Fueling a GT35r with 7th Inj and Flowtech 007

[MZ3 SBC]

nevermind...

[MZ3 SBC]

Not interested in debating the merits...

[reclino]

I would like to point out that your "bet" is high risk. You state "I would bet there is a tornado inside the manifold at 1 bar boost and plenty of fuel is getting to the cylinders."
This is a gamble not supported by logical thinking. There will not be even fuel distribution, therefore some cylinders are going to be lean,.and some rich. The lean cylinders will run much hotter, and be at risk of detonation. Have you got the resources and time required for the full engine rebuild that might be required when your bet fails?
If this was a $800 junkyard motor I would say send it. Even a simple refresh of a 930 engine is so expensive and time consuming. When this goes wrong it won't be simple.
I see you have the JS safeguard ignition, will be interesting to see how much timing this pulls out when that injector is dumping fuel. I have the same unit, hoping to only need it if an injector clogs or other type of system failure.

[RarlyL8]

The modified -145 FD will support at least 400whp, your unit should not be maxed out. You have an adjustable WUR, these two items are all you should need. I would start there first before doing anything else.
7th injectors were a band aid from an era before EFI. Yes it will help somewhat but is very far from optimal. The intake manifold does not have equal length runners and is designed to run dry. Yes many used 7th injectors but how long did their engines last? Back in the day it wasn't such an expensive proposition to rebuild these like it is now.

[MZ3 SBC]

Waste of time....

[reclino]

Well that's rather disappointing. I prefer the person on the other side of a debate to stand their ground and defend their position. Packing up and taking your toys home doesn't help anyone learn.

[MZ3 SBC]

Originally Posted by reclino

Well that's rather disappointing. I prefer the person on the other side of a debate to stand their ground and defend their position. Packing up and taking your toys home doesn't help anyone learn.

I feel the same way every time I come on Pelican. This debate as been beaten to death for over 20 years on Pelican and the same guys say the exact same thing on every thread re:7th inj without ever having TESTED and PROVEN thier statements and discrediting engine builders who have been around for 40 years....and nothing personal...just not helpful..... could a 7th inj be the cause of engine failure...sure....but so is worn out CIS components, misshifts, over boosting, igniton malfunciton.....I was looking for specific answers to my questions....not engage in key board debates.....no offense to anyone....

feel free to follow along on @outlaw34 on IG..... and watch my progress. I am by no means an expert..but have a lot of invested in this and I am open to listening to everyones knowledge from personal experience.

My motor is an original Andial style built 3.4 by Peter Dawe....it has had a 7th injector since the mid80s and the motor still has perfect leakdown and compression. I own the car for 7 years andonly recenty decided to use it.....if it does not work to my satisfaction....or I burn a hole on a piston...I will be the first to share that. But for now...I am using it with a SplitSecond AIC G1 stand alone to triggerabout .8 bar and 6000 RPM.....it works to well and dropped the AFR so 1.5 - 2 pts...my issue is the old bosch EV1 fat body Injectors are made for 3 bar....and the injector is fed off system pressure at 6.4 to 6.8 bar.....and this is causing the injector to drip....so I am looking to hear from others who are also using a 7th Injector.

I know its not perfect. I know there are questions about atomization and distribution, I know modern EFI and direct to cylider injection is much better. I read all the threads.

What I am testing and beleive is that
1) There is a lot of fuel to befound in a modified lambda based fuell head.
2) CIS FLowtech can get you very close to fueling a big GT35r at 1.2 bar to 6500
3) Ported heads and aggressive cams need more fuel than stock heads and SC cams
4) if you push CIStoo far you get more fuel where you needit and dont need it...
5) RPM Solenoid was the single best mod for the $$
6) YOu need a data logger and lots of time...I have done over 225 pulls on the same stretch of road
7) If you are too fat at cruise and low boost for better WOT /full boost feul...throttle response sufferes and spool slower and looselowrpm torgue...
8) not many solutions out there other than going full on EFI andengoine Management

So before I take tha step which I will asi will never sell this car....I wanted to bring it back to the spirit of the mid80s hot rod that this car exemplifies...

and so....I am pulling the new 7th injector and sending it back to see the magnet is stuck open because of running it at 100 psi...and finding a solution for installing a higherpressure rated 42lb injector ....Maybe I will use an injector holder and weldi ot to the IC...

