Is a VF23 still the turbo of choice?
08 January 2002, 12:39 PM
#1
Scooby Regular
Thread Starter
Join Date: Jun 1999
Posts: 814
Likes: 0
Received 0 Likes
on
0 Posts
I have an MY98 which has a Blitz filter, Samco inlet and intercooler hoses Forge dump valve, HKS EVC4, ported manifolds, GGR up pipe, Scoobysport down pipe and back box, Magnex centre and FSE fuel regulator.Phew! For the next step I am thinking about fitting a larger turbo which will eventually be followed by a FMIC. The question is, is the VF23 still the best compromise between performance/driveability/reliability/VFM etc? I don't really want to stretch to a hybrid because of the cost which is approximately £500 more expensive than an off the shelf VF23. Any comments?
Raymond.
Raymond.
08 January 2002, 12:49 PM
#2
Scooby Regular
Join Date: Dec 2000
Posts: 2,912
Likes: 0
Received 0 Likes
on
0 Posts
I am very happy with my VF24, it manages to put out 1.25 bar around 3400 rpm (depending on load)...I'm looking to get ~300 break with as little increase in lag as possible.
I believe the 23 isn't that much laggier, so if you're going for more power that'd be my choice.
The VF24 has an AR ratio of .63, the 23 .71 (same as the 22, but the 22 has a bigger inlet, and a different impeller).
/J
I believe the 23 isn't that much laggier, so if you're going for more power that'd be my choice.
The VF24 has an AR ratio of .63, the 23 .71 (same as the 22, but the 22 has a bigger inlet, and a different impeller).
/J
08 January 2002, 01:27 PM
#3
Scooby Regular
Join Date: Aug 1999
Posts: 1,561
Likes: 0
Received 0 Likes
on
0 Posts
VF23 is brilliant turbo. not as laggy as the VF22 which is also good by the way for UK cars. i have driven car with a VF22 which was also impressive. however if you are wanting 300bhp-320bhp there is no reason to go above a vf23.
my 2 euros worth
sam
my 2 euros worth
sam
08 January 2002, 02:09 PM
#4
VF23 is a very nice option if you don't want to go down the hybrid route 
The compressor wheel on the VF22 is, I understand weaker, than the one on the VF23, and only slightly bigger than the VF23. I beleive that a VF23 is safe for upto 1.4 bar, while a VF22 strugles to take more than 1 bar.
A VF28 exhaust housing (P18) and VF22 compressor housing with a hybrid cosworth compressor wheel makes a supurb hybrid and is safe for more boost than a stock engine can take, about 1.8 bar some I'm told...which is nice
The compressor wheel on the VF22 is, I understand weaker, than the one on the VF23, and only slightly bigger than the VF23. I beleive that a VF23 is safe for upto 1.4 bar, while a VF22 strugles to take more than 1 bar.
A VF28 exhaust housing (P18) and VF22 compressor housing with a hybrid cosworth compressor wheel makes a supurb hybrid and is safe for more boost than a stock engine can take, about 1.8 bar some I'm told...which is nice
08 January 2002, 02:22 PM
#5
Scooby Regular
Join Date: Oct 1999
Posts: 3,491
Likes: 0
Received 0 Likes
on
0 Posts
Raymond, I don't know if it's still the turbo of choice (hybrids becoming increasingly popular), but it still is a very valid choice I think.
It is a bit weaker low down, a lot stronger way up, and 300 BHP is a realistic target with them.
As I had told John Banks before, this is the boost I'm seeing in 5th gear (cold weather):
2800 RPM : 1.0 bar
3000 RPM : 1.2 bar
3100 RPM : 1.3 bar
...
5500 RPM : 1.2 bar
6000 RPM : 1.1 bar
6500 RPM : 1.0 bar
Spool up is not bad, but slower than a TD04. High end is mapped for safety and is not stretching the turbo.
You will need a fully mapable ECU though to get the full benefits, as you will have to play a bit with ignition timing low down to get it to spool up a tad quicker.
You can probably map it for more midrange grunt, but you have to start thinking about your gearbox at that point ... I preferred to stay under 270 lb/ft.
Uprated clutch is a must as well (AP Formula does nicely), as are colder spark plugs.
