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-   -   48 Dellorto + Eaton M90 tuning help (https://www.rx7club.com/1st-generation-specific-1979-1985-18/48-dellorto-eaton-m90-tuning-help-1007852/)

Gaijin samurai 08-10-12 05:40 AM

48 Dellorto + Eaton M90 tuning help
 
Hello,

I've not been on here for a while. I have sold the FD's and have a classic british sports car now runnign a 12a + Dellorto + Eaton M90.

I need some help. I am going to borrow a wideband and see what is going on but I know it's running rich as it stinks :lol: I am running 1-100 premix, Facet Redtop fuel pump and Filter King fuel filter/pressure regulator with fuel pressure gauge.

I've read somewhere that the base pressure should be 3 - 3.5 psi and the screw 2.5 - 3 turns (but didnt say clock or anti clock) for a n/a 12a.

Might just sell the supercharger and set it up n/a but I have no idea on the internals of the carb. I was told it was the Racing Beat one, so assuming it's all standard inside.

Any help?

thanks.

t_g_farrell 08-10-12 07:57 AM

Actually a NA Dell can only tolerate about 2.5 psi. Over 3 is going to cause rich running.

We need more info about the setup. Is it draw thru or blow thru? Whats the ignition setup?
Is the fuel pressure regulated by vacuum at all?

The idle air mix screws are usually about 2.5 turns out which would be anit-clock in british
terms :)

I assume you bought it with the eaton already installed. The previous owner maybe has it
setup rich to avoid detonation under boost.

Posting pictures will help too! I've always thought about using an Eaton as they are easy to
your hands on because their used in a number of domestic SC applications here.

snivley whiplash 08-10-12 07:59 AM

go t gruntled.com for dellarto info

Gaijin samurai 08-10-12 08:49 AM


Originally Posted by t_g_farrell (Post 11184588)
Actually a NA Dell can only tolerate about 2.5 psi. Over 3 is going to cause rich running.

We need more info about the setup. Is it draw thru or blow thru? Whats the ignition setup?
Is the fuel pressure regulated by vacuum at all?

The idle air mix screws are usually about 2.5 turns out which would be anit-clock in british
terms :)

I assume you bought it with the eaton already installed. The previous owner maybe has it
setup rich to avoid detonation under boost.

Posting pictures will help too! I've always thought about using an Eaton as they are easy to
your hands on because their used in a number of domestic SC applications here.

Thanks for the reply, the setup is exactly how I got it, so not really sure what's going on in there. Ignition I believe is stock apart from a FC2000 ignition system.

Tons of pictures.

http://i293.photobucket.com/albums/m...n/DSCF5116.jpg

http://i293.photobucket.com/albums/m...n/DSCF5103.jpg

http://i293.photobucket.com/albums/m...n/DSCF5114.jpg

http://i293.photobucket.com/albums/m...n/DSCF5268.jpg

http://i293.photobucket.com/albums/m...n/DSCF5264.jpg

http://i293.photobucket.com/albums/m...n/DSCF5270.jpg

http://i293.photobucket.com/albums/m...n/DSCF5115.jpg

http://i293.photobucket.com/albums/m...n/DSCF5263.jpg

http://i293.photobucket.com/albums/mm66/badkron/fpr.jpg

http://i293.photobucket.com/albums/m...n/fuelpump.jpg

Directfreak 08-10-12 09:34 AM

Looks very interesting. Post some more pictures from a little further away. So we can see the whole engine compartment at once.

t_g_farrell 08-10-12 09:41 AM

I'd like to see almost top down on the Dell and Eaton setup. Definitely looks like a drawthru.

When you get that wideband you need to make sure under full boost its running rich enough
so you don't get detonation. If you can do it on a dyno or road test.

Gaijin samurai 08-10-12 09:44 AM


Originally Posted by Directfreak (Post 11184626)
Looks very interesting. Post some more pictures from a little further away. So we can see the whole engine compartment at once.

Pic 2 not good enough?

Erm... I have:

http://i293.photobucket.com/albums/m...n/DSCF5125.jpg

But is far away. No top down pictures. I will do when I head back over on Sunday to ply about.

84stock 08-10-12 04:55 PM

very interesting

85TIIDEVIL 08-10-12 06:21 PM

I have a Dellorto setup in a 87 TurboII model RX7 on the stock S4 motor.... Right now it is N/A but from the searching I've done so far to go blowthru I've come across this from Robert @ Rotary Shack in a older thread:

"The Dellorto works great & w/my turbo plenum, the velocity stacks are eliminated as well as new jet covers being fabbed up to seal the carb. Once the carb is tuned you leave it alone. The settings don't change. People usually have other problems ie: bad spark, etc and start messing w/the carb instead of fixing the root problem."

I haven't gotten my hands into my own project yet so I can't offer any first hand experience.

sen2two 08-10-12 08:38 PM

I have actually been thinking about adding an Eaton M90 with a side draft Weber similar to yours. Do you have any pics of the set up not installed on the car?

Especially pics of the intake manifold set up...

