My Final Decision For My Car

[MissR34]

well it just seems like you are making it a big deal that i am chooing to want to supercharge my skyline, and it seems like you dont like the fact that i am "stepping out of the square" and doing something different.

and if i want to go wank facter then i will.

[mitchy_]

you can do whatever the hell you like, i'm not going to lose any sleep over your choice.

i was asking why you'd go with a blower that offers very much the same characteristics as a turbo, except at a higher price..

if i was to go a supercharger, i'd be aiming for something with no lag, and a very broad power curve, rather than a peaky figure that a turbo can deliver.

[inthisglass]

ok so let me get this straight,

you are spending more money than the entire car is worth,

to do something "different"

for results that are far less than anything conventional (tried and tested that works and is good)

and you expect everybody to post and say

"yeah awesome idea"

"i like how you have chosen to spend more money for less gains"

not everyones going to agree and say different is better

you must know that, so no point getting all annoyed at everybody who tells you so.

[MissR34]

there wont be much lag. it comes down to the tune aswell.

[funkymonkey]

most people who spend 100,000 on a car are buying something like an R35 GTR, or are pulling off a tax scam (and don't tell me half the big money autosalon entries aren't tax writeoffs). you're getting into debt to build this. just seems like you're making emotional decisions instead of rational ones that's all, and I'm sure half the people posting "against" you are trying to point that out.

everyone loves an innovator, but innovation at what cost?

[Mr. Oizo]

most people who spend 100,000 on a car are buying something like an R35 GTR, or are pulling off a tax scam (and don't tell me half the big money autosalon entries aren't tax writeoffs). you're getting into debt to build this. just seems like you're making emotional decisions instead of rational ones that's all, and I'm sure half the people posting "against" you are trying to point that out.

everyone loves an innovator, but innovation at what cost?

dont argue with woman logic

[KezR33]

For what it's worth, I think it's an awesome idea!

Keep us posted.

[funkymonkey]

in any case... if you want some pointers from guys who've done it before, have a good read of this thread:

http://www.driftworks.com/forum/drift-car-...rift-car-8.html

The build itself is fuckin epic.

They used an RB30 engine (aus spec RB30 block with RB26 head) and a Kenne Bell 2.8H twin scroll (which IMHO is the sweetest sounding supercharger when mated to a big Ford 5.4L).

http://www.kennebell.net/superchargers/for...elby/Shelby.htm

There's also a R34 drag car in NZ that runs 660hpish on a Procharger F1R Supercharger, again bolted to an RB30.

[R33_Dude]

Well there are two main problems with a vortech supercharger the first is lag, just like a turbo and the other is the considerable mechanical effort required to turn the supercharger.

Advantages are that they are compact, the boost increases at higher rpm so as to maximise the power adding potential, and they are incredibly efficient compared to roots and screw type superchargers. They are also quite cheap compared to a roots or screw.

If it was my money I would be doing something totally different, but its not its hers and I am intruiged by this whole project honestly because its not what i would do.

Cara, he did ask a simple question and its quite an easy one to answer - retract the claws.

EDIT: Also I just read your comment about there not being much lag due to tune. The only way to reduce lag on a supercharger is to increase rotational speed - i.e. increase engine rpm. Its not a turbo, tune won't help.

Edited April 27, 2009 by R33_Dude

[MissR34]

dude, i think i might just add, that the supercharger i am using is a centrifugal supercharger.

and no, lag is not an issue, because the supercharger dosent have to spool up like a turbo! and the fact that they are driven by the crankshaft,

and the root and screw type superchargers, are two totally different types of blower to the one i am getting.

[dyken]

Let people be, everyone no matter what do things people don't agree with or understand.

Like Cara building her car, I'm building a ford corsair.. Yes a ford corsair, it will be running a nissan awd system, now many of these do you think there is, considering there is no such thing in the world asaik of an awd ford coresair? Now I know I can spend a shitload less and have something better in everyone elses eyes but I'm building this for me and you would not believe the amount of people who have tried to stop me saying it is stupid for the amount i will be spending.

Project cars are project cars they always cost a shitload and things always get blown way out of proportion, that's what makes them so fun haha

Edited April 30, 2009 by Eug
thread clean up

[Oblivion]

Well to start off...

There is nothing about you doing this that makes sense....but thats kinda cool

Your money could be spent better elsewhere, but it were going to race it then I am sure you would.

You obviously have researched this and are keen on doing it, so I say good luck to you.

You WILL have problems and plenty will go wrong....there is no doubt, i had problems going from an rb20 to an rb25 and still sorting out issues

It WILL cost more then what you planned, it always does no matter how in depth you have gone into it.

You WILL get better bang for bucks from a turbo...but you aren't after that.

Did I mention good luck with it and that it is a crazy idea!!

