Nissan Forum banner

1 - 20 of 52 Posts

·
Registered
Joined
·
53 Posts
Discussion Starter #1
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.:D
 
Z

·
Guest
Joined
·
0 Posts
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.
 

·
One and only (sr20)
Joined
·
229 Posts
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
 
Z

·
Guest
Joined
·
0 Posts
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. :D
 
K

·
Guest
Joined
·
0 Posts
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?
 

·
Registered
Joined
·
53 Posts
Discussion Starter #7
Good question !

Kitryj said:
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.
 

·
One and only (sr20)
Joined
·
229 Posts
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??
 

·
Registered
Joined
·
235 Posts
sentragtr20 said:
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.
 

·
Registered
Joined
·
235 Posts
sentragtr20 said:
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.
 

·
One and only (sr20)
Joined
·
229 Posts
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.
 

·
Registered
Joined
·
235 Posts
sentragtr20 said:
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.
 

·
One and only (sr20)
Joined
·
229 Posts
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..
 

·
Registered
Joined
·
235 Posts
sentragtr20 said:
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..
Chris Allen's car has a GTiR motor in it. He has pistons, rods, cams but just realize when you are at that boost it may not be very reliable. Chris made about 500whp, not sure if that's your goal or 600whp? Those type of numbers are where you'd consider block sleeving, and definitely head studs. If you want your head to seal with that much boost you may have to use a copper head gasket and it may weap during normal use.

Do you know how many transmissions Chris has been through? I'd bet he's been through more transmissions than anyone else that owns an SR20.

Andreas Miko has done the Bluebird tranny swaps but those transmissions are very hard to find (FWD and LSD). I've talked with Andreas about this and he says they break as well although they are a little stronger.

I have doubts about these goals with what you are planning on doing, but hell, prove me wrong...I wouldn't be unhappy :)
 

·
One and only (sr20)
Joined
·
229 Posts
Yes, I was going to use a copper head gasket. It is one like they use on the 5000hp dragters. It is a soft copper,so it makes a perfect seal. I was also going to get it sleeved. I know a guy that can do it for a $1000.00.

I also know a guy that make far more horses with less boost. But he has far more money in to the engine. He made about 600hp with only 24lbs.

Plus another guy that makes the same hp as chris allen,with a us. spec sr20. So the gti-r part is not a factor.

I have a primera sr20.

How would the transmission get stressed?? How about i shotpeed it,and cryogenics.
 

·
Registered
Joined
·
235 Posts
sentragtr20 said:
I also know a guy that make far more horses with less boost. But he has far more money in to the engine. He made about 600hp with only 24lbs.

Plus another guy that makes the same hp as chris allen,with a us. spec sr20. So the gti-r part is not a factor.

I have a primera sr20.

How would the transmission get stressed?? How about i shotpeed it,and cryogenics.
600whp with 24psi? That turbo must be bigger than a T4 or does he have a bigger motor?

The GTiR is a small factor. It has a short runner intake manifold, better heads, oil squirters, and mechanical valve train which allows you to run more lift. Those things add up to more safety and probably 20-50 more wheel hp at higher boost levels.

Ah, so you are going to sleeve the block...you didn't say that before. Are you also going to use better head bolts or studs?

The gears on the Bluebird tranny are bigger than SR trannies but not much. Treating them will extend the life. My tranny (SR tranny) was shotpeened and Cryo treated and it lasted a while, but finally broke on my first pass running 20 psi (~392whp) as soon as I shifted to 3rd. It lasted a few years though.

Anyhow, push the limit and let's see what you can do! I'm just giving you advice on what I'ce seen, heard or experienced first hand. Good luck with your build up and keep me posted!
 

·
One and only (sr20)
Joined
·
229 Posts
Thanx for the help,but I will need all the help and advice as I can get. So if I ask stupid questions,bare with me. Thise stupid questions are need for me to ask.

Here is one right now. Will parts from a sr20 (rwd) fit onto a sr20 (fwd) like cams ect..
 

·
Registered
Joined
·
235 Posts
sentragtr20 said:
Thanx for the help,but I will need all the help and advice as I can get. So if I ask stupid questions,bare with me. Thise stupid questions are need for me to ask.

Here is one right now. Will parts from a sr20 (rwd) fit onto a sr20 (fwd) like cams ect..
I'm not really sure. But I know there are others on this board that can answer this question. Anyone?

I know some things are the same, but RWD SR20s are distributorless. I'm guessing the cams are the same, but I'm not sure.
 
1 - 20 of 52 Posts
Top