HTH,
Theo
It is a bit weaker low down, a lot stronger way up, and 300 BHP is a realistic target with them.
As I had told John Banks before, this is the boost I'm seeing in 5th gear (cold weather):
2800 RPM : 1.0 bar
3000 RPM : 1.2 bar
3100 RPM : 1.3 bar
...
5500 RPM : 1.2 bar
6000 RPM : 1.1 bar
6500 RPM : 1.0 bar
Spool up is not bad, but slower than a TD04. High end is mapped for safety and is not stretching the turbo.
You will need a fully mapable ECU though to get the full benefits, as you will have to play a bit with ignition timing low down to get it to spool up a tad quicker.
You can probably map it for more midrange grunt, but you have to start thinking about your gearbox at that point ... I preferred to stay under 270 lb/ft.
Uprated clutch is a must as well (AP Formula does nicely), as are colder spark plugs.
HTH,
Theo
08 January 2002, 02:50 PM
#6
Scooby Regular
Join Date: Feb 2001
Posts: 919
Likes: 0
Received 0 Likes
on
0 Posts
Theo, what exactly do you mean by "you will have to play a bit with ignition timing low down to get it to spool up a tad quicker" are you suggesting more advance and a leaner mixture on low rpm's (before 3000 rpm) ..... ?
Also are the following figures:
" 2800 RPM : 1.0 bar
3000 RPM : 1.2 bar
3100 RPM : 1.3 bar
...
5500 RPM : 1.2 bar
6000 RPM : 1.1 bar
6500 RPM : 1.0 bar "
for the IHI VF23 turbo ?????
thanx,
Carlos H.
Also are the following figures:
" 2800 RPM : 1.0 bar
3000 RPM : 1.2 bar
3100 RPM : 1.3 bar
...
5500 RPM : 1.2 bar
6000 RPM : 1.1 bar
6500 RPM : 1.0 bar "
for the IHI VF23 turbo ?????
thanx,
Carlos H.
08 January 2002, 03:05 PM
#7
Scooby Regular
Join Date: Oct 1999
Posts: 3,491
Likes: 0
Received 0 Likes
on
0 Posts
Carlos, that is exactly what we did, but again, each car/setup can be different, so I'm not suggesting others should do the same.
Mind you, this is a Unichip setup, so we advanced the ignition against what the normal ECU would give.
And yes, those numbers are for my VF23, measured last Sunday (about 2°C outside temp, 2 up in the car, after a few blasts, standard Subaru paper filter, decatted exhaust).
Mind you, this is a Unichip setup, so we advanced the ignition against what the normal ECU would give.
And yes, those numbers are for my VF23, measured last Sunday (about 2°C outside temp, 2 up in the car, after a few blasts, standard Subaru paper filter, decatted exhaust).
Trending Topics
08 January 2002, 03:18 PM
#9
Scooby Regular
Join Date: Oct 1999
Posts: 3,491
Likes: 0
Received 0 Likes
on
0 Posts
Jerry, I was pretty amazed myself ... I used my wife for datalogging I asked her to shout when the needle his "1", whilst I looked at the rev counter (and occasionally the road). Repeated the same thing for 1.1, 1.2 and 1.3 bar.
To be totally clear: the runs were started at around 2000 RPM giving it full throttle in 5th gear. I'm sure atmospheric conditions were ideal though. I'm planning to repeat this in summer.
The top end boost was not measured in 5th but in 4th gear, as otherwise my private road would have been a bit too short
I asked her to shout when the needle his "1", whilst I looked at the rev counter (and occasionally the road). Repeated the same thing for 1.1, 1.2 and 1.3 bar.To be totally clear: the runs were started at around 2000 RPM giving it full throttle in 5th gear. I'm sure atmospheric conditions were ideal though. I'm planning to repeat this in summer.
The top end boost was not measured in 5th but in 4th gear, as otherwise my private road would have been a bit too short
08 January 2002, 03:22 PM
#10
Scooby Regular
Join Date: Dec 2000
Posts: 2,912
Likes: 0
Received 0 Likes
on
0 Posts
I was out tweaking the wastegate control, and almost ended up in the ditch. Icy roads and loadsa power in 2:nd and 3:rd doesn't mix well.
