Brent 930

I sold my car last summer and it looks like I won't be getting another one for a very long time.

gsxrken

Brent- I had you down for a lifer. Hope all is well!

Brent 930

I am but without a car right now.

JBL930

Why is the 7th injector such a bad idea, and what is the difference between fuel enrichment and a 7th injector? Is there anyone out there with around 500fwbhp using stock (euro) CIS and a 7th injector safely? Or is it one of those scenarios where "it might be alright but you never know"? I know this is an old thread but it's very interesting and maybe there has been more experience with this in the last three years?

PorschePhD

Because the intake is meant to flow air, not fuel. Fuel is denser and will not flow as air. Introduce fuel in a air path and you have rich and lean spots creating real issue in an intake that already has a deviance from runner to runner as much as 33%. In a short time you will have a hole in a piston. I have a motor that we are doing right now that the bloke thought he could defy physics.

Fuel should be shot to the back of the intake valve for proper blending and cooling. Most enrichment systems do not do anything other than add fuel in the midrange where it is not a problem. The fuel head mod increase the range overall and adds fuel up top where needed.

Hope this helps.

JBL930

Thanks Stephen, that does make sense. How do the Rice and Andial enrichment things work, do they also add fuel to the intake manifold or separately to the injectors or something? Will modifying the WUR help with getting enough fuel in safely? Also how much does a fuel head mod cost, and would you be able to send a modified one to the UK and then reimburse me when I sent my standard one back? I wouldn't want to have to take mine off, send it to the US and wait for it to come back, obviously you would have to hold a deposit etc, I’m just curious
Cheers

SoFast

Brent,

What could you do to a car that is somewhat stock? I would like to get the most out of the car, but I am affraid of running lean. What would you suggest to get around 400 RWHP without major mods. Please help a newbie out. I plan on doing major mods in the next few years after I drive the car for a while

PorschePhD

These systems cause the control pressure to drop through the WUR. They do not use external injectors. As soon as the system sees .4 bar it dumps control pressure causing the plate to drop regardless of what the WUR wants to do.


Please drop me an email for pricing. I do not like to conduct business on the boards. Sorry, I try to keep things a bit more technical.

nathanUK '81 930 G50

Get the fuel head mod. Then get your WUR modded if when you check your AFR's you are not happy with them.
I wouldn't clutter up my car with the Andial.

I have one of Stephens modded USA fuel heads. I have been meaning to take some pics, it looks beautiful.

JBL930

Nathan, do you mind elaborating on what other stuff you've had done and what power your engine is putting out and also your AFR's across the range, I know mine was getting a little lean above 5500rpm and at it's worst it was 0.85 lambda (I don't know what the conversion is to AFR) at 6500rpm so a seventh injector was added just to bring it a bit lower for safety, I’m just a little concerned now about this seventh injector business and wondering what other options there are before going EFI, that's why I was asking Stephen about the fuel head mod, my WUR has been adjusted to flow more fuel already although it hasn't been made adjustable.
Another question for Stephen, I’ve searched a few threads that you've replied too regarding fuel heads, and was just wondering if you mod the US fuel head to flow like the euro one is there any gain in modifying my 87 euro one, or is it already flowing as much fuel as it can?
Cheers
P.S. I will send you an e-mail regarding my earlier questions

nathanUK '81 930 G50

My car is in pieces... I bought the car, no faults at all (apart from the horn). Got the need more bhp bug and took it apart for bolt on mods after owning 8 months. I keep buying parts and don't have them all fitted yet.

Here is my signature from Stephens Forum, www.turbo911.com

1981 UK 930. G50 shortened, 3.8RS Fibreglass Body Kit, 18" Alloys 8.5" F & 10" R, 225's F & 285's R, 3.8RS Colour Metallic Blue Paint, FIA Sparco Evo's, A/C and Air Pump removed, Electronic Boost Controller, GHL Headers.

Fitting - New service kit, Tial46 WG.

Needs Fitting - K&N CO Sensor, Round A/F Dial Gauge, K27 HFS, Kokeln IC, Stephen's Intake Assy & Fuel Head.



1983 UK 911 3.2 Carrera Sport Coupe. Black, Black Leather with Red Piping, Black Alloy Gear ****, K&N Air Filter Element, Turbo Tie rods.


I'm hoping for 400bhp at the crank, Stephen does not recommend going any higher with the stock rod bolts.

I would say you need to have a AFR gauge as you can then pinpoint you mixture much more accurately, any higher than 12.3 Air to Fuel ratio is bad news when on boost, too low/rich washes out the oil from the rings, not good either. Any lower than 12.0 is a waste of fuel.

Stephen told me the USA head is better modified than the euro modified, more flow. Get one and then tune you car with the adjustable WUR.

If I get my car back together before getting a wideband AF gauge I will just run low boost. I really like the sound of a Motec PLM with the best sensor, I am dreading how much those things are though. But as it has been said "You have to pay to play". I'm sure the PLM is cheaper than a engine rebuild.

Stephens modded fuel head is as far as getting the max fuel (bhp) into the engine with CIS as anyone knows. He says his heads will support 500bhp at the crank safely, maybe more.

Correct me if I am wrong guys.

JBL930

Thanks for the info Nathan, have you had your heads, intake manifold and injector blocks modified at all, or are you leaving those stock? That was one of the first things to get done on mine along with headers, turbo, IC etc. I've been advised to get an EBC, and I would like something to monitor the AFR as well, I’ve read a few threads that go on about knock sensors, apparently it's knock that does the damage? I suppose there are no end of safety devices you can install, I’ll have a word with my specialist and see what he says, it's 490 at the crank now and they are happy with it so I’m happy too, I read so many different opinions it gets confusing, maybe I should go down from a 1.0bar to a 0.8 or 0.9 spring? But then I’d miss the grunt, like you say, "you have to pay to play", hope you get yours back together soon, cheers

jetjox

This guy has perfected cis making over 600hp on the 930 motor. http://www.spezialmotorer.com/
This guy is very well know in Europe.

Joe

JBL930

This is interesting!!! Anyone else heard of this outfit? Or has anyone got one of these motors? Would love to know what they do with the CIS to get that much power safely!!
jetjox, thanks for the link!!!!!!

diabolos88

I thought that 500crank hp was the most a CIS could handle? These guys state OVER 600hp, they also have a 3.3L 950HP car.

supposedly the power is 950HP@7600 Torque: 1143Nm@4600

(With mufflers and 98 octane pump gas)

is this at all possible?