MAF sensor

[larrym]

This has been a very educational thread and I can confirm the results regarding a change in pipe size like I said previously my buddy went from 3" tubing to 4" and he ended with a couple extra psi on his first test run. He removed a 3.5" MAF and a Z06 card MAF in 4" housing and all 4" tube. It was kinda funny he said "man my car was pulling great with the 4" pipe" then looked at the boost gauge it was at 24 not 22 where he had set it for the old set up. I like my GEN2 translator and a simple way to learn how to tune lots of adjustability with the extender G chip. If I could start again I would probably go with the SD2 set up as you have even more adjustability. I probably would have been overwhelmed at first but it look pretty cool.

[daveismissing]

Rich, why don't you ask if anyone is selling an AXIS - a WTB adv on the other board?

[TexasT]

That's a good idea, ill try that.

[Scoobum]

Steve...here's what you're looking for. This is from Patrick Rubio just before he left Precision. Wish he was still there.


Mine's rated at 675 at the flywheel. Where are they getting that number from? I'm a dummy. Went back and reread your post. I see how they get it.



I found a chart from another board that gives a flow rating of 70.5 lb/min for the CEA 6262. Is there a way of calculating lb/min to cfm.

[TexasT]

Rich, I think Indy was a lot more interesting when the cars topped out between 160-180....now it looks like slot car racing to me.  Also, there used to be more disparity in the cars, it seems

I never really liked open wheel racing. And NASCAR pretty much died for me when Cale Yarborough retired. Drag Racing lost my interest when Lee Shepard got killed(Reher-Morrison isn't to far from my house and I used to pass by Paul Peyton's chassis shop when it was on little road in Arlington).

I do laugh at people who think they need an aftermarket computer. I guess not really laugh but feel sorry they don't know any better on their 12 sec car. If you are in the 9s, hey goin fast ain't easy.

 I do my car stuff like I do my investing and don't put money into stuff I don't understand.

[Steve Wood]

That is a very wise move on your part, Rich.  Magic is not for everyone and that is why so many are unhappy.  they did not understand what they bought

[Scoobum]

1lb/min x 14.472...so I'm getting roughly 1020 cfm's.

[Scoobum]

1020x.69 gives a HP of 703

[Steve Wood]

Steve...here's what you're looking for. This is from Patrick Rubio just before he left Precision. Wish he was still there.


Mine's rated at 675 at the flywheel. Where are they getting that number from? I'm a dummy. Went back and reread your post. I see how they get it.



I found a chart from another board that gives a flow rating of 70.5 lb/min for the CEA 6262. Is there a way of calculating lb/min to cfm.

Brad, there are formulas on line to do that...catch is lbs/min is density and you need to know pressure and temperature at a minimum to get into the ball park and humidity to be correct as I recall.

Try it another way, there are formulas online that will calculate wheel hp from your mph at the line and the car weight...They seem to work okay but are factored a bit as they ignore drag which costs you a little.  Joe has a chart on gnttype that is pretty real world. For computing hp vs mph.

Somewhere before I got led in circles, I was going to make the point that if your car made 675 hp, I would guess that you would run about a 10.2 at 132-134 mph. BUT, you are not trying to push the car because you are wise enuf to like to race every week end instead of building motors and the rest of the drivetrain.

I would guess as you pumped the boost up enough to get into this area, you find the car flattening  out and not going faster no matter how much boost you added at that point..   I would bet money that if you would get closer to the theoretical suggested by your turbo specs if you pulled the maf tube off the turbo and let the air enter directly into the bell and the car would pick up instead of flattening out.

For most of us, this is a theoretical discussion because we are not hard core racers because we pay for our own parts.  I have seen cars go faster just with a bigger filter that just not restrict the air flow any....at lower boosts with large turbos....tho

There is a large gray area between what can be done and what most of us actually do.  That does not contradict theory...just the size of our balls

[Scoobum]

Using the Wallace Racing Calculator from my ET and MPH...this is what I get.


HP from ET is 578 at the flywheel and 520 at the rear wheel.
HP from MPH is 627 at the flywheel and 564 at the rear wheel.


Vehicle weight of 3520 is included in the calculation. Discuss amongst yourselves.

[Scoobum]

Steve...you're correct as usual. Air density, temperature all factor into it. Gave myself a headache reading up on all the formulas.

[Steve Wood]

and that sounds about right to me for your current performance.  If you go any faster, you will need a cage....so even if you dare to go where man has never gone...it ain't gonna happen, I suspect.

You need to go fix Dan's car.  I bet he will try it!  LOL

[Scoobum]

Steve, I don't know what's wrong with Dan Kellers car. Boost is at 29.7 with high gear 02's in the 750's. His car weighs 4,000 with him in it. Best he's done is 11.5 at 121 on a 1.7x launch. PTC spec'd race convertor, roller cam, Champion heads, 6262 and alky. He's currently fighting a high BLM problem.

[Steve Wood]

Cam installed correctly?...do the logs show a gain of rpm in third gear or are the graphs flat whether he shifts at 4400 rpm or 5400 into third?

Leak down test?

[Scoobum]

Only thing I can think of is the ring gaps are wrong. No oil out the breathers...bu t no leak down test has been done. Engine is fresh. I'm working 6 days a week...and I haven't got the time.