R34 Gtr Garrett -5 Turbo Lag, Need Advise

[mr skidz]

And a graph with afr's plotted next to the line in question can tell you why it aint climbing.

But i doubt its that jem know there shit.

[XGTRX]

In saying that the first thing I noticed when changing to a 3.5 inch y pipe collector was how quick they spooled up in comparison. Quite a noticeable improvement from 3800 and had to adjust the ebc to stop a spike.

[baicai]

Do you have std cams?

Yes still on standard cams, would love to go 2.8L but no money at this stage.

[XGTRX]

Yes still on standard cams, would love to go 2.8L but no money at this stage.

you need my y pipes.

[XGTRX]

[baicai]

Here's a dyno of the Z-tune with same exhaust as mine except it's titanium. Much better graph but I guess it's all the work done to the motor internally that makes the difference. So now every one knows much power the Z-tune really makes, he he.

[baicai]

you need my y pipes.

Yes I agree, I'd grab it if you were in Sydney and also need your cat and cat back exhaust as well, LOL.

[Hadouken]

Isn't single 3.5 the same surface area as twin 2.5?

Id say the issue is that its 2.5" at the dumps where in a usual 3.5" exhaust setup it would have a beefier front pipe....

Just saying things for the sake of things

[Hadouken]

jems dyno figures didnt hold up that well at wtac dyno shoot out.

Just sayin

[mr skidz]

I missed it.

Were they reading low or something?

[Hadouken]

Jem were much higher.

[mr skidz]

Ahh, everyone would have been happy with the printout.

Edited October 30, 2015 by mr skidz

[baicai]

So after 2 years its finally time to bring a conclusion to this thread. Most of the lag has been fixed since last dyno run and only 2 parts were changed.

Replaced stock twin turbo pipe with Nismo inlet pipe, this I think made the biggest difference to the response and driveability of the car. Boost was slightly higher and coming on earlier as well. Despite what some people have said, this part made the biggest difference for me.

2nd part was changing the exhaust system. Replaced the nismo exhaust (3 inch) with mine's front pipe and tomei 3.5 inch exhaust. This lowered the restrictions and improved top end.

So in conclusion for low mount twins for driverability and reduce lag, best bang for buck is better merger of twin turbo pipe and bigger exhaust. All other mods such as dumps pipes, intercooler, intercooler hard pipe, decat, etc although made a small difference to mid-high did not do much to low-mid and driverability.

Dyno graph to follow.

Edited October 10, 2017 by baicai
spelling

[baicai]

[baicai]

Green curve is new tune, white curve is last tune, purple curve is new tune low boost.

[r32-25t]

this is how much I improved the response on a set of -5s with vcam and this was a very weak tune on 98 

[fatz]

Now as a single and get another 1k of extra boost down low

[r32-25t]

No thanks car is how I want it now 

[fatz]

Yea but you now have Subaru parts in you skyline.... so so dirty

[Mick_o]

35 minutes ago, fatz said:

Now as a single and get another 1k of extra boost down low

Don't forget about the extra 40+kw everywhere else big guy! ?