Known Member
Anybody use them? Thinking about picking up a set of his race headers with a T5 flange and egt bungs. Looks like a nice set and definitely cheaper than having a set made. Just looking for some feedback.
T4 flanged can do 1500+hp.
 

TIMINATOR

Active Member
Turbo header horsepower is but one of the criteria in choice, they have to fit, they have to last, especially at the temps and PRESSURE we run them at. Keep in mind, you can't get something for nothing, folks often mention that turbos make "free HP" from the normally wasted exhaust flow.
In reality, the back pressure in the exhaust system before the turbo is from one and a half to near twice the boost pressure seen in the intake!!!
I have seen some scary, piece of crap, home made turbo headers! But by getting the exhaust into the turbo, by any means, they will make more HP than they did unblown.
A freer flowing, well transitioned header not only minimizes the back pressure in the exhaust port, but retains a higher velocity (more kinetic energy) to spool up the turbo quicker, and usually to a higher speed, until the waste gate opens.
For those of you without a flowbench, a few simple tests can tell you how well the turbo header works.
Route the EXHAUST from a 5 or 6 HP shop vac thru each exaust port one at a time (make sure you make the flow straight into the tube in the same direction the port flow in the exhaust goes.)
Now put your hand over the other ports on that header, a well designed header will have a suction on the other tubes.
On our passenger side header, route the flow directly into where the crossover comes into, connect the crossover tube to the header in the same configuration first. Blow the air in and feel for any suction in the exhaust ports. Suction in the other exhaust ports is good! More is better!
In many poorer designs, the rear, passenger port gets pressure blown backwards INTO the port! This is a nasty restriction for that cylinder, causing a noticable HP loss there. This can cause that cylinder to run rich due to residual exhaust remaining in the cylinder. This can also happen to a lesser extent in the passenger side front port. Also, any header that dumps exhaust at a near 90 degree angle to the runner, also restricts the runner flow too.
By doing these simple tests, and analyzing several designs of headers, its easy to see which ones were designed on a flowbench, or not.
Just some random thoughts by an old guy that has been turboing cars and bikes for over 35 years!
TIMINATOR
P.S. many have run crappy designed headers on very fast cars, so now ya gotta question how much faster they could have run! Just sayin'
 

jay dcpt

Active Member
I already have the turbo so t5 it is. Most likely going to do a forward facing deal. Then turbo mount and cross over will have to be fabed. Probably going to mount the turbo in front of passenger wheel. Been talking with Don on this, he has been a big help.
 

SS/GN

Well-Known Member
I installed the T/A stock replacement. Quality was amazing , fit perfect ,great price and far superior to the stockers I had. Stock have gone low 9s so these are more than enough for most cars.
 

TurboWh1

Well-Known Member
I have been considering the T4 option. Does anyone have any feedback going from the Buick 3 bolt to T4? At what point is the T4 a considerable gain compared to the Buick 3 bolt becoming a restriction? I'm just thinking about the future and trying to avoid buying stuff twice. I also have a friend who recommended the TA header as well. Weighing all the options and looking for biggest bang for the buck.
 

TType85

Well-Known Member
I have been considering the T4 option. Does anyone have any feedback going from the Buick 3 bolt to T4? At what point is the T4 a considerable gain compared to the Buick 3 bolt becoming a restriction? I'm just thinking about the future and trying to avoid buying stuff twice. I also have a friend who recommended the TA header as well. Weighing all the options and looking for biggest bang for the buck.
The 3-bolt will support more power than most of us will ever make. The T4 opens you up to more choice in turbos and exhaust housing A/R sizes. If I were to do it again today I would not go T4, I would go v-band instead. Turbo's like the Garrett G30/35 series use a smaller frame than the normal turbos we use for the Buick so there are some challenges when it comes to a T4.
1667936579418.png

With the T4 there is no room to run an oil drain (picture above). That space is about the width of a finger. With a v-band there would have been much more room. As it is with some of the newer turbos (Garrett G, Borg Warner EFR, HPT, etc) they use a smaller bolt pattern but you can modify the OE return line to work. (picture below is from a BW EFR-9174, holes for the bolts had to be slotted to fit)
1667936891970.png
 

