Don't know, might try again today. Are you still buying the Injen though?

 

Hey E, so the X-Pipe itself is 2 1/4 too?

 

Eric, good choice on the 2.25" diameter. I think 2.5" would definitely hurt low speed velocity. Did the shop replace the stock connections at the cats or did they cut and add the X to the stock downpipes?

 

Yes everything was replaced except for the stock cats.

Yes 2.25in wide.

I am going to try this X-pipe setup with three different types of air filter setups.


I know everything looks pretty messy, but these are just experiments. Once I find the best setup, then I will really work on it.

here is the 1st one. The Jbrady airbox mod with heatshield

 

2nd setup HKS with heatshield

 

3rd setup. HKS with cold air box drawing cold air from the headlight cover that was removed.

 

The size of the HKS intake cone

 

On the 3rd setup pic - where are you drawing air from? Not alot of air comes through the headlight.

you get more by using that plastic airflow thing that goes in front of the grill.

 

Damn, I told you that was a huge intake filter. The other ones I have seen are only 1/2 as big. That HKS one is twice as big as your hand, hehe. Is that the one you used before back in 2001?

 

Yes you can totally hear the sucking sound like *whooosh* when this thing is hooked up. My only hope is that is sucks in so much air and does not loose hp like the K&N filter because it is probably like two and a half times bigger than it.

Well Im just hope that the intake will keep cool, and that the covers from the side parking lens and cover from behind the headlight will cool the intake. It is just a experiment for right now. I still do not drive the car long enough to get real results.

Dam gas prices just jumped through the roof this week. Freakin pissing me off

 

John (and others),

I have this concept in my head that may need some better ideas. First of all, the cats will be gone, the O2 sensors will be spaced out of the exhaust gas stream but still exposed to the exhaust gas. This will free up space and give more freedom in routing the pipes. The spaced out rear O2 sensors will receive lower frequency than the front ones, thus the ECU still thinks that the cats are still functional. More on this if any of you wish to find out more.

Next item is a 2-into-1 muffler (twin 2.25" to single 3", let's call this front muffler) that goes into an identical 1-into-2 muffler (basically just reverse of the first one, let's call this middle muffler). These two will form my X pipe which is slightly longer in the middle. The two mufflers are straight-through, perforated design and no louvres nor baffle plates, so they are reversible.

From middle muffler, the two pipes will finish into two rear mufflers that are straight through also. The whole set up has no baffle plates, no louvres, no cats. Eligible to be called "open exhaust" ? 4 mufflers with negligible "back pressure", do you guys think this set up will be loud ? Should I add two more mufflers (one for each side) between the middle muffler and rear mufflers ?

I admit that I'm infatuated with Burns Stainless X-pipe but it's $300+ ($138x2 + $50 set up fee) in T304 and 2.25" size and I still have to buy 3 mufflers (or 2). One Magnaflow (welded) stainless steel in twin 2.25" in/single 3" out is about $95 or so. The single 2.25" in/single 2.25" out is even cheaper at around $70-80 (depending length and case size). So, mufflers alone will be around $350 or so (yea, ouch). Add labor, mandrel bends and piping. This is getting rather expensive

Thoughts/insights ?

 

Eric, cool, I would like to see pics of the flange to cat area(s). Where did the shop get the flanges? Cut them off your OEM pipes? I am having flanges cut so that I can keep my stock pipes for later re-install if I so choose. These flanges are for 98+ cars and I have found enough differences to suggest that earlier cars would need different flanges. Also, please refresh my memory, did this replace a completely stock system or did you have a different modified system in place before this X pipe install?

Regarding your air intake variations: The 1st one is partially like I suggested but missing some important parts. I kept the stock over-the-radiator feed tube on mine as it functions to both seal the underhood area and provides a source of near ambient temp air flow. Cutting the front open is correct but I kept the area that supports the stock tube for the above reason. I then blocked the entire area from underhood heat and removed the seal around the headlight to provide the additional flow. Also, the shape of the stock box channels air very nicely into the stock MAFmeter. IMO, using an adapter is less effective in this area. The HKS uses a large area filter but still smaller than a stock filters area. Pressure drop differences between the 2 are probably not much. This makes the transition to the MAF and the feed to the filter the main differences. The goal of my mod is to provide the front of the filter with a large unrestricted chamber of ambient temp air.

