Figured this could be good for this forum. I will have another Dynotuning session by mid August.

This past weekend (June 18th) I got my car tuned at Modular Powerhouse by Jerry Wroblewski from SCT.

The car has the following mods (also in sig):

WMS High Velocity Intake System /w 90* bend before MAF. Stock MAF
Steeda Underdrive Pulleys Stock Alternator pulley
BBK O/R H-Pipe
Dynomax Race Bullet Mufflers - custom catback
180* Thermostat
Cleaned IMRC's

4.10 FRPP Gears
Aluminum Driveshaft
Fidanza Steel Flywheel
11" D&D Performance SHD Clutch

Venom VCN 1000 Nitrous .055" Pill (80-100 shot) with ~900 psi bottle pressure on the run shown.

And here's the graph



It may be difficult to see...the Torque lines for the N/A and nitrous runs are both faint blue or red in color.

NOTES
1. The first and only N/A Dyno pull was made with a rather sketchy tach signal reading from the wire connected to the passenger side Coil Pack wiring harness. The tuner corrected it after the initial run. This may account for the poor reading on the Dyno graph. As you can see, at about 4200rpm's the graph cuts off...where the torque is just climbing and a reading of 279 lbft. is taken. The run was shut down at 6100 rpms. Peak HP with a stock runner length intake is usually at 6200-6250 rpms, but it may not have been more than that. I would like to have run it again...but I wasn't able to.

I was a little dissapointed with the baseline numbers, but that's with 1 step colder plugs and a .035" plug gap. It's about average for the mods I have...but I dunno what she puts down after Jerry's tune, as he immediately jumped on the nitrous tunes. So who knows what it makes now. Hopefully at least near the 290 hp range, but that's optimism.

2. The first pull on the nitrous the A/F went to 15:1. The Venom Computer controlled nitrous kit is supposed to have a safety "lean condition" shutdown...but the nitrous didn't shut off so Tim got out of it.

The successive pulls on the nitrous netted the same result the motor going lean. So Jerry asked me if I had bigger Fuel Jets. I told him the Venom kit was a dry kit...and that the system pulsed the stock fuel injectors for the extra fuel, and then the nitrous was injected proprtional to the A/F seen by the forward oxygen sensors.

Jerry then told me the Fuel enrichment function of this nitrous kit was "Like a lesbian...It ain't doing Dick." What a character, lol. Jerry then added fuel in the nitrous tune, to try and compensate for this effect. The car then made the 331 hp and 389 lb ft. run. This was alright....But again i've seen 100 shot nitrous Cobra's make 40-50 more hp and over 500 lb ft. of tq. So something is off.

Appearently I have Run out of Fuel Injector according to Jerry. Doing the calculations (which i've done before) are netting a HP limit of about 330 rwhp for 24 lb injectors. My problem now however is that it's only spraying about a 50-60 shot of nitrous because Jerry says I'm out of injector. I've played around with the calculations before...and if I use a 0.8 BSFC then the horsepower capabilities of the 24lb injectors is roughly 330rwhp. But using a lower number such as 0.6 BSFC yeilds quite a bit higher number. So my thoughts are with my car running nitrous I am approaching or exceeding max duty cycle on the stock 24 lb. squirters. I have seen posts in this forum of people running stock (24lb) injectors on Supercharged,BB ,or stroked applications with cams and heads etc. making in excess of 350-370rwhp on stock injectors. I just think that the Nature of a nitrous motor (in which most cases make much more tq.) has caused me to reach this point. So in will go the 42 lb injectors.

Today I spoke with Jose @ Venom Performance, and he was extremely helpful. Jose informed me of several things. The first, was that they do offer custom nitrous jets in the .060" (100 shot) and .065" (125 shot) Nozzle sizes. He did say also...that most cars (even domestic V8's) namely GT's can only run the black .050" "75 shot" nozzle safely. What happens when the larger nozzle is used is the motor tends to lean out, and the A/F goes erratic for a number of reasons...but mainly because the stock fuel system (pump and/or injectors) cannot supply enough fuel. So theoretically (and in most cases) throwing in the larger pill will net less HP, due to the fact that with an erratic and high A/F ratio on the .055" Clear nozzle, the Venom module isn't going to inject much nitrous because the motor leans out.

Mine and Jose's recommendations for anyone running the Venom VCN 1000 kit would be to just run the .050" Black nozzle (60-75 shot) until you can get the car on a dyno for tuning and to see what's up with the A/F. Not only will the nitrous be safer...but it will make more power on the smaller nozzle due to the fact that you get a full hit on the smaller pill.