Once it running I will be checking CHT or EGT at each cylinder with my Innovate MTXsetup.

This is a streetcar not a track car. I do drive pretty hard but no where near the load it would see on track duty..while it will ne nice to know I will have some(!) peace of mind pulling to redline....that will be seldom and brief at those levels...

And do beleive that while the intake wouldnotbe very good in atomizing and distributing fuel under vacuum, at 1.1 to 1.2 bar WOT 6000 RPM.....that GT35r will be pacing those cylinders with fuel......

but I am just a former 2 stroke shifterkart racer...and learning as I go.....

[reclino]

Nice, thanks for coming back. Sounds like your well informed and have realistic expectations. DI fuel injectors operate at crazy high pressure, I wonder how the pattern would look at CIS pressure.
Would.love to see some pictures and explanation of CHT and EGT for each cylinder, that's a good idea,

[reclino]

The other option I see is using an old frequency valve upstream of the 7th injector you want. If you could time the injector to switch on first, then turn on the frequency valve a few millaseconds after. Then shut off the frequency valve and a maybe half second later shut off the injector...... Pressure drop control could be achieved depending on how the flow rates match up with the frequency valve acting as a gate keeper to the low z injector. A bit rube Goldberg, but so is CIS

[Tonger]

To the OP - By location your 7th injector essentially functions as a single point injector system. This would be fine if there were uniform distribution of fuel to all cylinders. This is not the case as fuel variability is significant from cylinder to cylinder in single point injector systems and it is really not in use today.

https://mechcontent.com/single-point-multi-point-fuel-injection-system/

When CIS Flowtech modified your fuel head, they took care to adjust it so that it flowed evenly to all six cylinders. The 7th (single point) injector unbalances this even distribution. I am far from a CFD expert but have seen enough CFD and observed fluid flow in biological flow systems to believe that this nonuniform distribution is real - although I can't 'prove' it to you on an internet forum. It is much better to adjust the WUR instead of adding the 7th injector since it affects all cylinders equally.

Here's what I think I have 'learned' about CIS and higher hp levels:

1. The modified 145 fuel distributor referenced by Brian above does not support 400 whp - not even close and CIS gets a bad rap because of this. There are different degrees of fuel head modification and it needs to be opened 'all the way' by CIS Flowtech to support 400 hp levels at redline. My FD made two trips to CIS Flowtech - the first time I got the 'normal' mod referenced by Bodart, the second trip Larry opened it all the way and I finally had enough fuel. The other key factor is to remove the Lambda which restricts flow in the fuel head via a frequency valve. The presence of the frequency valve is a phylical restriction in the system which cannot be completely overcome even by pulsing the valve more frequently. Eliminating the Lambda (78 and 79 cars did not have this) provides the least restrictive path for fuel allowing higher flow rates.

https://cis911primer.com/pages/descr_lambda.html

**To the OP: If you still have the Lambda, I believe this is a significant flow restriction for you. Elimination of the Lambda will likely get you the final amount of fuel that you need without the 7th injector.

2. Opening up the fuel head all the way to provide adequate fueling at redline will make you undrivably rich in the midrange, even if you have an adjustable Leask WUR. However, you stand no chance if you don't have the Leask adjustable WUR. I still recommend getting the adjustable WUR directly from Mr. Leask who will help estimate and set good initial cold pressure, warm pressure, and enrichment pressure starting points given your individual engine specification.
3. As the OP said, the RPM switch is essential to allowing the vehicle to not drown in fuel in the midrange and still have enough near redline. In my car, the RPM switch is set at 5500 rpm before the car is allowed to see the enrichment pressure.

