First Impressions of GT28RS

[BigMal]

Nah man, what he said was that was what he had been told....
I am still undecided on that one.

[Rupewrecht]

Mine was only ported and is still capable of flowing about 270hp apparently

[QuicKSilveR]

Mmm, the GT2860RS would lack a little power when using just a .64 Exhaust housing. It uses a much smaller Front wheel to the GT2871 and GT2876. Normally use the .86 Exhaust Housing on the Disco. But yeah, they are a great street performer.

I've just received my new turbo - a GT2876R (GT2540). I'm going to use the .64 exhuast housing on it the same. The ehxuast housing and the whole exhaust wheel is exactly the same specs as the gt2860RS but it uses a HUGE T4 style front wheel inside a .70 Front Comp Cover with 4" Intake.

I'll let you guys know how it goes. It was a hard choice choosing, with mates using GT2860s, 71s and 76s all getting good results. I'm hoping the lag is ok on mine.

[QuicKSilveR]

.....If you can take a little more lag, the .86 will give you more top end. My Turbo came with a .86, but being so large i swopped it for a .64

[ROB-80E]

Mal, the head isn't the problem. Mine flowed 200kw remember, and it was a stock head. Did you manage to get a GTR plenum in the end? I've also been intouch with Jaustech and they have seen 230wkw with stock head and cams...so yeah, i say again, not the problem.

I'm with nate in saying that i wouldn't think changing the hot side pipe would make a different, but you never know, it's cheap to try, so you may as well. I run a bend using 2" off the turbo then enlarge it to 2.5 for the rest of the bends on the hot side.

Any chance on seeing the dyno sheet? I'd love to see the curve. Also, why only 15psi? :S

[BigMal]

Actually I am happier to take a loss of top end for less lag.
Been thinking about the lower than expected output and when I compare it against
GTXWGN with 180kw @ 16.5psi against my 157kw @ 15psi, at the same boost he
would probably be 170kw and you then allow say another 10kw for the diff between
the 2871 and 28RS so I am only a couple of kw off what I should be getting. On top
of that my run was using the standard astina front bumper as my Cwest is off to
be repaired and I know from previous driving the heatsoak difference between the 2
bars is noticeable especially up top. I am thinking that putting the Cwest bar back on
and also increasing the turbo to i/c pipe to 2.5" over the present 2" will give me the
10kw I was concerned about.

Having driven the car now for 4 days have come to the conclusion I dont really want
any more power and especially at the expense of the bottom end response. Driving
the car like I did with the VF8 boosting to 5-7psi the GT28RS didn't even need to go
into boost to match that performance. Boosting it up I have noticeably worn the tyres
even just over the couple of days and my biggest concern is breaking things being my
drive to work car.

[Exodus323]

Originally Posted by BigMal

Driving
the car like I did with the VF8 boosting to 5-7psi the GT28RS didn't even need to go
into boost to match that performance.

I feel bad now im about to use a VF10
for those of you that dont know the vf 10 is the same as a vf8 except it has a bigger exhaust wheel (is that right mal?)

[BigMal]

Originally Posted by Exodus323

I feel bad now im about to use a VF10
for those of you that dont know the vf 10 is the same as a vf8 except it has a bigger exhaust wheel (is that right mal?)

Yeah the VF8 has a larger exhaust wheel which is why to hybrid them you
need to machine the VJ20 exhaust housing.

All I am saying is when I was just doing spirited fun driving not going flat out
I used to boost to round 5-7 pounds in the VF8 and now dont need to be in
boost to get similar results cause of the great low down response of the potato.
Considering you will be running about 15-16 pounds with your VF10 its not
like I am saying your turbo will be like mine with no boost. That would be rude !!!

[BigMal]

Hey Rob,
The reason only 15psi is 2 bar map sensor with the E6K. I could have bought
a 3 bar for $120 but considering I got only 12kw for the last 3psi I didn't think
in its present state another 2psi would give me much worthy of the $$$.
In the back of my mind also is a E6X which has a 2.5 inbuilt map sensor and
also the windows tuning program which I could look at running on a carpc and
displaying incar.

