bimbleuk
|
| posted on 17/6/07 at 03:17 AM |
|
|
Toyota 4AGE 20V + Rotrex initial results
So after my 6-8 month project to prepare a new engine and then supercharger it using a Rotrex has finally given some results.
I had one of those stressful days on Friday as there were a few teething problems to get through before finally getting some positive results right at
the end of the day. Mostly things like hooking up sensors and getting reliable readings, testing the Rotrex oiling/cooling system and upgrading my ECU
to a slightly less buggy version!
All I can say is I was standing by the rollers for a lot of the day willing the damn thing to work. Then later in the day pleading with the rolling
road operator to back off and limit the RPMs as it was bloody working too well! Not something that happens very often.
Spec. of the engine is a Toyota 20V 4AGE with head work, 1JZ-GTE 380cc injectors, CAT exhaust cam, Shiny plenum and a 4>1 exhaust system. The rest
of it all standard as Toyota makes em. The ECU is an OMEX 710 and mapped on the rollers at Mech Motorsport in Cheltenham.
I started with 160BHP @ 7200RPM and 123 lbs ft @ 4500RPM. Ended with 266BHP @ 7200RPM and 195 lbs ft @ 6900RPM. For reference boost starts to come on
at 3000RPM and peaks at 1 bar at 7200RPM. The Rotrex was geared to run to 8000RPM but I'd had enough by 7000RPM as the pistons are cast and CR
is 10.5:1. However the engine was working well with no sign of detonation at any time. Inlet temps were very good and stayed in the 30s which probaly
is probably why it worked so well.
I was just a bit apprehensive driving the thing back home as I was now on very worn semi-slicks in the rain. I did give it a couple of boots and yep
wheel spin is easy to achieve! However it was very docile when tootling along in traffic.
What I have learnt is that a 4.4:1 diff is far to short, I really need an LSD, My 2" exhaust system is not as restrictive as I thought it would
be and now my car sounds like a chav'd up Nova  I'll have to work on that as I can't currently plumb in a sealed dump valve. The
Rotrex C30-94 is probably too big for my current spec. but I was told it would work and indeed it did. Any kit which OMEX or RAW Engineering may now
produce will probably use the smaller C30-84 supercharger to start with.
Most frustrating thing is my new alternator died on the way back and my sump leaks oil all the time. So I can't even drive the damn thing till
I've sorted those things.
|
|
|
|
|
Wadders
|
| posted on 17/6/07 at 05:57 AM |
|
|
What a result, well done, looks fantastic too.
Bet you can't wait to fix those little problems and go for a good blast.
ATB
Al.
[Edited on 17/6/07 by Wadders]
|
|
|
RazMan
|
| posted on 17/6/07 at 06:52 AM |
|
|
I've been following your project for a while now and I am really pleased that the Rotrex it works so well - a great result getting over 100bhp
extra along with a healthy dollop of torque.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
|
|
|
DIY Si
|
| posted on 17/6/07 at 10:22 AM |
|
|
That sir, is good news indeed! Just a pain to have such silly little things go wrong to upset the day.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
|
|
|
tegwin
|
| posted on 17/6/07 at 11:48 AM |
|
|
Good resutls there!
And man, does it look good!!!!
|
|
|
bimbleuk
|
| posted on 17/6/07 at 09:06 PM |
|
|
I jumped the gun a bit on the failures as the alternator bracket was slightly loose. This had fractured a wire from vibration and so the charging
circuit was not working.
However its never that easy so I made another brace for the alternator and re-routed the wiring. Which meant moving my remote oil pressure sensor.
Which meant removing the exhaust manifold. Which then revealed two leaks on the underside past the gasket because the flange was slightly warped.
Anyway as a result I spent all today fixing those jobs and was too tired to bother going for a test
I also tightened all the sump bolts some more which may cure most of the leaking. Just goes to show how stressful a day on the rollers can be on a car
and not just the driver!
|
|
|
djtom
|
| posted on 17/6/07 at 11:44 PM |
|
|
That's an outstanding result for such a high c/r and cast pistons! You must have a hell of an intercooler to keep your charge temps so low.
Well done - especially on the fabrication work - the plenum looks great. You've given me inspiration to try to get mine finished now (had a crap
weekend remaking stuff that fitted fine when I first made it - without any gaskets. Grrr.)
Tom
|
|
|
bimbleuk
|
| posted on 18/6/07 at 11:28 AM |
|
|
I'm using a Toyota Mr2 Mk1 supercharger intercooler which were import only but they are available and are cheap (in fact I may order another as
a spare). They are a good size and as you can see the inlet/outlets are perfect for nose mounting. I spent time making sure the air entering the nose
cone is fuly ducted through both the intercooler and radiator. I've since added more partitioning to seal the front of the intercooler even
more.
