Best exhaust w/o internal mods?
 

I just went from a full ALBA pipe setup to the stock exhaust and Mr. HP endcap. Best damn pipe on the market handsdown (Mr. HP endcap that is). It is quite loud but in the dunes who cares. Just carry the stock endcap with you incase a quick swap is needed.[img]i/expressions/face-icon-small-smile.gif[/img]

Best exhaust w/o internal mods?
 

I don't believe the LTE are released for the DS yet.

Best exhaust w/o internal mods?
 

the hmf exast is the best exast you can buy for a ds and its a slip on it gives aroung 8-9 hp and thats with no airbox mods

Best exhaust w/o internal mods?
 

Mudstud is wrong about needing vacuum in the airbox. I know that rumor has been floated on this forum for ever. But, it is simply not true. The vacuum for the slide comes from the air speed in the venturi. Removing the lid helps if your setup is right, and it sounds like your (duneittilludie) setup is right. I got a big increase in power by removing the lid, and I proved it at Choke Cherry.

Again. the slide does not function by vacuum in the airbox. The air rushing, at a high velocity, past the holes in the slide causes a vacuum in the slide boot, which raises the slide. This is called the venturi effect. Its the same thing that pulls gas from the float bowl. Air speed is the key. Therefore, as long as you don't have a restricted exhaust or air box, the slide should work properly. If it doesn't, start checking these things out.

Best exhaust w/o internal mods?
 

gashog,

you might be alone on this one. Ive had my best results with the lid on. for example I took my lid off and rejeted and lost to the exact same guy I beat 15 min. ago with the lid on and rejeted. take off seamed improved but in the upper rpms I couldnt keep up.

I wonder if the elevation at choke cherry made a differance together with the lid off.? just curious where was your jetting B4 and after the lid on/off
JM2C

Sam

Best exhaust w/o internal mods?
 

keep checking the site ( lteracing.com) becuase the ds pipes will be there very soon

Best exhaust w/o internal mods?
 

Sam. I am using the K&N 185 and their needle (their jet kit). Drag racing isn't the best test. I used a very steep side shute (to the right) of Choke Cherry since I couldn't make it with the lid on and could make it with the lid off. A hill like that is the next best thing to a dyno. I also got another 800 RPMs out of the deal. After removing the lid, only the rev limiter stops it.

Bartlett. The stock DS (with stock endcap) may need the lid on, but that's only because it can't breath with that stock exhaust (no air speed). I have the HMF and lots more ponys. The rest is stock.
As for your experiment. I'll check it out for grins. Here is another one. Take a carb off of a DS and plug one end with plexiglass (so you can see through it). Next hook up a strong vacuum to the other end. Does the slide rise? No!! That's because air speed is the mechanism. The pressure inside the boot needs to be less than outside. The speed of the air flowing through the carb sucks air out of the slide by the venturi effect causing a vacuum in the slide boot.

I'm not the only one either. Jonny Raw has almost the same setup and his is just as fast. We both run without the lid or snorkels. It seems that duneittilludie has figured it out too.

Best exhaust w/o internal mods?
 

I think that i should further explain just how much of a performance gain i got by jetting up and removing the lid.Before i removed the lid and jetted up when i raced my wifes 440 up our short comp hill she was taking me by about 11/2 quad lengths but after i removed the lid and jetted up i was taking her by about 1/2 a quad length and that is a significant gain.When we raced on the flats through fifth gear she could just slightly take me and it was very close and now i start walking away from her and continue to do so as the distance gets further.I am not disagreeing with what i am hearing about needing the lid with the stock carb but i have to go with what works for me.I definitely have a better throttle response now which is the biggest reason that i changed to no lid and rejetted so although i can see your points about the constant velocity i think that i will stick with what is working.Thanks for all the ideas and opinions.

Best exhaust w/o internal mods?
 

Can't we all just get along. lol. I was just looking for some advice on a stock ds that needs exhaust and jetting[img]i/expressions/face-icon-small-happy.gif[/img]

Best exhaust w/o internal mods?
 

Sorry for turning this into a lid on or off debat. However, this myth has been perpetuated for a long time in this forum and its not true.
Proponents of the lid on theory say that the slide doesn't work without the lid on. Then when it is proven that the slide workes fine without the lid they say there is more power with less air. Sorry, but that makes no sense.

Bartlett. You said that the "ds NEEDS the air box lid on and the SNOKEL tube on to perform with a stock carb . no matter what pipe your running" without giving any scientific reason for it.
Let me state your side for you and you let me know if I get it right;
"An engine is an air pump. In other words air volume and air pressure make horsepower. We are talking about changing air volume and not pressure. Therefore, more air volume means more power. So, what you are saying is my strong smooth running DS will work better if I choke off the air."
Does this make sense? Of course not.

You also said "from what you have listed your ds dont sound like it is tuned". Well I'm saying that if you can't get your DS to run without the lid on, then you don't have yours tuned.

Again, I'm sorry for belabering the point so much. But, lots of people on these forums are spending a bunch of money on fancy carbs simply because they have heard this myth from people who don't know how to tune their stock carbs.