Turbo Sizing for M30 engine

[DRIFTBOY]

I've been researching turbo charger sizes for my planned turbo conversion.

After spending hours reading stuff on the internet I am quite baffled as to what will work and what won't!

A popular turbo that I keep seeing is the Garrett T04E.
And popular spec for these appear to be A/R .63 exhaust, A/R .50 compressor with .57 trim.

I believe Toby Unna is running something similar but with .84 A/R exhaust.

Would a .63 exhaust peak too early up the rev range on an M30, or get too hot?

It seems these make good power on Cosworths and RS Turbos etc, but what about a 3.5 litre 6 cylinder engine ?

Can anyone please advise? .... Ant?

Thanks,

Martin.

[gareth]

you utter utter utter swine! i want a turbo now!
are you going to be the first to try a FI LPG conversion? i want to have a play with that at some point

[blingsta]

have you considered a Holset?? i believe the man himself might have 1 on the shelf at A-Tech !

[Kos]

holset

[Andy335Touring]

You will want one if you get a ride in Tobys car

[Colonel Sanders]

oh yeah!! a holset!!!! i hae one of those on my 325..
whats wrong with a holset kos???

[blingsta]

Yeah Kos???

[DRIFTBOY]

I've heard good things about Holset too!
Not ruling that out at all!

It's just that I was watching a brand new Garrett T04E on Ebay which sold for £127, and not too far from me.

I didn't take it because I'm not sure if .63 A/R on the exhaust is a little small for an M30! ???

I'm not planning massive boost though as my E30 is my only car (apart from the 'Maseratty' but that doesn't count - it's shit!) so I don't want it breaking things more than it already does!

Gareth - I'd love to try LPG too but I'm not wealthy enough to do turbo and LPG.
I'm not wealthy enough for just turbo - but that's what credit cards are for!

Maybe it's best I go straight to Ant!

Ant - you might get a call soon!

[Colonel Sanders]

i actually opted to go with the holset than a garret gt35 i had.. heard nothing but good bout them from the boys across the pond runninwell over 500bhp on m20s..

[gareth]

Gareth - I'd love to try LPG too but I'm not wealthy enough to do turbo and LPG.
I'm not wealthy enough for just turbo - but that's what credit cards are for!

are you wealthy enough not to do it?!!!

[DRIFTBOY]

I'm not really wealthy enough for anything much!

[gareth]

[Kos]

erel, i dont think you best positioned to comment, you knowledge is very limited in this subject

i'll answer the questionwith a question

which turbo manufacturer (sp) is...
1 most comonly seen on race cars ?
2 most commonly fitted to factory turbo cars
3 most commonly fitted to big power cosworths, evo's, skylines

garrett

they have a proven track record and are the best, their range is huges and technology the best. i know holsets can be "fun" and come in with a bang but this has is issuse.

the on boost bang will take its toll on runnng gear
they tend to have a limited power range

my choice will always be garrett, and it will be a GT roller bearing unit, almost lag free ,power and its smoth through out the rev range.

they are generaly an industrial turbo but in recent times have been working with vehicle manufacturers and working on improved street aplications. the reason they get a lot of attention is because they are cheap and readily available, and the fact they are not heard of as much gives them "kudos". any respecatable turbo builder will tell you that the best turbo's are garretts.

[Ant]

^ disagree

Garrett are approx 3 years behind holset in the design of the compressor and turbine wheels, Holset is industry standard in heavy duty applications, also come with a million mile guarantee in the OE applications, no issues with quality there.

GT series are superb turbos, the GT37 in particular is a great choice but still limited by the availability of housings and trim sizes, indeed only the OE trims are available unless you wish to use old tech TD03-4 series wheels in the modern casing, not a great idea as they are 20 years apart on design and materials technology

fo the reason I outlined above, Holset will still be the weapons of choice for some time to come, but Garrett are getting there

cost is indeed another factor, Holset in non W/G housings are 15% cheaper than the equivalent GT series, move the W/G housings and the cost are same as TBH, neither are cheap when bought outright with no exchange unit.

Not wishing to get involved in a pi$$ing contest here, but sweeping statements on whats "best" only serve to confuse imho.

Smallish turbo= Garrett
Big Snail = Holset/Schwizer/Turbonetics hybrid
Crap Turbo= Xs-Power

Only my opinion of course, and should only be taken as such.

[Scoupe]

Crap Turbo= Xs-Power

lets not even start there lol, as soon as people see the prices they might start getting ideals in their heads

[e30_Turbo]

Having had both a Garret GT and a Holset I feel I can share my findings.

