Hi,

Im intrested to know what peoples Views are on what is the best Turbo for a 500/550HP Engine

we all know a T4 can make 500HP but what with Lag and boost threshold there has to be and is better turbos out there please give you views and what you think is the best turbo out at the moment

im not just talking about Garrett turbos either HKS, KKK, Turbonetics or any other you can think of

Opinions and facts wanted

 

Now this will be interseting, all the GT haters will be out..

 

i have been told a gt30 is the best 500bhp turbo there is

 

How about one of the latest ball bearing T4 options?

Also depends if you want to go down the route and minor inconvenience of an external wastegate etc.

 

Spool up times power ratings any more info?

 

was told people stay away from gt30 because they cant get them to work without surge problems on badly specced engines

 

glancy- badly specced engines and tiny exhaust housings.

on GT series turbos just pick the middle of the 3 options, the one the compressor was specced for in the first place.

 

was told that they are the best option with correct cam and head choice .i have an internal wastegate one for my escort in ma shed which a will try one day

 

Guys, you should stop using the old type turbos on your cossies...

Go ball bearing and you with be amazed!

The GT30 as proposed, if it is the garrett 3037S or 3082R or GT30R then yes i agree, is one of the best 500-550 crank ps turbos money can buy...

 

i prefere the kick up the arse u get from a T type turbo...........Mike R has different spec T4s on his website..........

 

Gatecrasher

Thats the million f***ing dollar question Ben!

Just remember to budget for a GT30, intial outlay is good until you start adding all the other gubbins needed like wastegate, wastegate manifold and the gt flange - just shy of 1800.00.......

And i'm not sure on this new roller bearing T4 either So MIGHT just got the GT30 route to save fucking around

 

I personally do not think it is wise to chose a turbo for it's "on-paper" spec. This is because quite often, the turbo has not been tested EVER on the engine it is supposed to be "the dog's danglies" for .

I have seen a couple of turbos that have been tested by Harvey that you would THINK that according to their specs "should" be the better than sliced bread , where the reality is that it falls short in actual flow due to the shape and design of the compressor wheel.

The best thing you can do is LISTEN to your tuner and go for the turbo that has been tested to the spec of engine you are wanting them to build you. Trying to pick a turbo on your own with help from "man down't pub" will be VERY hit and miss .

The only people I would EVER listen to regarding turbo choice and spec are those that have access to an engine dyno to actually TEST the flow / response and power outputs of these in the really world on a real engine.

As a prime example, the GT-K650 turbo on Andy Gallagher's Focus was supposed to be all singing and dancing compared to the T66 that WAS on it, and although it ultimately flowed a fraction more power, it lost 500rpm of boost threshold .

 

why are the gt series hated so much then? i thought they were supposed to be good.

 

I think a few people think they're quite weak and have heard a few nasty stories about them, think some have had SURGE issues with them too, i know alot of the Evo boys who have them and have NEVER had any problems at all, personal choice at the end of the day.


True what Mike says though, have a word with your builder/mapper and go from there...

 

Well Martin seems to like them on his cars, but then i guess his opinion doesnt count due to him not having a engine dyno...........

By the way i'm not biased towards him, as i may (IF PROVEN) go the T4 route off Mike R.

We need Mark S to jump in here as he'll have shit loads of Dyno data for the GT series.............

 

i would have a GT series any day, the surge issues IMO are all down to badly spec'd headwork and cams to suit the turbo flow characteristics, Its quite a commonly used turbo outside the ford scene.

Yes there is a scene outside fords.

 

Franco, i think Kev Atkins has been using the GT30 on his Evo for a good while now without any issues. Always seems to come up trumps in the time attack series aswell...

 

Agree Ryan, that's what we're saying about the turbo not suiting the headwork etc.

 

Franco,
Lee and Warren's GT35s surge their tits off and Doug's did the same (so he switched to a GT30, as he hated the GT35 THAT much), and Lee is wanting to do the same. But apart from that, your reasoning holds as much water as a sieve .

 

Dont overlook Karl Norris either as he's had lots of experiance with Garrett GT Series turbos.

