Custom Built Exhaust Collector

[MasterGuns]

I am about to install what I consider a unique exhaust collector on my 88. I is custom built by Mark's Pipes out in Hisperia, Ca (I think anyway). Has anyone known anyone to install this custom after market exhaust collector or perhaps done so themself. This ceramic coated collector elimates the box-type baffled collector and connects them to the exhaust with exhaust the same diameter as the exhaust headers. This collector allows each exhaust header to be directly connected to the exhaust. Should be a great improvement in the air flow. Does anyone have any information pertaining to this product and other modifications that had to be performed, i.e, jetting?

 

Help.

[Denden]

I put one on my '83 years ago. it was a little difficult because the ends of Mark's pipes aren't exactly the same diameter as the stock pipes. So using new exhaust gaskets, it was a tight fit, getting the ends in. A tailpipe expander will make the job a lot easier. I installed some Jardine mufflers, drilled out a little. At first I didn't re-jet, and it ran strong with more low end torque. Then I went up one size main jet, and found a lot more power at higher RPM's. If you decide to re-jet, you should also replace your 37.5 pilot jet with 42 pilot jet. That will really give it some kick. My '83 came stock with 42 pilot jets...all 1st gens could use them, it helps low end torque.

I added a crossover pipe between the 2 outlet pipes. It helped even out the idle and smoothed out the torque curve. if you just bought yours from Mark, I think it will already have this crossover, I think he said he was going to start putting them on all of his new ones.

(your '88 has 125 main jets, go up one size to 127.5, your stock pilot jets are 37.5, go to 42 pilot jet.)

[CrazyHorse]

How bad a hit did you take on mileage?

[Condor]

How bad a hit did you take on mileage?

 

Yep, Ditto....??

[Denden]

My mpg's went from mid 40's to low 40's. Depends a lot on how much I twist the throttle. But I don't recall ever getting less than 40mpg. I check my mileage at every fill-up. Let's me know if everything is working OK.

[CrazyHorse]

I put one on my '83 years ago. it was a little difficult because the ends of Mark's pipes aren't exactly the same diameter as the stock pipes. So using new exhaust gaskets, it was a tight fit, getting the ends in. A tailpipe expander will make the job a lot easier. I installed some Jardine mufflers, drilled out a little. At first I didn't re-jet, and it ran strong with more low end torque. Then I went up one size main jet, and found a lot more power at higher RPM's. If you decide to re-jet, you should also replace your 37.5 pilot jet with 42 pilot jet. That will really give it some kick. My '83 came stock with 42 pilot jets...all 1st gens could use them, it helps low end torque.

I added a crossover pipe between the 2 outlet pipes. It helped even out the idle and smoothed out the torque curve. if you just bought yours from Mark, I think it will already have this crossover, I think he said he was going to start putting them on all of his new ones.

(your '88 has 125 main jets, go up one size to 127.5, your stock pilot jets are 37.5, go to 42 pilot jet.)

 

Are the jets all the same for 86-93?

[Denden]

Are the jets all the same for 86-93?

Yep, all the same ('86-'93), even the California models.

[CrazyHorse]

One other question Denden dont the standard collectors already crossover in a common area?

[Denden]

One other question Denden dont the standard collectors already crossover in a common area?

No, the stock collector is split by a baffle...right side, left side. No crossover. So stock you have the 2 right cylinders dumping into half of the box, and the 2 left cylinders dumping into the left half. Mark's tubular collector is built so that the left rear and right front pair up, and the right rear and left front pair up. It's not exactly the best way to do it because of the Venture's unusual firing order, but it is necessary to make the tubes in a smooth curve. So the crossover tube evens out the pulses side to side.

Too bad I can't attach a wav. file, the tubular collector (plus my modified Jardine mufflers) give the Venture a different sound at idle (without the crossover I added last year). It kind of lopes like a funny car at idle, just a little louder than stock. When I get on it, well, everyone knows it.

Look at "view my photo gallery", '83 Venture. The picture of it without all the chrome extra's, has the modified Jardine mufflers, and the tubular collector, but you can't really see the collector from the side.

[Denden]

I think Don changed something, so we can upload sound files. Here's my '83 with Mark's tubular exhaust collector and Jardine mufflers with the downturn cut off to make a squared off end.

[Condor]

Denden, I tried to get it to play...even down loaded the latest and greatest Media 11 player, and nada. All I got was dead air.....

[Yammer Dan]

I got it!! That is one wicked sounding 1st Gen!!:bang head::bang head:

[Thom]

it plays on windows media player , sounds good

[a1bummer]

What did it cost? I sent an e-mail to Mark's last week and I haven't heard back from him yet.

[Condor]

Finally got it to play. That's one Bad A$$ sounding V4. Whew!!!

[Denden]

What did it cost? I sent an e-mail to Mark's last week and I haven't heard back from him yet.

Mine cost $160, but that was quite a few years ago, when he first started making them for Ventures. The last I heard he was selling the ceramic coated ones for about $200 (might be more now), and the Srainless steel ones for $300 (that was a LONG time ago). These are just ballpark prices from a long time ago, but it gives you an idea of how much they cost, I don't know his present prices).

You should probably just call him. He answers his own phone, nice guy to talk to.