The GT was much more aggressive and spooled really hard, the boost came on progressively and was very responsive in the lower rev range, it's power was low to midrange and only really struggled over 5k and 10psi. Full boost by 2k easy.
It was a T37 which was originally on a early skyline (r32) with garret internals, wheels were aprox 50mm cold side, 47 hot side. I would imagine that turbo on a M40 would have been a real monster.

Now the Holset is a totally different beast, it doesn't even spin the wheels on idea, the turbo itself won't even think about boosting until over 3k and the spool and pickup are lightening fast, not as aggressive as the GT but much more of a smack in the back of the head than a push in the back. I've seen some boost in 1st gear and 80% in 2nd but 3rd gear is where the real fun starts. Once your boosting and have the pressure up there are no limits, no matter how hard you floor it the turbo's got more, the noise is awesome and you just feel like there's more power than you could ever need.
I run mine at around 8/10 psi and it's rapido and I have run it at 20psi which was just too fast, cooked the brakes in about 5 mins!

Overall I do miss the "off the line" power of the GT but the seemingly power limit less Holset really works for me, I can drive all day without boosting at all, can plant it in 5th at 80 and see 110 come up in around 6secs (3.73 diff) or cruise @ 80mph without any tell tale signs it's boosted.

If you live in Milton Keynes then get a GT, if you live near a runway, get a Holset.

They're both great bits of kit but the important part IMO is getting the right one for you, I like having a big one, nuff said.

HTH, Mark.

[Kos]

you have some ponts there ant, but one you make i never commented on, reliability.

any turbo will be reliable as long as you look after it, i had an RS turbo which my mate had befor me and i sold it on to an other friend. same turbo on it for 6 years and 60,000 of miles, it was T3 tybrid and never had a problem with it oh an that car got driven like was stolen.

is there a turbo in the holset range like the GT roller bearings, instant throttle responce an spool up to full boost with almost no lag ?

you mentioned cost, and that will always be a factor in peoles minds, so the fact a holset is cheaper off the shelf makes it a more realistic chise to say a comparable garrett.

but hey it is new, better than buying some scrap from a scrappy's and it lasting 6 months like some people do

[e30_Turbo]

Holset HX-35 Turbocharger



Product Description

This could be the most technologically advanced bolt on turbocharger available today. Capable of producing more than 500 horsepower at the wheels and able to run in excess of 35 pounds of boost. This Holset HX-35 is the only turbocharger available with a "Map Width Enhancement" groove. This groove is machined into the inlet of the compressor housing to allow air to be fed to the second set of blades on the compressor wheel. This increases efficiency and overall air flow by more than 10%. All Holset turbochargers come standard with a 360 degree thrust bearing. This HX-35 turbocharger will bolt on to your stock manifold and downpipe without any additional modifications. This is a Direct bolt on for any 90-99 Galant VR-4, Eagle Talon, Plymouth Laser and Mitsubishi Eclipse. Oil feed and drain modifications required. Compressor housing is only available in a 4" Inlet and 2.5" Outlet. Also available with our monster 38mm internal wastegate and custom actuator (additional $150). Please email us directly for comparison pictures of the Holset vs. Garrett GT series compressor and turbine wheel.

[blingsta]

erel, i dont think you best positioned to comment, you knowledge is very limited in this subject

i'll answer the questionwith a question

which turbo manufacturer (sp) is...
1 most comonly seen on race cars ?
2 most commonly fitted to factory turbo cars
3 most commonly fitted to big power cosworths, evo's, skylines

garrett

they have a proven track record and are the best, their range is huges and technology the best. i know holsets can be "fun" and come in with a bang but this has is issuse.

the on boost bang will take its toll on runnng gear
they tend to have a limited power range

my choice will always be garrett, and it will be a GT roller bearing unit, almost lag free ,power and its smoth through out the rev range.

they are generaly an industrial turbo but in recent times have been working with vehicle manufacturers and working on improved street aplications. the reason they get a lot of attention is because they are cheap and readily available, and the fact they are not heard of as much gives them "kudos". any respecatable turbo builder will tell you that the best turbo's are garretts.

Kos, if my knowledge counts for nothing, then how about the facts above that have been pointed out to you??

everyone has their own opinions mate, and that was just a suggestion i made! and plus the big power cars your on about... whats their cylinder capacity compared to the one in question?? cosworth=2.0, skyline=2.5 and so on! your forgetting the bigger picture

[Ant]

Anyways, back on the topic @ hand

Martin, you need to size the turbo depending on where you want the boost to come in, smallish snail will add a lot of low-midrange torque but little HP up top, something the M30 doesn't suffer with is lack of bottom end shove.

