Any of you guys use a small shot of NOS to sprool your turbos to that rpm where they kick in ? I know of some guys who do just to get rid of that lag turbos have.
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Naw. If you've got a modern, efficent turbo and it's been sized out correctly for your application, lag won't be an issue. My turbo is capable of putting out 450 wheel HP but it starts making positive boost by 3200 RPM. That's not laggy really at all. I mean in an NA SE-R you'd have to be at higher RPM than that (6000 for example) to get all the power out of the motor, and by 4000 RPM I'm making far more than any bolt-on SE-R.
And that's only for a large turbo like the T3/T04e or the GT30/37. If you get a smaller turbo like a GT25 which is very efficient, size it properly, you'll still make a ton of HP and it will spool even faster than mine does. Turbo lag is only an issue these days if you don't know what you're doing with a turbo and you size it wrong.
Or a better turbo is a t-04. It is able to spool at 4000rpms and capable of higher than 500hp. With the right mods you can make more than 600hp on only 25lbs of boost. I have seen it in Japan
The T04 is not actually a better turbo than the GT30/37 though. The T04 uses older technology and it's not nearly as efficient, the efficiency island is much smaller, and the ones that make 500 HP (with a stage 5 wheel for example) don't make full boost till almost 5000 RPM.
The GT30/37 is more efficient and is ball bearing on both sides. On the efficiency map the GT is a full 10 points higher across the board than the T04e and the island is wider and longer. That means more power across your entire RPM band and it's a lot less peaky. It makes more power at the same boost level as the T04, and it spools up way faster... and that's not just from a stop, that's also cruising on the freeway. If you're out of the boost you just give it gas and the boost comes up so quickly it almost feels NA.
Now if you want 600 HP then you want a bigger GT series turbo like a GT35/40.
Originally posted by Kitryj My 84 300zxt has an AirResearch T5... how does it match up with the rest? And how do do you size your turbo, or adjust it to get more hp?
Yeah I was wondering the same thing.
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Originally posted by sentragtr20 How much is the GT35/40??
If you factor thr price differcnce the t-04 is the best for the money. And yes they make a t-04 with ball bearings.
On the Gt35/40 and GT30/37 what is the exhaust and intake a/r??
A straight T4 on a 2 liter motor or smaller would be super laggy.
Now maybe you mean a T3/T04E. That's what I have. It has a ceramic ball bearing but it's only a single ball bearing whereas the GT turbos are dual ball bearing with better bearings. They are also more efficient. But as you pointed out there is a price difference of about $800.
Originally posted by sentragtr20 A t-04 spools at 4000rpms which not really laggy. And yes it is a t4.
When you say spools, what exactly do you mean?
My turbo hits full boost (10psi street) at 3700RPM.
A straight T4 on a SR20 would hit full boost (set at the same level) probably about 500-1500 RPMs higher, depending on how the T4 is sized.
I suppose we are defining laggy in different ways. The GT30/37 on Aaron Labeau's car starts building boost under 3000 RPM. It hits full boost at about 4000RPM, however, it is very linear and you can control the boost quite easily with the gas pedal. On the other hand, my car hits boost hard and is much harder to control wheel spin. At 20 psi on my car, from 4k RPM to 5k RPM my car gained 180whp. Now it sounds pretty impressive, but it sure is hard to control. At 10 psi it is much more linear however.
Originally posted by sentragtr20 We are probally using two definitions. Do you know what a t-04 would spool at if I was wanting to run 30psi??
Or the Gt30/37 spool rate at the same psi??
I was planning on running 30psi or more when I get my engine done. I am building it before I accually go turbo.
Well if you plan on running 30psi you'll have to have a T04 that's on the large size to make it efficient up in that boost range. And if that's what your looking for you're looking at hitting full boost at 5k RPMs. THat's if you have a motor that could really handle 30psi with a large T04.
You really need to build a motor to handle this. How much money are you planning on spending? Seriously, a SR20 that can handle 30psi will have TONS of money put into it. Then you'll have to make sure the tuning is really good. Maybe you know what you're doing, but I have a feeling you just picked 30psi as a goal. What's your HP goal? That should be the real question. A car running that kinda boost will not really be a street car and you'll blow tranny's left and right.
It's not impossible, and if you reall would like to do this don't get too discouraged by my response. Just realize that you will have to spend more than the cost of a WRX to do this right.
I want a least 600hp. I wont be running 30psi all the time. Just at the track. I dont think I will be spending more money than a new WRX. All I am going to get is pistons,rods,cams,valves,valve springs, retainers,72lb injectors,ect...
Chris Allen ran 2bars of boost(29.0 psi) with less mods.
His only problem was the tranny So if I can some how take the gear box off a bluebird and exchange it. Then shotpeed it ,and cryogeenitcs.I think I will be fine..
Like I said I will only run that at the track, not all the time I will only run 18psi..
OK
So if I can some how take the gear box off a bluebird and exchange it. Then shotpeed it ,and cryogeenitcs.I think I will be fine..
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