Internal vs External gated GT30's
13-03-2008, 05:05 PM
#42
Happily retired
So Mike...
What you are saying is Garrett (honeywell) who have a multi million pound development budget and probably some seriously clever engineers have not been able to better their design for a 500 bhp ish turbo since about 1980????
Even though there have been vast improvements in materials and computer aided design since?
If a GT isn't better what the hell were Garrett playing at all those years??
As a final point, GT30/35s are now down to about £900 due to the weak dollar. I've never seen a new T4 for that little money.
What you are saying is Garrett (honeywell) who have a multi million pound development budget and probably some seriously clever engineers have not been able to better their design for a 500 bhp ish turbo since about 1980????
Even though there have been vast improvements in materials and computer aided design since?
If a GT isn't better what the hell were Garrett playing at all those years??
As a final point, GT30/35s are now down to about £900 due to the weak dollar. I've never seen a new T4 for that little money.
. If anyone uses a t4 over GT30 correctly specced they are bonkers completely bonkers its called progress. Dont bother to reply Euan it also applies to you.
13-03-2008, 05:06 PM
#43
So Mike...
What you are saying is Garrett (honeywell) who have a multi million pound development budget and probably some seriously clever engineers have not been able to better their design for a 500 bhp ish turbo since about 1980????
Even though there have been vast improvements in materials and computer aided design since?
If a GT isn't better what the hell were Garrett playing at all those years??
As a final point, GT30/35s are now down to about £900 due to the weak dollar. I've never seen a new T4 for that little money.
What you are saying is Garrett (honeywell) who have a multi million pound development budget and probably some seriously clever engineers have not been able to better their design for a 500 bhp ish turbo since about 1980????
Even though there have been vast improvements in materials and computer aided design since?
If a GT isn't better what the hell were Garrett playing at all those years??
As a final point, GT30/35s are now down to about £900 due to the weak dollar. I've never seen a new T4 for that little money.
At the end of the day, it makes no odds to me, as I could supply a GT30 just as readily as the T4s, I just prefer to sell things I believe in, rather than compromise.
Rod,
Instead of slinging mud (I thought you were a factual person
), why not compare the compressor maps 
.I take it you have tested a T4 roller bearing turbo to be able to say it is no good compared to a GT30?
Last edited by Mike Rainbird; 13-03-2008 at 05:09 PM.
13-03-2008, 05:11 PM
#44
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as far as whats a better turbo i have no clue maybe the GT30 is but from what figures i have seen with my own eyes and on here and in car im happy with the 80's Dinosaur for my current spec....
13-03-2008, 05:35 PM
#45
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Just came across this thread....
Now Im no expert and I can only repeat what someone with ALOT of knowledge has told me( as is the case with most people on here)
The T4 compressor map is VERY good and the turbo that Mike quotes as flowing 48 pounds foot of air is actualy rated ALOT higher than that on the compressor map. ( i have read these maps with my own eyes, again unlike most people who just quote what they have heard).
The only place where a GT turbo scores over a T4 is effecinecy at certain points nearing the end of the comp map.
There are so many questions asked on this tread its hard to answer them but I will try.
Rod...do you reall think Alan would stick with a T4 if he thought he could pick up a GT30 and get better results?
Its my mission to get some folks off here out in my car this summer to prove the improvemnts we have made are NOT mickey mouse and are infact cold hard facts.
Can anyone show me a 2 litre cossie that has more power than mine below 4k? On any turbo?
Now Im no expert and I can only repeat what someone with ALOT of knowledge has told me( as is the case with most people on here)
The T4 compressor map is VERY good and the turbo that Mike quotes as flowing 48 pounds foot of air is actualy rated ALOT higher than that on the compressor map. ( i have read these maps with my own eyes, again unlike most people who just quote what they have heard).
The only place where a GT turbo scores over a T4 is effecinecy at certain points nearing the end of the comp map.
There are so many questions asked on this tread its hard to answer them but I will try.
Rod...do you reall think Alan would stick with a T4 if he thought he could pick up a GT30 and get better results?
Its my mission to get some folks off here out in my car this summer to prove the improvemnts we have made are NOT mickey mouse and are infact cold hard facts.
Can anyone show me a 2 litre cossie that has more power than mine below 4k? On any turbo?
Last edited by rapidcossie; 13-03-2008 at 05:36 PM.
13-03-2008, 05:35 PM
#46
hi peeps
i dont know what to say on this subject but my first impressions of the gt30 on my car is great it's an interal wastegate version
i like the way it makes postive boost at low rpm even tho it's not alot it makes my engine feel like high comp as it pulls so easy low down
i have never had an external because i wasn't chasing bhp figures , all i wanted was a bit more top end power without the lag and this gt30 it has gave me that
i couldn't be botherd about another exhaust for the screamer pipe extra noise and might not pass track noise .
