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supercharged

beaver34 - 12/7/09 at 12:25 PM

any one running a supercharged engine on here,or have fitted one to an engine, if so what and how is it, thanks

widz - 12/7/09 at 12:36 PM

just fitted rotrex supercharger on my dax rush hayabusa covered 1400 miles 250 bhp approx it runs very smooth tons of grunt

PAUL FISHER - 12/7/09 at 12:36 PM

"bimbleuk" on here is using a toyota 4age with a rotrex supercharger fitted.
Mk sportscars ran a supercharged GSXR1000 demo car last year,rapid but not very reliable.

beaver34 - 12/7/09 at 12:40 PM

quote:
Originally posted by widz
just fitted rotrex supercharger on my dax rush hayabusa covered 1400 miles 250 bhp approx it runs very smooth tons of grunt

what have you done engine mod wise, do you run an intercooler?

thanks

widz - 12/7/09 at 12:46 PM

fitted spacer plate under barrel first regrind cams 440 injecters cosworth intercooler dynojet ignition module car has been great never missed a beat

jpindy3 - 12/7/09 at 02:49 PM

always run a intercooler if you dont its a good chance it will go bang

beaver34 - 12/7/09 at 02:52 PM

quote:
Originally posted by jpindy3
always run a intercooler if you dont its a good chance it will go bang

what from warmer air entering the engine?

omega0684 - 12/7/09 at 04:30 PM

on any forced air induction system you want to keep the air going into the engine as cool as possible! so its better to run an intercooler as air under pressure is warmer the air not under pressure!

[Edited on 12/7/09 by omega0684]

beaver34 - 12/7/09 at 04:37 PM

quote:
Originally posted by omega0684
on any forced air induction system you want to keep the air going into the engine as cool as possible! so its better to run an intercooler as air under pressure is warmer the air not under pressure!

[Edited on 12/7/09 by omega0684]

im aware of this, but there are plenty of car that run f/i that run without them, they dont blow up,

MakeEverything - 12/7/09 at 04:57 PM

quote:
Originally posted by beaver34

quote:
Originally posted by jpindy3
always run a intercooler if you dont its a good chance it will go bang

what from warmer air entering the engine?

Lol, I thought that.

Although the air under pressure is slightly warmer than that not under pressure, its velocity is greater, so as long as the intake is not sucking in engine Pre-heated air, then the problem solves itself.

Intercoolers are known to increase the power output of supercharged engines, but if the engine intake receives cool air by design, then an intercooler is not absolutely necessary.

I wouldnt have said that it would make an engine go bang just because an engine doesnt have one, but it will make it run hotter. There are things you can do to combat this though, which are cheaper than an intercooler, short term. A lower temp thermostat is one way.

Ninehigh - 12/7/09 at 06:42 PM

Sounds like a bonnet scoop would be a nice idea

djtom - 13/7/09 at 04:30 PM

A couple of points:

To correct the first statement above, air VELOCITY has no effect on air TEMPERATURE. Without an intercooler, the compressed air entering the combustion chamber will be hotter (regardless of how fast this air is moving) than the uncompressed air entering the supercharger.

At any reasonable level of boost the air exiting the supercharger will be a LOT hotter than the air going in due to the fact that you have compressed the air to a fraction of its former volume - remember the ideal gas law from school (pV=nRT) - you can't beat the laws of thermodynamics!

The primary thing that an intercooler is used for is to cool the inlet charge air to guard against detonation (i.e. uncontrolled pre-ignition of the inlet charge), as cold charge air is much better at resisting detonation than hot charge air. Detonation is a very quick way of killing an engine, either by melting the piston tops or by causing significant bearing damage through the increased and sudden loadings on the bearings.

An intercooler will also have a beneficial effect on power as hot air has a significantly lower density than cold air - therefore the cold air will result in more oxygen being available in the combustion chamber.

While I agree completely that an intercooler will certainly assist in lowering overall engine temperatures, it is not the primary reason for which they are installed.

And while I agree that in some cases having an intercooler is not strictly necessary (like in very low boost applications with an efficient super / turbocharger), in order to extract any real performance gains it will be necessary to fit one. In addition, by fitting one you will be running the engine further away from its absolute limits, which will give you more scope for warning of when things are going wrong before serious damage occurs.

Tom

MikeRJ - 13/7/09 at 04:53 PM

quote:
Originally posted by beaver34

quote:
Originally posted by omega0684
on any forced air induction system you want to keep the air going into the engine as cool as possible! so its better to run an intercooler as air under pressure is warmer the air not under pressure!

[Edited on 12/7/09 by omega0684]

im aware of this, but there are plenty of car that run f/i that run without them, they dont blow up,

Petrol engines running forced induction without intercooling will typically be running very low boost levels. I can't think of any modern super/turbocharged performance car that doesn't use some form of intercooling to be honest.

flibble - 13/7/09 at 05:48 PM

When I bodged a supercharger onto my mx6 I had no intercooler, at only 6-7psi it was ok, any more and things would have started to melt, after a lot of flat out runs you could feel the heat in the pipes so even that low boost was probably asking for a meltdown :

beaver34 - 13/7/09 at 06:00 PM

im not sayin i wouldnt need an intercooler, i will run one, also engine will run on omex managment so fueling is taken care of

C10CoryM - 15/7/09 at 08:49 PM

I've a factory supercharged V6 with no intercooler. Mine isn't running yet, but theres thousands of these engines out there running just fine.

