turbo sizing

[stacy]

Hi all, just a few questions on turbo sizing for a silver top 20 valve engine, it will be run in rwd i have some supercharged pistons and im leaning towards a t28 or t25, im not looking for huge power as the car is fairly light and id like to keep it reasonably streetable is this turbo choice worth while or should i look at some thing else, cheers

[whynot]

Cant say much about those turbos but I have a td05 16g on my silver top and it seems to be a good match. I have about 3psi by 3400rpm and full boost is before 4500.

There is also an on line calculator. Squirrel turbo calculator I think it is called.that may give you an indication of which turbo is a good choice.

[strx7]

a VF24 or VF23 from a late 90's STi would fit the bill nicely

[~SlideWays~]

a VF24 or VF23 from a late 90's STi would fit the bill nicely

Back in the day, 'flygt4' had one of these along with the 8.0:1 pistons (ST 20v head) and it was very laggy.

I've used a BB T28 from an S15 and it spooled so well that there was no real kick in the pants. That made 150kw @ 13psi limited by 365cc injectors. Still with 8:1 gze pistons and big port 16v.

I then used 8.9:1 gze pistons and a much bigger t3/04e and while it took a bit to spool, it was still perfectly drivable and could easily keep it on boost. with 200kw+ (that was with smallport 16v head)

Compression and IGN timing made a huge difference to spool. I don't have any experience with 20v heads but they should be better than the bigport 16v they were just too big for bottom end response, even with TVIS.

Also don't forget there are many variations of both T25 and T28's. I've got an old T25 with the huge 0.8 A/R exhaust housing which was too laggy.

[Dell'Orto]

Yup was not a good match for the motor really, it had a TD05.16g prior to the VF turbo and by all accounts was much nicer to drive. VF23 gave it a crazy top end charge though! If I kept it I was thinking of going to a GT28RS...ataI used one in his ae92 to very good effect

[~SlideWays~]

TBH I'd be looking at a TD05 16g, very robust turbo's and easy to source.

[KinLoud]

go for the 8.9 supercharged pistons
cheap from Mark (see toyota sponsor section)

[Crucible]

The AE101 Levin I owned had td05h and It went very well, not too laggy or too responsive. My mate has the same turbo on his Ae92 and it has noticeable differance in response.

The gt28-60 I put on my car before I sold it was near perfect, id use the same turbo again if i ever turbo another 4a. Think the hot side was around .48 was such a better car to drive compared to the old t3/4 .70 lag dog!

[Crucible]

Yup was not a good match for the motor really, it had a TD05.16g prior to the VF turbo and by all accounts was much nicer to drive. VF23 gave it a crazy top end charge though! If I kept it I was thinking of going to a GT28RS...ataI used one in his ae92 to very good effect

Ha yeah i drove that once, was laggy but that bb turbo kicked in hard once it come on.

[iOnic]

Get a TD05HR-16G6-9.8T and build a proper twin scroll manifold + 8.9 GZE pistons.

Even better if you can get the TD05HRA-16G6-9.8T

[Dell'Orto]

Yup was not a good match for the motor really, it had a TD05.16g prior to the VF turbo and by all accounts was much nicer to drive. VF23 gave it a crazy top end charge though! If I kept it I was thinking of going to a GT28RS...ataI used one in his ae92 to very good effect

Ha yeah i drove that once, was laggy but that bb turbo kicked in hard once it come on.

Yeah it was amusing to drive...Putting foot down at 100k in 5th would do nothing. Grab 3rd and stand on it would be 140k almost immediately

[strx7]

Back in the day, 'flygt4' had one of these along with the 8.0:1 pistons (ST 20v head) and it was very laggy.

Which one? they are different turbos. A 23 is a comprimise between spool and top end. where as a 24 has the smaller exhaust side and offers better low down punch.

[Dell'Orto]

Was a VF23

[thegreatestben]

Get a TD05HR-16G6-9.8T and build a proper twin scroll manifold + 8.9 GZE pistons.

Even better if you can get the TD05HRA-16G6-9.8T

Yeah I enjoyed a td05hr on my 7agte. Full boost achieved at 3500rpm (20psi) wheeee...

[evil_si]

Most fun turboed fwd 4age I've done was with a master power mp28, .48 hotside,
Excellent street car, power when you want it

I can do a New masterpower turbo and manifold from $1650

[stacy]

cool this is what im after useable information of people that have experience, the engine will be rebuilt and the pistons and rods are from an ae101 supercharged model and i think they are 8.5 to 1, im looking at hopefully 200hp at the wheels the vehicle is a mk1 escort, is this hp target realistic? cheers

[Grrrrrrr!]

200hp is not going to be a problem. There are several around running double that.

http://forums.toyspeed.org.nz/viewtopic.php?t=77200 for one

[thegreatestben]

cool this is what im after useable information of people that have experience, the engine will be rebuilt and the pistons and rods are from an ae101 supercharged model and i think they are 8.5 to 1, im looking at hopefully 200hp at the wheels the vehicle is a mk1 escort, is this hp target realistic? cheers

200hp really shouldn't be a problem at all

[Dell'Orto]

^Though 7AGTE. Still, 200kw isn't really a major from a 4AGTE, and I think a responsive 250hp is totally doable.

[iOnic]

For that sorta power (200hp) I wouldn't even bother with GZE internals. I'd leave it high comp and run an S13 SR T25G or a S15 BB T28 at most. TD05 is nice but that's really a 300+ turbo so response will never be as good as it could be on a 200hp setup. I'm a strong believer in running the smallest turbo that will get to your power goals without choking the engine up top and having as high comp as you can get away with for response and fuel economy.