I'll just have to wait until the roads dries up.
/J
Icy roads and loadsa power in 2:nd and 3:rd doesn't mix well.I'll just have to wait until the roads dries up.
/J
08 January 2002, 03:53 PM
#11
Scooby Regular
Join Date: Feb 2001
Posts: 919
Likes: 0
Received 0 Likes
on
0 Posts
Theo,
Something that seems weird to me is the fact that while I was using the stock air box with a panel filter my turbo spool time was quicker than with a cone K&N filter, although the K&N works better at higher rpms, I still think that for everyday use the std. air box still is better.
Carlos H.
Something that seems weird to me is the fact that while I was using the stock air box with a panel filter my turbo spool time was quicker than with a cone K&N filter, although the K&N works better at higher rpms, I still think that for everyday use the std. air box still is better.
Carlos H.
08 January 2002, 06:13 PM
#12
Scooby Regular
Join Date: Aug 1999
Posts: 1,561
Likes: 0
Received 0 Likes
on
0 Posts
have to agree with theo
the on the VF23 figures i was getting 1.2bar by 3200rpm but in 4th gear, and around 1.35bar by 3300rpm according to the data logs in 5th things did happen a good 200 rpm earlier.
increasing the advance did does increase you low end power for the obvious reasons and make the car feel torquier at the bottom end. but if you want to increase the turbo spool up eg between gears you would actually need to drop the advance so the unburnt fuel can spin up the turbo. at least this is how it worked for me with the link.
hybrid turbos are very good, and seem more and more popular. but is the VF28 a roller bearing turbo ? i thought it was not.
sam
the on the VF23 figures i was getting 1.2bar by 3200rpm but in 4th gear, and around 1.35bar by 3300rpm according to the data logs in 5th things did happen a good 200 rpm earlier.
increasing the advance did does increase you low end power for the obvious reasons and make the car feel torquier at the bottom end. but if you want to increase the turbo spool up eg between gears you would actually need to drop the advance so the unburnt fuel can spin up the turbo. at least this is how it worked for me with the link.
hybrid turbos are very good, and seem more and more popular. but is the VF28 a roller bearing turbo ? i thought it was not.
sam
08 January 2002, 06:34 PM
#13
Scooby Regular
Join Date: Oct 1999
Posts: 3,491
Likes: 0
Received 0 Likes
on
0 Posts
Carlos, yeah, funny one that ... I personally never fit a cone filter, and never regretted that either.
I'm sure the paper jobbie is more restrictive at higher RPM, but the turbo can easily produce the targets we set for it. Maybe the engine has to work a little harder to get there, but I doubt that it is a big deal.
As long as you use a MAF, you better stick to the standard intake system IMHO. I just change my paper thing every service.
Sam, glad to see your boost buildup was pretty much in the same area. As for gearchanges, I drove around with my dumpvalve completely blocked off for a week or so, and it really did wonders (and proved wat JF has been trying to tell us for ages), but I chickened out after a while and set it back to normal operation.
But back to the topic... I would like to hear some testimonials from people who actually fitted the hybrid turbos... Not that I'm going to change (I'm actually satisfied with the way my car runs now
), but I would like to hear if the extra oomph is really worth it, if drivability is better or worse etc... And also to see where the point of diminishing returns actually is.
I'm sure the paper jobbie is more restrictive at higher RPM, but the turbo can easily produce the targets we set for it. Maybe the engine has to work a little harder to get there, but I doubt that it is a big deal.
As long as you use a MAF, you better stick to the standard intake system IMHO. I just change my paper thing every service.
Sam, glad to see your boost buildup was pretty much in the same area. As for gearchanges, I drove around with my dumpvalve completely blocked off for a week or so, and it really did wonders (and proved wat JF has been trying to tell us for ages), but I chickened out after a while and set it back to normal operation.
But back to the topic... I would like to hear some testimonials from people who actually fitted the hybrid turbos... Not that I'm going to change (I'm actually satisfied with the way my car runs now
), but I would like to hear if the extra oomph is really worth it, if drivability is better or worse etc... And also to see where the point of diminishing returns actually is.
