MR2 Owners Club Forum banner
1 - 20 of 25 Posts

·
Registered
Joined
·
53 Posts
Discussion Starter · #1 ·
Hi all, me again...

As many know, I have been getting almost no luck with my MR2...

Further to my last post, I found that my downpipe has a crack in it and that my o2 sensor was totally shot! I have replaced the sensor and wired it in correctly, which has removed 2 stored codes (21 and 25)

I am currently in the process of waiting for my new downpipe and a replacement turbo, which I hope to put on soon. But i want to pick some brains about the power i was seeing before...

204bhp at the flywheel at 18psi boost!?! We all know this really is not right and i am not 100% sure if it is down to the bad o2 sensor at the time or something deeper? My base timing is 10btdc and i would hope the mechanical timing is all correct, a little harder for me to check, unfortunately.

Hopefully the dyno print out shows in this thread for you all to take a look at and give opinions on!

76325
 

·
Super Moderator
91t gen5
Joined
·
6,984 Posts
The ecu ignores the oxygen sensor at wide open throttle. I would do a leak down test to confirm you don't have a blown ringland.

How are you figuring BHP? You are dynoing the engine on a stand?
 

·
Registered
Joined
·
53 Posts
Discussion Starter · #3 ·
Engine is forged rebuild with amazing compression. So i really doubt its got a blown ringland... and it is true it ignored at WOT but if it had 2 codes would the ecu not put itself into any "safe" mode at all?
 

·
Registered
Joined
·
53 Posts
Discussion Starter · #4 ·
The ecu ignores the oxygen sensor at wide open throttle. I would do a leak down test to confirm you don't have a blown ringland.

How are you figuring BHP? You are dynoing the engine on a stand?
Engine in car on a dyno mate
 

·
Super Moderator
91t gen5
Joined
·
6,984 Posts
Engine in car on a dyno mate
Then you aren't measuring BHP (brake horse power) or flywheel HP. This is WHP (wheel horse power) it'll be lower than BHP.

What generation engine and what modifications have you done to it? What is amazing compression? There is normal compression and low compression.
 

·
Registered
Joined
·
53 Posts
Discussion Starter · #6 ·
Then you aren't measuring BHP (brake horse power) or flywheel HP. This is WHP (wheel horse power) it'll be lower than BHP.

What generation engine and what modifications have you done to it? What is amazing compression? There is normal compression and low compression.
No the machine they use does a conversion from WHP either way you look at it the numbers are too low...

Forged gen2 engine with gen3 efi
CT20
540cc injectors
SMIC intercooler
Decat
Blitz nur spec exhaust
bov delete
cone filter

Compression is 175-185psi between the 4 cyls
 

·
Super Moderator
91t gen5
Joined
·
6,984 Posts
Yeah a ct20b at 18psi shouldn't be that low. If it's true that their dyno is converting to BHP which is the first I've ever heard of you're basically making stock gen2 power. Why are you replacing the turbo? The next diagnostic step I would take is a boost leak test, you could have a loose or split coupler.
 

·
Registered
Joined
·
53 Posts
Discussion Starter · #8 ·
Yeah a ct20b at 18psi shouldn't be that low. If it's true that their dyno is converting to BHP which is the first I've ever heard of you're basically making stock gen2 power. Why are you replacing the turbo? The next diagnostic step I would take is a boost leak test, you could have a loose or split coupler.
Turbo leaks oil on the turbine side and i get some blue smoke now and then on cold starts after 5min of idle. shes fine when driving however.

Boost leak i would expect to see other signs tho, rpm issues, weird vacuum numbers and boost on the boost gauge?
 

·
Registered
Joined
·
53 Posts
Discussion Starter · #9 ·
Yeah a ct20b at 18psi shouldn't be that low. If it's true that their dyno is converting to BHP which is the first I've ever heard of you're basically making stock gen2 power. Why are you replacing the turbo? The next diagnostic step I would take is a boost leak test, you could have a loose or split coupler.

