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Discussion Starter · #1 ·
Hello guys, I am possibly thinking of going big(ish) single instead of my origional idea of twins. I am currently toying with the idea of using a top mounted T04R to give me approx. 500fwhp. Is this a laggy setup on a 2.6 motor? I would imagine it would be a good bit slower to spool than a pair of 2530's but as long as it is not vastly slower it would not really bother me. The car is road use only.

I have already purchased kit to go the twin route and do not know if will still be able to use it with the single, namely my Power FC. Will I have to change this for a non AFM type management?

Will my 550cc injectors be too small?

Can anyone who is running a T04R let me know their supporting mods and output.

I know a T04R is quite an old unit in comparison to 2530's/GT28RS's being bush bearing instead of ball bearing but I recently saw a post that bushes where almost if not just as good as ball bearings.

What do I need to look out for?

Thanks in advance for any info.
Cheers
Ian
 

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Discussion Starter · #2 ·
I have just read most of the T04R threads in the search area including Pikeys, very informative, teach me to search first before posting.......................... Anyone else with info. of any pitfalls to be aware of using this turbo?.

Cheers
Ian
 

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Why would you want an old T04R?

A T04Z is a much better bet, or even a GT35R.

The T04R doesn't come on boost til quite high revs, and gives poor power results considering. It's not just the bearings, it is just an old design best avoided. IMO of course.
 

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The reason I went for the T04R was more cost driven than anything else. If I had the money and the time I'd have gone for a GT35R (or something a bit smaller actually like a GT3076R) and custom specced the rest of it - but as it was, the T04R complete kit came up at a price I couldnt really refuse ;)

It was:

turbo
manifold (+ needed welding up - £50)
external wastegate + mini screamer pipe
downpipe
oil feed + return (needed small brass thread adapter - £5)
turbo - intercooler hard pipe + samco + clips
turbo - AFMs hard pipe + samco + clips
Z32 AFMs
Pair of Apexi filters

For £1500. A new turbo and decent wastegate would have cost that by themselves! :)

I wouldnt say the T04R gives poor power results!! I'm running mine at 1.2bar and it's nigh on 500bhp - HKS rate it to 680bhp. Yes it has a high boost threshold, but it's just about driveable if you're prepared to rev the car to 8000rpm to get it back on boost in the next gear - something I dont have a problem with due to how Ive specced my engine :)

You can use the PowerFC / AFMs as long as you get a 2-1 pipe from AFMs to turbo. It's a GReddy item I believe.

550 injectors are good for 550bhp - personally I'd go for 700s as it gives you a better margin and a potential higher output.

HTH :)
 

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Pikey said:
I wouldnt say the T04R gives poor power results!! I'm running mine at 1.2bar and it's nigh on 500bhp - HKS rate it to 680bhp. Yes it has a high boost threshold, but it's just about driveable if you're prepared to rev the car to 8000rpm to get it back on boost in the next gear - something I dont have a problem with due to how Ive specced my engine :)

HTH :)
Don't get me wrong, an old style turbo still produces the top line figures, but in your instance, a GT30R would give you 500bhp and a boost threshold less than half the revs your T04R comes in at. In terms of driveability a T04R just doesn't have it.

The likes of T04R's and the T67, 78/88's etc are the reason people think big singles are laggy. A modern equivalent like a T04Z or GT35R will run rings around the old style dinosaurs.
 

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"GT30R would give you 500bhp and a boost threshold less than half the revs your T04R comes in at"

But a GT30R wouldn't give 680hp so the comparison is rather unfair. Boost threshold is about 500rpm earlier on the T04Z, mainly due to the compressor housing improvements. I have T04R and it's still a decent turbo. It has the same wheels as the T04Z so it isn't quite as old school as you'd think.
On HKS website they have an example graph for an RB26 T04R, 1.7bar, 670ps at 7280rpm and 707Nm at 6370rpm.
 

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Discussion Starter · #8 ·
Thanks for the advice and comments chaps. Like you Pikey, it is the cost of things that is luring me down this path........ Revving me old RB26 to 8K does not worry me too much but this sounds like that the T04R does not really come on boost till well up the revs, 5500,6000?? This would make for a pretty peaky drive having to keep it at these revs to stay on boost. Maybe a GT30R looks a better option, will have to investigate further.... hhmmm decisions, decisions. :confused:

I realise that the T04R is an older blower but it can still produce the figures, I just did not realise just how hard you would have to work the motor to get it to do it. :eek:

(Dont laugh) Been looking at some of those dubious "Chinese copy" Garrett turbos on Ebay, I realise you only get what you pay for, but £650 for a T04, top mount manifold and external wastegate delivered...................... If one goes tits up, buy two for spares..lol:) Just hw bad are they?

