Here my question and hope you all can help.
I just finished my project. Its a Lotus Super 7 powered by Turbocharged Nitrous Hayabusa 1300cc.
http://www.mjmturbos.com/images/busa003.jpg
http://www.mjmturbos.com/images/busa001.jpg

I can't relate what I've done to this transition. Its a nightmare and I don't want to have a bad dream tonight. I converted this car using driveshaft instead of traditional suzuki chain-sprocket, lenko reverse gear, 6 speed sequential, Nissan skyline dual ballbearing turbo and a nitrous shot.
The rear are fully independent, cosworth quaife differential. The car weigh in at 950lbs and shooting for 370hp with no shot (over 400 with shot).

If I will do it all over again I rather use my conventional engine.
http://www.mjmturbos.com/images/s20001.jpg

So what do you think more drivable and powerful between the two?

 

Of course the F20c is going to be more driveable.. but whats more cool? lol I would keep the charged busa motor.. you have a nice peice of art powering your super 7.

 

Now, is the honda S2000 capable of handling a turbo without internal modification?
I assumed just a few boost not crazy boost.

 

my god.... why dont' people read other threads..... we have covered the fact that the stock s2000 motor can handle a lot of boost.....

THE S2000 MOTOR COMES WITH FORGED PISTONS AND RODS!!!!!!!!!!!!!!!

 

Darn....this is only my first post.
Man.......
Hmmmmmmm pretty nice threatment

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 03s2kblue &raquo;</TD></TR><TR><TD CLASS="quote">my god.... why dont' people read other threads..... we have covered the fact that the stock s2000 motor can handle a lot of boost.....

THE S2000 MOTOR COMES WITH FORGED PISTONS AND RODS!!!!!!!!!!!!!!!

</TD></TR></TABLE>

did you see the fact that hes new to H-T?

you dont have to yell at the guy

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tsunami 7 &raquo;</TD></TR><TR><TD CLASS="quote">Now, is the honda S2000 capable of handling a turbo without internal modification?
I assumed just a few boost not crazy boost.
</TD></TR></TABLE>


8 psi, conservative tune. Yep, holds up great(800 miles of hard driving so far!).

 

Sorry man...I m just looking for info just incase I blow my hayabusa engine, I will definetly will install my Honda s2000 engine.

I never been in the forums, I don't have time, on the other hand I also need some help. I don't know much about the s2000 intenals.
However, I know about turbocharging....a lot, I mean this.
I can help.

 

hahahaha. i wasn't yelling.. just stressing it hehehee. i've posted that at least 10 times hahahahahahaha..

but tsunami.... you'll be fine if you boost the f20c... just make sure you tune it properly..... tuning it is number 1..... without proper tuning it'll blow.... and if you're going really high boost it's wise to contact inline and get their 3mm headgasket to lower the compression... and you'll be set...

 

What about the Vtec?
I used to turbocharged a Toyota VVit and I have to disable that system.
Too much overlap is not good in forced induction...so what about the
S2000?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tsunami 7 &raquo;</TD></TR><TR><TD CLASS="quote">What about the Vtec?
I used to turbocharged a Toyota VVit and I have to disable that system.
Too much overlap is not good in forced induction...so what about the
S2000?</TD></TR></TABLE>


s2000's keep vtec even with turbo. the vtec crossover point is usually lowered when tuned

 

s2000's keep vtec even with turbo. the vtec crossover point is usually lowered when tuned


Can you further explain this to me?

Thanks

 

vtec is differnt then what toyota uses......

every turboed honda regardless if it's a civic or integra or a s2000 keeps the vtec....

vtec engagement is when the cams switch from low cam to high cam..... no for instance... on an s2000 (ap1) the vtec kick in roughly at 6000rpm (this also varries with altitude, throttle position, air flow, oil temperature)... how ever there is a very very very slight lag when vtec kicks in...... if you look at a dyno plot there is usually a little decrese or a little tiny dip in power when the vtec is engaged.. the lag is from the swap over from low cam to high cam...... now once you are tuning the car... most people drop the vtec engagement down a little for a couple of reasons...

1. vtec gives you more power, therefore the lower the vtec is the quicker you can achieve power (however if you lower it to much it's no good becaue the engine will not be spinning fast enough to take full advantage of the high cam.)
2. they lower vtec to flatten out the curve a little, if you can find the right ballance of here the engine is spinning fast enough and is able to take full advantage of the high cam at a lower rpm.... now this will all vary with the type of tuning you go with and other parts on the car... now when you see this on a dyno plot you won't see the little dip in power when vtec engages...

