turbo upgrade between t04e and gt35r?

[Tony D]

FYI: for my wifes bone stock L28ET in the 260ZT 2+2, yes, it has a GT30 sized turbo. I didn't have any illusions of trying to make anything more than 300-325 as a daily driver, and be able to pop my two-stage TurboXS Boost Controller for the occasional spunky higher-boost run. it's a nice turbo, but I wouldn't dream it would make that kind of power (400) on a stock L28ET!

[Gollum]

Let me be clear in that I agree with Tony and plan to build accordingly. That said, some people don't mind venturing into the 25+ psi levels and dealing with all that comes with it. I don't tell those people not to do it, only to know what they're going to be up against.

 

Also, there's a big difference between mild head work and serious head work. Some people will only see a measely 10-20% increase in horsepower after headwork, while others can see a solid doubling in horsepower. It all depends on how radical you want to go and how many RPM you want to run to reach peak HP.

[Koryu]

Thanks gollum, I will research that turbo. I'm sure it is cheaper too. Tony it looks like a great turbo on the map I attached, but that is just a reg old gt3076r. I imagine a gt3071 would be good around 300-325. I saw wigen-out did like 385 whp with a 50 trim an A cam and a port matched intake and head at 20 psi. With that info, is it hard to believe that I could get 12 whp with a gtx3076r? Here is the link.

http://forums.hybridz.org/topic/86245-went-to-dyno-day-today/

 

Here is the flow of a l28et stock

 

 

Here is the 50 trim

 

And here is the gtx3076r

 

 

 

So am I wrong to say that based on wigen-outs dyno of 385 whp 390 torque at 20 psi with an unported head (port matched) , and what the gtx3076r map shows, that I won't hit my goal? Looks like a good matxh to me at 20 psi which is around the 2.5 bar mark and 77% efficency mark. With a nicely ported head and a good cam I think I see a turbo good for 400-450 whp.

[Koryu]

Gt35r map

Edited November 8, 2013 by Koryu

[Gollum]

I think the turbo will work fine. But I also am slightly concerned about surge before you do any headwork. From what I can find on the new GTX it seems that it can hit 400whp easily enough worth of flow. I just hope you don't need 30psi to get there, because it's not going to like it. I'd say shoot for a 20-25psi build and what you end up with is what you end up with and just be happy.

[Koryu]

Yea I was looking at 20 psi to be honest. I think I could go up to 25 no problem. 20 psi on the 50 trim was almost 400 so with port work, a turbo grind and my new intake I should be there. The surge looks close in my opinion too, butuch better than the 35r. its tough to find a turbo that matches as good as a 50 trim

[Chris83zxt]

I think the turbo will work fine. But I also am slightly concerned about surge before you do any headwork. From what I can find on the new GTX it seems that it can hit 400whp easily enough worth of flow. I just hope you don't need 30psi to get there, because it's not going to like it. I'd say shoot for a 20-25psi build and what you end up with is what you end up with and just be happy.

 

As my mother-in-law has recently taught my 3yo and 2yo girls - "You get what you get and you don't throw a fit!" which the older one preaches to the younger one constantly now.

 

I don't think anyone is trying to talk you out of a 3076, they're just pointing out that bigger turbos can work if you do the legwork to prep your motor for them.  If I were you I'd stop second guessing yourself.  A 3076 will grow with your needs up to probably 450+ hp so you'll probably never need more (want more?  That's a different story.)

 

I was thinking 20psi for my build too when I started but now that I'm very close to being able to make that a reality I'm scared.  I'm thinking more like 14-15psi as a daily setting

 

I have a question for Tony, Gollum, or anyone with any experience/opinion on the matter really.  For a stock l28et, do you think you would get more immediate gains from:

1) Gutting the efi intake out and port matching the stock head

2) Ignoring the intake initially and having head work done first

 

Assuming of course equal quality of workmanship was put into either process.

[Koryu]

Well that was the purpose of this post to help me from second guessing lol. Its a big purchase and I like to get all my research done before I go. I like the feedback from tony and gollum, I don't feel like they are talking me out of it, the gt35r sounds good but without the supporting mods its not really better than a 50 trim IMO. Wigen-out got 385 whp with a 50 trim and big Phil got 388 with a gt35r at similar boost. So its more than just picking a turbo and I get that. I also read what jeffp did with the gt35r and it's hard to justify picking a 3076 over a gt35r. But I was mainly looking at what the 50 trim was doing and what the 35r was doing and wondering if the gtx3076r would fall in between those 2 and be a good match with the mods I plan on doing. It seems so to me and I have heard others say the 3076r was a good match but the gtx flows almost 10lbs more. As to your question, I would think the intake would be a better first place to work since the runners are smaller than the intake valves if I remember correctly. So on a stock head and stock intake, the intake would be the restriction. Tony would know better though.