Tom, you are following my previous thought processes. IMO, your design will expensive and probably less effective than Erics. The goal is to create a column of high velocity gas. Unless you know for certain that the inside of the 2-into-1 muffler you describe functions like the burns Y-pipe... you will loose velocity effectively killing low rpm power.

The stock Y pipe on my car and it would appear to be on ALL the various Lexus V8s are of 50mm diameter. 50mm = 1.97 inches. So, a 2" pipe (51mm) would be a slight increase. 2.125" (54mm) may be the best compromise but is not readily available sizing. 2.25" (57mm) is the easiest choice. 2.5" (63.5mm) would most likely kill low rpm power due to the velocity reduction. Larger pipes have more peak capacity but less velocity for a given comparable volume. The stock center pipe is 60mm (2.36") so going to a 2.5" may be sufficient. 2.75 (70mm) may be best but again, hard to find that diameter pipe and even harder to find that diameter (true inside diameter) in a muffler. 3" (76mm) is obviously available but possibly a LESS effective compromise than a 2.5" center section.

The following are variables that I would like to test to determine the best compromise.
Cat outlet to Y or X section:
2.00" (51mm)
2.125" (54mm)
2.25" (57mm)
2.36" (60mm)
I will start with the 2.25" and the others will have to wait for time and funding.

Y to Center section configuration.
2.50" (63.5mm)
2.75" (70mm)
3.00" (76mm)
I will start with 3.00".

Center section to Y out to mufflers configuration.
2.00" (51mm)
2.125" (54mm)
2.25" (57mm)
2.36" (60mm)
I will start with the 2.25" and the others will have to wait for time and funding.

X pipe configuration.
This can get complicated as the inlet and outlet sizes can be different so you could do 2.00" in and 2.25" out or any combination of the diameters in the Cat outlet to Y or X section above.

X pipe advantage. Only one section before the dual exhaust.

Y pipe advantage. Allows testing of various center section diameters and the addition of a center resonator.

Alternative to Burns X or Y pipe. Although of mild steel and not as precisely engineered the part Eric has on his car is IMO superior to the stamped section used by Peter Scott. It also must be affordable for this entire system to cost only $180. Another choice for both X and Y pipes with the same caveat is Dr.Gas where an X pipe kit is $200 and individual Y pipes are $100: http://www.drgas.com/street-cat.html

I don't think the $180 for Eric's system includes the rear mufflers. My guess is they were at least $150 each. So, $500-600 would be reasonable to duplicate his design.

For my car, the test system will probably run around the same and include flanges, O2 sensor bungs, Y to center pipe, center resonator, Y to muffler section, dual Walker Dynomax Super Turbos. Remember, my car does not have exposed tailpipes, just turndowns. The superturbos should be a good compromise between quiet and power. Once built I will test both with and without the mufflers.

 

John,

Responding to your comments. Yes, the inside of 2-into-1 muffler shaped just like Y-pipe, except that the pipes are perforated. Remember that this is straight through design. The price of one Burns Y-pipe is actually more expensive than the price for one Dynomax Magnaflow SS with 2.25" twin/single 3". Now, this 3" section will be very short as it connects the two mufflers and you listed 3" as an option.

I did email Burns (but no reply yet as this email is being written) asking what the "single pipe" size is for their 2.25" Y-pipe. My guess is 3" (twin 2.25" w/ 3" outlet). Using 4 mufflers, IMO, will reduce a lot of noise, but who knows, right ? Besides, JEG'S is local to me if I need a different kind of muffler.

I'm still very inclined to use 2" system since I will eliminate the cats which should reduce restriction quite a bit, not to mention the cats acting as expansion chambers (slows down exhaust gas velocity and cools it down). Now, if you are talking about 2 1/8" piping, Burns has either X-pipe or Y-pipe in that size.

Regarding total price, I will find out. But the 4 mufflers will be ~$350 (welded stainless steel no less !) so I have up to $250 to catch up to Eric's design. I think I can make it under $600. Maybe $650, but if it flows so much better and so quiet (I know, I want to have my cake and eat it too) , I'll pay the extra I'm also going your route of hidden mufflers with turndowns. I wish I had the money to coat the whole thing with ceramic coating

Eric's cost of $180 is only for the section between the cats and the rear mufflers (labor, pipe and X-pipe), right ?

 

I also want to try this X-pipe thing on my LS, but my 12 sec. car (0-60 time, not 1/4 mile time) it won't make any difference

 

Total piping with X-pipe was $180 and I got the mufflers dirt cheap, since I know the owner of the shop. So the total for the whole system was less than $250 if I can remember.