 

Ok....thanks for the explanantion. The Toyota is almost the same.

However, I will leave the Honda Vtec very low. I will not worry
if the engine does not spin at the lower rpm because my car only
weigh in at 950lbs.
In your case, the reason you are worrying is because your
car weigh more than my 950lbs.....far more
What do you think?

 

worrying?????

you dont' want to lower vtec to much on this motor.......the main reason to lower vtec is to flatten out the curve so you don't get that slight dip in power

 

BUT, as someone said, i dont know who...
the reason why we buy these vtec engine equipped cars is for the awesome technology of vtec itself....just keep it where it is at, also, some people raise their vtec points so they get a bigger jump in power...so vtec isnt just a noise that comes on.

 

you mean lower vtec..... hahaha. i dont' think anyone in their right minds would raise the vtec engagement point hahaha

 

no, raise....
check out importbuilders.com
This guy is pretty amazing check out the graph

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jeff - IB dude &raquo;</TD></TR><TR><TD CLASS="quote">Also, note in the above picture I might be able to bring the VTEC down like 100 RPM to make it more of a perfect straight line? You could do this, but if you do, you won't feel when VTEC comes in and it will be just a noise. I have a philosophy on this subject and I believe the Honda experience should be fun to drive. So what I do is set the VTEC 100, or even 200 higher than its "straight line" position, so that when the customer hits VTEC, the torque jumps up like 10 LBS and the HP climbs steeply up and he gets thrown back in his seat a little bit. It makes the car feel "quick" in that area, and makes it more fun to drive. On 2 liter motors especially, I like to make it steep after it hits VTEC so the customer can chirp the tires just hitting VTEC. Like this graph for example...
</TD></TR></TABLE>

http://www.importbuilders.com/tuning.html

And, I did it too, but only because I had 9500 redline with ti valvetrain

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 03s2kblue &raquo;</TD></TR><TR><TD CLASS="quote">vtec is differnt then what toyota uses......

every turboed honda regardless if it's a civic or integra or a s2000 keeps the vtec....

vtec engagement is when the cams switch from low cam to high cam..... no for instance... on an s2000 (ap1) the vtec kick in roughly at 6000rpm (this also varries with altitude, throttle position, air flow, oil temperature)... how ever there is a very very very slight lag when vtec kicks in...... if you look at a dyno plot there is usually a little decrese or a little tiny dip in power when the vtec is engaged.. the lag is from the swap over from low cam to high cam...... now once you are tuning the car... most people drop the vtec engagement down a little for a couple of reasons...

1. vtec gives you more power, therefore the lower the vtec is the quicker you can achieve power (however if you lower it to much it's no good becaue the engine will not be spinning fast enough to take full advantage of the high cam.)
2. they lower vtec to flatten out the curve a little, if you can find the right ballance of here the engine is spinning fast enough and is able to take full advantage of the high cam at a lower rpm.... now this will all vary with the type of tuning you go with and other parts on the car... now when you see this on a dyno plot you won't see the little dip in power when vtec engages...</TD></TR></TABLE>

If your talking about a purpose built motor, they most certainly would not retain vtec operation.

For 2 reasons, A: tuning - in order to maximize the power curve for a drag race or road race engine considerable time must be spent on a dynamometer, tuning for the low cam as well adds a considerable amount to that, given the fact this is going in a 7 the top speed of which I would imagine should stay lower than 140 for safety reason the FD would also be replaced with an appropriate size meaning rpms will never drop below the point of vtec activation anyway. something realtime racing has done for quite sometime now. And B: complexity. there are many things including a spike in oil pressure and added valvetrain weight that accompany vtec operation none of which is a good thing for a track car.

As I can recall the busa motor is considerably lighter and would be a better fit for keeping the weight down.

