631 WHP/ 554 ft/ib WTQ, GT35R stroker!
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Evolving Member
Joined: Dec 2005
Posts: 248
Likes: 1
From: Malaysia
631 WHP/ 554 ft/ib WTQ, GT35R stroker!
We've just finished a tuning session on my Evo with a newly rebuild Magnus 2.3 stroker motor running a .82/AR GT35R and HKS 280's on C16 fuel.
The engine came out perfect as we previously had head lifting at over 32 psi and valve float with the HKS valve springs. We're now using the new Cometic Phusion head gaskets with the gas filled fire rings and its perfect , no lifting even at 35 psi. Valve float is kept in check with the Supertech singles but COULD possibly still float at that boost levels when its hot. ( happened once in between a run)
With the ignition timing set at 19 deg at 35 psi, with an A/F ratio of 12:1, the car pulled 631 WHP with a massive 554 ft/ib of WTQ on the AWD Dynojet. Full boost came in at 4500 rpm and it pulls to 7500 rpm cleanly. We tried making adjustment from the previous +2/-1 cam settings on the HKS 280's, setting it at 0/-1, the car lost 400 rpm on the spool and lost 20 ft/ib of WTQ but WHP was around the 629 mark. The stroker motor obviously didn't like the intake retarded and thus we proceeded to advance the intake to +3 leaving the exhaust at -1. Instantly she picked up another 15 ft/ib of WTQ at the same WHP and boost levels. There seems to be a slight hump at over 6000 rpm area on the graph and we wondering if its starting to choke a little bit just over at the sort of boost levels we're hitting.
We intend to run the 1 A/R housing to see if we can push a little more out of it. I was planning to run a 50 shot of nos but the motor's prone to knocking at this stage, I don't know if this due to the additional dwell time of the stroker setup at TDC.
We found out during the rebuild that the 7 bolt 4G64 diesel crank is not a hardened crank and due to time constraints did not nitride the crank. We 're just a bit worried on running nos on the motor with this crank. Anybody heard of a broken stroker crank with nos?
Am trying to post a graph but have no site to host the graph file. Any help will be appreciated.
The engine came out perfect as we previously had head lifting at over 32 psi and valve float with the HKS valve springs. We're now using the new Cometic Phusion head gaskets with the gas filled fire rings and its perfect , no lifting even at 35 psi. Valve float is kept in check with the Supertech singles but COULD possibly still float at that boost levels when its hot. ( happened once in between a run)
With the ignition timing set at 19 deg at 35 psi, with an A/F ratio of 12:1, the car pulled 631 WHP with a massive 554 ft/ib of WTQ on the AWD Dynojet. Full boost came in at 4500 rpm and it pulls to 7500 rpm cleanly. We tried making adjustment from the previous +2/-1 cam settings on the HKS 280's, setting it at 0/-1, the car lost 400 rpm on the spool and lost 20 ft/ib of WTQ but WHP was around the 629 mark. The stroker motor obviously didn't like the intake retarded and thus we proceeded to advance the intake to +3 leaving the exhaust at -1. Instantly she picked up another 15 ft/ib of WTQ at the same WHP and boost levels. There seems to be a slight hump at over 6000 rpm area on the graph and we wondering if its starting to choke a little bit just over at the sort of boost levels we're hitting.
We intend to run the 1 A/R housing to see if we can push a little more out of it. I was planning to run a 50 shot of nos but the motor's prone to knocking at this stage, I don't know if this due to the additional dwell time of the stroker setup at TDC.
We found out during the rebuild that the 7 bolt 4G64 diesel crank is not a hardened crank and due to time constraints did not nitride the crank. We 're just a bit worried on running nos on the motor with this crank. Anybody heard of a broken stroker crank with nos?
Am trying to post a graph but have no site to host the graph file. Any help will be appreciated.
Originally Posted by GTREVO
We've just finished a tuning session on my Evo with a newly rebuild Magnus 2.3 stroker motor running a .82/AR GT35R and HKS 280's on C16 fuel.
The engine came out perfect as we previously had head lifting at over 32 psi and valve float with the HKS valve springs. We're now using the new Cometic Phusion head gaskets with the gas filled fire rings and its perfect , no lifting even at 35 psi. Valve float is kept in check with the Supertech singles but COULD possibly still float at that boost levels when its hot. ( happened once in between a run)
With the ignition timing set at 19 deg at 35 psi, with an A/F ratio of 12:1, the car pulled 631 WHP with a massive 554 ft/ib of WTQ on the AWD Dynojet. Full boost came in at 4500 rpm and it pulls to 7500 rpm cleanly. We tried making adjustment from the previous +2/-1 cam settings on the HKS 280's, setting it at 0/-1, the car lost 400 rpm on the spool and lost 20 ft/ib of WTQ but WHP was around the 629 mark. The stroker motor obviously didn't like the intake retarded and thus we proceeded to advance the intake to +3 leaving the exhaust at -1. Instantly she picked up another 15 ft/ib of WTQ at the same WHP and boost levels. There seems to be a slight hump at over 6000 rpm area on the graph and we wondering if its starting to choke a little bit just over at the sort of boost levels we're hitting.
