R34 Gtt + Full Exhaust Mod - 164.7rwkw

[nuffsaid]

Where can we get one of those from?

[666DAN]

Notice the stock map drastically pulls timing under load, I've had a play with it and now the car pulls to the redline instead of bogging down.

[Abo Bob]

I have only recently come to understand why putting an after market exhaust on causes the boost to increase.

It's because there is less restriction on the exhaust getting out of the turbo which means it doesn't have to push as hard but since it still comes out of the exhaust manifold with the same pressure it spins the exhaust wheel faster.

Obviously the impeller goes faster too which pushes more air hence more boost.

The other thing is that the exhaust takes the path of least resistance. Once you have an aftermarket exhaust on this can often be through the exhaust wheel rather than out of the wastegate even if it open as far as it goes.

So blaming the actuator for the boost increase in not right.

Also if you look at a stock dump pipe, the waste gate can't actually open all the way and the gases coming out of there go at right angles into the main flow so I think this restriction causes more gas to go through the exhaust wheel rather than the wastegate and this increases the boost.

If whoever said they had the stock dump maybe put a nice split dump on there they might find they have better boost control.

[666DAN]

As Adam said! I noticed with my split dump-pipe boost only crept up 1-2psi max.

[Haxorz]

Results back in for the Power FC install and tune.

R34 GTt + Full Exhaust + Power FC = 180rwkw.

Will be picking up car after work today. Was a little disappointed, was hoping for 190rwkw, but all dynos and cars are different I suppose. No 'before' run on that dyno was taken unfortunately.

I was told the car needed some serious re-mapping. Practically EVERY value on the maps were changed and it took the tuner a long time. The cruise was leaned out nicely for good economy. The power curve isn't the nicest but it drives much better than it looks.

So, if the two dynos were at least somewhat compareable, the Power FC gave me an extra 15rwkw top end (which seems about right) and hopefully some better economy. Hopefully a really sweet mid as well.

I was told my limitations are basically either the turbo or the exhaust. I have a Bos importing split dump/front, catco (small) high flow cat and custom 3" cat back (consisting of one 4" resonator and a magnaflow muffler with a 4" tip).

I'll add some more comments after I drive the car, do a few tanks through it and have been driving it for a bit.

Edited September 29, 2006 by McCracken

[Bass Junky]

CHARTS OR BAN

[Abo Bob]

Does the cat have full 3 inch flanges?

What boost is it running now?

[Haxorz]

To my knowledge, yes. It's this cat .

I know you got 190rwkw with your rom tune. Do you have a Jap brand exhaust? I really thought my exhaust was pretty good (even though it's custom) and only have one muffler as well (albeit not a huge one)!

Boost starts at about 9, goes up to 10.5, then back to about 10. From what he described it seems to follow a similar curve as the one on the dyno graphs posted before, without the 2 stage thing though.

Dyno graphs and other information will be posted once I get them.

[Abo Bob]

I was running 12 psi back then. CES split dump and Fujitsubo cat back.

Take out your restrictor.

I think 12psi on the street and 10psi on the track is the rule that will give you power and safety.

btw I made this rule up but I think it's a good one.

We are interested to see the dyno graph with AFR in particular but the boost one too. Don't care about torque.

[Haxorz]

CHARTS OR BAN

BTW - What is this? Are you suggesting I post a dyno chart or some moderator should ban this thread? Is it OK if I pickup my car first?

The dyno graph is attached for your enjoyment. It shows power and boost. As you can see the power curve isn't as nice as it was, but that's life I guess. As I mentioned previously, a lot of time was spent on this tune, and if the filename is any indication that looks like 41 runs on the dyno however this is just my guess and could be wrong.

Notes on the limited driving I've done so far. I think the car revs a bit lower, around 800-900 now. Unfortunately I didn't take a measurement of my pre-tune idle so I may be incorrect. Anything other than wide open throttle the car drives also exactly as I remembered it. Obviously it pulls harder under throttle due to the increase in power. I was expecting a fraction more but it's still more fun nonetheless. I'll keep an eye out for fuel economy over the next few weeks and post some results.

The car also seems to not choke as much if I boot it and then yank my foot off the accelerator. It sort of 'coasts' a little bit more, just like my R33 did when I first went the dump/front pipe.

Boost now comes on harder due to the removal of the 2 stage thing. No suprises there. I guess the graph says most of it. Unfortunately all this dyno graph was all I got, no before 20x20 maps were talken although they were requested (and I don't have a hand controller so I can't give you any post maps).

