Lazeum

Hi, I ran as well a mech fuel pump with my setup (F54/N42 with mild cam) and 40DCOE with 32mm venturis. I'm using a wideband to tune the engine and I had some issue with rich conditions at high rpm which proved the pump was good enough. Now, I go with a new head, port & polish + a more agressive Rebello cam, I'll have to check it out again to make sure the pump can handle the extra air and fuel supply. I also have a regulator setup at 3,5 psi (I have a electrical pump disconnected also)

I'm going with a "street" ported/polished P79 made by Braap with adviced Rebello cam. The new comp ratio should be around 9.0-9.3.

I currently have: F54, N42, flat tops, MSA stage II (scheinder 274/274), 6-2-1 header, 2.5" exhaust, 3 weber 40DCOE, electronic ignition. Comp ratio is around 10.3 Timing had to be backed up a LOT to make no knock with 92-93 pump gas (28° total which is lame). To increase whp but also streetability, 2 choices: - To go with bigger cam to lower dynamic compression - To change the head with less compression and/or better chambers Both of those changes will alow you to increase timing since you'll delay knock threshold. I've chosen the 2nd solution It still have to be installed. for your info, car is nice to drive and feels good (plenty of torque). power starts to be smooth at 2500rpm but it falls down quite fast at 5500rpm. It is nice BUT it can be much better... and it will, I'm sure To reach 100mph on open road is easy. I estimate the power to around 200hp at the crank when I compare with my DD (same weight - 140hp) but I did not dyno it (would it make sense anyway since you cannot really compare dyno # from different dynos?!?!) I'm planning to change the head around Xmas if the weather is not too cold, I'll post some updates if any are available

you should definitely keep the triples Those are great carbs with good performance and noise. They should not make your gas mileage worse than any other carbs if they are setup correctly. There's a post it on L6 section with tons of info. I started from scratch with mine and now there are almost fully tuned, only by me. it has been very rewarding, I'm considered by others like a carb tuner now (even if I'm far from being one!)

I would check the fuel pump... however, what you've done sounds logical to me to fix the issue. However, we did not have the issue you've here and some of us have high HP output engine too with no needle valve issue I'm aware of. Regarding your fooling issue at idle, you might want to try one step hotter plugs if you haven't done it already Beware of knock but it might do the trick. btw, you definitely need a wideband: that's a amazing tool to tune your engine!

If you're talking about the needle valve, I've made some trials in the past with mine. I went from 175 needle valve to 200. I've seen some changes, those might have an impact on carbs behavior. i said "might" since I don't know for sure if the impact is due to the valves or because of gas management system (mechanical fuel pump with regulator - since I also have a unplugged electrical pump - a noisy Carter unit) Are you sure your problems did not come from a pump not big enough to supply the correct fuel quantity?

Why not using the half shafts as a puller? You compress them first and then you pull quickly on them, they will extand until they bottom out, it will pop out the ring that retains the stub axle with the hit. This is what I did and it worked well. You do not have to use a lot of force to do so.

Yes you can do it, it depends how your exhaust is attached. You might have to remove the 2 bolts with nuts that hold the mount to your diff, which is more difficult than to remove the bar since bolt are easy to access.

I'm glad I was able to help you A spring set for the distributor helped me to add couple of degrees more into play mine was mostly knocling at high load (it's $20 if I'm not wrong...)

I heel-toe everyday with my cars, it is like an habit. I do it just for fun for over 6 years now. It helps to save the gearbox as well Besides some training, I've never done any track day. It might be something to test. Regarding the video, do not forget the nature of the car, it's a relatively small engine with a huge turbo. Power band is most likely super narrow, pilot has to play a lot to keep the engine is the right rpm under boost. Left foot braking also allows him to keep some gas to keep the boost. Taping on the brakes might also change weight distribution to introduce the drift when entering in a curve.