So in summary you need at bare minimum three things for 400 whp and CIS - 1. Fully opened fuel head by CIS Flowtech - mine is non lambda. 2. Adjustable WUR with good control pressure starting points from Brian Leask. and 3. RPM switch.

These three things are common with the folks I know who have gotten their modified cars to run acceptably well on CIS.

4. Other factors such as Euro fuel lines (larger inside diameter), Bosch 044 fuel pumps, and euro CIS injectors can help even more - I am employing all of these.
5. A real time and data logging AFR meter is essential - you will tune the adjustable WUR to the AFR. After tuning the car acceptably, use CIS gauges to record WUR pressure values of working setup for future reference and share them with other users so that they can get up to speed faster.
6. Dyno time is the most efficient way of tuning allowing user to make changes and see changes in real time - otherwise tuning can take months.
7. Take care to ensure that your fuel pump, WUR, and RPM switch are all getting adequate voltage. Old wiring, marginal fuses, and poor quality red fuel pump relays can all be sources of poor running.
8. Drive your car regularly - CIS hates to sit, especially with untreated fuel.

Here are the WUR parameters that work for me. I can't get an ideal AFR curve like with EFI but it works acceptably well and I can enjoy driving the car.

Cold Pressure 2.1 bar, Warm Pressure 3.75, Enrichment Pressure 2.0, RPM Switch 5500 rpm

Idle AFR is set at ~13.0, cruise AFR ~14.3

for 1.1 bar of boost on a 3.3 using Garrett GT35R twin scroll turbo with 964 cams and a Garretson long neck IC.

I still adjust the idle AFR on the metering plate for winter/summer changes to compensate for air density changes using my AFR meter. It's a simple 3.5 mm allen key adjustment and I don't have to make any other changes.

**To the OP - if you still want to do the 7th injector, it's your car. I just think there is a much safer way to solve the problem and would strongly recommend against others doing what you are doing.

In the end, I'm just butting in because there are good folks like Chris Carroll at TK and Cole (miss the dude) who have taken time to help me and I'm just trying to pay it forward.

[RarlyL8]

A modified -145 FD will support 400whp, I've been employing this method for literally decades. There is a range of adjustability, 400whp being the upper range with the standard modification. I've been consulting and testing for CISFT for years on the 930, helping them improve their product. I don't expect to get any credit from them, that's how business and human nature work.
A lot of testing has been done on fuel distribution as this becomes more critical for engine longevity in track applications. For a street car it is not so critical as you don't spend much time on boost and these cars generally don't get a lot of miles on them. I'm not aware of any of the track cars that I have been involved with using a 7th injector as it is not needed and would negate the effort that went into balancing the fuel delivery per cylinder.
If you want to use a 7th injector that is your prerogative. I don't think you will find much R&D info on them past simple one point AFR readings which are less than optimal due to the reading being an average of all six cylinders.

[flightlead404]

Originally Posted by RarlyL8

The modified -145 FD will support at least 400whp, your unit should not be maxed out. You have an adjustable WUR, these two items are all you should need. I would start there first before doing anything else.
7th injectors were a band aid from an era before EFI. Yes it will help somewhat but is very far from optimal. The intake manifold does not have equal length runners and is designed to run dry. Yes many used 7th injectors but how long did their engines last? Back in the day it wasn't such an expensive proposition to rebuild these like it is now.

Heck I'm getting over 400 whp on a 3.3 with stock lambda fuel head

400 is not a crazy number.

