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What is your MAX BHP on STOCK T25 Turbos ????


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Discussion Starter #61
Gav,

Yes they have steel internals and a 'cut back wheel', basically a modified exhaust wheel that will flow a little more gas than standard IIRC.

RK did them for me after the 2nd hand 2510's I bought and gave to him to fit turned out to be only fit for weighting down paper :bawling:, (yes I did get my £ back). IIRC the whole job cost £900 including labour and VAT etc. Included in that was was two new exhaust housings as mine had cracked and accounted for a fair few hundreds of the bill.

At the time I could not afford new turbo's and as mine ceramics had gone and my car was on Ron's ramps with no turbo's I had no option but to get them rebuilt. But with my recent mods I have proved, (to myself), that they still had plenty of legs left in them and have given me the grunt I always wanted. Now Ron's has rebuilt my engine with uprated internals, if I get any probs with the turbo's 2860 will go in for 550+hp.
 

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So with the 550cc injectors you are making 500+bhp at the flywheel?

I am worried that I'm not gonna make 500bhp as I still have the standard afms and fuel pump but according to my tuner he is saying different, he is good mates with someone who has a couple of skylines, one is around 600bhp + for the track, the other is around 1000bhp for the strip, my injectors, ecu and a few other bits came from him, from all I have read on the forum and by asking members when the subject has come up the afms are good for 450-475bhp max, not sure on the fuel pump.
 

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I have not yet dyno's my car so don't know for sure what its making, but its going to be in that area.

550cc are good for 500bhp, but standard AFM's aren't, that why I binned mine and went MAP sensor. I also have a standard pump and its delivering all the fuel I need at this point. :)
 

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This thread has only a few posts and allready a mess of different tuning options.

1)Whats the purpose of keeping the original AFMs if you remap the engine via an F-con or setup it up via PFC???
Is the airflow through the standard AFMs not restricting . . . a bigger and shorter piping for the Turbo inlet with a cone-filter, is that not better then keeping the AFMS (even if you put them on an aftermarket indution piping)?

2) Whats the limit for injector size on N1s, 500cc is not enough for 500HP , but is 600cc not too much on that setup?? Its not like putting 1000cc injectors would make a difference on the N1 Turbos?

3) 500+HP with 500cc+ injectors . . . . is the fuel delivery still OK? Or do we need an upgraded fuel pump, like the Nismo one???

4) Intercooler wise, if the AFMs are gone on the induction, what to get??? There is a variation in same capacity intercoolers for different blow off pipings (the pipe that goes from the induction behind the intercooler in to the Blowoff systhem has to go or not??)

5) euhhh what else???:D
 

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This thread has only a few posts and allready a mess of different tuning options.

3) 500+HP with 500cc+ injectors . . . . is the fuel delivery still OK? Or do we need an upgraded fuel pump, like the Nismo one???
I was told with 500cc injectors you'll only realise around 450-460cc in actual real world applications- Something about duty cycles and the injector struggling to acheive maximum flow. So for 500hp look to use 600cc injectors to be sure you get the right kind of flow.

Also upgrade the fuel pump as a result as I'm told the factory fuel pump sitting in the tank only really supports factory / or a little bit larger injectors.

On a side note - I'm also told the fuel rail is quite alright upto 500hp applications - anything larger and you may need to look at a larger one.

Again this information is what I've read & asked when talking on the subject and may or may not be accurate to a given engine setup.
 

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550cc injectors will be fine for 500hp, you can also up the fuelpressure with an aftermarket regulator if duty cycle goes over 90% (about the max you should safely go on injectors) and they'll be able to supply more then enough fuel.

Oh and the std rail is upto the job aswell.
Although you'll best need to upgrade the std fuelpump to be safe ;)
 

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I think when you look at Kingsley`s setup the biggest thing are the cam-mods and pulleys. This makes a hudge difference through out th erev range.

So can we say that :
standard engine + N1 Turbos + 550-600cc injectors + PFC = [email protected] approx.????

or will the standard fuel pump not deliver on that spec??
 

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Voiced my concerns again to the tuner, he has already spoken to his mate who the reprogrammed ecu, 550cc injectors and relevant other bits came from, he has already arranged for a dyno run as soon as i have run the engine in and the oil has been changed ready for it,
As soon as I know what the car makes it will be posted, including the spec of all mods on the car,
 

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I was told with 500cc injectors you'll only realise around 450-460cc in actual real world applications- Something about duty cycles and the injector struggling to acheive maximum flow. So for 500hp look to use 600cc injectors to be sure you get the right kind of flow.

Also upgrade the fuel pump as a result as I'm told the factory fuel pump sitting in the tank only really supports factory / or a little bit larger injectors.

