J
J-GTi-R
Guest
They are well designed... for a 2.0l engine. As Edd is well aware, the standard head is definitely restrictive on the stroker kit. The reason why he's not getting real power over 5.5k rpm is purely down to the head not being able flow enough air for the engine's requirements. Hence to get the maximum benefit of his 2.2 stroker he's definitely going to need to spend his further £3k on head work to get the engine to breath properly, cams, BIG valves, plenty of work on a flow bench...Nad said:
E
Edd
Guest
Jason is right, as i already knew 
the engine demands so much friggin air that the head will need massive work to get the benefits.
However we will see how well it goes with the 3037 on as that should pump in a bit more air.......but it may still not be enough...
the engine demands so much friggin air that the head will need massive work to get the benefits.
However we will see how well it goes with the 3037 on as that should pump in a bit more air.......but it may still not be enough...
skiddusmarkus
Active Member
Before you spend a fortune on headwork,why not ask Jason Gant what he's had done to his?He's already running low 11secs on standard gearbox and organic clutch so 10's are possible.I doubt very much he's had £3k's worth of headwork.
Maybe the head is more restrictive with massive power but I'd guess that the standard turbo is more of a problem on your engine Edd.It can only flow so much and is more likely to be the problem that the valves which other people seem to be getting 400+bhp out of no sweat as did your car before you swapped the turbo/manifold and injectors.You say the injectors are maxing out,maybe the turbo is too.
I remember Justin somebody or others(no offence,can't remember surname) R being featured in Jap Perf(think Ashbhp bought the car)and the hybrid T28 wasn't able to supply enough air at higher revs either.
Maybe the head is more restrictive with massive power but I'd guess that the standard turbo is more of a problem on your engine Edd.It can only flow so much and is more likely to be the problem that the valves which other people seem to be getting 400+bhp out of no sweat as did your car before you swapped the turbo/manifold and injectors.You say the injectors are maxing out,maybe the turbo is too.
I remember Justin somebody or others(no offence,can't remember surname) R being featured in Jap Perf(think Ashbhp bought the car)and the hybrid T28 wasn't able to supply enough air at higher revs either.
E
Edd
Guest
Jason Gant runs a 2.0 engine so his headwork won't necessarily be suitable for me, but maybe for others on 2.0's.
I doubt i'm maxing the turbo as i'm only running 0.8 bar now and have knocked the injectors down to 99.4% duty :roll:
Std turbo is going now as the car's crap with it on.
Just got to make up all new pipework for intercooler and turbo
I doubt i'm maxing the turbo as i'm only running 0.8 bar now and have knocked the injectors down to 99.4% duty :roll:
Std turbo is going now as the car's crap with it on.
Just got to make up all new pipework for intercooler and turbo
skiddusmarkus
Active Member
I don't understand why a strokered 2.2l engine's head would struggle over a 2l(or 2045cc assuming 87mm pistons) engine if they were making the same power.To make that power,they're both going to need the same amount of air and fuel assuming things like engine management&mapping are to the same standard.
The 2.2 might will need less boost to do it but not more/less airAll you're doing is making the air pump(engine)bigger so for each stroke you take in more air,so you'd need les revs to make that power than a 2l.
If I'm off the mark here,someone please explain it to me in words of no more than 3 syllables :lol: .
The 2.2 might will need less boost to do it but not more/less airAll you're doing is making the air pump(engine)bigger so for each stroke you take in more air,so you'd need les revs to make that power than a 2l.
If I'm off the mark here,someone please explain it to me in words of no more than 3 syllables :lol: .
J
J-GTi-R
Guest
It's not really to do with power, it's air flow that's causing the problem. They way it was explained to me was, say you have the strongest internals in the world, 'strontium' crank, rods, pistons etc so no matter how hard you rev the engine, it's won't self destruct due to component failure. Your engine now has no component based rev limit. However it still has a rev limit, which is dictated by the amount of flow the head allows. Edd's internals are probably good enough for 10k rpm, but as it stands, he will always run out of revs (and thus will not make any more power) because his head is restricting air flow above 5.5k rpm.