[flightlead404]

Originally Posted by MZ3 SBC

I feel the same way every time I come on Pelican. This debate as been beaten to death for over 20 years on Pelican and the same guys say the exact same thing on every thread re:7th inj without ever having TESTED and PROVEN thier statements and discrediting engine builders who have been around for 40 years....and nothing personal...just not helpful..... could a 7th inj be the cause of engine failure...sure....but so is worn out CIS components, misshifts, over boosting, igniton malfunciton.....I was looking for specific answers to my questions....not engage in key board debates.....no offense to anyone....

feel free to follow along on @outlaw34 on IG..... and watch my progress. I am by no means an expert..but have a lot of invested in this and I am open to listening to everyones knowledge from personal experience.

My motor is an original Andial style built 3.4 by Peter Dawe....it has had a 7th injector since the mid80s and the motor still has perfect leakdown and compression. I own the car for 7 years andonly recenty decided to use it.....if it does not work to my satisfaction....or I burn a hole on a piston...I will be the first to share that. But for now...I am using it with a SplitSecond AIC G1 stand alone to triggerabout .8 bar and 6000 RPM.....it works to well and dropped the AFR so 1.5 - 2 pts...my issue is the old bosch EV1 fat body Injectors are made for 3 bar....and the injector is fed off system pressure at 6.4 to 6.8 bar.....and this is causing the injector to drip....so I am looking to hear from others who are also using a 7th Injector.

I know its not perfect. I know there are questions about atomization and distribution, I know modern EFI and direct to cylider injection is much better. I read all the threads.

What I am testing and beleive is that
1) There is a lot of fuel to befound in a modified lambda based fuell head.
2) CIS FLowtech can get you very close to fueling a big GT35r at 1.2 bar to 6500
3) Ported heads and aggressive cams need more fuel than stock heads and SC cams
4) if you push CIStoo far you get more fuel where you needit and dont need it...
5) RPM Solenoid was the single best mod for the $$
6) YOu need a data logger and lots of time...I have done over 225 pulls on the same stretch of road
7) If you are too fat at cruise and low boost for better WOT /full boost feul...throttle response sufferes and spool slower and looselowrpm torgue...
8) not many solutions out there other than going full on EFI andengoine Management

So before I take tha step which I will asi will never sell this car....I wanted to bring it back to the spirit of the mid80s hot rod that this car exemplifies...

and so....I am pulling the new 7th injector and sending it back to see the magnet is stuck open because of running it at 100 psi...and finding a solution for installing a higherpressure rated 42lb injector ....Maybe I will use an injector holder and weldi ot to the IC...

Once it running I will be checking CHT or EGT at each cylinder with my Innovate MTXsetup.

This is a streetcar not a track car. I do drive pretty hard but no where near the load it would see on track duty..while it will ne nice to know I will have some(!) peace of mind pulling to redline....that will be seldom and brief at those levels...

And do beleive that while the intake wouldnotbe very good in atomizing and distributing fuel under vacuum, at 1.1 to 1.2 bar WOT 6000 RPM.....that GT35r will be pacing those cylinders with fuel......

but I am just a former 2 stroke shifterkart racer...and learning as I go.....

I see your comment about bringing it back to the mid 80's. It you are looking for period mods only then fine.

But otherwise you should seriously look at the FrankenCIS with an eWUR and controlling the ignition. It will work much better for you than the old-school "semi-adjustable" WUR and RPM solenoids.

[MZ3 SBC]

And ...still not one comment on how the 7th injector was supplied fuel. This thread was started to hear from those who have used a manifold installed 7th injector controlled by a stand alone controller that is triggered by a hobbs swith /rpm or something like that. My issue which I have since solved for was that the type of injector that was used was a Bosch 914 2.0 injector from D jetronic. It runs at a 3 bar system pressure. I tried T'ing off the system pressure feed line. But isover whelming the injector.

I searched for a fuel pressure regulator that would dead head off the sytem pressure and feed the 7th at 3 bar. I spoke to all the big FPR companies like Aeromotive and Kinsler..and no such beast exists....only bypass // return units for that kind of pressure.

I considered feeding ( T'ing ) off the control line between the WUR and Fuel Head - but even though the CP will be between 30 and 55 PSI which should work with the inj, I think it leaves more unanswered questions at this point.