I've always been impressed by video with on board videos to watch foot work Here's one of these, Group B drivers were nuts... Left foot braking is the only way I found not to be bored with AT cars also

You're welcome I'm running 28-29° TOTAL timing vs. 34 or 36° stock which is lame. I have a mallory ignition that helps me to play with the curve. I have 10° at idle. My way to fix that is to get a new custom head (Braap) with new cam (Rebello) and some work done to it

Very nice build! It is me or you have urethane bushings on the TC rod link? I haven't experienced failure myself but I would avoid that based on comments from users

I have the same setup except for the cam; to get rid of knock, you'll have to play with timing, AFR won't help you much I have scheinder cam (MSA stage II) in the car so far, with such a compression ratio you have to run big race cams to lower dynamic compression ratio to avoid knock. For your info, my setup tested with a wideband sensor gave the best results with: Main 135, Air 195, emulsion tube F11, Accel pump 45 Idle jet are 50f9 and work fine, idle is smooth at 850/900 rpm. This will also depend on your venturi size and other parameters. My car was difficult to tune until I noticed one needle valve was crushed, making fuel level in bowls not accurate.

Happy B-day!!!

A bolt is not made to flex under load A bolt is used to create tension into a system to help friction to take the load. In your application to know the grade of the bolt (and the torque you should apply) you need to estimate the force each joint could introduce. Since I don't know what would be the load, I cannot answer your question with some figures. Here is a quick calculation: Radial load per joint / Friction = Min Proof load in Bolt You can use afterwards some charts for bolts (wiki), min proof load will provide you the size and the grade of the bolt you'd like to use. Another solution is to use a big bolt and call it a day if it is not intented to move to much (no loosening over time) This method help to get the correct stress inside a bolt to just reach the end of the elastic phase of the bolt.

It looks like a Ferrari Daytona, that's worth some pennies I'm not a big fan of the shape; it looks ok but compared to other ferraris, I'll say so-so. V12 engine sounds amazing according to people that have seen the car running

I second that, I threw away the uni-sync to use the hose method. Make sure also to have the hose at the same location for each barrel. If you stick the tip of the hose deeper, the sound will change. I just use my fingers as bumps on air horns to locate hose the same way. Moves are fast since you just have to listen for 2-3 seconds each time, so holding the hose with a consistent way helps. Other people say this method is not good enough, I kind of disagree since my idle is more than acceptable.

I think the money question is not only related to initial cost... It might cost some money over time to get some triple carbs tuned correctly. There's more than just power I guess also with side draft carbs such as noise, feelings, etc. If you change to ITB, I would also change the distribution to have fully tuneable ignition table as well to take advantage of the ECU => $$$$

Is that cheating? I've seen it many times. I've always been honest and chose "purchase" when it was to buy stuffs (even when I knew nothing bad could happen) Could Paypal find out and charge us some fees for mis-information?

I have a mallory Unilite with no vaccum and it works good. It is tunable as long as you purchase the springs kit. In addition to the distributor I have a Hyfire unit (equivalent to the MSD 6AL) People are saying the unit is fragile, some high tension can destroy it but so far so good. I kept the stock ballast for this reason. You'll need also to rewire a little bit everything with an adapter if you want your stock tach to work properly. Regarding vaccum location, it does not really matter anyway since all intakes runners are linked together (the web between them is hollow)

To be very honest, you should try to read books first Books on the following link about Webers are great source of info that should allow you to start on your own. http://www.carburetion.com/books.asp

You start to ask very specific question. I don't think we have enough info to answer so far. Head, head work? Cam Spec? timing? Regarding Aux venturi, I have no idea. Have you checked how the throttles move inside the bore? you might have something else that has moved. Then your question regarding power after 5.5k, it is difficult to answer with no data. I would try to go with smaller air jets (richer to be safe) and see if it improves, if not, try to go bigger. If your cam is stock, loss of power after 5.5k would not surprise me. I found a wideband sensor to be an amazing tool. You should try to get one or to borrow one to check where you stand. You should find some around 300$. In the long run, it might cost less money than the library you might end up with to run Webers how they should

Yes, you are missing something, it should be 2x9 not only 9 (because the dizzy turns once whereas engine turns twice to do one full cycle - 4 stroke engine ). So you should be around 32° then which should be good.

According to others, 14-18 btdc should be the way to go with Webers and 34-36° total. Every car is different thou, you'll have to test to check what you should achieve (more degreee is not always better neither)