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actually spent a good couple hours today talking to a few tuners around, JEM, Unigroup, Even had a chat with couple of the boys from GCG. ( who always try and tell me the -5's are responsive. ( so there customers say)

Each one said -5's are a much better option, apart from unigroup saying it depends on your application, All said there is really not much diffreance in response, Yet top end power and room for bigger set up will be lost in the future going -9's unless you plan to buy another set of blowers

"responsive" is a subjective term, that is, different people have different ideas on what can be considered responsive or not. It will not help you make a decision. You want to know something objective, like "1 bar boost by X rpm".

Of course it depends on application, and therefore Unigroup are the only sensible opinion out of the bunch.

I've been in Ash's car on 9's and later on 5's. The 9's in the hills were great, I was seriously impressed for a 2.6. Just seems a waste IMO on a built engine to not push more HP. Now his car IMO feels even better with the 5's, but in a slightly different way

It's too much of a personal choice for any of us to help you get over the line, it's a choice you need to make. Maybe just flip a coin lol

Edit; I know Unigroup have -9 and -5 results on the dyno which are comparable but you'll come to the same issue; what do you want

"responsive" is a subjective term, that is, different people have different ideas on what can be considered responsive or not. It will not help you make a decision. You want to know something objective, like "1 bar boost by X rpm".

Of course it depends on application, and therefore Unigroup are the only sensible opinion out of the bunch.

Well said on both points

I've been in Ash's car on 9's and later on 5's. The 9's in the hills were great, I was seriously impressed for a 2.6. Just seems a waste IMO on a built engine to not push more HP. Now his car IMO feels even better with the 5's, but in a slightly different way

It's too much of a personal choice for any of us to help you get over the line, it's a choice you need to make. Maybe just flip a coin lol

Yet I don't like the -5s for the simple reason of just how much more responsive the -9s were :)

All comes down to personal choice. If i have a 2.8 - no question -5s are the choice.

I have no doubt in my mind a -9 equipped GTR is faster in the hills as it's simply easier to drive. The roads i go on i know well, and my car is very well sorted. With -5s the car is a handful to really enjoy. Even doing Mt Baw Baw earlier in the year, -9s would have made the car much faster.

With -5s you need to drop 2 gears all the time to get it to at least 4500-5000pm and you have to ring 8000rpm all the time, you fall off boost soon as you are off throttle and so on. The -9 are up and moving almost as soon as you touch the throttle and there is next to no between gear lag and you never need to drop back that extra gear.

Linear power does feel "boring" and hence i changed to -5s, and it is certainly fun to drive from a top end perspective in a straight line - but realistically unless you are over 140km/h the -5s are pointless... And 140+ is instant impound... :/

Nismoid your main application for your car seems to be through the hills/bends, Which i understand the importance of response in that sense, But would you still swing the way of -9s for a highway cruiser with the ocasional bend on the way.

From the dyno sheets i compared the -9s shit all over the 5s up untill about 110km per hour, Then the 5's take over....Then you loose your licence.

But yer.... End of the day.....i cant find someone to ride in with -5s so i cant compare like you.

Linear power does feel "boring" and hence i changed to -5s, and it is certainly fun to drive from a top end perspective in a straight line - but realistically unless you are over 140km/h the -5s are pointless... And 140+ is instant impound... :/

Ash thats I point I try hard to drive home and the reason why all I'd ever change a std capacty GTR to is those 707160-9/GTR GTSS turbos . Power from 4000 (-5s) may be great but you have to drive silly fast on public roads to be able to access that power .

I don't honestly know for sure but I doubt a GTR with standard gearing is really set up for high rev power only .

Really it doesn't matter if its a GTR an Evo an STi or an XR6T etc .

Cars that are nice to drive "in the mountains" are ones that can be kept on the boil without reving piss and pick handles out of them and nothings worse than falling off the bottom of the strong power range almost all the time .

The real killer is having a Mk1 Camry donk under the lid at cruising speeds and going back two or more gears looking for revs tells the real story .

Once again your calls but in a relatively heavy car I think the go is turbos that work when you most often need them or more cubes .

A .

Edited by discopotato03

And I totally agree with you :)

Nismoid your main application for your car seems to be through the hills/bends, Which i understand the importance of response in that sense, But would you still swing the way of -9s for a highway cruiser with the ocasional bend on the way.

From the dyno sheets i compared the -9s shit all over the 5s up untill about 110km per hour, Then the 5's take over....Then you loose your licence.

But yer.... End of the day.....i cant find someone to ride in with -5s so i cant compare like you.

Indeed - I like to give it a solid drive on weekends & also motorkhana/hillclimbs. I must say @ Circuit Battle last year (Thunderdome) the -5s were good, speeds of 180km/h were seen so stands to reason the performed really well.

If it was just a pure street car and you weren't interested in 1/4 mile then -9s without a doubt. More response off the lights, less needing to rev the knackers out of it. -9s go alright for what they are and make for nice driving experience when around town, combine with a big GTR 7000rpm launch they are no slouch.

You've got a built motor so run 20-23psi through them in the midrange. They will drop off to ~18psi by 7500rpm and you'll be looking to shift. They do come on nicely by 3400rpm though so it's a nice broad range.

Just tuned deano's 32gtr with -5's. Here's a comparison with michaels t517z's. I am installing -7's to a 32gtr this week and will tune next week. So i will have a direct comparison between them all soon.

I would put my own cars results up with them but its on E85 so its not a good comparison

0b2ca184.jpg

To me that dyno sheet with -5's is what the 9s can do, But much sooner. 120 odd kw at 100km/ph were as by that stage -9s would be well into the 150kw range.

Looks like after about 150km per hour is were the 5's really take off?

I've posted that comparo before, 6-7 on the same graph.

The -9 and -5 look very similar on paper response wise, go and drive them however you soon see there is much the dyno does not tell.

On the street, Realistically, Would you say the -5s are 1000Rpm Later? or a bit sooner. same tune/set up (for argument sake)

From what i can see, alot of the dynos show all the 5s at around 100kw at 100-110km/ph with the exception of two i found sitting at 140kw and another at 130.

On the street, Realistically, Would you say the -5s are 1000Rpm Later? or a bit sooner. same tune/set up (for argument sake)

From what i can see, alot of the dynos show all the 5s at around 100kw at 100-110km/ph with the exception of two i found sitting at 140kw and another at 130.

Not 1000rpm, closer to 500-700rpm

But the thing you cannot see on a dyno sheet, and you can feel on the street - how they pickup in between gears, on/off throttle etc which is what i keep saying.

^^I'm with Ash

Not RB26 but I think comparable. Switching from a GT-RS to 2835ProS the dyno prints are very similar but the ProS ultimately makes more power.

On the street the GT-RS is so much more lively with small throttle openings, changing lanes is so much easier and was always willing no matter what gear. The ProS is much nicer on wide open roads but but requires more throttle and a whisker longer to get going.

It is hard to believe that they feel so different to drive considering the overlays were so similar. On a heavy car like the Stagea I would prefer to go back to the GT-RS for day to day driving.

Based on the above I wouldn't hesitate to go -9 for a 26....but I would have to think long and hard about going -5's.

Just tuned deano's 32gtr with -5's. Here's a comparison with michaels t517z's. I am installing -7's to a 32gtr this week and will tune next week. So i will have a direct comparison between them all soon.

I would put my own cars results up with them but its on E85 so its not a good comparison

Take care of michaels car :thumbsup:

good friend of mine

So bro, (op)

What happened to making the decision yesterday?

You have all the information in the world. All of us have elaborated so much in this thread, that you should know by now what you would much rather want.

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