Subaru Impreza STI - Track progress
#61
i need to see about a stronger 6speed with dccd also.
none of the 2.5's were strong out of the box.
Speak to Alyn at AS Performance* re building a strong one. He does all sorts of kit and machine work for Subarus including CDB inserts, 14mm stud and rear thrust conversions along with all the choices for internals and ancilliaries.
Failing that try Paul Finch. He's also on here and has a great reputation.
*No, i'm not sponsored by Alyn!
Speak to Alyn at AS Performance* re building a strong one. He does all sorts of kit and machine work for Subarus including CDB inserts, 14mm stud and rear thrust conversions along with all the choices for internals and ancilliaries.
Failing that try Paul Finch. He's also on here and has a great reputation.
*No, i'm not sponsored by Alyn!
#62
@DDS789 your turbo, would you know roughly how big the exhaust side is on it in comparison to a vf24? Speaking to craig i think i have a turbo idea to try that will give power but also minimal lag- vf24 exhast billet on ball bearing and 50mm compressor. wtih this ill do a venturi uppipe to aid flow and gas speed. ££850
basically I believe mine isn't far from this spec
http://www.bptstore.com/Subaru-WRXST...rger_p_23.html
Although there power estimate is a little higher than what mine is so maybe slightly smaller housings
#63
my worry is the small exhaust side trying to drive a large compressor but back in the 5gt turbo days i done similar and ensured i had plenty of energy going to the exhaust turbine and on ball bearing it was ok. you probably already have but with this spec id say venturi uppipe and probably headers will benfit
Last edited by GT_MAXER; 02 December 2020 at 11:53 AM.
#65
not much of an update but here goes-
Turbo has been changed-
VF35 exhaust with 30mm wastegate, 48mm extended tip compressor wheel in modifiied housing, step gap rings and uprated actuator. As im still standard engine i have it setup 1.5bar and will probably run 1.4 on the big track sessions. i get 1.5bar mid revs and it does tail off at about 1.45bar high rev range. (some work to be done here on duty and potentiall the 'venturi' uppipe i got made.
New headers as old ones had a crack so thought id change and 3 port up pipe that i had custom reduced gradually to match the turbo intake (pipe reduces from approx 6cm on the intake to about 4.5on outlet turbo side).
Rear ARB is now on the hardest setting, i tested this friday on the track and it has made a small difference, the next mod is the front caster mod (potentially with a 3-4mm plate put in there also. I just need to source the right longer bolts with correct thread pitch to have the plate installed).
Track test on Friday wasnt great, my AFRs were around 9-10 and i couldnt map out so i knew i had an exhaust side leak ( when i got home i found one on the uppipe joint and one on the downpipe joint to the turbo) this must have had a massive impact on performance and potentially some spool, running this rich must kill power.
Turbo has been changed-
VF35 exhaust with 30mm wastegate, 48mm extended tip compressor wheel in modifiied housing, step gap rings and uprated actuator. As im still standard engine i have it setup 1.5bar and will probably run 1.4 on the big track sessions. i get 1.5bar mid revs and it does tail off at about 1.45bar high rev range. (some work to be done here on duty and potentiall the 'venturi' uppipe i got made.
New headers as old ones had a crack so thought id change and 3 port up pipe that i had custom reduced gradually to match the turbo intake (pipe reduces from approx 6cm on the intake to about 4.5on outlet turbo side).
Rear ARB is now on the hardest setting, i tested this friday on the track and it has made a small difference, the next mod is the front caster mod (potentially with a 3-4mm plate put in there also. I just need to source the right longer bolts with correct thread pitch to have the plate installed).
Track test on Friday wasnt great, my AFRs were around 9-10 and i couldnt map out so i knew i had an exhaust side leak ( when i got home i found one on the uppipe joint and one on the downpipe joint to the turbo) this must have had a massive impact on performance and potentially some spool, running this rich must kill power.
#66
Looking good mate
Be interesting to see the results of the turbo
What suspension are you running?
If coil overs you can switch the top plates round from left to right so the camber adjusts for caster and camber diagonally
Be interesting to see the results of the turbo
What suspension are you running?