We intend to run the 1 A/R housing to see if we can push a little more out of it. I was planning to run a 50 shot of nos but the motor's prone to knocking at this stage, I don't know if this due to the additional dwell time of the stroker setup at TDC.
We found out during the rebuild that the 7 bolt 4G64 diesel crank is not a hardened crank and due to time constraints did not nitride the crank. We 're just a bit worried on running nos on the motor with this crank. Anybody heard of a broken stroker crank with nos?
Am trying to post a graph but have no site to host the graph file. Any help will be appreciated.
The engine came out perfect as we previously had head lifting at over 32 psi and valve float with the HKS valve springs. We're now using the new Cometic Phusion head gaskets with the gas filled fire rings and its perfect , no lifting even at 35 psi. Valve float is kept in check with the Supertech singles but COULD possibly still float at that boost levels when its hot. ( happened once in between a run)
With the ignition timing set at 19 deg at 35 psi, with an A/F ratio of 12:1, the car pulled 631 WHP with a massive 554 ft/ib of WTQ on the AWD Dynojet. Full boost came in at 4500 rpm and it pulls to 7500 rpm cleanly. We tried making adjustment from the previous +2/-1 cam settings on the HKS 280's, setting it at 0/-1, the car lost 400 rpm on the spool and lost 20 ft/ib of WTQ but WHP was around the 629 mark. The stroker motor obviously didn't like the intake retarded and thus we proceeded to advance the intake to +3 leaving the exhaust at -1. Instantly she picked up another 15 ft/ib of WTQ at the same WHP and boost levels. There seems to be a slight hump at over 6000 rpm area on the graph and we wondering if its starting to choke a little bit just over at the sort of boost levels we're hitting.
We intend to run the 1 A/R housing to see if we can push a little more out of it. I was planning to run a 50 shot of nos but the motor's prone to knocking at this stage, I don't know if this due to the additional dwell time of the stroker setup at TDC.
We found out during the rebuild that the 7 bolt 4G64 diesel crank is not a hardened crank and due to time constraints did not nitride the crank. We 're just a bit worried on running nos on the motor with this crank. Anybody heard of a broken stroker crank with nos?
Am trying to post a graph but have no site to host the graph file. Any help will be appreciated.
Last edited by VTECH8TR; Aug 2, 2006 at 06:57 AM.
Originally Posted by GTREVO
The stroker motor obviously didn't like the intake retarded and thus we proceeded to advance the intake to +3 leaving the exhaust at -1. Instantly she picked up another 15 ft/ib of WTQ at the same WHP and boost levels. There seems to be a slight hump at over 6000 rpm area on the graph and we wondering if its starting to choke a little bit just over at the sort of boost levels we're hitting.
I would get a eagle crank the new one they have out it's a lil better if not = to oem crank. Check out the ams site to get more info. It's only about $800 then they also have the big dog which is top of the line. You should check it out it might help. Great numbers to man. I hope your running the dual fuel pump setup with 1000cc injectors with the injector driver box. Just to insure you have all the fuel you need.
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Originally Posted by GTREVO
The engine came out perfect as we previously had head lifting at over 32 psi and valve float with the HKS valve springs. We're now using the new Cometic Phusion head gaskets with the gas filled fire rings and its perfect , no lifting even at 35 psi. Valve float is kept in check with the Supertech singles but COULD possibly still float at that boost levels when its hot. ( happened once in between a run)
Thread Starter
Evolving Member
Joined: Dec 2005
Posts: 248
Likes: 1
From: Malaysia
94AWD coupe,
I have no means of a site to post my graph but Ang Weng Yan has offered to post it up for me sometime today. Hopefully it'll be up by tomorrow.
Kevin D,
At extreme boost levels, when doing a dyno run or a quarter mile run the motor goes into misfiring mode and settles down after 2 min's or so at idle. At that very same time, the power level drops significantly. That is what valve float is. With the previous HKS valve springs, the problem is so prominent that anything above 32 psi will float the valves.
As for head lifting, there is no blown head gasket. Water from the overflow tank gets pushed out on boost at high boost levels and very little at low boost levels. When we disassembled the motor , the HKS metal head gasket showed no signs of leak or a blown syndrome. Head was slightly warped, had to re surface both the head and the block as well as trying out the new head gasket from Cometic to make it work.
Am gonna try ted B's suggestion today of advancing the exhaust cam a little to see what happens on the dyno.
I have no means of a site to post my graph but Ang Weng Yan has offered to post it up for me sometime today. Hopefully it'll be up by tomorrow.
Kevin D,
At extreme boost levels, when doing a dyno run or a quarter mile run the motor goes into misfiring mode and settles down after 2 min's or so at idle. At that very same time, the power level drops significantly. That is what valve float is. With the previous HKS valve springs, the problem is so prominent that anything above 32 psi will float the valves.
As for head lifting, there is no blown head gasket. Water from the overflow tank gets pushed out on boost at high boost levels and very little at low boost levels. When we disassembled the motor , the HKS metal head gasket showed no signs of leak or a blown syndrome. Head was slightly warped, had to re surface both the head and the block as well as trying out the new head gasket from Cometic to make it work.
Am gonna try ted B's suggestion today of advancing the exhaust cam a little to see what happens on the dyno.
