XNWRX

I'm currently looking for the best turbo replacement on STi7 (currently VF35). I would like it to be direct bolt on without any adaptation.

I was thinking about the PE 1820 but having a look at its flow map below :

http://cherrypicker.tripod.com/turboupgradeforvg30dett/id6.html

this turbo seems to be not very efficient above 1 bar (15 PSI)which means that mid-range torque won't be very high. Even at the red-line, it's not good for more than 1 bar.

Has anybody got a best idea knowing I'm looking for high mid-range torque and high rev HP (let's say about 1.4 bar @ 4000RPM and 1.2 bar @ 6000RPM with high air flow) ?

Thanks


[Edited by XNWRX - 12/19/2003 10:40:38 AM]

Misha

APS SR40?


[Edited by Misha - 12/19/2003 11:27:05 AM]

Andy.F

TD05/06-20G ? 400+ top end with no loss of midrange (assumes supporting mods)

Andy

XNWRX

Hummm :-)
I love that APS SR40. What a wonderfull Sumo, direct bolt-on

http://www.airpowersystems.com.au/wrx/aps_turbo_technical.htm

XNWRX

Andy, I think that the 20G is not direct replacement. Some adaptations must be done. Am I right ?

Having a look at the APS SR40 turbo and their exhaust systems, it seems that their exhaust down-pipe can not be fitted to their turbo because of wastegate/turbine separation !!!!! That's strange.

Does a magnex 3" to 2.5" down-pipe will fit ?

john banks

Can't think what adaptations you would need for a 20G on an STi, should bolt on.

Look for multiple results on similar specs of vehicle to your own.

Don't believe all the marketing material and colourful graphs as the results to support them can be thin on the ground.

IMHO avoid underperforming VF turbine wheel hybrids and go for a Mitsubishi or Garrett turbine wheel for a substantial upgrade on the OEM turbo. Others will disagree on this. They will also disagree with my preference that for a nice road car that is actually a performance upgrade in the real world that you should be able to get full boost at least as early as half the RPM at which you make peak power. Otherwise you are making an unfriendly road car, you may not mind, but your performance will suffer, proper midrange torque is king. Quick throttle response in lower gears comes a lot later than where a turbo makes 1 bar boost in 4th or 5th gear.

XNWRX

OK John, Andy, you convinced me for the TD06-20G but :

- will it really outperform the VF35 ?
(remember I'm currently running my VF35 at 1.6bar @ 3300RPM for max torque of 490Nm @ 3800RPM and 1.2 bar @ 6000RPM for 350 HP. I would like to run the VF30 at a lower boost in the mid randge, and still 1,2 bar @ 6000RPM for, I hope, more than 380 HP) ?

- where can I buy one at a good price ?
(I know you have good contact with some guys who can provide me one, but I'm leaving in France. You know I'm oftenly comming over around Manchester, Leeds, Lincoln and also Bury-St Edmonds/Cambridge)

cheers

[Edited by XNWRX - 12/20/2003 3:54:31 PM]

STi M'8

Hey !!! XN ******

Me think you're planning to kick my ***, mate

john banks

Best results on TD05/06-20G are about 100 BHP ahead of the VF35 on the same rollers and same octane.

I would suggest you get andyf9000@hotmail.com to supply you a turbo as he is the one that first popularised this turbo on Subaru engines, and his turbos have been impeccably reliable in use and are well priced, as well as delivering a consistent 400+ BHP with FMIC & headers and correct mapping on pump fuel at 1.4-1.45 bar boost.

beryllium

hi XN
you are planing less than 44" at la chatre 4.
i am planing less than 45" with Andy 's TD05.16Ghttp://www.scoobynet.co.uk/bbs/images/icons/icon7.gif

beryllium

hi XN
you are planing less than 44" at la chatre 4.
i am planing less than 45" with Andy 's TD05.16G

XNWRX

Thanks John, I will email andy and let you know...

Hi Gérald...you are a much better driver than I am...so I'm trying to get the best of my car to fill the gap ;-)

Beryllium...let me guess who you are...Hervé ? can't see who else it could be from Nîmes France...no way, you'll always be ahead of me whatever I can change on my car : GT Turbo are unbeatable :-)

The Fixer

XN WRX, I would be interested to see your results with the Andy F TD05/06 20G on the STi7 so I can compare results withe Lateral MD321 on my STi 8.

Let me know how you get on?

Conrad

XNWRX

No prob conrad, as soon as I'll have made the conversion, I will let you know.

Denmark

iTrader: (2)

The only problem is that you are not going to get that big midrange nm,as you cant give it over 1,3bar,becourse of the compressorsurge.

On mine at 1,45bar it will make compressorsurge from 4000-5000rpm,
So Andy how far away is the fix with that cover you are testing

Skassa

Andy.F

XNWRX you have mail.