 

thats if you're making a track car.....

vtec is allows our cars to be very fuel efficient....

also.. with a stock s2000.. i never drop out of vtec when i'm going through my gears....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Doubledeala &raquo;</TD></TR><TR><TD CLASS="quote">no, raise....
check out importbuilders.com
This guy is pretty amazing check out the graph

http://www.importbuilders.com/tuning.html

And, I did it too, but only because I had 9500 redline with ti valvetrain</TD></TR></TABLE>

ok i just read it... from what i see of it.. he's got differnt cams in the car.. jun or toda.... toda cams are usually vtec killer cams.. so they practically get rid of vtec....

and his method of tuning is to raise vtec so you supposidly feel the jump and make your wheels chirp.. which is ummm well who cares? it's just his method of tuning.. raise the vtec to strighten out the power curve, no need to do any air/fuel tuning. (which saves you money on the dyno and saves time) ... however vtec kicks in later...

now honestly why would you do that.. if .... you could just lower vtec do some air/fuel tuning to straighten out the power curve, and have vtec kick in earlier... and make just as much power as the other way...

i would prefer to have vtec kick in earlier then later... just my oppinion....

 

then what's the point of vtec when you have a dip in torque early on??
Like i said, we want the vtec because of the "cool" wailing....and the jump in power. I couldn't feel jack squat when vtec hits, then you raise it a bit...and THEN people are like wtf...nice vtec! not - "wait..is that vtec? that louder noise?"

 

Let make it simple.
To me, the Vtec system is nothing but shifting to a taller lift cam to breath and exhale more. More volume of air more power.
If you let the Vtec on at early stage, you might not pass the emission because
the ECU is not program to synch at that stage (AFM might be screwed up). I don't know ur ecu, but this is true.
However, I mentioned that if u bring the Vtec down to operate say 5,000rpm, its
ideal for my car because the weight issue (950lbs). In your case, if you open
at low rpm and your car weight 3 times my car, probably will bog down (considering the F20 engine does not have a great torque).
A higher lift cam will surely affect emission. This is the reason why muscle car will
never pass. Their cam is fix position and deliverately dump fuel with no rules.
Because of their big displacement, there is no issue to use a higher lift cam
at early stage due to abundant of torque.
However, Vtec starts with a good calculated air fuel mixture in a smooth camshaft.
Smooth camshaft or stock camshaft for emission standard will always pass the emission however you need to generate power somewhere along the line and this
is where the high lift come in duty. You said Vtec will come approx 6,000rpm therefore way pass the emission guideline. MVD will not test your car at 6,000rpm.
That's where the Honda engineer based the Vtec operation.
Well, what do I know about your F20.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Doubledeala &raquo;</TD></TR><TR><TD CLASS="quote">then what's the point of vtec when you have a dip in torque early on??
Like i said, we want the vtec because of the "cool" wailing....and the jump in power. I couldn't feel jack squat when vtec hits, then you raise it a bit...and THEN people are like wtf...nice vtec! not - "wait..is that vtec? that louder noise?"</TD></TR></TABLE>

dude do you know what vtec is??? like seriously.... if you like vtec becaue of the "cool" factor then you're a ricer... sorry man.. but it's true...

vtec was created for fuel efficentcy, when it's on low cam you save fuel and get better fuel mileage....

and about you not feeling the vtec kick in... i guess you didn't really drive your S properly.. cuaes i know i feel it every single time i engage vtec, and i'm sure everyone else on this board that drives the car properly also feels it...

as for the vtec engagement.... here is one that engages at the stock 6000rpm...

as you can see there is a very slight dip in power, but like i said very slight and very quick, this is while the cams change from low cam to high cam... but you can still see that umm well 10lb/tq that you're so crazy about....

now all that guy is doing is moving it further back to like 6300 or higher.... no real tuning at all just raising the vtec.....

and what you are failing to realize... i can do the same exact thing by lowering the vtec to around 5600rpm - 5800rpm... do some AIR/FUEL tuning and have the same exact increace and flatten the tq curve so there is NO dip in power... and be in VTEC before you will....

 

I think that VTEC has several reasons for existing.

1) Performance. 2 different cam lobes give a wider power band.
2) Fuel economy. No sense running a monster cam at low RPM's when a smaller cam would improve economy.
3) Probably the biggest reason, Drivability. The wider powerband in 1) is the #1 reason why they would design variable valve timing systems. It allows the engine to put around town and then have that jekyl/hyde personality when you drop a gear and step on it.


For a car like the 7, VTEC engagement doesn't matter as much. The car will be quick anyways.

I'd recommend lowering it only a few 100 rpms to smooth out the power and torque curve. That will give maximum throttle response and will improve the drivability of the car. I'm sure you could find some dyno plots on the net and compare.

As for turbocharging, you should check out some of the other threads in this forum. Frankly, after reading the inline-pro thread I now want to buy an S (Did before, but wasn't happy with the moddability.)