Yes I have fitted a GTR intake plenum so that part is covered.
Turbo exhaust manifold is not tuned length but the runner size is what I would
expect and looking inside the collector part see no restrictions.
Exhaust is 3" all the way through with a mad custom stainless muffler with
dual 3" outlets and a magic performance 4" cat(tested in zoom 734cfm flow)
and a 3" SR20 dump so I cant see the exhaust being the restriction.
Fuel is covered by a walbro pump, malpassi and the Skyline GTR 444cc
injectors(which I love to death) and know this is all fine as there were
no problems on the dyno.
That leads to the last item the I/C piping which cant be the hybrid cooler or
the 3" cold side pipes so the only thing that I can think of in my whole
setup that could be at all restrictive is the 2" from turbo to intercooler.

I will post up the dyno sheet soon. I forgot it on the day but the guy printed
it out I just gotta go get it will hopefully do it this weekend.

[BigMal]

Its an old pic but in case you hadn't seen the custom manifold here it is.

[Exodus323]

yes mal that would be rude im only kidding anyway. the vf 10 is only a starting point just to go up a step from stock so maby i will be able to boast a little about how my car goes after conversion insted of doing a stock conversion and and posting numerous post on how good my car goes.

[Dogo]

hey Mal just wondering if you've hooked up the water cooling or just oil still ?

my vf12 is (still) sitting in the box

dave

[BigMal]

Originally Posted by Dogo

my vf12 is (still) sitting in the box

I hear you mate and know how you feel.
1. My rear shocks are still in the box bought them last year.
2. My bonnet is still bent (3 years) the replacement bonnet been in the
garage 1 year still haven't modified it.
3. My VT SS rear wing still hasnt been finished 2-3 years.

Its never ending.

Anyway for the VF12 I did dodgey I used the copper pipe hose fittings
to reduce from the subaru size (used subaru banjo's and outlets) down
to the 5/16 mazda water ends. Looked bad but worked. For the Garrett
I did it properly with speedflow fittings. The 2 90deg fittings were $25 each,
the adapters on turbo were $10 each, 1 metre blue gates -6 hose $13
and 2 Earls hose end fittings $8 each. The look Priceless...sorry much better
I bought the fittings a couple each week so it didn't really seem like $100
but the look is so much better I know the copper stuff was only $15 but
it did look shocking I wouldn't do that again.

[BigMal]

I forgot to mention that the ones on Jynx's VF8 were the Subaru fittings with 5/16
fittings welded on you can see the top one in the pic above if I didn't go speedflow
that would be the way I would go just need a welder mate.

[ROB-80E]

Originally Posted by Exodus323

yes mal that would be rude im only kidding anyway. the vf 10 is only a starting point just to go up a step from stock so maby i will be able to boast a little about how my car goes after conversion insted of doing a stock conversion and and posting numerous post on how good my car goes.

The whole compressor side is bigger than the VF10 as well as the exhaust wheel.

Hey mate, don't let it get to you...it would be rude of me to say that I made more power than mal with my VF10 hybrid setup than his VF8. hehehe

Mal - Welcom to my world with the tyres. I don't get what you mean with the map sensor either...i know that air pressure is 14.5psi but why does that effect the map sensor having to be a 45psi sensor?? The MT's come standard with a 20psi capable map sensor. :S

[Exodus323]

Im not letting it get to me.
Im just looking forward to my conversion once its turbo them ill start really looking into performance. but it will most likely be quick enough for me any way.......well for a little while

[BigMal]

Rob
The E6K uses an external map sensor being 2bar = normal atmosphere(1bar)
+ 1 bar boost so 15psi is all it will read. You can buy a 3bar = 30psi and
simply swap them out. The E6X comes with an internal 2.5 bar which will
read up to 22psi.

http://www.tweakit.net/shop/product_...roducts_id=821

And Rob I have always been jealous of the performance you have got. RESPECT
I can also live with the wearing tyres as long as the gearbox survives. Its a bit
concerning you only got 6 months from your last box if I read the fordlaser posts correct.
This weekend weapon weekday shopping trolley is a hard juggle I know I always want
more but I have to have reliability .....

[BigMal]

I dont have a scanner so heres a pic of the dyno read taken with my phone.
This is the final tune where he backed off timing a little for lower fuels not that it dropped by much.
Comes on full boost at 3700rpm

[Exodus323]

I was there when tat was being done all of you should here his car come on boost
good time for all

[ROB-80E]

Interesting that little flat spot you have there just after reaching full boost...is it noticeable when driving? I'm wondering if it has anything to do with the reason it's not making a little more power.

With my box, yeah it only lasted that long, but I think i may have ****ed up when i put it back together...so yeah, may have been induced. But i'm not taking any chances this time, hence why i'm putting in the straight cut 3rd. But my car is the same...i drive it to work and back everyday.