08 January 2002, 10:07 PM
#17
Scooby Regular
Join Date: Aug 1999
Posts: 1,561
Likes: 0
Received 0 Likes
on
0 Posts
yeah Jerry
doing the internals is good but on it is own does not achieve anything. so you will get new interenals, FMIC and up the boost, eh.....ah but you won't get more than 320 bhp this way.... turbo is too small. so you change the turbo or otherwise why the hell did you go for the internals in the first place. good one eh..... hold on a second my exhaust system is now too small to i better get a 3" all the way now, oops here we go again . now i have got a car that produces 350-360bhp, only to realise that there is no chance in hell the gearbox and clutch will last, so you blow another 4000 grand on a dog gear box and a paddle clutch, ooops
and you end up with a car that is a pig to drive in around town, a car that is a complete ******* to fix if anything goes wrong, and it will be few years old by the time, and you will be able sell for only 1/3 of what you have paid for if you are lucky.
just call me a pessimist
sam
doing the internals is good but on it is own does not achieve anything. so you will get new interenals, FMIC and up the boost, eh.....ah but you won't get more than 320 bhp this way.... turbo is too small. so you change the turbo or otherwise why the hell did you go for the internals in the first place. good one eh
..... hold on a second my exhaust system is now too small to i better get a 3" all the way now, oops here we go again . now i have got a car that produces 350-360bhp, only to realise that there is no chance in hell the gearbox and clutch will last, so you blow another 4000 grand on a dog gear box and a paddle clutch, ooops and you end up with a car that is a pig to drive in around town, a car that is a complete ******* to fix if anything goes wrong, and it will be few years old by the time, and you will be able sell for only 1/3 of what you have paid for if you are lucky.
just call me a pessimist
sam
09 January 2002, 08:01 AM
#18
Scooby Regular
Join Date: Dec 2000
Posts: 2,912
Likes: 0
Received 0 Likes
on
0 Posts
Sam...stop it, yer starting to sound like me mother.
a, A dogbox is so
AND it'll let u do those 6k drops.
b, A real car should make lots and lots of sound.
c, Comfort...wassat...?
d, There's always the possibility of keeping an everyday arsehauler.
How interesting would a fully specced car be....is there anyone out there with all the goodies?
/J
a, A dogbox is so
AND it'll let u do those 6k drops.b, A real car should make lots and lots of sound.
c, Comfort...wassat...?
d, There's always the possibility of keeping an everyday arsehauler.
How interesting would a fully specced car be....is there anyone out there with all the goodies?
/J
09 January 2002, 07:32 PM
#21
Scooby Regular
Thread Starter
Join Date: Jun 1999
Posts: 814
Likes: 0
Received 0 Likes
on
0 Posts
Sam,
Would that little birdy be called Kevin?? According to Training WRX the standard ECU should be OK with the VF23 so I was going to suck it and see. Also, Nito is running an HKS monster turbo and FMIC with the standard ECU - are you saying that it definitely won't work? The problem, as usual, is getting the ECU tweaked. The only 4wd dyno is at Star (ignoring AVA for the moment) and I think that they only tweak VWs etc. I don't want to start fiddling with a Link myself the way you did!!
Alan - Am I missing a story here? Do tell..........
Raymond.
Would that little birdy be called Kevin?? According to Training WRX the standard ECU should be OK with the VF23 so I was going to suck it and see. Also, Nito is running an HKS monster turbo and FMIC with the standard ECU - are you saying that it definitely won't work? The problem, as usual, is getting the ECU tweaked. The only 4wd dyno is at Star (ignoring AVA for the moment) and I think that they only tweak VWs etc. I don't want to start fiddling with a Link myself the way you did!!
Alan - Am I missing a story here? Do tell..........
Raymond.
09 January 2002, 07:35 PM
#22
Scooby Regular
Join Date: Dec 2000
Posts: 2,912
Likes: 0
Received 0 Likes
on
0 Posts
I do think Nito runs an EBC to control boost though...the main concern is lean running, with high EGT's and possible detting as a result....and in worst case damaged pistons/turbo.
Besides...you won't see much benefit of more air if you don't put more fuel in it...
/J
Besides...you won't see much benefit of more air if you don't put more fuel in it...