To negate the torque monster effect of the smaller trim turbos you can drop the CR to effectivly move the torque and HP gain up the rev range where you want it to be, of course the N/A power is dropped and you'll need more boost to make the same figures but the curve should be just that, small snail's give a flat torque response, Rapid off the light but a real pig in the wet.

a few deciding factors.....

Where you want the unit to spool in the rev range ( load dependant but close enough for this excersise )

How much Boost you're looking to run min/max

How much space is available..... thats often the biggest factor in packaging a snail install.

What other mods are done to the engine in terms of N/A tuning alreeady in place.

stock M30 is 9:1 CR so in terms of "state of tune" for N/A its medium ( korma) for Turbo its vindaloo.

TBH, you could use a large trim T3/4 hybrid with a big A/R hot and coldside and get gains, but the main reason for some many hybrid variations being available is everyone wants something to suit them, so as usual its horses for courses.

For the M30 I'd use something like a big trim GT37( £1K approx) or a Holset HX40 ( £740 ish outright NEW + external wastegate cost) both would be superb in the app and capable of the 400HP plus range with ease.

I'll shut up now

[Kos]

erel, i dont think you best positioned to comment, you knowledge is very limited in this subject

i'll answer the questionwith a question

which turbo manufacturer (sp) is...
1 most comonly seen on race cars ?
2 most commonly fitted to factory turbo cars
3 most commonly fitted to big power cosworths, evo's, skylines

garrett

Kos, if my knowledge counts for nothing, then how about the facts above that have been pointed out to you??

everyone has their own opinions mate, and that was just a suggestion i made! and plus the big power cars your on about... whats their cylinder capacity compared to the one in question?? cosworth=2.0, skyline=2.5 and so on! your forgetting the bigger picture

but what turbo's do they use ?? i'm not discussing capacity of engines here i'm talking about proven track records of turbo units.

you answer of "holset" is child like and has no thought behind it.

any way the garrett getting its fair share of positives here

and any turbo will have to be matched to the engine its going on and what sort of power you want.

[Colonel Sanders]

if your rich, or just want the best go for the garrett, but if you want a great turbo the same as a gt for little cash go for holset!

http://www.e30tech.com/forum/search.php ... ac99312cba

search holset...


read that from e30tech many a story on holset, peppe on there is on a holset as is most of the swedes with the big power m20s, he is doin 11 sec 1/4 miles, not bad for a deisel turbo me thinks?
whats the point in spendind 1500 sponds on a turbo when you can spend a few hundered quid for a turbo that will do exactly the same job, plus for that money you can have a few extra housings to change round your application, if it goes pop, (from what i heard a garrett will go before a holset) get another cheap..
job jobbed.

[Toby_Unna]

Martin, largely by accident/good luck it seems that my turbo is pretty much spot-on for this application. running at 7psi max it starts spinning up at 2.5k as you roll the throttle on in the higher gears and wil then make full boost from 3-6k where it's just starting to feel like it's given its best.

7psi is enough too, i keep getting the urge to wind it up as everything is in place and ready, but for road use it's bloody well fast enough thank you

if you want to do everything right/properly first time (something i'm extremely bad at ), i would stay away from the XSPower stuff even though my turbo/WG/BOV have been faultless so far. Give A-Tech a call and discuss, but when my monkey metal XSPower tubby sends the compressor blades through the bonnet i'll 99% be putting a Holset on, I've heard not a bad word about them, other than from Kos who doesn't own one

[Toby_Unna]

just found this, I think this is the turbo I have...

Prod.#
RB20AV6030 T3/T4 .50 COLD .83 HOT Price
$375.00

T3/T4 .50 COLD .83 HOT
USA or INTERNATIONAL
Super Stage V WHEEL - Brand New

T3/T4 STAGE V Turbo NEW, Honda, Mitsubishi .50 .83
a.. T3 6 bolt outlet turbine housing .83 A/R
a.. 76 trim T350 turbine wheel (stage 5)
a.. T04E housing 2.5" inlet 2.5" outlet
a.. 56 trim GT40 compressor wheel 2.41/3.22 (61mm inducer) and flow 65lb/min
a.. Divided Turbo Flange


it's about 2/3 of the way down here.

http://www.ssautochrome.com/level.itml/icOid/1489