Whats up with 2.2 stroker kits

[ChrisS]

If you pm your email address i'll send you some photos of the crank and rods.

 

[marcymarc]

If you pm your email address i'll send you some photos of the crank and rods.

Pm on its way matey

 

[stevepudney]

The biggest restriction to the SR20 is the head flow that’s why you see big HP numbers and low torque numbers. You could switch to the VVL head to get a bit better flow on the top end but still to small really.
Example the Mitsubishi 4G63 the head from 90-94 was very high flow, these motors are making the same if not more torque than HP out of the same 2L displacement 600+ no problem (race fuel of course).

The SR20DET head needs to be opened up to achieve good power and torque from being stroked. Amongst other things it would need over sized valves 1 mm and allot of work on the exhaust ports, they are way too small, that’s why we have to run big boost to get horse power. What we really need is less PSI and more volume, that would produce a more balanced torque/power curve. Also the T-25 housing is too small, T-3 would show a huge improvement in spooling and volume.

Basically if you only enlarge the displacement of the bottom end you will see larger torque figures lower in the map but you will see it drop off very fast in the top end as you max out the heads flow rate.

If you did both match an SR20 2.2 - 2.3 - 2.4lt stroker to a SR20 head that can keep up with a good high volume turbo you should see a huge improvement and more close range between torque and HP figures.

Then all you have to consider is the power train Gearbox, Diff's & Transfer box. The problem is it's all a question of ££££ and getting the balance between all the above right.

On a sensible note

So with all that in mind, the 2 ltr SR20DET engine in the GTIR will produce a reliable 400+ break as a 2ltr, and at 400+ break the GTIR becomes a VERY fast car for our British (crap) roads and with skill and if pushed will annihilate most other vehicles on those roads.

To my mind anything over 400 - 450 break in a GTIR road car becomes dangerous, as at it will start to loose traction and power in the engine is no good to anyone if you can't put it on the tarmac.

In a road car I think a power of a big stroker kit would be total waste of a huge amount of time, money and effort but in a specialised well set up competition car could be very useful.

Thought & comments

 

[ChrisS]

To my mind anything over 400 - 450 break in a GTIR road car becomes dangerous, as at it will start to loose traction and power in the engine is no good to anyone if you can't put it on the tarmac.

In a road car I think a power of a big stroker kit would be total waste of a huge amount of time, money and effort but in a specialised well set up competition car could be very useful.

Thought & comments

Mine makes approx 430ish at the fly. Dont have any real tracion probs but the sort of speeds it gets to very quickly do make it of limited use as a road car.

I have a T3 turbine aswell.

 

[marcymarc]

The biggest restriction to the SR20 is the head flow that’s why you see big HP numbers and low torque numbers. You could switch to the VVL head to get a bit better flow on the top end but still to small really.
Example the Mitsubishi 4G63 the head from 90-94 was very high flow, these motors are making the same if not more torque than HP out of the same 2L displacement 600+ no problem (race fuel of course).

The SR20DET head needs to be opened up to achieve good power and torque from being stroked. Amongst other things it would need over sized valves 1 mm and allot of work on the exhaust ports, they are way too small, that’s why we have to run big boost to get horse power. What we really need is less PSI and more volume, that would produce a more balanced torque/power curve. Also the T-25 housing is too small, T-3 would show a huge improvement in spooling and volume.

Basically if you only enlarge the displacement of the bottom end you will see larger torque figures lower in the map but you will see it drop off very fast in the top end as you max out the heads flow rate.

If you did both match an SR20 2.2 - 2.3 - 2.4lt stroker to a SR20 head that can keep up with a good high volume turbo you should see a huge improvement and more close range between torque and HP figures.

Then all you have to consider is the power train Gearbox, Diff's & Transfer box. The problem is it's all a question of ££££ and getting the balance between all the above right.

On a sensible note

So with all that in mind, the 2 ltr SR20DET engine in the GTIR will produce a reliable 400+ break as a 2ltr, and at 400+ break the GTIR becomes a VERY fast car for our British (crap) roads and with skill and if pushed will annihilate most other vehicles on those roads.

To my mind anything over 400 - 450 break in a GTIR road car becomes dangerous, as at it will start to loose traction and power in the engine is no good to anyone if you can't put it on the tarmac.

In a road car I think a power of a big stroker kit would be total waste of a huge amount of time, money and effort but in a specialised well set up competition car could be very useful.

Thought & comments

Feckin hell Steve thats a damn good little write up

God help Rishi then if 400 - 450 bhp is dangerous :lol:

So was i right in thinking then that a stroker kit is the way to go for big power dispite the fact it would be stupid to do so in a road car?