On a side note - I'm also told the fuel rail is quite alright upto 500hp applications - anything larger and you may need to look at a larger one.

Again this information is what I've read & asked when talking on the subject and may or may not be accurate to a given engine setup.

Between 90-95% is what can be expected from the injectors if the pump can flow enough fuel, which equates to 450-475bhp on 500cc injectors,

so theoretically 550cc injectors could make 495-522bhp fingers crossed
 

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ok, well i went and had my turbos rebuilt with an n1 steel wheel kit. Just had her dyno and she put down 396rwhp and 330rwtq at 17psi. injectors we at 100%.

Mark
 

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it would be good to know how much power would stock turbos with steel internals flow at 25 psi.
You hear other people out there running very high boost on turbos, like 30 to 40 psi... and not big turbos but the medium sized.
 

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Discussion Starter #76
it would be good to know how much power would stock turbos with steel internals flow at 25 psi.
You hear other people out there running very high boost on turbos, like 30 to 40 psi... and not big turbos but the medium sized.
I am running just over 22.5 psi, (1.55 bar to be correct), but I won't find out the actual output until I get it on the dyno in a couple of months.

I'll keep you posted though. ;)

So your saying you've heard others running 30-40 psi through standard turbos? :confused: :confused: :eek:
 

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Most of the info seems about right to me .

The limiting factor is the obviously the "slowest" piece of the chain

Injectors will comfortably give 90% of cc in bhp in any case without maxing out ( 500cc - 450 etc)

Standrd fuel pump however no chance at 500 (IMHO). I was told to change mine at 400

Cams and headwork will help a lot but its best to do all the engine to the same level rather than try to get the most out of one part.

So it may well be possible to get 550 hp with silly head work daft cams uprated fuel sytem and stock turbos modified running on stupid boost.

But it would be much more sensible to change the turbos to GTSS (for example)

But a very interesting thread if somewhat theoretical over 500.
 

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Discussion Starter #78
Brian,

Cheers for your input, its greatly appreciated. :)

I am not sure though if you were referring to my spec with your comments, or other posting to this thread.

My engine is now fully forged, albeit with a standard but brand new crank.
Now the car is finally mapped with a D-Jetro PFC so I no longer have MAFS and so have gained a little there. It feel a lot quicker than it was before at 400bhp, and I don't want to put my neck on the line or say something that may tempt fate, but it does feel 500+ from what I have felt in from other 500 cars over the years.

I too was concerned about my standard pump, but Ron, (RK), said he wouldn't mention it to the mapper and just see what he'd get out of it before it ran out of fuel. I was expecting 1.3-1.4 bar, but when I picked it up I found it was mapped to 1.55 bar as it was still getting fuel and every thing felt fine. I must add that my brief was not for a grenade that would kill something, but to leave a margin. The injectors are showing 95% at full revs at 1.55 bar, so maybe I'll look at a fuel pressure regulator later to add a margin of safety on them.

Anyway, my finances are now directed in other directions, 2 young kids and a wife who's maternity pay has run out, so we're on one wage :(. The a few months ago I found the the head had cracked when being refitted after the rebuild, something that is getting more common with engine of these age now. So last month another £1k was spent which I could have done with out a Christmas time :mad:. But my brother has said he'd help out and buy me a dyno session for Xmas, but I won't be going yet as we'll also be taking his MX5 once the custom turbo conversion is finished, (he's hoping for ~300bhp). So hopefully in a few months I'll be able to answer my own question that I started this thread to find out. :D

Fingers crossed. ;)
 

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Brian,

Cheers for your input, its greatly appreciated. I am not sure though if you were referring to my spec with your comments,


Not at all Scott
My comments were not about any specific car especially yours which is still one of my favourite road 32s

Its so easy to be clever with hindsight about the spec someone could or should have chosen and that inconvinience money always pays a part.

We all think we have got the spec right when we do it . I can think of a couple of things I should have done and couple I didnt even think of. (and that was after hours of discussion with Rob) when my engine was done.
So I am now "stuck" with my spec as well which although good isnt what I would do if I had to do it again (gulp)


Re performance
All engines are different and one well put together with spot on map can easily put a higher spec one to shame. (And any built by ron will be in this catogary)
If hes happy with the motor then I certainly would be .

I may in fact also be able to contribute to the thread soon as my 32 will be finished .
Then we can find out what figure the thread starts from as the car will be totally stock inc exhaust.
 

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Then we can find out what figure the thread starts from as the car will be totally stock inc exhaust.
That would be very interesting Brian.

Maybe you should start a weep-steak thread.

My money is on 312 bhp. ;)
 
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