Realistic Td05 20g power
 

I have seen lots of varying power claims for this turbo with supporting mods and diff fuels used.

Basically for those people who use this turbo or tune it is capable of real 380bhp with supporting mods and optimax fuel with no octane booster/additives etc. What boost pressures would you use to achieve such a bhp output and what kind of lbs/ft would you achieve

Thankyou.

P.S I have searched and the 18g look like it may do it but it may not be a 100% sure thing.

380 - 400 should be seen with supporting mods with the 20g.

I have the 18g on a Newage and I'm sure that I'm running in the region of 380 following my remap (plus ported headers; wrapped decat 3" exhaust system; fuel pump etc)

Run max boost of 1.55..............

I decided on the 18g for its better mid range. The 20g would be better for the top end but "on road" I felt the smaller unit would suit my needs better.

Pretty sure Ninnybobs runs over 400 bhp on the 18g on his bugeye.

Mine made 383bhp and 340+lb ft at 1.49 bar on a STi 4 using BP ultimate obviously i have all supporting mods in place.








Did i mention it's for sale could save yourself a few quid ;):)

My original thread regarding which turbo to plum for might help mate

https://www.scoobynet.com/td05-18g-v-t519542.html

Note AndyF's post/ graph on page one provides a useful comparison between the 2.

HTH

Thanks for the replys, i dont mind 340-350lbs ft but with a 7800rpm rev limit i feel the 20g running 1.5bar right through if i can avoid surge is my best bet. It feels like my vf34 is running out of puff above 7000rpm (340bhp 340lbs/ft 23psi) the 20g might just fill the gap above this point.

I'd expect the VF34 to have run out of puff before the 7K revs..............

Even with the 18G I rarely rev above 6300. Just no point. The 20G will have a better pull at the top end no doubt about that but I was put off slightly by the stories of boost creep etc on that particular unit.

I'm satisfied with my choice but still wonder what the 20G would have been like. On a seperate note the bigger turbo will be more useful if you have further plans to mod in the future?

The 18g by the looks of it really suits the 7000-7200rpm cars, the 20g really looks like the better choice for a car with 7500rpm-8000rpm rev range. If it can be made to avoid surge and be fully spooled by 4000rpm on a 7800-8000rpm rev range car it just might be the better choice of the 2 for me.

A 20g with a good set up should be making 1bar by 3000-3300 and full boost by just after 4000 rpm. but it does require some careful mapping to prevent surge in the mid range not using a large diameter inlet pipe helps to control compressor surge.

I'd have to try a car that spools a 20g on a 2.0l by 3k rpm (1bar)!

F

I reckon 1 bar by 3600-3700rpm and fully spooled by 4100rpm.

Yes:

20g on Sti v3 given 407 bhp @ Well Lane and a more believable 380 at Powerstation on Optimax and NF
Will spool quite low down, runs 1.6 bar at 5000K and keep on delivering to about 7500 @ 1.3/1.4
No surge
Horrendous consumption when using it.

Looking to try the 18g this Xmas for better drivability/mid range.

The 20g is good, you need to drive in the boost zone ina focused kind of way.

Get it right and the car is ballistic.

No vids this time 'cause Floyd will shout at me! :D
Graham

You still got the 407/380 bit in ;) I'm not sure why you keep posting those figures because everyone must surely know them by now :p

F

The 18g Andy F fitted did quite well. Heres what he said on his site.

AFP 5-18 turbo was fitted to our MY03 WRX demo car and after a few wastegate and map adjustments, power climbed to 378bhp and torque was 365lbft (still on sti8 tmic) Full boost from 3200rpm right to the 7000 rev limit. This is how they should have come from the factory !

my old 18g was really on song right through the range, didnt run out of puff at all and we dropped the limit to 7750.

Floyd: Sorry, just answering the original question, but it shows how some get different results, and to be fair to me i have couched that with the Powerstation RR which i believe 'more' than Well Lane.

Will be interesting to see the difference of the 20g verses the 18g with nothing else changed other than a re-mapping by AndyF in the spring.
Measuring the difference on a hill climb and not a RR that is!

Graham.

Graham : Your comparative figures will be interesting.

Generally I think an 18G is a 360 bhp turbo and the TD05-06 20G in like for like situations is a 380 bhp turbo.
My 95 WRX Wagon was producing 385 bhp on Optimax plus NF in every day trim running 1.55 bar on either TEG or Dastek Rollers. In fourth gear on the level road, 1 bar was 3300 rpm with 1.55 bar by 3700.
As a result of further work and the fitment of a SIGMA ECU the car is now producing 420.7 bhp on the same rollers, same fuel. 1.65 bar and a little more to come as we are only mapped to just over 6000 rpm. I regard this as a spectacular result for a TD05-06 20G and not representative. 1 bar in fourth is 31-32 with full boost of 1.65 bar by 37 but there are minor surge issues to resolve at the next mapping session.
The surge is a result of a mismatch of the 05 exhaust side with the 06 compressor side and I am looking in to a possible resolution of this deficiency.

The "deficiency" is that the TD05 exhaust wheel, spools the 20G compressor wheel too quickly for a 2.0lt engine.

The effect is the 20G compressor wheel flows more air than the engine can consume, and you get a pressure build up ahead of the turbo, causing the turbo to stall, or surge.

http://www.turbobygarrett.com/turbob...r/faqs.html#t9

The only way to cure this on a specific turbo, is to reduce its efficiency.

This can be done by either running less boost at the point of surge, or by reducing the amount of air the turbo can flow, by resticting the intake.

One common mistake is to over size the intake pipe, with one of the large bore silicon versions.


Mark.