The car is very much still driveable, it's not like I'm driving a 'modified car' if that makes sense. I'm happy with this, it was one of my tuning aims and also the reason I went the Power FC over the S-AFC. I've driven some pretty wild 32's in the past, good power but as a daily driver they were awful.

Tips for anyone getting a tune:

- The car ended up being at workshop for 3 days even though the orignal estimate was 2. No big deal really, I'm paying these guys for their tuning ability not their estimation skills, but if I had have dropped the car off on a Thursday I would have been without a car for the weekend so keep this in mind I guess (same goes for any type of mechanical work really).

- Ben @ Racepace knows these things like the back of his hand and inside out. His knowledge was evident during our discussion of the tune. Some lessons he learnt from the track were used in the tune.

- Two of the check engine warning sensors were disabled, injector max and air meter max as my car is a long way away from making that power anyway. Just the knock sensor warning is enabled.

- The tune took half a tank of petrol. Make sure to fill the car with whatever you normally run on it.

Would I recommend it? Look, to me, the car drove great before, and now it's pretty much the same with a bit more power. No extra lag, nothing like that and hopefully economy will be unaffected. Was it worth the cash? That's really up to the individual. I guess the real question is was it an upgrade that 'made sense' at my level of modification. It's still early days, but I think the answer is yes. I wanted to get a bit more power but was uneasy with a few of the downsides of the FMIC (potential loss of response, attraction from police/theives, potentially modding engine bay, snorkle, fan, etc - now I know there are coolers that don't have ALL of these negatives but none are void of all). I also wanted to maintain driveablity.

Another reason I went the Power FC before the FMIC was because I was under the impression that I could achieve something more like 190-195rwkw but for me this wasn't the case. I guess if I ran 12psi I probably would, but without a convenient way to switch this around (EBC or valve) I'd rather leave the thing set on 10ish and forget about it.

In the meantime, if anyone has any specific questions on it feel free to ask. I hope my little write up helps any other Skyline boys and girls out there considering the Power FC.

Edited October 2, 2006 by McCracken

[blah_blah]

Thanks for the write up, it has been very useful.

[Haxorz]

Glad I helped. I charted these figures up in Excel. Didn't turn out exactly as I wanted them but here you go (using only 7 data points). I'm not sure how scientific this is, as they were different dynos, but enjoy anyway!

[Haxorz]

Ladies and Gentlemen, boys and girls,

I have just been offered a great price on a used Blitz LM intercooler. Dimensions are 610 x 266 x 68mm. This is the type that has the 180degree bend and utilises the stock IC piping.

I've never been a fan of the FMIC upgrade on the R34, due to loss of response and all those posts I read about the stock IC being efficient up to 200rwkw, although this is at a price too good to refuse and I was a bit disappointed with my 180rwkw after my Power FC tune.

Questions (Prefer personal R34 stories only):

1. Will fitting this alone and running the same boost (10psi) give me a power increase on my R34 GTt?

2a. Will fitting this allow me to run higher boost (say 12psi) safely? 2b. What sort of power increase could I expect?

3. Will I lose a noticeable amount of response due to the length of the pipes?

4. Is this cooler to big for the stock turbo?

5. Some people have noticed improved fuel economy. Is this the case?

6. How different will my power curve be? I just want zippy street performance up to the regular speed limits, I'm not into track.

7. Will boost come on later? Same? Earlier?

8. What will my power graph look like? Will it be better, worse or same below say 5000rpm?

8. Even at a low price is this modification worth it?

From what I've read around here I'm guessing it'll take me to say 190rwkw @ 12psi and I'll lose some responsiveness. This to me seems to be a poor upgrade decision IMO unless I were definatley to go a turbo upgrade as well.

Edited October 3, 2006 by McCracken

[666DAN]

I've got a front mount with 180 degree pipe, similar setup to what you've mentioned. I didn't notice too much of a change, the bennefit to you will be the complete lack of heat-soak with the bigger I/C. In summer I could heat my sidemount one up quickly, if you've got a borderline tune it'll start to ping, the FMIC is like a bit of an insurance policy, get it

[Bass Junky]

1. Will fitting this alone and running the same boost (10psi) give me a power increase on my R34 GTt?

Sort of. people say it's up to 10-15rwkw gain, but really, I'm not sure.

The gain to to be had in stable intake charge air temps.

2a. Will fitting this allow me to run higher boost (say 12psi) safely?

Not really. The turbo limits the amount of boost safe to run, not the intercooler.