Mr.Spool

Well-Known Member
I have been considering the T4 option. Does anyone have any feedback going from the Buick 3 bolt to T4? At what point is the T4 a considerable gain compared to the Buick 3 bolt becoming a restriction? I'm just thinking about the future and trying to avoid buying stuff twice. I also have a friend who recommended the TA header as well. Weighing all the options and looking for biggest bang for the buck.
I like the 3 bolt.
It spools real fast and can make serious hp and torque.
The new turbos are awesome in a 3 bolt.
70mm on the turbine side is about as big as a wheel can be put in due to material on the .85 housings.
Inmo
Anyone that wants to do and target 1200+hp
Will need to go 4 bolt due to backpressure from the limitation on the ex housing material and the turbine wheel itself.
I've been 3 to 1 backpressure on a 3 bolt.
So guys that think they need 4 bolt really need to look at turbine wheel,comp wheel,comp cover,engine and wastegate strategy
 

TType85

Well-Known Member
So guys that think they need 4 bolt really need to look at turbine wheel,comp wheel,comp cover,engine and wastegate strategy
Yeah, my choice of going to 4-bolt was mainly due to going to the external gate and if I was buying new headers why stay 3-bolt?

It's great that HPT has come out with a new 3-bolt housing with a stub for a external gate so now there is even more choice on the 3-bolt side.
 

TurboWh1

Well-Known Member
Yeah, my choice of going to 4-bolt was mainly due to going to the external gate and if I was buying new headers why stay 3-bolt?
I agree, that was another factor for me as well. I would also like to move to the external gate. Feel like I will have better control over the boost.
 

SS/GN

Well-Known Member
I guess it depends on how fast you want to go. Lots of 3 bolt 8 second cars. I think if your going 4 bolt and over 1200 HP your looking at aftermarket block and the list goes on.
 

TurboWh1

Well-Known Member
I guess it depends on how fast you want to go. Lots of 3 bolt 8 second cars. I think if your going 4 bolt and over 1200 HP your looking at aftermarket block and the list goes on.
That also seems to be consistent with the turbos offered through many of the major turbo manufacturers.
 

Mr.Spool

Well-Known Member
Yeah, my choice of going to 4-bolt was mainly due to going to the external gate and if I was buying new headers why stay 3-bolt?

It's great that HPT has come out with a new 3-bolt housing with a stub for a external gate so now there is even more choice on the 3-bolt side.
There was always a choice.
On one of my cars it has a 3 bolt
External gate
And boost controller with co2.
Works awesome.
 

Mr.Spool

Well-Known Member
I guess it depends on how fast you want to go. Lots of 3 bolt 8 second cars. I think if your going 4 bolt and over 1200 HP your looking at aftermarket block and the list goes on.
Be surprised what does and doesn't brake at that power level😉
Let's just say a 109 and a 3 bolt turbo can really take a beating and fly
 

TurboWh1

Well-Known Member
There was always a choice.
On one of my cars it has a 3 bolt
External gate
And boost controller with co2.
Works awesome.
Sounds nice!! Would you mind sharing DP, boost controller configuration? I'm currently running a Houston DP with a Lorenz boost controller.

I've watched some videos on a tool called boost leash. It looks bada$$
 

TType85

Well-Known Member
Sounds nice!! Would you mind sharing DP, boost controller configuration? I'm currently running a Houston DP with a Lorenz boost controller.

I've watched some videos on a tool called boost leash. It looks bada$$
The external gate / electronic controller is great. I have a 9psi spring in mine so with the controller off I get 9-9.5psi with no creep. Controller on (running Holley system, dual mac valves, using compressor pressure instead of co2 right now) I have had it set at 22psi and it was keeping it within +/- .5psi. I was also able to ramp the boost in so it didn't just blow the tires off. With co2 there would be even more control.
 

Mr.Spool

Well-Known Member
Sounds nice!! Would you mind sharing DP, boost controller configuration? I'm currently running a Houston DP with a Lorenz boost controller.

I've watched some videos on a tool called boost leash. It looks bada$$
I'm not going to go into a huge amount of detail as it's a nt car
But...
When you run co2 you can apply pressure (dome) on the gate and with a good boost controller you can adjust not just the overall boost but the ramp rate😉
 

Mr.Spool

Well-Known Member
The external gate / electronic controller is great. I have a 9psi spring in mine so with the controller off I get 9-9.5psi with no creep. Controller on (running Holley system, dual mac valves, using compressor pressure instead of co2 right now) I have had it set at 22psi and it was keeping it within +/- .5psi. I was also able to ramp the boost in so it didn't just blow the tires off. With co2 there would be even more control.
And the ability to make more boost and dome pressure 😉
 
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