176WHP was made just found it on the very bottom of my dyno sheet
 

·
Super Moderator
91t gen5
Joined
·
6,984 Posts
Turbo leaks oil on the turbine side and i get some blue smoke now and then on cold starts after 5min of idle. shes fine when driving however.

Boost leak i would expect to see other signs tho, rpm issues, weird vacuum numbers and boost on the boost gauge?
You'll never know you have a boost leak by the boost gauge. Since you're on gen3 efi you can take your cold pipe off and drive the car like normal you just won't have boost. So you can see why you won't see drivability problems from a boost leak unless it's from the intake manifold or throttle body. A vacuum/boost leak on the intake manifold or throttle body will affect any engine no matter what ecu it has.
 

·
Registered
Joined
·
53 Posts
Discussion Starter · #11 ·
You'll never know you have a boost leak by the boost gauge. Since you're on gen3 efi you can take your cold pipe off and drive the car like normal you just won't have boost. So you can see why you won't see drivability problems from a boost leak unless it's from the intake manifold or throttle body. A vacuum/boost leak on the intake manifold or throttle body will affect any engine no matter what ecu it has.
So a boost leak pre-throttle body may be stealing 90bhp from me? Seems a bit excessive, but guess I could give it a shot? ill try and find a shop that can do a test
 

·
Super Moderator
91t gen5
Joined
·
6,984 Posts
No, boost leaks anywhere in the intake will reduce power, I think I went over you a little.

Just watch this video

 

·
Registered
Joined
·
44 Posts
Does the car momentarily cut out a few times between 5k and 7k?
Do you have a new MAP sensor?
How are you controlling boost?
How are you getting Boost pressure?
 

·
Premium Member
Joined
·
13,442 Posts
Definitely double check mechanical timing. One tooth off on the timing belt could cost you quite a bit of power.
 

·
Registered
Joined
·
53 Posts
Discussion Starter · #15 ·
Does the car momentarily cut out a few times between 5k and 7k?
Do you have a new MAP sensor?
How are you controlling boost?
How are you getting Boost pressure?
No cutting out,
No new map sensor
Manual boost controller
What do you mean how am i getting boost pressure?
 

·
Registered
Joined
·
53 Posts
Discussion Starter · #16 ·
Definitely double check mechanical timing. One tooth off on the timing belt could cost you quite a bit of power.
Bit hard to check being a gen2 engine... would mean the engine mount would need to come off etc wouldn't it?
 

·
Super Moderator
91t gen5
Joined
·
6,984 Posts
Bit hard to check being a gen2 engine... would mean the engine mount would need to come off etc wouldn't it?
No difference between engine generations. Remove the valve cover and when the crank pulley is lined up at 0 degrees the cam notches should line up with the hole in the cam cap.

 

·
Premium Member
Joined
·
13,442 Posts
Bit hard to check being a gen2 engine... would mean the engine mount would need to come off etc wouldn't it?
As J.harris said, it's not too hard. You can in theory do it without even pulling the valve cover, just using the dots on the cam gears. You might need a mirror to see them.
 

·
Registered
Joined
·
53 Posts
Discussion Starter · #19 ·
As J.harris said, it's not too hard. You can in theory do it without even pulling the valve cover, just using the dots on the cam gears. You might need a mirror to see them.
Cam gears are the harder way as gen2 timing cover is a real pig to remove when in the car.
 

·
Premium Member
Joined
·
13,442 Posts
Cam gears are the harder way as gen2 timing cover is a real pig to remove when in the car.
Yeah, I know. Come to think of it, I remember modifying mine to remove the one bolt in the middle (cut that protrusion off of the plastic and capped it with a metal knock out plug). That makes it a lot easier to remove in the future. Somehow I did get it out the first time though, with it in the car. But that was a LONG time ago.
 
  • Like
Reactions: J.harris
1 - 20 of 25 Posts
Top