84stock 08-10-12 08:55 PM

better yet we want video

Gaijin samurai 08-12-12 11:16 AM


Originally Posted by sen2two (Post 11185217)
I have actually been thinking about adding an Eaton M90 with a side draft Weber similar to yours. Do you have any pics of the set up not installed on the car?

Especially pics of the intake manifold set up...

I can get some pictures, didn't go over to the garage today, it's far too warm to be in there today. Maybe one evening I'll get over there and take the GoPro to get some video :icon_tup:

sen2two 08-12-12 02:41 PM

cool.

Gaijin samurai 08-18-12 03:08 PM

Got some more pictures today of the SC setup.

http://i293.photobucket.com/albums/m...n/DSCF5453.jpg

http://i293.photobucket.com/albums/m...n/DSCF5454.jpg

http://i293.photobucket.com/albums/m...n/DSCF5456.jpg

http://i293.photobucket.com/albums/m...n/DSCF7009.jpg

And some other toys :nod:

http://i293.photobucket.com/albums/m...n/DSCF7002.jpg

Video will be uploaded soon...

Gaijin samurai 08-18-12 03:40 PM

Video:

rx7freak13v 09-26-12 06:40 PM

omfg!!!!!!!!!!!!!!!! this is truly the most badass thing i have seen lately. im building a 4 port bridge port for a dd/ autocrosser and im planning to add a weber. i have given so much thought in the past about a supercharger and one day i want to do it. i hadn't given any thought to a draw through system which seems like it would solve all of the downsides i have came up with.

not to pry, but any idea on how much boost it's cranking out? any porting work? i must know more about this please :D

Gaijin samurai 09-27-12 03:22 AM


Originally Posted by rx7freak13v (Post 11235942)
omfg!!!!!!!!!!!!!!!! this is truly the most badass thing i have seen lately. im building a 4 port bridge port for a dd/ autocrosser and im planning to add a weber. i have given so much thought in the past about a supercharger and one day i want to do it. i hadn't given any thought to a draw through system which seems like it would solve all of the downsides i have came up with.

not to pry, but any idea on how much boost it's cranking out? any porting work? i must know more about this please :D

Thanks

Boost is 08bar it's it's a stock port 12a :nod:

It is a lot of fun, it's running much better now and I've done about 100 road miles in it. If you want to know more fire away and I'll try my best to answer.

bo0557 09-27-12 11:59 AM

what happened to the rx4 did the chick owner sell it on..

is the blower any good - did you make the kit of buy it?

rx7freak13v 09-27-12 12:29 PM

is that .8 or .08 bar of boost? i ask because it looks like .08 which would be less than 2 psi, ut .8 is about 11 psi....hmm.

hows the power curve on that thing and when does it run out of breath? does it pull all the way to 7k (8k?) i've thought about a supercharger many many times, but the setup i always thought of was blow through not draw through and when you engine flows air quicker then the manifold can build pressure you end up with a 16psi pulley putting down 4 psi boost to the engine. with the draw through set up, it is pulling the air into the engine instead of trying to compress it before the throttle body. hmm....i would love to see a dyno chart. great looking set up sir. hats off to you!

Gaijin samurai 09-27-12 01:03 PM


Originally Posted by bo0557 (Post 11236645)
what happened to the rx4 did the chick owner sell it on..

is the blower any good - did you make the kit of buy it?

Jo is still the owner of the RX4, it's had a rebuild, bigger ports, 5 speed conversion and lots of other things doing to it over the past few months. Engine is back in now, got to put the gearbox in and get it started.

I didn't build the car, it's exactly how I purchased it.


Originally Posted by rx7freak13v (Post 11236682)
is that .8 or .08 bar of boost? i ask because it looks like .08 which would be less than 2 psi, ut .8 is about 11 psi....hmm.

hows the power curve on that thing and when does it run out of breath? does it pull all the way to 7k (8k?) i've thought about a supercharger many many times, but the setup i always thought of was blow through not draw through and when you engine flows air quicker then the manifold can build pressure you end up with a 16psi pulley putting down 4 psi boost to the engine. with the draw through set up, it is pulling the air into the engine instead of trying to compress it before the throttle body. hmm....i would love to see a dyno chart. great looking set up sir. hats off to you!

Sorry, 0.8BAR 11PSI boost. And as for the power etc, I've not taken it over 5k yet. It pulls VERY hard. But I have no idea what the AFR is doing so haven't pushed it. It's running dead rich at the moment.

I need some time on the dyne with a wideband and screwdriver to set it up but I am running out of time as I am moving to Chamonix, France in a few weeks. The car will be garaged in England until I decide what to do with it :scratch:

rx7freak13v 09-28-12 10:22 AM

11 psi is pretty damn good for a supercharger set up with a linear powerband. im loving the idea. hopefully in the next few months it can get a wideband o2 and some dyno time :D. i've never seen such a set up before so i am very impressed and excited about it. please keep us posted on it, or better yet. start a thread on it when you actually start playing with it please


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