2860-5S Vs T04Z 1/4Mile Times

[sickr33]

Hey we have plenty of threads on power out puts for both these turbo kits.

But what about 1/4mile times??

Car?

Power and boost?

Stroke?

Turbo kit?

Weight reduction?

Tires?

[sickr33]

Iok ill get us started

R32 GTR

2.6L

2860-5s

434hp at 20psi

11.8 @196km

Full weight with passenger

Very old federal 595s (big wheel spin)

[R31Nismoid]

Too many variables really, especially between R32 and R34 given weight and 4WD differences.

Either way a T04Z equipped should be faster, they make more power on a sorted setup.

[sickr33]

I created this because I'm entered in race wars (thankyou antilag)

And I trying to decide weather to keep the -5s and keep upping the boost hoping to make power.

Or dich them and use the GCG T04Z with 6Boost manifold that I have laying around??

Who has driven both what did you like best?

Its not a daily car!!

It's for fun!

[Piggaz]

434hp at 20psi

And I trying to decide weather to keep the -5s and keep upping the boost hoping to make power.

I'd be looking at your setup. You're a bit behind the 8 ball in regards to your power vs boost.

[Hadouken]

I have more than that on -9's

[R31Nismoid]

I'd be looking at your setup. You're a bit behind the 8 ball in regards to your power vs boost.

This... 19/20psi should be showing a good 30rwkw more.

123mph is roughly 320rwkw in a R32 GTR so your dyno reading is right, but for the amount of boost it's pretty poor. 320rwkw is -9 power @ 20psi, not -5s @ 20psi.

-5s should be closer to 127-130mph (370-400rwkw) on 20-24psi

Fix the setup before changing it is always a good rule of thumb.

[sickr33]

Yer I'm not sure about 434hp because it was at ovaboost dyno ( lowest reading dyno in Perth as far as I know)

Also

(full weight plus fuel and 2 passengers aprox 80kg each)

I think its fair to say total weight would be 1500kg at least!! (3307 pounds)

Put that in a 1/4 mile calculator with 196km (121mph)

Comes back with 481.5HP!!!

Does sound right???

[sickr33]

So where to look? 

Arc induction box 

Tomei manifolds 

Tomei dumps 

HKS front pipes twin 70 into 85mm

3" decat pipe 

HKS  silent exhaust fitted after tune!  95mm according to nengun!

Had kakimoto dual 70mm cat back exhaust (too loud) 

PFC 

Nismo AFM's 

Tomei type B cams (set to 0) 

Port polished head

Hard inter cooler pipe kit (JJR I think) 

Stock intake pipes and twin turbo pipe 

Stock plenum 

HKS copy 100mm intercooler (could this cause restriction? 

I have trust 115mm intercooler laying around!

Forged bottom end nothing special

So I would start at the intercooler easy 

But would the 3" decat pipe be too small? 

maybe 3.5" would be better? 

After that should I look at Greddy induction  kit?? 

Maybe a plenum? 

[R31Nismoid]

Yer I'm not sure about 434hp because it was at ovaboost dyno ( lowest reading dyno in Perth as far as I know)

Also

(full weight plus fuel and 2 passengers aprox 80kg each)

I think its fair to say total weight would be 1500kg at least!! (3307 pounds)

Put that in a 1/4 mile calculator with 196km (121mph)

Comes back with 481.5HP!!!

Does sound right???

Your MPH is near on perfect for the power you are making, if anything the MPH is a little low (but no more than 2-3 MPH). So the dyno is more certainly not reading low, it's right on the money IMO.

If you had a passenger/full tank of fuel then that explains why your MPH is a bit down so don't worry about it.

Forget the drag calcs, they dont take into account diffs/gearing and other things. I've never found them to be accurate for GT-Rs

As for your parts list the potential problems would be

1. 3" de-cat

2. the apparent 3.5" exhaust. Most jap exhausts have a inbuilt restrictor in them near a muffler to help reduce noise, so they are not a true 3.5". People have found them taper down to 2.75" in some occassions which is a major issue

3. Intercooler might be a problem... A stock GTR intercooler is fine for 400rwkw so not really sure why you'd go to a potentially inferior item

Your Airbox should be fine, the plenum is more than fine (good for 400rwkw+) so probably start at the exhaust side which is where most issues usually come from.

[sickr33]

Ok well I have changed the exhaust to HKS (no restrictors from what I can see and after reading for hours have come to the conclusion that it doesn't have any! Sounds like kakimoto do!!

so is a 3" decat really going to be restrictive At about 500rwhp??

Ok I will change intercooler should I go back to stock?? or put the 115mm Trust one on???

Twin turbo pipe?? It this a draw back at this power level

I have seen people modify them or just replace with HKS or Greddy but has there been gains in going this???

And last AFM's?? (using PFC)

I have a spare vipec so I could remove them

I have heard of people removing the mesh? Gains??

[R31Nismoid]

Yes if the rest if 3.5" - going to 3" will choke.

To test simply drop it from the front pipe merge and dyno run it, you'll soon see.

Cooler - test the pressure drop pre & post cooler, decide from there.

TT pipe - again no. Factory piping is fine for 400rwkw. They only mod the stock one to avoid compressor surge/shuffle, you shouldn't have that with -5s.

AFMs - again not a restriction. Two Nismo AFMs will flow 400rwkw no worries. Mesh it was proven gives no tangible result either

[sickr33]

Ok thank you very much

Sorry but one last question I read an interesting post about valve springs and not making power?

When valve springs were changed power was greatly increased??

Could I run into this problem with the -5s or the T04z??

Head was rebuilt but stock springs were reused (all checked rates etc)

[sickr33]

Ok thank you very much

Sorry but one last question I read an interesting post about valve springs and not making power?

When valve springs were changed power was greatly increased??

Could I run into this problem with the -5s or the T04z??

Head was rebuilt but stock springs were reused (all checked rates etc)

[R31Nismoid]

If the head was rebuild then springs wont be an issue, again they are fine for 400rwkw/24psi on a refreshed head.

[bodge]

Late last year I changed my -5 set up to a to4z setup. The most I could ever get out of the -5 set up was 380rwkw. Even though the dyno stated that power it never felt like it. I took it back and they found that it was only only making 330rwkw. They found a few problems which they tried to rectify and the best I could manage was 365rwkw on pulp and 25psi of boost. I changed to a to4z with a .84 rear housing and on 20psi it now makes 415rwkw. It is a little more laggy compared to -5s but once on the roll the big single certainly has the muscle in the top end which is what l wanted. Although I have not run it yet, it gives you an indication on what power you can expect if you change over.

At the end of the day the decision is up to you.

[sickr33]

Ok cool thanks for all the help

[Hadouken]

Dont you reckon your exhaust would have been a restriction then?

Anybody can slap on a big turbo and make some numbers

[R31Nismoid]

Dont you reckon your exhaust would have been a restriction then?

Anybody can slap on a big turbo and make some numbers

Exactly

A T04Z setup well on PULP will smash out 440rwkw comfortably, would go higher on E85

[bodge]

The exhaust on the car is the same the only difference is the front pipe. The size is 4 inch for the front pipe and 3.5 inch the rest of the way. It is a race pace item.