Will be interesting to see in the flesh when it's done...as long as you don't polish everything under the bonnet or cover everything in carbon fibre.

Again good luck and keeps us posted or blogged, should be good to see what you can fit into the engine bay of an R34.

Cheers Ro.

[MissR34]

hey dude thanks

i wont be polishing or carbon fibreing everything under the bonnet lol

the piping will be made of the same material that my intercooler piping is made up (aluminium or some shizz?lol) so that will prob be the real bling bling part of it!

[STATUS]

Good luck with the charged project it is great to see something different, we do a lot of chargers here on big displacement v8's and i love them to death.

Honestley im not a big fan of them on smaller engines as they need to be revved hard ( see boost graph, ive included a typical charged graph too, overlayed with a turbo curve.) to gain the most benefits the power is way too linear (like a 45 degree ) turbos tend to make more much more mid and similar top end. Hopefully the builder can adress this and im sure he / she will.

In my experience the little bit of bottom end gain is not worth the mid range loss on smaller capacity engines.

Here are some nice charged cars weve had in lately.

Edited April 28, 2009 by URAS

[R33_Dude]

dude, i think i might just add, that the supercharger i am using is a centrifugal supercharger.

and no, lag is not an issue, because the supercharger dosent have to spool up like a turbo! and the fact that they are driven by the crankshaft,

and the root and screw type superchargers, are two totally different types of blower to the one i am getting.

I realise they are different. I was pointing out to someone who posted earlier on as to why you would use a centrifugal supercharger.

I will say this, and I will say this clearly: Centrifugal superchargers experience lag. On small capacity applications they only reach usable boost (psi gained minus rotational force required) at around three thousand rpm.

Here are some references to prove what I am saying:

"Due to its design and lack of low-RPM boost it is often employed on near-standard compression engines" - http://en.wikipedia.org/wiki/Centrifugal_supercharger

"One of the disadvantages of the centrifugal supercharger is that the centrifugal compressor works best over a rather small RPM range" - Sport Compact Car Engine & Driveline Handbook (You would have to buy this or look it up on google books. Page 27, near the bottom.)

It is also in my engineering book on superchargers, I would scan it up for you but alas I have no scanner at the moment and the book is packed away with about a million others. It says something along the lines of centrifugal superchargers building boost with RPM, however lag conditions are created at low RPM, hence why they can be used on mechanically standard engines as the volumetric efficiency of an engine falls when RPM rises. Thus the supercharger compensates by increasing air flow at higher RPM improving power, response and torque throughout the upper mid range and top end.

Essentially a supercharger isn't a supercharger. Screw superchargers produce constant boost. Roots superchargers produce boost down low but seem to lose steam at the top end (quite inefficient too). Centrifugal suffers at the bottem end but the trade off is top end.

EDIT: I have another quote from Sports Compact Car Engine and Driveline Handbook: "Thus even though the centrifugal supercharger is connected to the crankshaft, it still suffers from power lag, a non-linear power delivery sometimes worse than that of even a fairly aggressive, large sized turbo."

HOWEVER

"Centrifugal superchargers are more thermally efficient than the roots blower"

Just as I have been saying all along. But no I can't be right.

 

Edited April 29, 2009 by R33_Dude

[mitchy_]

Just as I have been saying all along. But no I can't be right.

of course you can't, you have a differing opinion!!!

[THR34T]

+ Million for this idea. cant wait to see it Cara! i was gonna attempt supercharging mine a while ago but my plans have changed

am very keen to see this when finished!

[Oblivion]

of course you can't, you have a differing opinion!!!

So how is what she is doing wrong??

Yes there are cheaper ways of getting power and better gains from having a turbo charger...but she is not after that.

So why pursue on the idea?

You and I may not do it cause there are the better ways.

She wants something different.

I am sure there a better trackable cars then your R31...but you like it.

[Turbz RB-25]

So how is what she is doing wrong??

Yes there are cheaper ways of getting power and better gains from having a turbo charger...but she is not after that.

So why pursue on the idea?

You and I may not do it cause there are the better ways.

She wants something different.

I am sure there a better trackable cars then your R31...but you like it.

Buddy.... Did you have a look at that fork picture on page 2 of the thread?

If you did, have another look, it will explain EVERYTHING.

They aren't saying what she's doing is wrong, they are saying that you can have something more powerful, more drivable, with LESS cost.

People are usually rational i.e. comparing projects with cost vs benefit analysis.

This idea appears irrational to me.

Spending that much money merely to have a supercharger.... WA WA WI WA!

You've got my complete respect now...........

Once your car is done, can we meet up and get freaky in the back seat?

[R33_Dude]

Don't get me wrong I want to see how this project turns out. I'm very interested. I just want to make sure she has all the facts first.