/J
09 January 2002, 08:49 PM
#23
Scooby Regular
Join Date: Aug 1999
Posts: 1,561
Likes: 0
Received 0 Likes
on
0 Posts
THE ecu itself should be ok but it is the boost that will become really out of the ecu's reach.
basically the TD04L and the VF23 are completely different. couple of way to go around it, either by fitting an Electronic boost controller. or you can get rid of the soleniod which is what is causing the problem and fit a Dawe type device to control the boost to the desired level. obvsiously you won't be able to run that much more boost than standard because the fuel cut limit thing as well.
so you can either go for the VF23 with a link, unichip etc...
or the other way would be with boost controller, apex i is the best around just now and then get fuel controller apexi also do some really cool ones
sam
basically the TD04L and the VF23 are completely different. couple of way to go around it, either by fitting an Electronic boost controller. or you can get rid of the soleniod which is what is causing the problem and fit a Dawe type device to control the boost to the desired level. obvsiously you won't be able to run that much more boost than standard because the fuel cut limit thing as well.
so you can either go for the VF23 with a link, unichip etc...
or the other way would be with boost controller, apex i is the best around just now and then get fuel controller apexi also do some really cool ones
sam
10 January 2002, 12:43 AM
#24
Alan, as I understand it the standard VF22 compressor wheel is made of chocolate coated cheese, ie it's chuffing weak
My hybrid though is anything but weak, the cossie wheel is far stronger, and with the P18 exhaust housing the spooling up is very good (obvioulsy it's no TD04) It will also hold boost right through to the red line.
Checking my datalog from my last run on the rollers I got the following boost response:
3000rpm - 0.5bar
3250rpm - 1.1 bar
3500rpm - 1.25 bar
3750rpm - 1.25 bar
4000rpm - 1.25 bar
and so on to the red line at 7000rpm!
Now I'm running a link ecu with max boost set at 1.25 bar, and it's trying to control boost from 3100rpm.
What I don't know about my hybrid is how much air it is flowing, it would seem that unless my MAP sensor and Boost gauge are both wrong (and wrong to exactly the same tune!) I'm potentially producing more power with 1.25 bar than a similar car, with a similar map, fitted with a VF23 running 1.4 bar...Peak power (I'm not going to say the figure on here for various reasons )was at 6800, but it wasn't the true peak. The general consensus is that the true power peak with this turbo should be around 7500rpm which is interesting, especially as I plan to be running around 1.5 bar sometime soon with and engine that can rev to 8500
My hybrid though is anything but weak, the cossie wheel is far stronger, and with the P18 exhaust housing the spooling up is very good (obvioulsy it's no TD04) It will also hold boost right through to the red line.
Checking my datalog from my last run on the rollers I got the following boost response:
3000rpm - 0.5bar
3250rpm - 1.1 bar
3500rpm - 1.25 bar
3750rpm - 1.25 bar
4000rpm - 1.25 bar
and so on to the red line at 7000rpm!
Now I'm running a link ecu with max boost set at 1.25 bar, and it's trying to control boost from 3100rpm.
What I don't know about my hybrid is how much air it is flowing, it would seem that unless my MAP sensor and Boost gauge are both wrong (and wrong to exactly the same tune!) I'm potentially producing more power with 1.25 bar than a similar car, with a similar map, fitted with a VF23 running 1.4 bar...Peak power (I'm not going to say the figure on here for various reasons
)was at 6800, but it wasn't the true peak. The general consensus is that the true power peak with this turbo should be around 7500rpm which is interesting, especially as I plan to be running around 1.5 bar sometime soon with and engine that can rev to 8500
10 January 2002, 12:57 AM
#25
Scooby Regular
Join Date: Jul 2000
Location: Glasgow
Posts: 3,040
Likes: 0
Received 0 Likes
on
0 Posts
Hi Tim
Interesting figures you give there.
My own VF22 has no probs holding boost targets to my redline which is 6500. No point in going further up the rpm's when there's no more power to be had.
But you've got me wondering now.
I have a UK car and peak power (on mine)is at 5800rpm. This to me seemed normal but am now wondering if the turbo has anything to do with this, as some (UK)cars produce their peak power at different rpm's.