[Tony D]

Jeff P was CONVINCED that he needed to size a turbo for 30 psi to get his 500RWHP goal.

 

Now, after consorting and being corrupted by me, his Rebello Block sits in storage (having made a bit more than his 500RWHP goal) and now he's playing around with a bone stock bottom end cranking 475 to the rear wheels under 20 psi.

 

The power may be in the boost. But the REAL power is in the flow. Look lower on the maps, to the right and see what you can do. As Gollum said, what you do to make 200HP on an N/A is the same stuff you will do to a turbo car and get a big boost instead of an incremental, evolutionary one.

 

Personally, since he makes 400HP to the rear wheels so easily on a ported head, with a cam on an otherwise stock L28ET (yes, the intakes flowed 218 or 225 CFM....but he's running a STOCK Extrude-Honed Intake and LOSING 30CFM over an ITB setup per hole!!!)

 

With that Senza Intake, I would be very interested to see what the boost will be on his engine.

 

Frankly, he never listened to me about keeping that GT35R set at 8psi and just running up to redline to see where his power peak is.... Now, every day he regrets it because "man it just pulls to 7400 and I have to shut it down!" He's making near his original power goal at HALF the boost he thought he needed and has a car that acts like a VERY BIG N/A engine when it comes to power curve. It just pulls and pulls and pulls. Not peaky, nothing like that. Frank280ZX said his car was a "Threeshits" car, you step on it and go 'HSIT!' then, as you pass 4,500 and it's pushing HARDER you go 'HSIT!' again, and then you shift and it puts you back HARDER! Repeat.... 0-120-30 in 1/2 mile easily on street tires.

 

Flow.

 

Flow.

 

Flow.

 

I would be interested to bench-up our Senza Intakes and see what the ports flow for the naysayers earlier in the build thread!!!

 

It will make a difference, and how much we can quantify on JeffP's car, for sure. It's documented out the hiney!

[Gollum]

With that Senza Intake, I would be very interested to see what the boost will be on his engine.

 

You have no idea how much this keeps me awake at night...

[Koryu]

I can't wait either. I've been giving it some thought tony, the gt35r sounds great for me as long as I could get those results at 17-20 psi. After that Im afraid it won't be as efficent. But I'm in the same boat with the gtx3076 after like 25 psi. I saw the graphs for spool on a dyno between the to, but I wonder on the street which one would hit 400hp first. I like the Idea of a almost 500 rwhp motor with full boost by 3400 or so. Hard to beat those numbers and they are real world proven. Wish I saw real world results for the gtx3076r on our motors

[Tony D]

That low compression L28ET bottom end spools the GT35R to 2-3 psi at any rpm, and makes a soft full boost between 3,000 and 3,200. Previously with far more boost the TO4 turbo he had hit HARD at 3,000 but like a switch. You went from 150 to 450HP inthe blink of an eye.

 

Now with the bigger cam (remember stock intake, so it's really only flowing 190 CFM per port without the Senza Manifold) USES that 2-3 psi. And makes power, with the cam coming on after 3500, the car is already on- boost and pulling when the cam torque peak gets good, and gives the second of the "three shits"!

 

Now, the car pulls like a larger NA motor from any speed and acts like a cammed L-Series that has the cam come on at 3,200 when it hits full boost.

 

Frankly he was making the same HP at 17psi and 7400 as he was cranking 21 psi at 6800!

 

Leading me to torture him endlessly on what would have happened had he just left 8 or 10 psi (remember 380ft-lbs at 8.39psi at 4500!!!) and run that Rebello all the way up to actual power peak.

 

Sadly Jeff thinks maybe GT42 for that mill, with a docile and totally street able 850hp will be the result.

 

What he really is thinking now is like Japanese Style "Turbotony" build with a GT35X and the forged bottom end running 17psi and praying it has the flow to support the HP it should make.... I don't think it will...but it will be interesting to see an L3.0 at 8,200 and 15psi of boost...

 

"Can You Say Electramotive?"

 

Muahahahahaha!

[Koryu]

Sounds amazing, and good on him for his search for more power while most of dream about it and live through his builds. Btw, anyone ever use the Kamaeri cams?? I have been looking at regrinds and I don't want my to chance a schnieder cam or other non japanese billet. I have read a lot of good things about Kamaeri and they have some sick L motors that have been built with there parts. The camshaft is very important and even though very costly, like there twin idler kit, I can't help but think what kind of power they make.

[Tony D]

Isky will grind to your engine...and not that expensively.

 

Check what people who did back to back comparisons of cams, that's another component that need not be offshore sourced.

[Koryu]

Yea after looking at prices and comparing results, Isky is my best option. I don't think Kameari does custom grinds like a turbo one either. But they sure can build an engine and there parts look top notch but so is there price. Like you said no need to source outvof country. But I do have a lot of respect for these other companies such as Kameari engine works. I will get an Isky custom grind and get my rockers refurbed.