I think it's the best substitute for a t34 with .63 as mine makes boost quicker than the t34 and makes more power after 6,500 k thats all i wanted
i would say that my engine has about 400+bhp with it on genuinely , i wont know untill i have it live mapped
this turbo was a straight bolt on with a few mods to the 2wd head
as for my engine spec i couldn't tell you what spec it is even if i wanted too
compression i dont know cams i know .....ported head unsure
my gt30 is a turbo dynamics supplyed and fitted by martin
im well chuffed with it
Paul if you was looking for over 500bhp you would be better off with the 2wd mainifold
marco
i dont know what to say on this subject but my first impressions of the gt30 on my car is great it's an interal wastegate version
i like the way it makes postive boost at low rpm even tho it's not alot it makes my engine feel like high comp as it pulls so easy low down
i have never had an external because i wasn't chasing bhp figures , all i wanted was a bit more top end power without the lag and this gt30 it has gave me that
i couldn't be botherd about another exhaust for the screamer pipe extra noise and might not pass track noise .
I think it's the best substitute for a t34 with .63 as mine makes boost quicker than the t34 and makes more power after 6,500 k thats all i wanted
i would say that my engine has about 400+bhp with it on genuinely , i wont know untill i have it live mapped
this turbo was a straight bolt on with a few mods to the 2wd head
as for my engine spec i couldn't tell you what spec it is even if i wanted too
compression i dont know cams i know .....ported head unsure
my gt30 is a turbo dynamics supplyed and fitted by martin
im well chuffed with it
Paul if you was looking for over 500bhp you would be better off with the 2wd mainifold
marco
Last edited by marco polo; 13-03-2008 at 05:36 PM.
13-03-2008, 05:44 PM
#49
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In regards to the exhaust manifold I wouldn't want over 500bhp so would the 4x4 manifold be ok/response any better/worst
Spool up is my main concern not outright power so If the GT30 spools quicker then that would straight away be my preference over the T4
Spool up is my main concern not outright power so If the GT30 spools quicker then that would straight away be my preference over the T4
13-03-2008, 05:50 PM
#51
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Would they be willing to post it up? or could you post it up?
It would just be interesting to show the two compressor maps side by side (one super dooper T4 and one properly spec'ed GT30).
It would just be interesting to show the two compressor maps side by side (one super dooper T4 and one properly spec'ed GT30).
13-03-2008, 05:55 PM
#53
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Mikes car is the one for the T4 and lee "porkie" has a GT30 on his engine witch is pretty sorted engine aswell
or you can wiat untill my engine and Kelvins are done in the next few months and probebly get a go in both at a track day or somthing
13-03-2008, 07:41 PM
#56
in that case the 4wd manifold will be ok and it will spool up quicker than your exhisting t38 .. full boost might be the same as t38 (3.200rpm kicks like a mule trows you back in the seat .. well in a 2wd anyway )
you have a t38 on your car so you would know the differenace if there was any it's hard to describe something if people have not experianced it
i found out what caused the miss fire the dizzy cap was fooked cracked
marco
Last edited by marco polo; 13-03-2008 at 07:47 PM.
13-03-2008, 07:53 PM
#57
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Porkies is on 3.9 aswell Benji.
Paul, i believe you are aswell now arnt you?
mine shouldnt be far away from being on the road, but knowing how quick Ben works he will possibly be on the road before mine - but the offer is there if you ever wish to paul.
Paul, i believe you are aswell now arnt you?
mine shouldnt be far away from being on the road, but knowing how quick Ben works he will possibly be on the road before mine - but the offer is there if you ever wish to paul.
13-03-2008, 10:50 PM
#58
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I will be on 3.9 as the rear ATB diff is and the gearbox has just has its step off gears done.
I'm pretty sold on the GT30 so we'll have to see
...guys I hope to get mine back on the road for central day
I'm pretty sold on the GT30 so we'll have to see
...guys I hope to get mine back on the road for central day
13-03-2008, 11:22 PM
#61
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mike isn't the weak point on GT series turbo's
the bearing cartridge?
i believe it is!
so if this has been used to BB the T4 then
its now as fragile as the GT's imo!
????
the bearing cartridge?
i believe it is!
so if this has been used to BB the T4 then
its now as fragile as the GT's imo!
????
13-03-2008, 11:46 PM
#65
And i'd hazard a guess that even a few T3 equipped cars would have more power below 4k even though they would be weezing like an old man reading a porno by 5k.
Lee
14-03-2008, 12:36 AM
#66
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One comparison on the same rollers for you
dingy - on T35 63
euan - on hooky home mod T4
MikeR - on standard T4
Dingy 3000 = 192, 3500 = 248, 4000 = 275, 4500 = 295
Euan 3000 = 170, 3500 = 256, 4000 = 290, 4500 = 355
MikeR 3000 = 68, 3500 = 123, 4000 = 199, 4500 = 253
All at wheels
dingy - on T35 63
euan - on hooky home mod T4
MikeR - on standard T4
Dingy 3000 = 192, 3500 = 248, 4000 = 275, 4500 = 295
Euan 3000 = 170, 3500 = 256, 4000 = 290, 4500 = 355
MikeR 3000 = 68, 3500 = 123, 4000 = 199, 4500 = 253
All at wheels
Last edited by Mike Rainbird; 14-03-2008 at 08:48 AM. Reason: To include MikeRs figures
14-03-2008, 08:50 AM
#67
Chip,
I don't think Alan would allow it, as he has spent a long while hunting down the compressor map for a T4 for his own comparisons (you try and find one).
