finboy's ghetto mod of the day: Anti-Lag valve

[finboy]

one major downside of a turbo'd car is the dreaded lag off the line until the turbo spools. it makes bogging a launch easier, and can fuck up a race for you.

the cheap solution?

the D-valve

a 2 way check valve sold at princess auto for 15 dollars. placed a couple inches from the throttle body on the upper intercooler pipe, this valve will remain open under vacuum (requires a filter) and as soon as boost reaches the valve, it slams shut and you have boost. a Y-pipe or barb will be required to mount it to the pipe.

the turbo dodge guys using these are reporting upto 6 psi at idle

not sure how well it would work on MAF cars, for for map car's it is ideal. sizes range from less than an inch to over 2 inches. I chose 2 inch as it is closest to my throttle body size. it measures around 10 inches long, but the ends could be trimmed down if needed. the 1 1/4 inch is only about 5-6 inches long and much easier to install.

here is a link.
http://www.shelbycsx.com/csx321/buildup/dvalve.htm
enjoy.

ps, i realise many will call this mod ghetto as hell, but it works so why not try it?

[Scat]

Whoa
thats pretty cool.
Makes me want to try it out....but I'm not willing to risk fucking anything up.

[GTS Jeff]

are there any downsides to doing this?

[EK 2.0]

Wow Adam, thats pretty cool...

Just a question, us DSMer's can get ECU's that build boost off the line for us, I mean they do a lot more than that, but thats one of the features to the Stutterbox ECU, is there something available like that for the Turbo Dodges??...Just curious...

[finboy]

Originally posted by CycloneAWD
Wow Adam, thats pretty cool...

Just a question, us DSMer's can get ECU's that build boost off the line for us, I mean they do a lot more than that, but thats one of the features to the Stutterbox ECU, is there something available like that for the Turbo Dodges??...Just curious...

most of the turbo dodge guys are stuck in the past, they just recently started doing calibrations. i'm looking into megasquirt so this should help me nicely.

as for downsides to this thing, well it will ugly up your engine bay, and might not work for MAF cars.

[LUDELVR]

full throttle launch...I'll stick with that for the mean time!! hahahaha nice idea though.

[Toma]

6 psi at idle?

It CAN'T work like you describe.

Idle speed is controlled by the airflow into the engine. A 1/8" hole is all you need to "idle".

There is only one way to get boost at idle/no load with a turbo. Massively retarded timing, and excess fuel. Great for race cars, god awefull for street cars....the extreme heat will wipe out your turbo and manifold very quickly.

FWD turbo cars only lag off the line if your turbo is sized wrong or the turbo is just BIG.

You want boost off the line.... load the car up against the parking "break" while slipping the clutch

Toma

[finboy]

thats what all the turbo dodge guys are saying and there are a TON of threads on it over there.

who knows, but i'm going to give it a try, whats the worst it can do

[Toma]

Those guys are all idiots.

The worst that can happen? You waste $50 and your time.

[finboy]

Originally posted by Toma
Those guys are all idiots.

The worst that can happen? You waste $50 and your time.

50, it was like 15, i could see it giving possibly better trottle response off idle. inlet is directly at the throttle bdy instead of in the turbo, through the intercooler, and the piping.

[Boost Infested]

why? i think d valves are F*cking stupid! lag from a t3?

i saw that 3 years ago.... i am still laughing about it.

[Toma]

Yeah, but how much air do you need just off idle? YOu said $15 for the valve, then you need a T, extra rubber couplers (the 2" ones are $10 each), or some welding?

That is the most ridiculous thing i have ever seen.....next to the electric blowers.

AND if it only shuts under boost, then you are wasting anything the turbo assists while still in Vacuum....

[LancerShelby]

Hey Adam, how does it make your engine bay messy if there's no engine in it.......oooooooo Get the car running first, then play!!! It's fucking May 7th!!!! You should be out breaking parts by now

[finboy]

Originally posted by LancerShelby
Hey Adam, how does it make your engine bay messy if there's no engine in it.......oooooooo Get the car running first, then play!!! It's fucking May 7th!!!! You should be out breaking parts by now

BURN on me, lol.

waiting for the first paycheque from the city then the motor and tranny get put in (need to balance turbo, haven't been payed in a month). i pretty much have the drivetrain sitting beside the car waiting to put it in, bu the turbo needs to go on first, another beautiful downside of non crossflow.

my target date is before june first, things left to do...
-install 2 brake lines
-bolt in motor and tranny
-reinstall fuel tank AGAIN
-grease balljoints and tierod ends
-exhaust and alignment

so little and yet so much

[csx321]

Hey, ya know us Dodge guys are notoriously cheap bastards.

The sole purpose of the D-valve is to provide a *small* improvement in throttle response. It's easier to suck air in right in front of the TB than to pull it all the way through the air box, compressor side, piping, and intercooler.

This technique has been used from the factory on some turbo Yamaha bikes. (See this article: http://www.xs11.com/pix/turboarticle.jpg .) Although the article's description of the "reed valve"'s operation is obviously wrong, it serves the same purpose as the D-valve. They describe it as opening under boost, but, uh...I don't think a big hole in the intake tract under boost would be a Good Thing.

All that said, I don't have the D-valve on the CSX anymore. For one thing, it's not my daily driver now, so I don't care about throttle response.

The stuff about building boost at idle is bull, of course. I don't know where that came from.