2b. What sort of power increase could I expect?

see Q2a

3. Will I lose a noticeable amount of response due to the length of the pipes?

No. I noticed absolutley bugger all difference in response. I fully expected a lack of response, but didn't really notice that much.

4. Is this cooler to big for the stock turbo?

No

5. Some people have noticed improved fuel economy. Is this the case?

WTF? don't know how or why.

6. How different will my power curve be? I just want zippy street performance up to the regular speed limits, I'm not into track.

Not a huge amount different.

7. Will boost come on later? Same? Earlier?

Same

8. What will my power graph look like? Will it be better, worse or same below say 5000rpm?

Same

8. Even at a low price is this modification worth it?

Yep, cos you will always want more power, and above 200rwkw, you need the cooler.

BASS OUT

[Abo Bob]

Ladies and Gentlemen, boys and girls,

I have just been offered a great price on a used Blitz LM intercooler. Dimensions are 610 x 266 x 68mm. This is the type that has the 180degree bend and utilises the stock IC piping.

I've never been a fan of the FMIC upgrade on the R34, due to loss of response and all those posts I read about the stock IC being efficient up to 200rwkw, although this is at a price too good to refuse and I was a bit disappointed with my 180rwkw after my Power FC tune.

Questions (Prefer personal R34 stories only):

1. Will fitting this alone and running the same boost (10psi) give me a power increase on my R34 GTt?

2a. Will fitting this allow me to run higher boost (say 12psi) safely? 2b. What sort of power increase could I expect?

3. Will I lose a noticeable amount of response due to the length of the pipes?

4. Is this cooler to big for the stock turbo?

5. Some people have noticed improved fuel economy. Is this the case?

6. How different will my power curve be? I just want zippy street performance up to the regular speed limits, I'm not into track.

7. Will boost come on later? Same? Earlier?

8. What will my power graph look like? Will it be better, worse or same below say 5000rpm?

8. Even at a low price is this modification worth it?

From what I've read around here I'm guessing it'll take me to say 190rwkw @ 12psi and I'll lose some responsiveness. This to me seems to be a poor upgrade decision IMO unless I were definatley to go a turbo upgrade as well.

1. No

2. Yes, 10-20rwkw

3. yes

4. no

5. on the highway it was for me.

6. You will lose zip but that's not relevant to the power curve. It will be the same.

7. later

8. same

8. Debateable. Dan is right about insurance. Might as well get it and put the boost up but don't get it and not boost.

[nuffsaid]

Great thread as Ive got similar plans and ideas.

However everyone has a different opinion and contradictory results which makes it hard =|

Interested in what more people have to say, thanks for your input so far fellas

[Abo Bob]

I wrote mine while Bass was posting his so I missed it.

1. Will fitting this alone and running the same boost (10psi) give me a power increase on my R34 GTt?

Sort of. people say it's up to 10-15rwkw gain, but really, I'm not sure.

The gain to to be had in stable intake charge air temps.

In theory the lower temp should increase the power. In practice...

2a. Will fitting this allow me to run higher boost (say 12psi) safely?

Not really. The turbo limits the amount of boost safe to run, not the intercooler.

True but; Safe for the turbo is boost related, safe for the engine is intercooler related.

2b. What sort of power increase could I expect?

see Q2a

3. Will I lose a noticeable amount of response due to the length of the pipes?

No. I noticed absolutley bugger all difference in response. I fully expected a lack of response, but didn't really notice that much.

I didn't expect it but I got it.

4. Is this cooler to big for the stock turbo?

No

5. Some people have noticed improved fuel economy. Is this the case?

WTF? don't know how or why.

Me either.

6. How different will my power curve be? I just want zippy street performance up to the regular speed limits, I'm not into track.

Not a huge amount different.

7. Will boost come on later? Same? Earlier?

Same

You have a whole big intercooler and associated plumbing to pressurise. This needs more air. Maybe I'm just talking about response here rather than boost threshold.

8. What will my power graph look like? Will it be better, worse or same below say 5000rpm?

Same

8. Even at a low price is this modification worth it?

Yep, cos you will always want more power, and above 200rwkw, you need the cooler.

Haha, generally vey true.

BASS OUT

Damn you Bass for making me think.

[Bass Junky]

[Taso84]

100% u should get it...

1) It'll make ur engine last longer

2) u'll need it later anyway if u plan to go over 200rwkW

3) On hot days u will notice ur car runs much better than what it used to

4) Less chance od detonation/pinging which is a very good thing

5) It looks fully sik