I always thought max bhp at particular rpm was governed by the cams fitted.
If that is still the case, then what cams are you using to produce a peak at 6800rpm?
My boost is 1 bar at 3000 and 1.2 bar at 3300rpm with the VF22.
Haven't tried a higher boost target cause am still waiting on an FMIC to be fitted before raising the boost.
Interesting figures you give there.
My own VF22 has no probs holding boost targets to my redline which is 6500. No point in going further up the rpm's when there's no more power to be had.
But you've got me wondering now.
I have a UK car and peak power (on mine)is at 5800rpm. This to me seemed normal but am now wondering if the turbo has anything to do with this, as some (UK)cars produce their peak power at different rpm's.
I always thought max bhp at particular rpm was governed by the cams fitted.
If that is still the case, then what cams are you using to produce a peak at 6800rpm?
My boost is 1 bar at 3000 and 1.2 bar at 3300rpm with the VF22.
Haven't tried a higher boost target cause am still waiting on an FMIC to be fitted before raising the boost.
10 January 2002, 01:01 AM
#26
Scooby Regular
Join Date: Jul 2000
Location: Glasgow
Posts: 3,040
Likes: 0
Received 0 Likes
on
0 Posts
Re: VF22 compressor wheels.
I remember some time ago,there was a bad batch of VF22's made so amybe that's where the weakness thought came in to it, but, touch wood, I haven't had a problem with mine.
Oh boy am I gonna regret saying that!!!!
A
(already lookin' for a replacement turbo................)
I remember some time ago,there was a bad batch of VF22's made so amybe that's where the weakness thought came in to it, but, touch wood, I haven't had a problem with mine.
Oh boy am I gonna regret saying that!!!!
A
(already lookin' for a replacement turbo................)
11 January 2002, 12:28 AM
#27
Alan, My hybrid was spec'd to give me a power peak near the top end because I use the car on track a fair bit (although I haven't with the new set up yet) The compressor wheel that I am running is larger thana VF22 (quite a bit larger) and my exhaust housing has an enlarged wastegate button.
IMO I get the best of both worlds, reasonable spool up time and it pulls like a train to well beyond the red line.
Apart from 440cc injectors, my engine is stock 98 uk, which means that I've got really bad piston slap, and will need to replace the engine soon. I'll be building (getting built) something around an Sti 4 engine, although it will have a closed deck block, forged rods and forged pistons...plus a few other things
I've got and HKS front mount and HKS headers on the car which both effect where peak power is produced...it's nice though, but a bit of a handful in the wet
IMO I get the best of both worlds, reasonable spool up time and it pulls like a train to well beyond the red line.
Apart from 440cc injectors, my engine is stock 98 uk, which means that I've got really bad piston slap, and will need to replace the engine soon. I'll be building (getting built) something around an Sti 4 engine, although it will have a closed deck block, forged rods and forged pistons...plus a few other things
I've got and HKS front mount and HKS headers on the car which both effect where peak power is produced...it's nice though, but a bit of a handful in the wet
13 January 2002, 06:08 PM
#28
I was about to buy a VF23 from MRT, but after speaking to them I changed it to a VF30 instead.
New design, suppose to have about the same lag as a VF23, but quicker spool and flows almost like a VF22.
Will be really interesting to se how it will boost vs. the VF23
when I but a new ecu in.
New design, suppose to have about the same lag as a VF23, but quicker spool and flows almost like a VF22.
Will be really interesting to se how it will boost vs. the VF23
when I but a new ecu in
.
13 January 2002, 06:57 PM
#30
Scooby Regular
Join Date: Feb 2001
Location: Greece, previously Syd Australia
Posts: 2,833
Likes: 0
Received 0 Likes
on
0 Posts
I was told buy another tuner in OZ, (who had recommended the VF30 to me orginally and also said the above, like MRT said), that after extensive tests they found that the VF30 did not suit the cars up to MY00. It only suited the new cars because of the variable cam or valve timing. He then recommended the VF29 and that this was the turbo that was hot in OZ for the older cars at the moment. I'm not a techie so I don't really know. It is confusing.
Cheers,
Wrexy.
Cheers,
Wrexy.