If coil overs you can switch the top plates round from left to right so the camber adjusts for caster and camber diagonally
#67
hi, they are tein superstreets or something like that. so just put the left on the right and right on the left and rotate the bottom to suit?
I might just do the caster mod first as i feel thats all i really need now and some camber.
might go another shakedown tomorrow on track as ive the fueling sorted now with airleak on exhaust side.
I might just do the caster mod first as i feel thats all i really need now and some camber.
might go another shakedown tomorrow on track as ive the fueling sorted now with airleak on exhaust side.
The following users liked this post:
#70
G
#73
Famous last words as they say but to be fair Mr. Subaru did build an ok engine, for a 1998 standard 'soft' engine and still the same clutch i have to say im suprised it still goes ok! Especially since ive done all the mapping and small mods!!!!
Kirkistown on Sunday i arrived without laptop charged and hadnt time before going there to setup my fueling so i was running 12AFR throught he rev range ( i always want to run 11 up to 6800 were i lower to 10.8ish. But for the first 2 sessions i was still giving it a good blast apart from both straights were i didnt rev out fully or go flat to keep the load down. @plexo lent me his laptop, downloaded my ESL software and we plugged in to allow me to quickly give it alot more fuel and lower boost to be safe. This helped but i also found an annoying uppipe leak which impacted AFRS also and boost so i was down on power again due to this fooking uppipe, new bolts ordered!
So the day went well and the car performed well, engine lived its life in the 5500-7500 rev range during the day, EGT's seems to stay around 800-900 on a hard thrashing. Geometry changes have worked so far and i feel i now have a good base after i went agressive 3.5camber on front and a caster mod with 4minutes toe out. Whiteline ARBs seems to work well, rear may be too hard on full hard setting if its a wet day we will see. Swirl pot works well, i can run to almost empty now without issue (as i found out as my fuel gauge has stopped working). Brakes are amazing and are actually showing the weakness now of the tyres on hard braking due to the tyre ground coverage.
I can be more agressive in all corners but for now im still adjusting to new settings on the car, Deptors i can probably got another 4-5mph faster and hairpin i will start using 2nd to see if that helps. 1.06.20 lap time still and from harrys laptimer i am faster in the corners and out of them but down on straightline speed due the boost leak i think.
Next mods will again hope to make it slightly faster, nothing drastic i enjoy the small incremental changes plus i think the front needs PPF from following so many cars the front is like a war zone with tyre marks, stone chips and the remains of R888s.
Kirkistown on Sunday i arrived without laptop charged and hadnt time before going there to setup my fueling so i was running 12AFR throught he rev range ( i always want to run 11 up to 6800 were i lower to 10.8ish. But for the first 2 sessions i was still giving it a good blast apart from both straights were i didnt rev out fully or go flat to keep the load down. @plexo lent me his laptop, downloaded my ESL software and we plugged in to allow me to quickly give it alot more fuel and lower boost to be safe. This helped but i also found an annoying uppipe leak which impacted AFRS also and boost so i was down on power again due to this fooking uppipe, new bolts ordered!
So the day went well and the car performed well, engine lived its life in the 5500-7500 rev range during the day, EGT's seems to stay around 800-900 on a hard thrashing. Geometry changes have worked so far and i feel i now have a good base after i went agressive 3.5camber on front and a caster mod with 4minutes toe out. Whiteline ARBs seems to work well, rear may be too hard on full hard setting if its a wet day we will see. Swirl pot works well, i can run to almost empty now without issue (as i found out as my fuel gauge has stopped working). Brakes are amazing and are actually showing the weakness now of the tyres on hard braking due to the tyre ground coverage.
I can be more agressive in all corners but for now im still adjusting to new settings on the car, Deptors i can probably got another 4-5mph faster and hairpin i will start using 2nd to see if that helps. 1.06.20 lap time still and from harrys laptimer i am faster in the corners and out of them but down on straightline speed due the boost leak i think.
Next mods will again hope to make it slightly faster, nothing drastic i enjoy the small incremental changes plus i think the front needs PPF from following so many cars the front is like a war zone with tyre marks, stone chips and the remains of R888s.
Thread
Thread Starter
Forum
Replies
Last Post
SumoPower
Trader Announcements
0
11 February 2016 11:47 AM