New Turbo Setup

[JonnoHR31]

iirc the IAT sender and the ecu coolant temp sender are the same, so it'd work as a IAT sensor.

But the problem is, you cant simply remove all the coolant temp compensations in the ecu. its used for general enrichment, cranking injection times, cold idle, overheating protection and cold timing protection.

have a look at the cranking injector times in the standard power fc map, theres a massive difference between hot and cold start. once you wire it up the way your saying it probably wont even start, let alone run properly.

[Rolls]

Good points jonno, I didn't realise it was factored into that many things, thought it was just the cold start ignition and fuel that was it.

[Room42]

iirc the IAT sender and the ecu coolant temp sender are the same, so it'd work as a IAT sensor.

But the problem is, you cant simply remove all the coolant temp compensations in the ecu. its used for general enrichment, cranking injection times, cold idle, overheating protection and cold timing protection.

have a look at the cranking injector times in the standard power fc map, theres a massive difference between hot and cold start. once you wire it up the way your saying it probably wont even start, let alone run properly.

Ahh yes you are right that there is more than the water temp correction to think of.

Acceleration enrichment is rpm dependent so it is not affected by the coolant sensor unless there is a water temp correction involved.

The cranking injection times are something to consider also. As you are aware these can be changed according to coolant temp. It is possible, under certain conditions, having the signal at 40 degrees when the engine is at 80 degrees could flood the engine.

In regard to cold idle I guess you would have to either disable the aac or put a switch on it. Then it could be a pain in the ass to start or at worse the mixture would be lean under whatever temp the sensor was reading, assuming that you used the coolant temp sensor as an air temp sensor. This could be resolved with the water temp correction..

My cold ign correction is all set to zero. I just don't flog my car when its cold, but you are correct in saying that is has dependency on the coolant sensor input. As far as overheating protection goes you would have to keep an eye on the aftermarket temp gauge. This would not affect the ecu tho.

I have altered my cranking ms times from stock. It is 25ms at 10 degrees and 14ms at 50 and 80 degrees. My car does start ok using even as high as 50ms at 80 degrees. Not that I would but it is just an example.

I think that it would be worth trying to use the coolant sensor for intake temp, although there is a high likelihood that the car would not end up satisfactory. I personally would try it as I can adjust everything for the swap. I would not recommend it to anyone that cannot do the work themselves and tune their own vehicle.

This seems to be one of those mods that is best achieved by using the right equipment in the first place, ie: a suitable ecu.

[Room42]

Another quick update. I got the car back from the exhaust shop today. I got a 3 inch mandrel bent dump made with a fitting for my wideband sensor. The guy did an excellent job and it was a fair price. The car is a lot quieter (dur) and has lost 3 psi from having the exhaust hooked up. Replacing the stock cat is next on the list. I have a manual boost tee so its all good. I haven't done much driving cos its peak hour so I'll make a little vid later when the missus gets home.

Lag. Yes there is lots of it and if I wasn't going to use the rb30 in the shed and eventually a put a 3.4L in it I would have bought a smaller and cheaper turbo. Still even off boost the car goes almost as good as my v6 vt commodore so I'm not complaining. There is almost no boost under 4000rpm. If I flatten it at low rpm I can get some boost down low but not much. At 4000 the car goes ok and at 4500 or so it goes spastic.I'll just make this clear now...In my opinion a gt35r is too big for an rb25det doing street duties. I can live with it tho and it wont be long before that lag drops over 1000rpm with the new motor.

I bought a new bolt type clamp for the part of the piping that keeps popping off and it held 16 psi. I will turn it up a little more tonight but I needed to get home and have a rest after work. Its been a long day. Oh btw the wastegate is f**king loud. Its a quiet car then its screaming its head off. I'll be getting a screamer pipe plumbed into the exhaust next week or whenever.

Anyway rest now...

[zebra]

.82 turbine housing?

[Room42]

.82 turbine housing?

Yep. 4 bolt rear.

[zebra]

sounds about right...its why im not a huge fan of the gt35s, they are even a bit lazy on the 4L ford donks (1.06 rear)

[Room42]

I think it should go pretty good with 3.4L tho. The torque off boost will be a lot nicer too.

I forgot to mention before about my tune. The afr's are still spot on and there was a max of 14 knock at any time. I'll get comfortable with the new power and find my preferred boost level then put it on the dyno. Give it a few weeks tho.

[Harey]

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.

[Room42]

So I just made a little vid of going up the road and then to the pizza shop. Saw 20 psi, popped of the boost gauge hose and slipped the clutch in 3rd So much for a hd clutch...