Say you take a standard engine and bullet-proof it's internals. Putting the best of everything on it and setting it up perfectly, it makes 400bhp maximum. If the head is standard and everything else is perfect, the 400bhp limit will be because of the flow restriction of the head. So you now can port and polish, flow and cam the head and now you have 450bhp, because you can now flow 50bhp worth of more air into the engine as it revs out. By stroking an engine however, by rule of thumb, a 10% increase in capacity will move the to power to 10% earlier in the rev range, so then what happens is the rev limit set by the flow of the head then moves to eariler in the rev range and it starts running out of puff.
In engine design, you will know where you want the power, how much power you want and will design the head with the right flow characteristics to be able to achieve that. The GTi-R head does flow well, but with mechanical valve gear, it's been designed to rev and thus needs good flow characteristics. However, if you want serious power, you need head work
If your previous engine made 400 bhp, putting a 2.2 stroker kit on it it will still only make 400bhp, because that's all the head will allow. However, do all that head work again, and it can now not only make 450, but as it makes that power earlier in the rev range and as long as the flow rate can take it, it will make even more power because the stroker and headwork allows essentially gives you 10% more rpm in which to make more power.
I hope that helps...
Say you take a standard engine and bullet-proof it's internals. Putting the best of everything on it and setting it up perfectly, it makes 400bhp maximum. If the head is standard and everything else is perfect, the 400bhp limit will be because of the flow restriction of the head. So you now can port and polish, flow and cam the head and now you have 450bhp, because you can now flow 50bhp worth of more air into the engine as it revs out. By stroking an engine however, by rule of thumb, a 10% increase in capacity will move the to power to 10% earlier in the rev range, so then what happens is the rev limit set by the flow of the head then moves to eariler in the rev range and it starts running out of puff.
In engine design, you will know where you want the power, how much power you want and will design the head with the right flow characteristics to be able to achieve that. The GTi-R head does flow well, but with mechanical valve gear, it's been designed to rev and thus needs good flow characteristics. However, if you want serious power, you need head work
If your previous engine made 400 bhp, putting a 2.2 stroker kit on it it will still only make 400bhp, because that's all the head will allow. However, do all that head work again, and it can now not only make 450, but as it makes that power earlier in the rev range and as long as the flow rate can take it, it will make even more power because the stroker and headwork allows essentially gives you 10% more rpm in which to make more power.
I hope that helps...
E
Edd
Guest
I think Ian H will disagree with then 10k rev limit :lol:
I was told i couldn't rev over 7k without valve springs done. I believe the bottom end is rated to 8500 though but the head certainly isnt
I was told i couldn't rev over 7k without valve springs done. I believe the bottom end is rated to 8500 though but the head certainly isnt
The standard head doesn't seem to be a restriction until around 450bhp ish and even then its probably still ok though you would see gains with a ported head 8)
The problem with Edd's engine will be the turbo is to small and also probably doesn't help that its running a unmapped pfc either with a bigger free flowing turbo on the bhp will raise alot and will move up the rev range alot further 8) stroker engines aren't really designed to rev either there more about extra torque than bhp at high rpm of course than can be made to rev highly but the shorter stroke 2l engine would be happier to do it.
My old engine hit the limiter at 7500 rpm before it made max power and that head was standard just the addition of the larger turbo that made the difference.
Once Edd gets his big turbo on max power will probably be around the 7k rpm point where as with the 2l it would probably be closer to the 8k rpm point.
He'll also need to change the puny mongoose exhaust for something much bigger to make the most of his mods think 3.5"
The problem with Edd's engine will be the turbo is to small and also probably doesn't help that its running a unmapped pfc either
with a bigger free flowing turbo on the bhp will raise alot and will move up the rev range alot further 8) stroker engines aren't really designed to rev either there more about extra torque than bhp at high rpm of course than can be made to rev highly but the shorter stroke 2l engine would be happier to do it.My old engine hit the limiter at 7500 rpm before it made max power and that head was standard just the addition of the larger turbo that made the difference.
