STi 7 & 8 block strength (hypereutectic quest. inside !)
22 November 2003, 02:58 PM
#1
Scooby Regular
Thread Starter
Join Date: Feb 2003
Location: STi8 G spec (400+hp)
Posts: 179
Likes: 0
Received 0 Likes
on
0 Posts
Hi there,
I know some people in here are already tuning 2.5L USDM short blocks, but I'm still looking forward to 2.0L performance
My STi8 is actually fitted with a custom 4' to 3' bell mount type decat dp, 3' straight line, NGK Platinum 7 and a -sonic- Forge dump vlv.
After multiple set-ups to get the boost curve I was looking for, playing around with restrictors, differents "in line" pipe junctions btw T and solenoid, boost creep, etc... I finally gave up and let the Apexi AVC-R take the boost control.
Obviously, the boost creep issue is still there but I never get more than 1.05 @ 6000, quite under my target, so I let it be.
With acurate monitoring, focusing on injector duty and AFR, I set the following : steady 1.40b from 3000 to 5500, gradualy decreasing to 1.25b @ 6000, 1.05 @ 7000 and 1.00 @ RL...
My main concern was to keep it under 90% ID and still on the stk ECU AFR target (more or less around 10.8:1, as far as I can see).
Knock level is still very low : always positive timing, from 6 to 10, very similar to what I get with std boost level in fact (I'm always running BP RON98 unleaded).
According to many readings, most of us belive those (T6?) hypereutectic pistons can cope with high load... but does anybody know where is the heat limit ?
I have no EGT gauge, so that I don't really know where I'm standing... I don't expect to that close to the limit, but until I get one, some third party experience might be useful.
Yes, I mean bad experience...
How much boost do you mates run with this block ?
According to "reliablility" web reports, 1.40 seems to be the reasonable maximum boost, whatever rpm it is.
But some may have other experience.
This time I mean good experience (so far)
Cheers
I know some people in here are already tuning 2.5L USDM short blocks, but I'm still looking forward to 2.0L performance
My STi8 is actually fitted with a custom 4' to 3' bell mount type decat dp, 3' straight line, NGK Platinum 7 and a -sonic- Forge dump vlv.
After multiple set-ups to get the boost curve I was looking for, playing around with restrictors, differents "in line" pipe junctions btw T and solenoid, boost creep, etc... I finally gave up and let the Apexi AVC-R take the boost control.
Obviously, the boost creep issue is still there but I never get more than 1.05 @ 6000, quite under my target, so I let it be.
With acurate monitoring, focusing on injector duty and AFR, I set the following : steady 1.40b from 3000 to 5500, gradualy decreasing to 1.25b @ 6000, 1.05 @ 7000 and 1.00 @ RL...
My main concern was to keep it under 90% ID and still on the stk ECU AFR target (more or less around 10.8:1, as far as I can see).
Knock level is still very low : always positive timing, from 6 to 10, very similar to what I get with std boost level in fact (I'm always running BP RON98 unleaded).
According to many readings, most of us belive those (T6?) hypereutectic pistons can cope with high load... but does anybody know where is the heat limit ?
I have no EGT gauge, so that I don't really know where I'm standing... I don't expect to that close to the limit, but until I get one, some third party experience might be useful.
Yes, I mean bad experience...
How much boost do you mates run with this block ?
According to "reliablility" web reports, 1.40 seems to be the reasonable maximum boost, whatever rpm it is.
But some may have other experience.
This time I mean good experience (so far)
Cheers
22 November 2003, 04:31 PM
#2
Scooby Regular
Join Date: Aug 2002
Posts: 912
Likes: 0
Received 0 Likes
on
0 Posts
If you can link into the diagnostice socket, you can actually read exhaust gas tempr for yourself as sensor is fitted in "uplink pipe" prior to turbo linkup.
Nominals are 670 -980 [c].
Have seen these units handling over 1.6 without problems over past 3 yrs. [maxing at 1.75 without shortening life].
Nominals are 670 -980 [c].
Have seen these units handling over 1.6 without problems over past 3 yrs. [maxing at 1.75 without shortening life].
22 November 2003, 07:07 PM
#3
Ecu Specialist
The STi's do not have an EGT probe, thats reserved for the WRX.
I would not run a std engined STi7/8 above 1.5 mid range and 1.35 held to the redline and even that would be VERY dependant on the individual car and would require a custom mapped ecu to go with it. A WRX should not exceed 1.4 mid peak and 1.3 taper to 1.2 held.
The eutectic pistons are not as strong as made out to be so be careful.
cheers
bob
I would not run a std engined STi7/8 above 1.5 mid range and 1.35 held to the redline and even that would be VERY dependant on the individual car and would require a custom mapped ecu to go with it. A WRX should not exceed 1.4 mid peak and 1.3 taper to 1.2 held.
The eutectic pistons are not as strong as made out to be so be careful.
cheers
bob
23 November 2003, 07:01 PM
#5
Scooby Regular
Thread Starter
Join Date: Feb 2003
Location: STi8 G spec (400+hp)
Posts: 179
Likes: 0
Received 0 Likes
on
0 Posts
Tanks Bob for the input...
I'm actually considering pushing one step further, let's say to a steady 1.45b (with slight overshoot) and still tapered at the top end...
RSV, how long have you been running this boost ?
I'm actually considering pushing one step further, let's say to a steady 1.45b (with slight overshoot) and still tapered at the top end...
RSV, how long have you been running this boost ?
23 November 2003, 09:55 PM
#6
Scooby Regular
Join Date: Aug 2003
Posts: 2,881
Likes: 0
Received 0 Likes
on
0 Posts
Internals should be fine upto 440~450 ish BHP, its only cars near 500 that have had problems in Auz. You'll be lucky to get anwhere near that sort of BHP on 1.5 bar. What turbo you running?
Conrad
Conrad
Trending Topics
25 November 2003, 08:42 PM
#8
Scooby Regular
Join Date: Aug 2003
Posts: 2,881
Likes: 0
Received 0 Likes
on
0 Posts
G-Force extract about 350 BHP on Standard VF35 & Top Mount With Gems @ 1.5 bar (ish). Theres no reason why you shouldn't be able to get it either on ECUTEK or GEMS.(assuming you have induction kit, performance recirc valve, full decat etc)
Conrad
Conrad
25 November 2003, 09:24 PM
#9
Scooby Regular
Thread Starter
Join Date: Feb 2003
Location: STi8 G spec (400+hp)
Posts: 179
Likes: 0
Received 0 Likes
on
0 Posts
I was on similar figures with 1.40b boost @ torque rpm and 1.35b @ max power (about 6000)... without any remap.
My opinion is that v.8 ECU 990 5512 is doing very well on RON98 and 3' full decat, as far as boost is not held to high regarding injectors duty.
My target values (top) seem to be a maximum as I get some knock going further from 4500 to 6000 (monitoring knock signal, knock correction plus some nice det cans.)
More than that, I have the impression that MAF reading is maxing out around 250g/s... can anyone confirm ?
My opinion is that v.8 ECU 990 5512 is doing very well on RON98 and 3' full decat, as far as boost is not held to high regarding injectors duty.
My target values (top) seem to be a maximum as I get some knock going further from 4500 to 6000 (monitoring knock signal, knock correction plus some nice det cans.)
More than that, I have the impression that MAF reading is maxing out around 250g/s... can anyone confirm ?
Thread
Thread Starter
Forum
Replies
Last Post
Mattybr5@MB Developments
Car Parts For Sale
1
18 November 2015 07:49 AM