I have found a few modern EV14 style 42 lb injectors that can handle 90-100psi have better spray patterns. There are a number of billet single injector holders that I can use to mount it.

So I was curious how it was fueled back in the day.....so far my experience has not been a positive one with the 7th injector. I NEVER said I was sure it worked but said it wasused by some pretty smart guys. I did say I wanted to test it myself and needed some help if anyone had any answers to my quesitons. But alas, here I find myself in a discussion about the merits to my dismay....Does everyone feel they need to save me by reshaping the thread and add thier views on a different topic? Especiallly after I explained I already heard thier views ; ) ... I dont recall asking if it was a good idea. I do recall stating I read a dozen threads around this topic here and on Rennlist. All the same guys saying the same thing....and not one person stated they had it and destroyed the motor. sure its a forum and its a good discussion and we all share a passion.....so no harm no foul!


Yes I do have ignition control via J&S which pulls 2 degrees of advance per 1 PSI of boost to a max of 16.

Tonger: I appreciate your jumping in and sharing your experiences to others that you so graciously shared with me. You have been extreemely helpful to me,and so has my good Jacob Asbury Larry and Dale at Flowtech,my buddy Rey Flores and Brian Bodhart and all those who share and comment here on Pelican.

I was planning on starting a dedicated thread to discuss what I did and what the results where and how I got there...this was not that thread...But since we are here now despite my efforts to just find out from someone /anyone who fueled a 7th injector with NON fuel head delivered fuel (* as in a frequency valve feuler set up ...because the fuel head is already maxed out..and I need additional fuel) to be delivered out side the fuel head. My understanding of a feuler / frequency valve digital WUR...effectively does what an adj WUR does...but does not ADD more fuel than what the fuel head can flow. Changing to frankencis ( whatever) will never happen. I am too far down this road....and would go EFI before that. I tried reading the threads a few times.. KISS.....CIS mxed with 7th or EFI

My set up: I am using a BC with a .9-1 bar spring. With a manual BC ( with ramp ball and spring) I am seeing 1 bar by 3100 RPM....and 1.25 spike ( which I had to rectify by removing the ball) at 4000 and them a smooth 1.1 to 1.15 to redline.

Like Tonger I am Running the maxed Flowtech 007 set at WCP 3.8 b and Enrichment CP 2.1 b and RPM pill at 5500 i was see perfect cruise ( 13.8) and on boost AFRS to 5500 in lowto mid 11s. however at 5800 crossed 12 and at 6200 it was 12.5. I am looking to fuel to 6700 -7000. My motor has ported heads, custom 158 webcam and 3.4L....so it breaths well over 6000.

Recently I added the7th Injector...it is triggered to fire progressively by at 5600 RPM to 8000 at .8 bar and up.
My AFRS dropped to 10-105 on full boost...the front end of the curve being so rich reduced torgue and delayed spool up...at 100 psi once the 7th inj opened...itdripped andmy cruise AFR dropped to 12.5 and I can smell fuel....so I have removed it until I settle the issue. I may connect the AIC to the CSV....just to see how that would work.

I have recently tested removing the boost controller and just running without the 7th injector at those CPs depicted above.....

The front end of the curve is fat in 10's upper midrange good then crossed into 12's over 12k.similar lethargic spool.

I changed the spring to .7 and increased boost to 1.1 without the ramp ball....and still too high over 6000 RPM.

Sure I can drive the car...rarely pull over 6k....but like Brian said...this is a street car...and the amount of time I will be boosting over 6k willbe seldom and brief....so some fuel from a 7th injector is still BETTER than no fuel.....

If I learned anything since I have manged to fuel theGT35r fairly well...there is nothing like it a 1.1 to 1.2 bar...andat some point the car will convert to full MOTEC or AIM EFI.....