Once Edd gets his big turbo on max power will probably be around the 7k rpm point where as with the 2l it would probably be closer to the 8k rpm point.
He'll also need to change the puny mongoose exhaust for something much bigger to make the most of his mods think 3.5"
skiddusmarkus
Active Member
This is what I can't understand.My point is the head would be just as restrictive on a 2litre as it is on a 2.2litre.People have put bigger turbos on than the 3037 on 2litre cars and got mid 11s with no headwork or cams(Mark Evans).Ashills did too with no headwork,at least I don't think he did(not including cams)and with a 3037 equivelent.Edd said:Jason is right, as i already knew
the engine demands so much friggin air that the head will need massive work to get the benefits.
However we will see how well it goes with the 3037 on as that should pump in a bit more air.......but it may still not be enough...
If the capacity is only 10% bigger,how can it demand more than 10% more air at the same rpm?A stroker kit isn't black magic,it's just increasing the displacement.
It's a bit misleading for new members who might think that you have to have thousands of pounds worth of headwork if you get a stroker,when all it will probably take is a decent turbo,cams and mapping.
I think it's more likely the turbo too,we all know that they run out of puff at about 6500rpm and the stroker kit is exxagerating that effect.
This is all my opinion and based upon limited mechanical knowledge
.
E
Edd
Guest
I'm not saying people have to spend thousands with the stroker, i'm saying that if you want to push it to the limit you will need to spend a lot.
However i think big turbos on stroked engines is a bit of an unknown, the only one i know of is Bruce's which as far as i'm aware has always had some form of problem somewhere. As 381bhp 407lbs torque at 2+ bar was definitely not the correct figure.
Maybe Ian who has more knowledge of the stroked engines (more so on skylines) might be able to comment on the GtiR head and what is needed on a stroked engine.
My engine might not need the headwork with the 3037 on, it might be fine, only time will tell.
As for 3.5 inch exhaust i would love one but who the hell would make one :shock:
can't find anyone near me who does bigger than 2.5 inch, also wouldnt 3.5 inch be too big a bore for backpressure?
I know shaun on his seahaven evo has 4 inch exhaust and that thing sounds evil :shock: 8)
However i think big turbos on stroked engines is a bit of an unknown, the only one i know of is Bruce's which as far as i'm aware has always had some form of problem somewhere. As 381bhp 407lbs torque at 2+ bar was definitely not the correct figure.
Maybe Ian who has more knowledge of the stroked engines (more so on skylines) might be able to comment on the GtiR head and what is needed on a stroked engine.
My engine might not need the headwork with the 3037 on, it might be fine, only time will tell.
As for 3.5 inch exhaust i would love one but who the hell would make one :shock:
can't find anyone near me who does bigger than 2.5 inch, also wouldnt 3.5 inch be too big a bore for backpressure?
I know shaun on his seahaven evo has 4 inch exhaust and that thing sounds evil :shock: 8)
Try asking Bruce spence where he got his done as iirc his was something like 4" turbo back any decent exhaust maker should be able to make up whatever exhaust you want.
As for back pressure you don't want any on a turbo car do you think all those cars running side exit bloody short exhausts running silly quick times had back pressure built into them :lol:
If back pressure is required its created between the engine and turbo and i'd say there'd be quite abit there already
Maybe even think about having a Rc, Jason Gant style exhaust where it comes out the front of the car :twisted:
any decent exhaust maker should be able to make up whatever exhaust you want.As for back pressure you don't want any on a turbo car do you think all those cars running side exit bloody short exhausts running silly quick times had back pressure built into them :lol:
If back pressure is required its created between the engine and turbo and i'd say there'd be quite abit there already
Maybe even think about having a Rc, Jason Gant style exhaust where it comes out the front of the car :twisted:
E
Edd
Guest
I've thoguht about front of the car (it does make the best sense) but i think a) the back of the car would look silly
b) i would get battered by the cops :lol: :lol:
b) i would get battered by the cops :lol: :lol:
J
J-GTi-R
Guest
It is, but the way a stroker works, i.e. it shifts the power down the rev range by 10%, it will mean you hit the maximum flow rate of the head earlier, thus whereas on a 2.0l engine you'd be reaching max flow at say 6500 rpm (and the power curve flattening off at that point), with a stroker you'll now be hitting the max flow rate and thus peak power at 5800 rpm or so, so it now feels like it's not pulling any further beyond that rpm because the head is restricting revs. But if you flowed the head so that at 5800 rpm the head wasn't restricting air flow on your 2.2 stroker and had a red line of 7k rpm, you have an extra 700 or so rpm to make useful power from.