The vid is a bit crap cos its dark and the camera isn't fixed. Anyway I'll upload it and it should be ready in half an hour

[Room42]

The upload failed. I'll try again tomorrow afternoon.

[snozzle]

I have a GT35 on my stock rb26 with poncams, i get 1 bar of boost by 4000rpm in 4th and full boost by around 4300rpm. I see that everyone looks at "lag" differently, to be honest i dont think my setup is laggy at all.

As for the exhaust side of things, Im running a 3" dump to a decat which is also 3" and the catback is 3.5". Setup is making 485hp at all 4 hubs on 20psi so my 3" dump is not a restriction

I feel comfortable knowing the 0.82rear housing is getting rid of all the heat at high rpm quickly as compared to a 0.63. I rather my engine breathe better than come on boost a few hundred rpm earlier!

To give you an idea on how much fuel you will need for a GT35 running 20pounds, my sard 700ccs are running at 89-92% with the stock FPR and an intank 044. Not sure on what my AFRS are though as i forgot to ask my tuner.

As for the RB34, or even an RB30 for that matter, id go a TO4z with a 1.0x housing, a 0.82 gt35 seems kinda small for an engine like that?

Edited October 11, 2011 by snozzle

[Room42]

I have a GT35 on my stock rb26 with poncams, i get 1 bar of boost by 4000rpm in 4th and full boost by around 4300rpm. I see that everyone looks at "lag" differently, to be honest i dont think my setup is laggy at all.

As for the exhaust side of things, Im running a 3" dump to a decat which is also 3" and the catback is 3.5". Setup is making 485hp at all 4 hubs on 20psi so my 3" dump is not a restriction

I feel comfortable knowing the 0.82rear housing is getting rid of all the heat at high rpm quickly as compared to a 0.63. I rather my engine breathe better than come on boost a few hundred rpm earlier!

To give you an idea on how much fuel you will need for a GT35 running 20pounds, my sard 700ccs are running at 89-92% with the stock FPR and an intank 044. Not sure on what my AFRS are though as i forgot to ask my tuner.

As for the RB34, or even an RB30 for that matter, id go a TO4z with a 1.0x housing, a 0.82 gt35 seems kinda small for an engine like that?

Hey man I think the boost in my car comes on about 300 rpm later than yours but then I don't have cams and I'm down 100cc in capacity. I checked the injector duty cycle after giving it some at 20 psi and they were at 56%. I'm using 900cc @ 3bar jecs injectors.

I spoke to an engine builder here in Perth who has built rb's including a 7xxrwhp rb26 and he recommended the gt35r for a the rb30. It might be too small for the 3.4L but realistically I'd rather the turbo come on earlier and still be able to put out 500hp or so to the wheels.

About the exhaust, I asked the exhaust bloke about making me a bigger exhaust for the power I will make and he said 3 inch will be fine just delete the cat. So yeah a big cat is on the list. Right next to a new clutch

[Hanaldo]

Hey man I think the boost in my car comes on about 300 rpm later than yours but then I don't have cams and I'm down 100cc in capacity. I checked the injector duty cycle after giving it some at 20 psi and they were at 56%. I'm using 900cc @ 3bar jecs injectors.

The 100cc difference in capacity is more like 60cc. It would make fark all difference, especially if you have VCT enabled and working properly. I think you will find that 300rpm is down to a restriction with the stock cat, will be interesting to see how it goes with a big high flow cat fitted. I know I picked up about 500rpm of response when I upgraded my cat and that was with the stock turbo.

[Harey]

Setup is making 485hp at all 4 hubs on 20psi so my 3" dump is not a restriction

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?

[snozzle]

Well i wasnt expecting any more power than the result i got and i got around 25hp jump from going 18 to 20psi, If the dump was a restricition id assume the increase in power would be less? Fuel system would be maxed out at around 510hp so the boost was capped at 20psi and tuner made sure there was plenty of fuel in there to keep my pistons happy

Edited October 12, 2011 by snozzle

[Harey]

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!

[Room42]

I will be getting the exhaust replaced from the dump back next year. I'll get a cat before then tho. When I mentioned the clutch slipping it didn't just slip. It hit the limiter at 7600 as soon as it came on boost in 3rd. It's rooted now. I'll pull the box out and have a sus soon.

[SimonR32]

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?

He has an external gate venting to atmosphere... Don't you have an internal gate? Totally different ball game when it comes to exhaust flow

[Room42]

http://www.youtube.c...h?v=cpyXkX7aeMo

Here is a quick shaky vid. Watch out for frequent swearing. After you see the clutch slip in 3rd cut to near the end where I show under the bonnet quickly.

14psi @ 4050rpm and 20psi @ 4400rpm.

Edited October 12, 2011 by Room42