 

[stevepudney]

To my mind anything over 400 - 450 break in a GTIR road car becomes dangerous, as at it will start to loose traction and power in the engine is no good to anyone if you can't put it on the tarmac.

In a road car I think a power of a big stroker kit would be total waste of a huge amount of time, money and effort but in a specialised well set up competition car could be very useful.

Thought & comments

Mine makes approx 430ish at the fly. Dont have any real tracion probs but the sort of speeds it gets to very quickly do make it of limited use as a road car.

I have a T3 turbine aswell.

well, mine makes about that and is only an 87mm 2lt (I do run 1,7 bar though) .

I get torque steer at 50 - 60 mph in 3rd in the dry if I plant it, if I get this when trying to over take on a narrow damp or wet road things sometimes get a little hairy.

If any worse I would class that as dangerous in the wrong hands.

 

[stevepudney]

The biggest restriction to the SR20 is the head flow that’s why you see big HP numbers and low torque numbers. You could switch to the VVL head to get a bit better flow on the top end but still to small really.
Example the Mitsubishi 4G63 the head from 90-94 was very high flow, these motors are making the same if not more torque than HP out of the same 2L displacement 600+ no problem (race fuel of course).

The SR20DET head needs to be opened up to achieve good power and torque from being stroked. Amongst other things it would need over sized valves 1 mm and allot of work on the exhaust ports, they are way too small, that’s why we have to run big boost to get horse power. What we really need is less PSI and more volume, that would produce a more balanced torque/power curve. Also the T-25 housing is too small, T-3 would show a huge improvement in spooling and volume.

Basically if you only enlarge the displacement of the bottom end you will see larger torque figures lower in the map but you will see it drop off very fast in the top end as you max out the heads flow rate.

If you did both match an SR20 2.2 - 2.3 - 2.4lt stroker to a SR20 head that can keep up with a good high volume turbo you should see a huge improvement and more close range between torque and HP figures.

Then all you have to consider is the power train Gearbox, Diff's & Transfer box. The problem is it's all a question of ££££ and getting the balance between all the above right.

On a sensible note

So with all that in mind, the 2 ltr SR20DET engine in the GTIR will produce a reliable 400+ break as a 2ltr, and at 400+ break the GTIR becomes a VERY fast car for our British (crap) roads and with skill and if pushed will annihilate most other vehicles on those roads.

To my mind anything over 400 - 450 break in a GTIR road car becomes dangerous, as at it will start to loose traction and power in the engine is no good to anyone if you can't put it on the tarmac.

In a road car I think a power of a big stroker kit would be total waste of a huge amount of time, money and effort but in a specialised well set up competition car could be very useful.

Thought & comments

Feckin hell Steve thats a damn good little write up

God help Rishi then if 400 - 450 bhp is dangerous :lol:

So was i right in thinking then that a stroker kit is the way to go for big power dispite the fact it would be stupid to do so in a road car?

Bear in mind that when I mention dangerous this is only my opinion.

And in my opinion to get "the best" from a stroked engine you would have to do all the head work and make the power train bullet proof to get the most out of the time, money and effort involved in building a stroked engine e.t.c.

 

[ChrisS]

well, mine makes about that and is only an 87mm 2lt (I do run 1,7 bar though) .

I get torque steer at 50 - 60 mph in 3rd in the dry if I plant it, if I get this when trying to over take on a narrow damp or wet road things sometimes get a little hairy.

If any worse I would class that as dangerous in the wrong hands.

Ive 400lb of torque aswell though. Traction in a straight line is fairly ok, wet i can spin the wheels up and get a sidewards, especially coming off roundabouts and stuff. Dont really suffer any torque steer.

 

[stevepudney]

well, mine makes about that and is only an 87mm 2lt (I do run 1,7 bar though) .

I get torque steer at 50 - 60 mph in 3rd in the dry if I plant it, if I get this when trying to over take on a narrow damp or wet road things sometimes get a little hairy.

If any worse I would class that as dangerous in the wrong hands.

Ive 400lb of torque aswell though. Traction in a straight line is fairly ok, wet i can spin the wheels up and get a sidewards, especially coming off roundabouts and stuff. Dont really suffer any torque steer.

This partly my point, if you can't use all the power available then surely it's wasted on our roads. If the car had a power/torque = @ around 300 - 350 ft lb it would be far more stable. I find my car far easier to use at 1.4 bar on the B roads cos I can use almost all the power, at 1.7 bar it can be a right handful and generally the roads aren't long enough to use all the power.

Then again I suppose driving style and ability do come into this equation.

Again my point, that stroker rebuild must have cost a small fortune and just as an example, you have 400 bhp & 400ft lb of torque. My forged rebuild I did myself and has produced 400+ bhp and 347 ft lb of torque, so is that little extra power really worth the extra money you spent on a stroker rebuild ??