BTW all my figures previously were just hypothetical.
skiddusmarkus
Active Member
Yeah I understand that J.Lets say(guesstimates) the head is good for 450bhp,500bhp with mild porting.The stroker might make that at 6000rpm,the 2litre at 7500rpm.
The way Edd's talking is that his engine is already struggling for air while only running 0.8bar!That's probably going to be about 270-300bhp on that engine.If the head can flow 400bhp then why's he running out now?I think it's the turbo is holding him back as it's 13 years old and only rated for around 300bhp or so.Stick the 3037 on and it will pull to the limiter I bet.
Edd-how dd it pull with the GTRS on?
The way Edd's talking is that his engine is already struggling for air while only running 0.8bar!That's probably going to be about 270-300bhp on that engine.If the head can flow 400bhp then why's he running out now?I think it's the turbo is holding him back as it's 13 years old and only rated for around 300bhp or so.Stick the 3037 on and it will pull to the limiter I bet.
Edd-how dd it pull with the GTRS on?
E
Edd
Guest
It died at 6k with the GTRS on :shock: :lol:
peak power was at 6200rpm ( i suspect peak power now about 5600rpm)
The car was flat over 6k and just didn't wanna pull much, so it was change gear time.
peak power was at 6200rpm ( i suspect peak power now about 5600rpm)
The car was flat over 6k and just didn't wanna pull much, so it was change gear time.
i did have all the head flowed/ported mate and also the throttle bodies bored and polished but had standad cams i recon edds problems lies in turbo rather than head as mine still pulled like crazy with standard cams at what i think must have been very close if not offer 450bhp and it hit limiter in every gear just so dam fast with mad cams and big valves it would be very interestingskiddusmarkus said:This is what I can't understand.My point is the head would be just as restrictive on a 2litre as it is on a 2.2litre.People have put bigger turbos on than the 3037 on 2litre cars and got mid 11s with no headwork or cams(Mark Evans).Ashills did too with no headwork,at least I don't think he did(not including cams)and with a 3037 equivelent.Edd said:Jason is right, as i already knew
the engine demands so much friggin air that the head will need massive work to get the benefits.
However we will see how well it goes with the 3037 on as that should pump in a bit more air.......but it may still not be enough...
If the capacity is only 10% bigger,how can it demand more than 10% more air at the same rpm?A stroker kit isn't black magic,it's just increasing the displacement.
It's a bit misleading for new members who might think that you have to have thousands of pounds worth of headwork if you get a stroker,when all it will probably take is a decent turbo,cams and mapping.
I think it's more likely the turbo too,we all know that they run out of puff at about 6500rpm and the stroker kit is exxagerating that effect.
This is all my opinion and based upon limited mechanical knowledge
S
stuart rawlinson
Guest
The T28 turbo on the 2.2 in a nut shell dont supply it with enuff air at 4500 rpm its out of puff and was s**t to drive its a mis match for the stroker, low down it was very nice your RS tubby was not up to the job the standard ent got a chance poor thing
Edd you will notice the diff with the bigger tubby on believe u me
4th and 5th will be lk 1st and 2nd
the standard ent got a chance poor thing Edd you will notice the diff with the bigger tubby on believe u me
4th and 5th will be lk 1st and 2nd
J
J-GTi-R
Guest
Yes sorry, got caught up in heads and flow and forgot about the tubby...skiddusmarkus said:
But now I'm confused as if the turbo is making a steady 0.8 bar, then why would it still not rev well beyond 5.5k rpm?