Oh and the Rotrex SC if well matched can be very efficient at compressing air with minimal heat added.
|
|
|
NS Dev
|
| posted on 18/6/07 at 04:14 PM |
|
|
a lovely job, did you make the inlet manifold? Very nicely done and properly engineered!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
|
|
|
bimbleuk
|
| posted on 19/6/07 at 02:59 PM |
|
|
Lets just call that plenum a prototype! I actually bought it from someone in Malaysia vie ebay. Looking at it there wasn't much I could do to
improve it especially for the money they were asking.
However on my car I managed to crack the plenum around the edge of the cast domed section. After cutting it apart the consensus was the flat baffle
plate between the trumpets was too thin and had failed from vibration. Very hard engine mounts and high RPM weren't helping. This was before the
rotrex was fitted.
Anyway I've been feeding my findings back to the guy making them so I get another one with a few modifications.
|
|
|
bimbleuk
|
| posted on 21/6/07 at 11:20 AM |
|
|
Thought this may be of interest as its a good way of illustrating the increase the Rotrex has had on power.
|
|
|
MikeRJ
|
| posted on 21/6/07 at 12:49 PM |
|
|
quote:
Originally posted by bimbleuk
I'm using a Toyota Mr2 Mk1 supercharger intercooler
That looks very, very simmilar to the stock Mk2 MR2 Turbo intercooler, which is easily and cheaply available as many people upgrade them.
|
|
|
thomas4age
|
| posted on 21/6/07 at 01:37 PM |
|
|
brilliant Justin!
good going on that, I don't even want to know how 266 20v hp would feel like.
amazing what strong computing power can do for you these days having 10:1 compr running on 1bar of overboost and not having detonation, good
intercooling is key i think!
hopes just gone up heaps for my twin charged 10:1 compr 1uzfe V8
can you explain what the difficulties where regarding keeping knock out of sight? ignitionwise, how much retard and how much power did that retard
cost
the exhaust systems are more then capeble of doing this power, but you seem to have a different one than I have.
Grtz Thomas
If Lucas made guns, Wars wouldn't start either.
|
|
|
bimbleuk
|
| posted on 23/6/07 at 06:32 PM |
|
|
Mike, you're probably right there I knew it was from an MR2 and I bought it from Fensport for about £40 or something and they had a few.
As for detonation there were no signs of it on the rollers but then the operator is very experienced and has a good feel for the thresholds. Actually
it was only me jumping up n down telling Dave to stop or he would have carried on mapping to 8000RPM!
OMEX and Mech Repairs/Motorsport use a fair amount of ignition advance on the 20Vs up to 34 deg or about that to get the power. Amazingly my engine is
only a few degrees less advanced! As a safety measure Dave backed off the timing by a couple of degrees and immidiately lost 20-30BHP and the exhaust
note sounded wrong. So its likes a lot of timing advance.
|
|
|
bimbleuk
|
| posted on 23/6/07 at 06:35 PM |
|
|
Oh and my exhaust manifold is over the chassis at my request as I wanted room below it to move the alternator and get as little heat under the bonnet
as possible. The under chassis manifold killed my alternator and heated the top water hose. Seems to work both NA and SC anyway.
|
|
|
oadamo
|
| posted on 23/6/07 at 07:03 PM |
|
|
what size pipes are on your exhaust manifold
adam
|
|
|
thomas4age
|
| posted on 23/6/07 at 09:17 PM |
|
|
good to hear that the engine will cope with this little retard on boost,
I just hope the 1uzfe will be the same, altough thet's not near as much advanced as the 20v when NA tuned.
btw can Mech motorsports also map engine's alone? or do they need the whole car? (dynowise)
grtz Thomas
If Lucas made guns, Wars wouldn't start either.
|
|
|
bimbleuk
|
| posted on 24/6/07 at 12:18 PM |
|
|
Adam - I'll probably have to verify this but I thnik the primaries are 1 5/8" and I've always thought they a bit oversize for the NA
engine.
Thomas - I had a look at the ignition map and the main map is more advanced at high RPM. Part throttle it is up to +40deg and nearer 34 deg at high
loads and high RPM (6600 - 7200 RPM). I just need to work out what MAP sensor readings might be doing to retard this.
Mech Motorsport only do chassis dyno work.
[Edited on 24/6/07 by bimbleuk]
|
|
|
