cossie51

As above has anyone fitted one of the new Garrett G25-550 or 660 turbos on a YB engine yet as I have killed my T34 on my car running it on its limits.
my mapper use to swear by the BW EFR turbos but after mapping a few none YB engines on the new Garrett G25 turbos he thinks it would work well on my car and is suggesting we use one of these rather than the EFR turbo.

Caddyshack

See what Mark Shead thinks.

i think Cossiedave May have tried one.

cossie51

Has Mark shead run one to compair it to the EFR then ?
Im looking for first hand experience of this turbo from someone who has seen the results..

turbotrev

Mark will say use an EFR turbo

Cheers Paul

cossiedave

iTrader: (1)

Not me mate

cossie51

Looks like I'm going to be the first to try a G25 series turbo on a yb then.
I have spoken to my mapper today and given him permission to order it ready to fit once the tubular manifold is made..
Let's hope it's as good as he tells me or it could be an expensive mistake!

turbotrev

Will be interesting to hear your results, keep us posted.
What power are you aiming for?

Cheers Paul

Caddyshack

Sorry, thought you had one.

how are you doing? Have you got the torque back yet and what’s the alloy block latest?

cossie51

I'm not chasing numbers and don't really care what It comes out at.

Im after the drive ability and having the power and torque where it's needed which my mapper tells me I will have with this turbo !

cossiedave

iTrader: (1)

Alloy block is getting there just pistons and rods now is 577bl not anoth lol

turbotrev

I hear ya but if you don’t have a rough power figure in mind how can you spec the engine and turbo?
that makes no sense?

Who is your mapper?

Cheer Paul

cossie51

Paul it makes perfect sense ! Plus it's a turbo and manifold upgrade not an engine build.
If you can have 600+ bhp but it drives like crap and you have to fight for traction in every gear, what's the point ?
By mapping it for drive ability you can use the power it has which makes for a quicker road car.
No point in having more power than you can put on the ground and I'm not interested in bragging rights down the pub of how much power my car has !

Mapper is Grant baker of GB Enterprises Ltd.

c20tbo

iTrader: (1)

Im sure my mate has used one of the new Garrett turbo's and gave it a really good review, that was in a 2wd saph

cossie51

Cheers for that , mine is a 2WD SAPPHIRE.

Will find out if I've made the right choice once it's all done.

Adam-M

Would be interested to hear why your mapper prefers the new Garret to an equivalent sized efr

visa_broke

interested to hear how you get on

turbotrev

Im not saying you have to have 600hp plus and chase numbers I’m just saying when choosing a turbo you need to know roughly what kinda power your aiming/specced for.

Im guessing your engine is almost standard?

If you’ve been maxing out a t34 your probably around the 400hp area, so you may not be wanting to fit say a 550hp rated turbo to your engine?

Mark Shead saw a nice 500hp to a semi standard engine on a 7064 recently so will be interesting to see if the g25 is as good as that is....

Not heard of Grant Baker before either, I look forward to your findings...

Cheers Paul

Caddyshack

What are the diff ratios like on the 2WD saphs? Some of the Cossies were geared for nearly 190mph and they become a bit more lively with a more suitable ratio which I think makes the gears feel a little closer too.

cossie51

They had a 3.62 CWP in them from factory but mine is now on a 3.9 cwp and plated diff.
it accelerates quicker than before but 70mph is now 3.5k rpm.

markk

iTrader: (2)

The new G series look to be a great spec. The blade design on the turbine is where Garrett had been so far behind for many years. The GT series was just a change to the compressor wheel really in a vane attempt to re find lost ground. The totally new frame G series have bot new turbine and compressors.
Again re-using the Ti-Al (titanium alumnide) or Mar-M materials for the high temp ranges where efficiency and reliability needs to meet. Of course BW were there first in the EFR series but there has been other manufacturers who have used this technology for years. The MHI series had the TI-Al materials in the 90's, Holset had the turbine efficiency in the 90's, combined together MHI and Holset had great journal offers in the mid to late 2000's. It was just Garrett who kept trying to resurrect the old T series in one guise or another.
Having not tested one yet, but I do feel that the G series will be up there with the EFR. Garrett had no reason not to be.

cossie51

My crank and rods are standard but pistons have been changed for pocketed ones and head has been ported and polished and bigger inlet cam plus a few other bolt on bits and pieces.
Unrestricted inlet meant 23psi peak holding 21psi which made 425.6bhp but turbo couldn't flow anymore.
The budget for a few upgrades got a bit out of hand last year so had to draw the line and as it was making over 400 bhp decided to leave the turbo until it started to fail.

i was happy with the power it had so told Grant to just make sure it drives as well if not better than with the T34, if it comes back with more power which I already know it will then it's a bonus. Wasn't bothered about the numbers just how it put the power down.

Adam-M

425 out of a t34 running 23psi sounds optimistic

cossie51

Not if you understand how air flow and pressure work !

standard inlet use to give 32 psi. With the larger inlet you flow the same amount of air but can't built up the pressure due to no restrictions. The T34 couldn't physically flow more pressure due to it being maxed out.

smiley

205 block?

cossie51

No 200 block !

smiley

Nice !!!

Will P

The G25 is a really good turbo, it's transient response is noticeably different to the older GT units. It won't make the headline figure of '550 bhp' in the real world, but high 400's are achievable.

cossie51

From that comment I'm guessing you have tried one ?
the one ordered for my car is the G25-660. Not going to push it hard as current bottom end spec wouldn't take it but wanted the potential for the future.

scoooby slayer

iTrader: (4)

425 hp with a t34 at 21 psi is physically impossible lol

Adam-M

My thoughts exactly, maybe if it was high comp with a mega ported head running race fuel lol

cossie51

Less restriction = more air flow at lower pressure.

its not down to the pressure of boost that makes the power, it's the amount of air volume you can get in to the engine !

scoooby slayer

iTrader: (4)

A t34 flat out cannot flow enough air to make 425 hp that's the whole point, unless you've got a modded one ?

cossie51

Dyno graph shows the figures and as far as I know the turbo is a standard T34/63. This was running it on its limit as it couldn't make anymore boost.

Adam-M

Sorry looking at wrong bit

stevieturbo

Dynojets would be higher reading than some others.

Although numbers largely irrelevant, they're all different. How it performs is what matters.

scoooby slayer

iTrader: (4)

Interesting it's more than I'm aware one can flow, has the car done any 1/4 mile or timed 30-130 mph runs ?

scoooby slayer

iTrader: (4)

I agree Steve that's why I always do timed runs before and after to see the real world gain Vs Dyno plots

But if the Dyno is correct I'm struggling to get my head around how a t34 can physically flow enough to support 425 hp

stevieturbo

Although the graph does seem to show a nice spread of power

Rsmat

iTrader: (2)

I'll just leave this here ..

scoooby slayer

iTrader: (4)

I remember when stu did that I started The thread iirc