Look at my thread in the Resto section to see the cartridge used - the shaft is still more substantial than the GT range.
I don't think Alan would allow it, as he has spent a long while hunting down the compressor map for a T4 for his own comparisons (you try and find one
).Look at my thread in the Resto section to see the cartridge used - the shaft is still more substantial than the GT range.
Last edited by Mike Rainbird; 14-03-2008 at 08:51 AM.
14-03-2008, 09:02 AM
#70
You can see how much better the roller-bearing T4 is than a standard T4 from Dumped's figures (where I added in my old Sapphire's run) - the only thing we are missing is a GT30
.However, I think you have to admit, that is VERY impressive for a shonky "prehistoric" T4
.
14-03-2008, 09:05 AM
#72
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For 500-550bhp I got recomended a GT3082, internaly gated, using ATP ultimate internal wastegate. Should be able to tell you how it works in a month or so :-D
14-03-2008, 11:42 AM
#77
PassionFord Post Troll
So there is no compressor map available for the cossie T4?
Only the opinion of one guy who has supposedly seen one?
How can a fair technical comparison with a GT series be made. It can't.
Also don't forget that the improved spool up of the GT is not all down to the RR core. It will probably have improved designed wheels that are more effecient across a wider range of airflows. The new wheels and rotating assembly will probably have a lower moment of inertia.
I wonder what a garret engineer would say if you asked him what was better, a T4 or a GT?
Only the opinion of one guy who has supposedly seen one?
How can a fair technical comparison with a GT series be made. It can't.
Also don't forget that the improved spool up of the GT is not all down to the RR core. It will probably have improved designed wheels that are more effecient across a wider range of airflows. The new wheels and rotating assembly will probably have a lower moment of inertia.
I wonder what a garret engineer would say if you asked him what was better, a T4 or a GT?
14-03-2008, 11:47 AM
#78
So there is no compressor map available for the cossie T4?
Only the opinion of one guy who has supposedly seen one?
How can a fair technical comparison with a GT series be made. It can't.
Also don't forget that the improved spool up of the GT is not all down to the RR core. It will probably have improved designed wheels that are more effecient across a wider range of airflows. The new wheels and rotating assembly will probably have a lower moment of inertia.
I wonder what a garret engineer would say if you asked him what was better, a T4 or a GT?
Only the opinion of one guy who has supposedly seen one?
How can a fair technical comparison with a GT series be made. It can't.
Also don't forget that the improved spool up of the GT is not all down to the RR core. It will probably have improved designed wheels that are more effecient across a wider range of airflows. The new wheels and rotating assembly will probably have a lower moment of inertia.
I wonder what a garret engineer would say if you asked him what was better, a T4 or a GT?
14-03-2008, 11:49 AM
#79
PassionFord Post Troll
To prove my point about the improved wheel design over the T4 being partially responsable for the quick spool up and not just the BB cartridge see below taken from the Garrett website:
"New compressor and turbine wheel blade designs have improved the overall efficiency of both sides of the turbocharger.
The result: the engine spools up to boost quicker and reduces losses in the engine system (i.e. your engine does not have to work as hard for the same boost level).
GT products use the latest aerodynamics"
"New compressor and turbine wheel blade designs have improved the overall efficiency of both sides of the turbocharger.
The result: the engine spools up to boost quicker and reduces losses in the engine system (i.e. your engine does not have to work as hard for the same boost level).
GT products use the latest aerodynamics"
14-03-2008, 12:08 PM
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The comparison above is still apples and pears. Euan's has had a lot of work on it to mitigate the restrictions, maybe a gt30 would be even better on it 
Comparing mike's which is higher compression ratio, milder cams etc etc whole different comparison. Dingy's was even higher cr.
Why do people get so wrapped up in saying their way is best on the internet? I used to do this and still dont understand the want for boasting rights. If you find something that works good for you and you are happy to tell others do so, if not dont. If your business/livelyhood is based around optimising cars etc it might be quite obvious why you do not release all your homework.
Why you would say people have "supposedly" seen a map, are you calling them lying cunts?
Net can be an odd place.
Comparing mike's which is higher compression ratio, milder cams etc etc whole different comparison. Dingy's was even higher cr.Why do people get so wrapped up in saying their way is best on the internet? I used to do this and still dont understand the want for boasting rights. If you find something that works good for you and you are happy to tell others do so, if not dont. If your business/livelyhood is based around optimising cars etc it might be quite obvious why you do not release all your homework.
Why you would say people have "supposedly" seen a map, are you calling them lying cunts?
Net can be an odd place.