Cheers again
Ian
 

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Discussion Starter · #10 ·
Cheers Lightspeed, those power/torque curves dont look too bad. Do you know if that is on a standard motor?

What size injectors and boost are you using on your set up?

I am really only looing for 500fwhp, maybe a T04R is a bit on the large side for that sort of hp anyway...........

ATP sell GT30R's for quite a reasonable price.

Quick question..... what do you do with the surplus O2 sensor, I assume my PFC can bw switched to run a single sensor?? Also, would I still need to run 2x Z32 AFM's or would one manage the 500hp?

Confused
Ian
 

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If you are looking for only 500 bhp fly, single turbo is a VERY expensive way to achieve these numbers.

Kingsley have made around 480bhp fly with a set of Standard R34 turbo and a set of CAM. This will be the best setup. If you have the money, go for a set of nice stainless steel manifold, and maybe some mild head work, then I am sure you can see 500 bhp. GT-SS is the next best step, and it will see around 550 fly.

This is my graph for a T45S turbo. Basically this is so old it was replaced by the T04R. And to be honest, I don't think it is all this bad. About 520bhp hub at only 1.3 bar. This is a BIG desiel turbo that have big everything (thick shaft, etc), so it is made for extreme use and not efficency.



Full boost around 4700rpm on this map. and it make good power by then already.
 

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Oh, another thing I read up and I thought I will share:

Someone said on one of the forum I saw that he had someone with a R33 GTR using a GT30 turbo.

The problem with it is that it is too good. When it is within boost threshold, it goes from 0-18psi instantly...

This basically cause massive wheel spin as the power comes on too fast. But if you feather the throttle, then you may loose all boost and bog down with massive lag. Until it comes on full boost again and cause the wheel spin problem.

He said he actually perfer the slower turbo such as T04R and TA45s where the boost comes on more gradually...

Again, I couldn't comment on that until I actually drive a car with a GT30r or GT35r. But I guess it does have some sense in it.
 

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Once you get to 4500rpm it starts to get going, by 5500rpm you're on full boost. I have my shift light set to come on at 7700 rpm, with the PowerFC's rev limiter set at 7800, and you're back on boost in the next gear :D
 

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Cornhoolio said:
Quick question..... what do you do with the surplus O2 sensor
My downpipe has holes for both O2 sensors :)
 

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Nocturnal said:
Oh, another thing I read up and I thought I will share:

Someone said on one of the forum I saw that he had someone with a R33 GTR using a GT30 turbo.

The problem with it is that it is too good. When it is within boost threshold, it goes from 0-18psi instantly...

This basically cause massive wheel spin as the power comes on too fast. But if you feather the throttle, then you may loose all boost and bog down with massive lag. Until it comes on full boost again and cause the wheel spin problem.

He said he actually perfer the slower turbo such as T04R and TA45s where the boost comes on more gradually...

Again, I couldn't comment on that until I actually drive a car with a GT30r or GT35r. But I guess it does have some sense in it.
If its rubbish at part throttle thats a MAPPING issue (ie its only been mapped properly at full throttle, seen this done soo much, proper mapping takes all day, not an hour...).

Should be able to control it perfectly at part throttle, thats the point of a throttle, to be able to have a middle ground.
 

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Has anyone got a good site for compressor maps, I am struggling to find some maps for some of the older garret/hks units such as the T04R, T45s, T51s and T51R
 

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lightspeed said:
"sounds like that the T04R does not really come on boost till well up the revs, 5500,6000?"

More like 4500

"
Looks like this engine was fitted with some high duration cams.
Peak torque at 6.7K, and still producing good power at 8.2K. Not many would settle for this setup on a street car.

Graph doesn't quite match up with the peak torque quote at 6370RPM.
 

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T51r and 3l comes alive @ 3800 and is @ 1.2b by 4500. I'll have some graphs in a month or so.
 

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R32 Combat said:
T51r and 3l comes alive @ 3800 and is @ 1.2b by 4500. I'll have some graphs in a month or so.
Cheers Andy, do you have the A/R for your unit so I can compare it to this T51S I have, I will be pushing it with 3L too so probably a good comparison for me
 

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Discussion Starter · #20 ·
Does the extra 400cc's really make that much difference to the turbo's earlier spool even taking in to account the exhaust side of a T51R must be huge in comparison to that on a T04R.................. I dunno, is it? :chuckle:

Looking at these two turbo's in a 2.6 vs 3.0 comparison, would the larger T51R not swallow the extra air from the 3ltr engine and spool at an approx. similar point as a T04R fitted to a 2.6? (taken that both motors are running same size valves, cams, inlet and exhaust setups)

I would have thought the earlier spool would rely more on a combination of more efficient flow and extra cc's rather than just the capacity hike itself, especially when fitting a larger turbo to the larger capacity engine.

Correct or just absolute boll0x? :chuckle:

Cheers
Ian
 
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