The tech also told me that one it wasn't the first time someone told him a car was seeing a Lean condition under a nitrous hit on the dyno...when the Sensor for the Dyno was located in the tailpipe. In many instances (not mine ) cars with catalytic convertors do not provide an accurate A/F reading at the tailpipes...as the cats convert some HC's anyway...reducing the A/F and making it lean out. I do have a minor exhaust leak at the H-Pipe crossover, and maybe this was playing with my A/F. The best thing always when getting a car tuned is to get/use welded exhaust sensor bungs for the readings on a dyno run.

I am mailing my Venom Control module back to Venom-Performance, and Jose is going to check everything out on the bench to ensure proper operation. Then he is going to customize the module to provide more fuel enrichment...which will inherently increase the proportion of nitrous injected. I am also having two custom nozzles made - .060" 100 shot nozzle. and a .065" 125 shot nozzle. I know however, that this will require a tune.

In conclusion...I've run out of injector. So I am going to probably go with 42 lbers, and check into seeing if it's possible to just mail the chip off and get the 42 lb injector file loaded and be able to plug the chip back up and keep on trucking while I change out the nitrous jets etc. to try and find the missing power on the spray. Then the next hurdle I believe I will encounter is pegging the stock MAF, as I hope to make close to 400hp/500 tq after sorting out the injectors and nitrous module/jets.

Umm, that's not it but until I get the video uploaded everyone chew on this with me Please...

Philip K.

 

Some good info "Lightning247" you stated that you are returning your control module to Venom to customize the Fuel enrichment? I didnt know they could do this? Wouldnt a good tune work out better? My system seems to cut off at the top end when using the 100shot (.060) But I figure that was normal cause it probably detected a lean condition? which is what I notice on my A/F indicator the red light comes on in 4th gear! plus Iam still on a stock tune! :color: Runs fine with the standard 80shot or (.055 nozzle) Iam also running MACs Highflow Catted H-pipe so I wonder if that is a contributer to my car runnin a little lean? Ill be switching soon to a Pro-chamber and gettin a Tune! let me know how that fuel enrichment process goes with your module?

Will

 

also, guys that s/c and are using 24# injectors are crazy. Min should be 30# injectors.

 

I would use .6 as a BSFC on a PA car and .46 on an NA car. Yes Jerry is a character....a very smart one.


Adam

 

Hey guys,


I spoke with Jose at Venom and I told him about my appearent lack of fuel enrichment...and he said he would test the module. He said everything checked out, and he increased fuel enrichment within the module...which should inherently increase nitrous as well. I recieved the two larger nitrous Jets as well... .060" and the .065" nozzles.

The next step is ordering my 42lb injectors along with a 90mm MAF. I'll be getting a Kirban Adj. FPR and installing the Walbro 255lph Intank Pump i have sitting in my basement. All this installed and i'll be getting a new tune by Randy Haywood in Raleigh NC (I just can't afford to drive to Atlanta again.) He seems to be a Modular Guru (and Jerry recommended him) So that's the plan for now.

I'm going to double check all the wiring to the harness/fuel injector wires...then we'll go from there.

Car pulls so strong on the spray now since the tune...Pulls alot harder N/A also.

I'm thinking about getting an ignition upgrade...Like the Jacobs Mileage master kit or something similar...just to help with the short gap for N/A and on the big shot.

I will have the video up soon....It's been extremely difficult finding a File converter because the camera we used uses quicktime (GAY) and I need to convert it to be able to host it...plus some editing as soon as its in .wmv format.

I'll keep ya posted!

Philip K.

 

As a Venom user, I am very interested in this thread. I am still using my stock injectors and fuel pump and run the silver nozzle. Car pulls a lot stronger with the silver nozzle then with the black, and my plugs look great.

I have 24 lbers and a focus pump ready to install. Now, I am wondering if I should go bigger with the injectors.

I also have colder plugs and I am gapped at 0.40. I always wondered how much a tighter gap costs you in perf when n/a. Any thoughts on this.

 

MTs#1, Ive been debating the 24lbs. inj. also still uncertain lots of guys up here are telling me to go with 30lbs. with the nitrous set-up? I think it all depends the power level you want and the driveability you expect out of the car? By all means go head and upgrade the fuel pump. iam also using the SVT Focus pump.

The colder plugs didnt effect any driveability on mine that I can notice. I have them gapped @35 and car feels great!

 

when i go nitrous...forged...i'll be getting fuel pump and 40's and mass air sensor too