Skassa, you should be making approx the same torque at that boost
(490nm = 355lb-ft) The difference being that the 20g will hold the torque higher up the rpm range.
AlanG is prepared to further test the ported cover although he is already making over 350lb-ft at 1.4 bar, I will publish any findings

Andy

XNWRX

John,
I've got into contact with Andy. I have questions :

Andy told me that the TD05/06-20G won't be direct replacement if the car has the tumble generator valve inlet manifold. I'm sure that the STi7 has no TGV as only the WRX01/02 has, but what about the inlet manifold ? Is it the same as the WRX's one ?

and what about the downpipe ? mine has no inlet for the turbo's wasdtegate outlet (just as the stock downpipe is). Won't it be a problem as I saw that it will be for the APS SR40 ?

john banks

If the wastegate gases are restricted it could encourage boost creep.

AFAIK there should be no fitting problems on STi7 as there are no TGV's to my knowledge.

XNWRX

Good, thanks John. I do not have any boost creep with my current VF35. My exhaust pipe is 2.5" only ;-)
And if I see any boost creep, I'll buy a scoobysport or a vishnu 3" to 2.5" downpipe (dual-pipe).
Andy, I think I'll place an order very soon :-) Just email me how to proceed


[Edited by XNWRX - 12/21/2003 6:57:21 PM]

STi M'8

Xavier,
I'm afraid compressor surge in the midrange will give you some disapointing results.
Are you planning to run a programable ECU or still use your WP ?

Note I will be in Paris from Monday to Wednesday

Cheers

PS : I guess beryllium is better known as gécé8.

EMS

Badly mapped VF35......

One of the fastest MY99 overhere in Holland does have a VF35. In real world a car with TD05 20G (with about 30 HP more!) is only able to beat him when he REALY uses the gearbox. Start @ 3000 RPM and the VF35 car is GONE!

I could be a different story on the 1/4 mile, when you can start at high revs and keep the revs within the powerband. Could also be a different story on a 2.5.

If you want big HP (and not too bad spool up), the TD05 20G is a good choice. If you want (quite) immediate throttle response, keep the 35! (I couldn't find another 340 HP turbo with that quick boost build up when the throttle is floored)

P.S. I don't like turbo's that are on boost when the corner is finished..... (that is why I want to use a Twin-scroll setup on a 2.5 in my car )

Mark.



[Edited by EMS - 12/21/2003 8:19:45 PM]

Andy.F

Sti M8 - not sure what you mean by "disapointing results." Have you run one of these turbos yourself ?
They do need to be mapped by an experienced tuner for best results. 1 bar boost from 3100rpm with 380+ lb-ft and 440 bhp is possible if using octane booster

Andy

The Fixer

XNWRX, I can also confirm there are no TGV in the STi 7 just as John B said. Not sure whether the downpipe you have will fit the TD05/06 20G, perhaps Andy can comment on whether it uses a VF series exhaust housing or something different?

Conrad

[Edited by RSVR Racer - 12/21/2003 9:16:09 PM]

XNWRX

Mark, no problem about turbo spool-up. I have my own electronic for fuel and boost controller and, for example, I manage to get 1.6 bar at 3200/3300RPM in 5th with the VF35 without boost spike...not so bad isn't it ?
I wan't to keep good torque in the mid-range and increase HP close to the red-line. I'm confident in andy's developpements on the TD05/06-20G.

Gérald (MI-8), I'll still use my WP and be sure I won't be disappointed ;-) I'll be with you on Monday night for a pizza ;-)

Thanks Conrad, the only question was wether the STi7 was having the same inlet manifold (without the TVG) than the WRX01/02 or not.

[Edited by XNWRX - 12/21/2003 10:09:40 PM]

beryllium

Hi guys
XNWRX is an electronic génius.
really

XNWRX

Thanks Gérald (Beryllium)...but your are a Genious as well regarding software...you still haven't sold any WPSM in the UK ?

beryllium

Hi XN
i sell nothing,i only purchase.

bebeu

XNWRX, you should install the biggest one in order to follow french GT m8

hi all french owners.

john banks

Mark (EMS), I agree with you, except we were talking peak power figures being up to 100 BHP apart - this is where this came from:

Best 20G result at Star on ordinary fuel is 415 BHP (Alan G). Best VF35 (with TMIC, but AVCS) is 318 BHP, best VF23 is 323 BHP. These are about 10% less than you might see on some other rollers where 340-350 BHP might be commonplace on the VF35, but so would I expect 440-450 on the 20G? So is it unfair to say there is up to about 100 BHP difference? This is using the extra boost potential of the 20G not running it at the same boost as the VF35 which is a bit pointless.