scoobytyson

Can anyone tell me if the md321t turbo would be to laggy on a spec c 05 model as there is not many options on a bigger twin scroll, would be looking to make around 430bhp if poss.

MrRA

You need to talk to Turbo Dynamics and Iain Litchfield. There are number of options you could take for a twin scroll that would make that power, some of which Iain tested when developing the original and MK2 T25.

Can I ask though, why are chasing a headline figure? Surely you would be better off fitting a slightly bigger twin scroll unit that would make slightly less peak power but spool much quicker and deliver better driveability.

gussy

iTrader: (2)

I asked the same question myself a while back and in the end decided to go for the latest twinscroll upgrade to be honest I found it to be a cracking bit off kit its the same turbo that is on Ians special edition so I belive,you dont lose any off the low down punch but you gain midrange top end power boosts to 1.6 bar leveling out to 1.4 on powerstations rollers gives 415 bhp/398 llbs and no lag or surge at the end off the day it makes a very very quick road car even better on track tho because of the better midrange breathing you can hold the car in gear longer without having to change up to come back down again if you know what I mean.

scoobytyson

I have been it touch with Turbo Dynamics but there price for the bigger twin scroll was well over £2000 + VAT and that would get me around 400bhp which is only 35bhp more than i have now so thought i'd be better off going for a bigger single scroll

SPEN555

I have wondered if anyone has done an MD321 in any form on the twin scroll. Changed up-pipe from twin to single of course. Would be very interesting to compare to the upgrade Gussy has above.

scoobytyson

Is your new turbo the MD366S?

MrRA

Could be done as the MK2 T25 uses a modified up pipe that goes from twin to single scroll.

Was that for a completely new unit or using yours as a trade in to do the mod work to it?

SPEN555

It is detailed here on powerstations website;

PowerStation

It is the stage 4 conversion.

As it says IHI I don't think it is an MD ???

MrRA

It is a hybridised twin scroll IHI unit with a Garret core and modfied compressor wheel.

scoobytyson

I think it was £2400+VAT for a new unit

gussy

iTrader: (2)

well it must have gone up in price from when I got mine by a hell of a lot???

LitchfieldImports

The large Twinscroll unit Powerstation sell is very similar in size/concept to what Turbo Dynamics do when they make the MD321. There are a number of options available which keep the twinscroll design. HKS also do a Turbo with their own exhaust housing.

Iain

SPEN555

Iain what options are there?

For example, it is quite easy to get 360/370bhp with essentially a decat and re-map. So for say £2k outlay you get approx 60bhp increase. Going to the next stage seems to be £3k/£4k to get 30/40bhp. Now if there was a turbo for the 2.0l twin scroll which sacrificed say 500/700rpm before coming on boost and gave a solid 430bhp and 410ft lbs+ torque and came in at circa £3k mapped now that would be a nice product (going from the 360/370bhp starting point).

ZEN Performance

What dyno did you use for the current power figure?

scoobytyson

It was on a dyno dynamics rolling road, do you think the MD321T would be to laggy?

Jolly Green Monster

iTrader: (4)

Lag as in between gearchange recovery no.. laggy as in full boost point no not really around 3700rpm. If it is a concern then consider the MD321H

Simon

scoobytyson

Would i be right in saying the 321h is good for 400bhp and the 321t around 450bhp

LitchfieldImports

Hi Damian,

The 400bhp turbo Powerstation fit produces the power at 1.4bar and could be worked harder if required. They have seen over 400bhp but most of the customers that have had it fitted use there car hard on the track so 400bhp is a nice safe number.

This turbo does not spool up much slower than standard so I'm sure their would be options of a bigger versions. I have tried a number of smaller versions. It's based on the Garrett GT30R range.

Iain

Jolly Green Monster

iTrader: (4)

on straight road fuel yes pretty much.

The H spools like a VF turbo btw....

Simon

Bob Rawle

The 'H will also do 400 bhp at 1.3/1.4 bar

bob

charlesk

Mine has , and the car hasn't lost any responce drivability either (VF28 before).

scooby-tc

iTrader: (2)

Can you get these any cheaper on an exchange basis and if so where from ?

SPEN555

Hi Iain,

Thanks for reply. I spoke to Rich about the 400bhp stage 4 conversion when I was down there. With the mods on my car he estimated it would cost circa £2.8k. So I have ummed and arred over it and I keep thinking I am paying nearly £3k for 40bhp and similar torque which then seems expensive (but extracting more and more power is )

Maybe I could have two maps, one pushing the turbo to say 430bhp and the other on the normal 400bhp. On track if my EGT's started to get too high I could come into the pits and switch to the other map and monitor as I go along?

Maybe in the interests of science Iain you should push the 2ltr twin scroll block to see what it's limits are as you know you like the track days

p.s. Enjoyed your sideways action on the handling circuit at SSO.

MrRA

I honestly couldn't tell you. As far as I am aware, Turbo Dynamics are the only company doing this sort of mod.

SPEN555

I personally would go to Powerstation rather than TD. TD will require what spec you want your turbo hybriding to. The consequences of speccing it wrong could translate into a car which on the road drives horrible. Powerstation/Litchfield have done that R&D for you and have produced some nice hybrids which suit ther car. I know Iain went through some pain to get the right turbo for the T25. It's okay when you are doing it for commercial reasons but when doing it on your own car you have to get it right first time otherwise it becomes very expensive.

All IMHO of course.

MrRA

Turbo Dynamics supply the turbos to PS AFAIK.

SPEN555

That maybe so but they supply multi-varieties to Powerstation probably running into double figures. Now some of these will have been development and turned out to be an unsuitable spec. You need to pick the right one as I can imagine TD won't be forthcoming in giving you that info and I cannot see why Powerstation would give away their R&D for free and advise you which one to choose

IYSWIM.

stevebt

iTrader: (8)

when i spoke to turbo dynamics about a larger possibly rotated twin scroll turbo or fitting a gt30r , i was told just fit the gt30r so i did

stevebt

iTrader: (8)

have you considered that if you fit this to a spec c you will have to change the downpipe and the headers an up pipe ??

LitchfieldImports

Turbo testing is expensive and often the results are disappointing dispite the best efforts to work out what is needed Not for the faint hearted.

I have recently tried a few smaller versions of the Twinscroll Garrett to find something that would spool as quickly as standard (or quicker) but give much better flow rates at higher rpm The first version simply did not work and suffered surge thoughout the rpm. This was a produced with TD's considerable experience on what should work but until you test something you never really now. However it did serve as a good marker when comparing it's performance/design with the larger 400bhp turbo that Powerstation have previously fitted. The new version seems much more promising but testing is ongoing