That being said, you would be silly to not put a intercooler in if possible. You gain a lot more power potential and do it safer.
For example, a car I helped build (383ci +15psi boost) used a centrifugal blower and 2 air/air intercoolers. It was able to lower the air charge below the air intake temp which allowed for a LOT more power.

And Tom is correct. Any time you compress air you make heat and lots of it. You get about 15-18F increase of temp in the air charge for every 1psi of boost added. Touch the head of your air compressor next time its running and see how hot it is.

bimbleuk - 17/7/09 at 01:49 PM

I have been playing with superchargers since the mid 90s, all Toyota engines up till now.

I think your enquiry is too broad so you would be better off investing in a decent book such as "Superchared" by Corky Bell and do some reading initially to get a good grounding.

I've built up a lot of practical experience as well as reading countless posts on forums, some useful, but mostly second hand info. So if I started posting about my projects and experiences I could go on for days!

You mentioned using an OMEX ECU well they have a lot of experience with forced induction and specifically the Rotrex as they are a reseller. So there's as good a reason as any to consider the Rotrex as a base. However the initial purchase price of the Rotrex puts a lot of people off.

Link to Supercharged

[Edited on 17-7-09 by bimbleuk]

Ninehigh - 17/7/09 at 06:09 PM

quote:
Originally posted by C10CoryM
Touch the head of your air compressor next time its running and see how hot it is.

I'm getting an image of it being a cheap way to remove your fingerprints

I've heard they get up to 200 degrees, iirc...

beaver34 - 17/7/09 at 06:21 PM

quote:
Originally posted by bimbleuk
I have been playing with superchargers since the mid 90s, all Toyota engines up till now.

I think your enquiry is too broad so you would be better off investing in a decent book such as "Superchared" by Corky Bell and do some reading initially to get a good grounding.

I've built up a lot of practical experience as well as reading countless posts on forums, some useful, but mostly second hand info. So if I started posting about my projects and experiences I could go on for days!

You mentioned using an OMEX ECU well they have a lot of experience with forced induction and specifically the Rotrex as they are a reseller. So there's as good a reason as any to consider the Rotrex as a base. However the initial purchase price of the Rotrex puts a lot of people off.

Link to Supercharged

[Edited on 17-7-09 by bimbleuk]

thanks, i am looking at there rotrex kits, ive found so fdar that you get what you pay for normaly, its a duratec engine i will be using, going to get that book and study it before i start, thanks al

bimbleuk - 18/7/09 at 05:10 AM

Hmm Rotrex + Duratec and you're using an OMEX well you have chosen a good combo because that's exactly what OMEX have been playing with for a while now. They were commissioned to produce a kit for one of the top manufacturers and have basically spent a year doing this.

goaty - 18/7/09 at 08:41 AM

thats handy.
This is exactly what i am building too.
My pistions and rods are on order so waiting for there arrival. Gotta start finding bits so i can think about dropping it in for the winter....Be handy having someone else building one at the same time

goaty - 19/7/09 at 01:38 PM

just to change this a little bit, but what would be a better intake set-up??
Manifold witha single large TB on it running a map sensor most likely.
OR
ITB's with a plenum to pipe it up...but how wellw ould thi swork and what sort of metering would be used??

I know the Nissan Pulsar's run this set up, jst not sure how exactly.....

beaver34 - 19/7/09 at 04:27 PM

quote:
Originally posted by goaty
thats handy.
This is exactly what i am building too.
My pistions and rods are on order so waiting for there arrival. Gotta start finding bits so i can think about dropping it in for the winter....Be handy having someone else building one at the same time

i have an issues with supercharging with the steering colum on mine, as the car is LHD, what pistons and rods are you suing, i was going to run on stock internals

beaver34 - 19/7/09 at 04:29 PM

quote:
Originally posted by bimbleuk
Hmm Rotrex + Duratec and you're using an OMEX well you have chosen a good combo because that's exactly what OMEX have been playing with for a while now. They were commissioned to produce a kit for one of the top manufacturers and have basically spent a year doing this.

yeah ive spoke to the guys at omex, also the guys at jamsport do off the shelf kits for rwd fitment, they alod do the cosworth inlet's for rwd fitment too, which look quite good

goaty - 20/7/09 at 06:41 AM

i am using Wossner forged low comp pistons and steel rods. going 1mm oversize too.

As for the cossy inlets, they seem quite expensive so i will prob modify or make something else fit.

bimbleuk - 20/7/09 at 10:31 AM

quote:
Originally posted by goaty
just to change this a little bit, but what would be a better intake set-up??
Manifold witha single large TB on it running a map sensor most likely.
OR
ITB's with a plenum to pipe it up...but how wellw ould thi swork and what sort of metering would be used??

I know the Nissan Pulsar's run this set up, jst not sure how exactly.....

I am running ITBs with a single inlet manifold but it adds complication so a single TB will save a lot of additional hassle.

Otherwise the throttles need to be very well balanced, open at the same rate and even then it can still cause some extra mapping issues due to turbulance at each TB.

goaty - 20/7/09 at 08:57 PM

i have read this too, it involves running two maps etc so prob will make something else with single tb to make life easier.
cheers again