I have said what I can...shared what i have learned..thanks those who help.....so debate on.IF anyonecan share any speicific insights to how a true stand alone7th injector was fueled off CIS system pressure....please let me know

[Alan L]

I have around 400 rwhp on an 007 mod FD. Yes - it struggles for fuel. Changing to euro lines gave me about 2% more fuel - I measured the difference. The 007 gets me to around 12.5 AFR at 6000rpm, depending on conditions. So it is on the edge of where you want to be.
I have the Leask rpm switch, that helps. I have a modded adjustable WUR - my design. But you get to a point where reducing the WP makes nil difference. Around 2.5 bar you are done. I have measured it.
I have tried using the cold start injector - which is more or less what you are asking. And yes, it did drop the AFR around 1 AFR from memory. It is far from perfect, but at the point where you are going to blow a piston, it is better than nothing.
Alan

[MZ3 SBC]

Originally Posted by Alan L

I have tried using the cold start injector - which is more or less what you are asking. And yes, it did drop the AFR around 1 AFR from memory. It is far from perfect, but at the point where you are going to blow a piston, it is better than nothing.
Alan

thanks Alan- pretty much same for me ....12 at 5800 12.5 at 6000 and 12.8 at 6300

I am am asking specifically about a dedicated 7th injector ...installed beliow the CSV....separate and distinc. Where it is fed fuel from ....and which injector was used.

That is what I am asking. And yes I will only use it onoccassion over 6K...

the stand alone AIC units seems tobe a better way and super easy way to progressively adjust fuel as RPM increase than the syemts from30 years ago.

here is a picture of how it was installed below the CSV.



Everything has been replaced, restored , calibrated, from electrical, punps, lines,hoses, fuel head maxed,adjWUR,airmeter unit.....

[Alan L]

From memory, and this goes back a yr or three, I had trouble piggy backing it to the rpm circuit. It is not a strong signal - derived to run a tach only basically. I already had a shift light and Leask switch running off it. I think the circuit fell over when I tried for a 3rd apparatus.
Alan

[RarlyL8]

I've removed several of these types of systems over the years and I believe all of them were fueled by the return line on the fuel distributor.
Are you installing the 7th injector because you happen to have one or did you choose it purposely? The reason I ask is there are other piggyback style old school systems such as the ANDIAL fueler. That system used an EFI injector in the WUR outlet line to manipulate the control pressure on boost. The system was adjustable in 10% increments which is an advantage over the static version 7th injector which just dumps unmetered fuel. Does yours have electronic adjustment?

[MZ3 SBC]

Originally Posted by RarlyL8

I've removed several of these types of systems over the years and I believe all of them were fueled by the return line on the fuel distributor.

That is interesting and something I have notvconsidered. The return line must be much lower than the feedline. But I itmay not deliver a consistent pressure stream.

I considered tapping off the control line...but I have to test the effect on CP when the injector draws fuel at WOT. I assume it will drop CP ....but that should be a non issue since the CP will be at the lowest effective point anyway...so return line is intersting. The fuel demand is not great for a few seconds of pulses...betweem 6K and 7k.

Thanks - I will look into that further - maybe connect the FP gauge and log the return line pressure during WOT.

I know my comments are long,,,,amd most are skimming and drawing assumptions...so ....I will split them up

[MZ3 SBC]

Originally Posted by Alan L

From memory, and this goes back a yr or three, I had trouble piggy backing it to the rpm circuit. It is not a strong signal - derived to run a tach only basically. I already had a shift light and Leask switch running off it. I think the circuit fell over when I tried for a 3rd apparatus.
Alan

Thanks Alan...I do not have any issues with drawing the RPM signal. I draw from my J&S Ignition system and it has no problem providing a signal to the BL Solenoid as well as the SplpitSecond AIC unit. I draw an RPM Signl from the 14 pin harness ( black/putple) wire for my Innovate Gauges....

I read about about drawing too much from the 14 pin here on Pelican...so I split the load. Lots of good info here on Pelican to be found..thanks...