Harey

Nah if you want more power (and happy for more lag) get some -5s and sell the -7s. Dont bother hiflowing them. Otherwise, if you are all about response keep the -7s and get as much as you can out of em as you have already planned.

Yeah dont get me wrong thats a tonne of power and it sounds like a heap of fun! Just providing some advice while the thread owner is getting his exhaust made up. I was spewing after I chose a smaller exhaust and then threw it out and went bigger. May as well go big straight up, especially with RB34 and a GT35!

Yeah I recommended a 3.5" catback as you already have. How have you come to the conclusion that a 3" dump is not a restriction? Because its making good power?

Great work mate! Sounding good. Yeah definitely pick up a 100 cell metal cat (I recommend from Venom), the stock cat will be restricting it a lot. With a GT35 I would recommend a 3.5" outlet to the cat and then 3.5" from there onwards. 3" catback is too small for a GT35. Ah yeah a 3.4L will definitely help with the spool hahaha, that will be unreal.

But the previous dyno graph shows the 35R has more response and more top end over the -7s??

I would guesstimate less than 10rwkw different between a quality 100 cell metal cat 5" body and a decat pipe at 550rwhp.

I would strongly recommend a 100 cell metal cat, I bought mine from Venom and it was only $60 more than a ceramic 200 cell cat from just jap or others. Venom can sell them with the factory flanges so it just bolts on. That will mean that you cant get an on the spot fine as you have a cat. If you do get sent for an emissions test I would still recommend changing it back to the standard one though to be safer.

I know its hard to hear as a newbie to search, you just want to hear the answers. But the answer is it depends on so many different things about what you want out of the car, which you havent specified. The best way to understand this is to read through the different topics on this forum and get a good overall understanding. If I was going to drop $20k to modify a car I would be researching the crap out of it. Important things which I was not aware of before owning a rwd skyline: - Lag, being a small 2.5L engine if you go for any more than 250rwkw on 98 fuel then you will notice an increase in lag. This continues to increase as you go higher in power. Over 300rwkw and you wont be seeing full boost to after 4000rpm at best. That only leaves you with less than 3000rpm of useable power assuming the standard rev limiter. But since you are talking about building the engine you could potentially raise the rev limiter with the right engine mods and this could be ok - Traction with a rwd, even the standard turbo with a few mods and tune can be hard to launch in 1st gear without heavily breaking traction (with standard type tyres). I have 280rwkw and it can break traction in second gear even with wide grippy tyres. - Axle tramp, I experienced a fair bit of axle tramp (wheels bouncing up and down as you break and regain traction), to resolve this you need to address the suspension which can be tricky to work out what is causing it. Super stiff coilovers can make this worse. - Fast, the other thing is how fast a skyline can be without huge power figures. They are a lighter car and dont need the huge power figures of an XR6 Turbo to be fast. My car with 280rwkw is very quick, I would expect to run high 11 second 1/4s with a good launch and is plenty for the street. Have a good think about it all and do plenty of research. If your talking about dropping a tonne of cash then I would look at a GTR, that way it should hold its value better and you have some hope of getting big power to the ground. Best of luck!

I have a fix for that! Set of injectors, a Z32 AFM and a tune

If its a 100 cell metal cat in good condition it will make bugger all difference even at those power levels. However, yeah a quick decat pipe as a test will tell you for sure.

You could make that with a GTX3076 with a lot better response. Depends what you want out of the car.

I suppose the question is how hard do you want to run it? Turbo is capable of between 330-500rwkw

+1 for George at Venom! Very happy with my 3" 100 cell (5" body) cat.

The GTX wont be a step backwards, the question is how much better will it be. On an rb25 and if you are happy to run more boost ie 22+psi then yes you will notice quite a difference. My only question is will this be the same on an rb30, is there someone who is an expert on compressor maps who can comment? I think the ATR43G3 is also an excellent turbo and being plain bearing seems to be more reliable. I think either way you will be happy.

Bit confused by your opening post, is Garrett going to honour your warranty and give you a credit? If so, then you would choose a garrett turbo simply for convenience. Just to confirm you are happy with how the 3076 performed before it failed? I read the sentence a few times but just wanted to make sure. If so then I think a GTX3076 would be a perfect fit, from my reading you wont gain much at 17psi but when you increase the boost you should notice large increases in hp as the GTX turbo comes into its efficiency. If you dont get a credit with Garrett then yes the ATR43G3 is a great option too! Or maybe a kando T67

Very interesting regarding the gear ratios, I suppose you could even use 1st gear for some really tight corners then too. Yeah its all personal whether you want linear torque or lag and then a rush. horses for courses.

NOICE!! What did it make on 98? Guessing ~300-310rwkw? E85 FTW!

Is abe running a 0.82 rear? Does he have cams? Great result! Car looks tops in the photos too

yes the 1/4 time itself varies a lot with tyres, how good the driver is at getting the car off the line etc etc. However the mph gives a very good indication of the power/weight of the car. Given most of our cars would be similar weight it will show very well the power of the car. You can do 10 runs ranging from poor launchs to your best launch and as long as you rev out the gears and change fairly well your mph will only vary by 1-2mph. Can be much better then comparing dyno sheets from different types of dyno in different states etc. I just cbf getting down to calder haha and its normally on a friday night.

What sort of power are you making out of your R32 GTR? If its highly modded and making big power then I would definitely want to get the tune updated to get the most out of the cooler change (assuming the standard one is a restriction). If its only lightly modded then yeah dont worry about a retune, but I wouldnt worry about the cooler either. The standard gtr cooler is fine for big power 350kw etc.

Dont understand that, if your low on petrol you shouldnt be hitting boost at all, so the boost controller wouldnt come into it. Like your explanation above, you needed to do it. Also like your plan to mod the gts-t, 3-4k makes a huge difference on the RB25!

Yes its all good to say "300rwkws with SS1's response" but I will wait for the dyno sheet. That would be a phenomenal achievement. I would go through the dyno sheets and choose the one that suits you best.

here here! If you wait for the perfect turbo you will never have one!

Well said GTScott. SargeRX8, a hiflow turbo can be all sorts of different specs depending on what you ask for. You choose a large hiflow so of course you need those other things.

Well for a kando turbo you need to customise some piping for an external wastegate. Whereas the Hypergear turbo will bolt straight in as its internally gated. Then you just need to compare the turbo results, this will vary on which turbo of each variety you choose. I have not seen many td06l2-20g results on rb25s so that might be hard. Whereas there are tonnes of Hypergear results to look at. Obviously Tao is trying to sell you a turbo hes not a charity but I think for sub 300rwkw with the standard manifold, bang for buck is pretty bloody hard to beat.