He's live mapped quite a few cars on GT30's. Some of these engines are running very close to the turbo's strength limit, with huge boost figures just to see just how much punishment these turbos can take (by customers request I should add. )

 

In my opinion it is 100% crucial that you go with the turbo that your tuner suggests will work with the engine he has built you .

 

Im currently specing up a Gt30 for the Zetec enegine, totally agreee mith Mike R its improtant that you spec the turbo to the spec of the engine etc not the other way round.

I found out the hard way on the current engine, i presumed a and b will work with c, it fits so it will work.

Caused nothing but problems when mapping so had to change items.

Build the engine then spec the turbo to work best with that application.

 

Doug, what boost are you running on yours?? what power did yours make Doug?? i can't remeber reading/seeing it anywhere.

 

But would that be as much to do with the mapping? Seems some peoples headwork gets a kicking when maybe capping the boost would cure the issues.

Ps answer my bloody email from yesterday

 

2.6 BAR peak, 2.2 BAR held well it was, but I turned it down to 2.4 BAR as with the Quaife ATB front diff the car felt like a 400 BHP FWD RST on 165 wide tyres under hard acceleration

I can put up an Interpro RR graph of when it was on 2.2 BAR peak, it was over 550 BHP then.............Not been near a set of rollers for over a year, so dont know what the power/torque is at the moment.

 

I don't personally think that is the way to do it .

In MY opinion, the first thing you need to do is decide on the power you WANT to achieve. I would then chose a turbo that will either comfortably / just about achieve this - depending on how you want the car to drive. I would THEN build the engine to work with the given turbo (cams, head work etc). This way, it will be perfectly matched.

All my engines have been built this way .

 

Yes, you can map out surge, but when you have to do this all the way to 6000rpm, you know there is a mismatch of specs somewhere....

 

So your saying Lee's and Warrens do this? (Sorry i havent heard these 2 cars so can't comment).

 

I'm runnin GT35.

Doesn't surge, but am runnin a NMS base MAP @ mo & only bar boost !

Was lead to believe the surging issue's was down to Head/Cam spec too ! Mine seems to work but the timing might be well backed off ! It is laggy !

Jb

 

Mike- you can slag GT series turbos all you like, but its NOT the problem of the turbo, as in the non-cossie world everyone uses counltess GT series turbos with no issues etc.

Your valued opinion on them holds as much water as your opinion on ALS it seems

There IS more to the world than you/harvey have experienced mike

 

I don't know about Lee's, but yes, Warren's does (as I have driven it) and Ahmed had to cap the boost to this point. Even then, it LIVES on the surge line .

If Lee sees this, I'm sure he will comment. However, I know that his definitely needs the map sorting, as they keep saying that they're going to do this, but just never get round to it .

 

Mike, old skool tuner/engine builder = old skool solutions

 

so there is actually no point in using that turbo if the boost has to be capped and it lives on the surge line? Makes no sence as to why they use it in the 1st place then

 

 

Please find the point in my posts where I slag the GT turbos . I think they are GREAT turbos when they are correctly matched to an engine spec / mapped properly .

And Harvey has done LOADS of GT turboed cars . However, in back to back tests the T-series roller-bearing ones have better flow capabilities for high power cars . The GT ones are not the be-all and end-all of turbos - as I have said, you pick the turbo and then build the engine around that - not the other way round .

Doug,
I think you will find that Harvey is at the fore-front of turbo development . MY choice to go with the T4, as I wanted to retain the ALS and wanted a turbo that could take this kind of CONSTANT abuse. I don't know of ANY other engine that Harvey has built recently that has a T4 on (other than at the customer's request - as in wanting to have a cheap 500bhp spec).

 

Hence why Doug down-sized and Lee wants to.

 

So now the T4 is for Gyppo's.....................Great sales pitch Mike!

 

A road car with a mismatched big turbo on capped boost is actually horrible to drive IMO, as you've only got the real potential of that big turbo on the last 20% of the rev range.

 

I understand about the problems with using too big a turbo for the head and cam spec , would there be any problems running too small a turbo??
The engine im getting built justnow has enough head work to flow a GT35 a but due to wanting the gearbox to last untill i upgrade and already having a nearly new T38 sitting thats going on justnow.