 

[ChrisS]

Dont have any real tracion probs but the sort of speeds it gets to very quickly do make it of limited use as a road car.

This partly my point, if you can't use all the power available then surely it's wasted on our roads.

Agree totally. Its still nice to know that you've got it though

 

[marcymarc]

Chris

Have you got plans for bigger power out of your stroker?

 

[ChrisS]

Not sure what im doing with it at the moment. I really need to get a full 3inch system and 272 cams with higher lift to help it breath better, before upping the boost some more.
Am also toying with the idea of getting rid and just using my old one at a more user friendly 330ish aswell.

 

[Rishi]

See i did think about the stroker kit... I could have had one custom made to any spec i want... Stroker Kits have many advantages....

:arrow: With the longer stroke you can also generate more heat earlier in the rpm range thus spool up a turbo quicker than with a 2L

:arrow: Longer stroke or even larger bore piston you are increasing displacement which is an instant torque booster...

:arrow: Now reving a stroker setup to 7000rpm is the equivelant to reving a 2L to 8250rpm... Thats just a rough guess as i couldn't be bothered to do the calculation... So reving a stroker higher is very stressfull... Not only that but you also have to consider piston speed...

Was thinking of a 2.3stroker for next year with a larger turbo but will wait and see...

But...

i decided to go with the 2.1L for now... Spent a lot of money on engine development... Massive work all over really... Not going to go into it but as Steve mentioned Head Work is important and i have done some extensive head work to mine...



Rishi

 

[marcymarc]

Not sure what im doing with it at the moment. I really need to get a full 3inch system and 272 cams with higher lift to help it breath better, before upping the boost some more.
Am also toying with the idea of getting rid and just using my old one at a more user friendly 330ish aswell.

Toying with the idea of getting rid of the car its self or the stroker?

Also mate , what turbo are you running?

 

[stevepudney]

See i did think about the stroker kit... I could have had one custom made to any spec i want... Stroker Kits have many advantages....

:arrow: With the longer stroke you can also generate more heat earlier in the rpm range thus spool up a turbo quicker than with a 2L

:arrow: Longer stroke or even larger bore piston you are increasing displacement which is an instant torque booster...

:arrow: Now reving a stroker setup to 7000rpm is the equivelant to reving a 2L to 8250rpm... Thats just a rough guess as i couldn't be bothered to do the calculation... So reving a stroker higher is very stressfull... Not only that but you also have to consider piston speed...

Was thinking of a 2.3stroker for next year with a larger turbo but will wait and see...

But...

i decided to go with the 2.1L for now... Spent a lot of money on engine development... Massive work all over really... Not going to go into it but as Steve mentioned Head Work is important and i have done some extensive head work to mine...



Rishi

Rishi, Talking of head work, if we were going to use .5mm - 1mm larger valves I wonder what/who's stock valves we could use in the SR20 head.

 

[Rishi]

See i did think about the stroker kit... I could have had one custom made to any spec i want... Stroker Kits have many advantages....

:arrow: With the longer stroke you can also generate more heat earlier in the rpm range thus spool up a turbo quicker than with a 2L

:arrow: Longer stroke or even larger bore piston you are increasing displacement which is an instant torque booster...

:arrow: Now reving a stroker setup to 7000rpm is the equivelant to reving a 2L to 8250rpm... Thats just a rough guess as i couldn't be bothered to do the calculation... So reving a stroker higher is very stressfull... Not only that but you also have to consider piston speed...

Was thinking of a 2.3stroker for next year with a larger turbo but will wait and see...

But...

i decided to go with the 2.1L for now... Spent a lot of money on engine development... Massive work all over really... Not going to go into it but as Steve mentioned Head Work is important and i have done some extensive head work to mine...



Rishi

Rishi, Talking of head work, if we were going to use .5mm - 1mm larger valves I wonder what/who's stock valves we could use in the SR20 head.

1mm might be a little much for our head... I was thinking along the lines of 0.5mm oversized...

AND... I can have them custom made for £160 ish...

I looked at certain valves that might fit but the groves and fitting are very slightly different... Custom made ones are a better option esp at that price...

Going to go down that route for next season... Was going to cause too much of a delay this time round so i'm having them made in a few months time so that i can just fit them at the end of the season or maybe when it gets a little quieter so i can test the setup before the winter weather hits...




Rishi

 

[stevepudney]

Was that £160 a set or ???

 

[ChrisS]

Toying with the idea of getting rid of the car its self or the stroker?

Also mate , what turbo are you running?

Whole car. Got some things planned this yr i could do with raising some cash for. Turbo is a turbonetics T3/T4 hybrid roller bearing one.