As I said before I am trying to track down boost loss problems, some exhaust leaks and try to cool the motor down.

First things first. ARE has done a phenomenal job of working out the kinks in this kit and have now pretty much redesigned the whole system from adding an oils scavenging system, new rad and overall fitment issues. Kudos to Stew who probably knows every bolt in my car better than he ever wanted to. ARE also built the motor in my car and it has run strong for 2 1/2 years even before the turbo without any hiccups. I am extremely happy with the support and workmanship ARE has put into my car. They have even worked out vibrations and squeaks it has picked up along the way, making the car smoother and more enjoyable to drive.

My car under WOT will spike to about 8 psi during any run and quickly bleed off to about 5 psi. Boost response is slow and the car has to work harder to keep boost up. At the track the car noses over with every shift meaning it has to catch up from the previous shift obviously slowing it down. The car was dyno tuned an maintains a safe, rock solid 11.9 A/F ratio, our baseline was 490 rwhp and 608 rwtq. Fuel pressure remains a constant 60 psi at WOT

Today we decided to replace the passenger side manifold (ported 2001 log) with a freer flowing Mac shorty header and make dyno pulls to determine the results if any. The goal was to see if we could make the car work less hard, help in cooling and hopefully stabilize the boost. We decided not to make any other changes to the tuning or anything else on the car to keep it a fair test. We weren't expecting too much but it turned out very very well.

I got to the shop at about 9:00am and they started working on it right away. Out came the manifold and in went the header, the cross over tube had to be cut down and flanged to fit the cross over pipe. ARE welded the cross over tube were it connects under the tranny to remove a clamp and permanently solve one exhaust leak problem. I measured the tubing and manifold:just for comparison

Old Stuff:
2001 manifold - Exhaust port 1 3/8 inside diameter
2001 collector - 2 1/4 inside diameter
Cross over tube - 2 1/8 inside diameter

New Stuff
Mac Shorty - Exhaust port 1 5/8 diameter
Mac collector - 2 5/8 inside diameter
Cross over tube - 8" shorter same inside diameter

The total job including re and re, fitting, welding and finishing took about 3 hours.

Wade and I both took the car for a test drive to see how it ran, impressions from both of us were the car idled better, ran smoother and the motor no longer sounded like it was working too hard. As a side benefit it is now quieter and valve train is more muted. We both got one big surprise (remember nothing else was changed on the car or it's setup) at WOT the car now saw 12 psi and it held full boost through WOT pulls tailing of to 10.5 psi near the end, it tells you something when you can free boost with one change . The car also spools quicker and feels snappier. It looks like we solved the boost bleed issue and managed to solve a huge restriction in the car. The car also seems to be running cooler, and today is quite warm.

We strapped the car to dyno and Wade made two pulls. The result was very interesting as the car made the same power and held boost, but surprise surprise the A/F mixture was now 10.4 which is a huge change. The car richened up dramatically, the curve was smooth and power did not drop away as before. It was very interesting to see my maxed out injectors no longer working very hard at all. The super rich A/F more than covers off the lack of gain on the dyno and if we were able to tune back to 11.9 today, I think we would have made some pretty impressive gains, that will be done when I get back from vacation. The guy that tuned my car at ARE was away today so that part will have to wait.

I would have to say that this one change made a big difference to the car, made it more tunable, better running and removed a huge restriction in the exhaust. This time well spent. I will be heading to the track next Wednesday night to see how it all works out.

Paul

 

Good to hear man. I guess I'll contemplate doing this as well. Were you able to buy just the one header or did you have to buy both?

 

I called Mac and they were more than happy to sell me just one header

 

Rock on. I think I'll try that

 

how much was just one? what do you think about the jba shorty?

this is something i will HAVE to try at some point since well its the exact same issue i'm having... thanks for making the headway

 

Wow...Congrats on this... and thanks for sake of many.. including MM.. for doing this test.

Definitely some good info!

I am very interested to know the new numbers it puts down... goodluck!

-Jarrod

 

Sounds very interesting Paul.

Don't you have a 415ci aluminum motor? I would think you'd be looking for like 600 - 650 rwhp with a big motor + big boost. I'm just basing this off the fact that I see h/c/Vortech 9 psi cars click off 500 - 550 rwhp.

 

ARE get's the accolades for figuring this out not me. They are definitly on the right track, it was Wade's idea.

Mightymouse,

I'm sure any shorty header would do, just be careful that the collector gives you room to cut down the cross over tube. The header itself cost me about $190 to my door. I figure Rob should give me a free T76 for all the bugs I've worked out for his kit NOT!!!!!!!!!!

RICE ETR,

Once I get it tuned I'll let you guys now what it makes. I am still astonished at picking up 4 psi for the sake of an exhaust change

Pro Stock,

Yes I have a 415 CID motor. the goal is 600+ but the restrictions have definitly been holding it back and the motor was working way too hard. When tuned I think you will see some nice numbers. BTW I don't think those blower cars are making the kind of RWTQ my car makes

I still need to tune in the new injectors and have the exhaust tubing Jet Hot coated.

Paul

 

I should add, I don't completely understand your conversations about turbos, T74 thrust mount vs the other one you wanted, but I'd think you would want to shoot for 650 rhwp (easy tune) and 700rwhp (more aggressive) but still on pump gas or 100 octane. Your number definitely point to a restriction based on the modest HP and the huge torque.

 

Hahahaha, just ordered 1 of their headers and the fuggers charged me $200.

 

That's awesome, congratulations!

Is that a different header than the regular mac mids? I am just wondering if those are the ones I have now. It's nice to see a legitimate breakthrough on the tuning of these kits.

-Geoff

 

Warbird your post makes me that much more confident in picking ARE for my build.I have been following your threads since you did the QMP kit.I knew Wade and crew would resolve the design flaws in the QMP system.I think ARE should market their own kit considering the R&D they had to do. to ARE and you for figuring out a big road block with the QMP turbo kits.

 

reason i ask is jba makes a shorty that will bolt right to the crossover, as it is made to work with a stock y pipe.

 

Best thing to do Dave is to just call JBA directly. Also from what I understand the shorties don't flow much better than stock, so a ported stocker would probably flow near the same. If your stocker isn't ported your welcome to my ported/coated one.

 

Mightymouse,

You'll probably still have to make adjustments to fit. The Mac has an O2 bung in the collector which made it easy because when we cut down the cross over tube I lost the bungs there. I'd call JBA and tell them what you plan because most headers, even ones that bolt up to the stock Y-Pipe need to be adjusted. Cutting the cross over is not that difficult.

White Hawk,

Standard Mac LS1 header, looks like you cut a break, we made no modifications to the header itself

ARE422DP,

Funny thing is Wade was talking about that today. He already has his own TT for the C5 that is working out very well and they have the tuning pretty much down pat on these cars. I have heard about your motor and it sounds impressive I hope to hear much more about it, ARE builds some of the fastest car arouns

Paul

 

Hey, being a cheap bastard pays off every once in a while! Those have flare connectors on them, right? did you just trim off the old crossover and then flare it? Or did you weld a piece on to the end of the old crossover. Thanks for the info.

-Geoff

 

We cut down the the cross over tube and welded a new flare connector to the tube. The sdvantage of the flare connector is it gives you some built in adjustment and they rarely leak . I have removed my EGR system and air pump so I capped off the connectors as well.

Paul

 

Good job!

Now all you need to get another 50RWHP is a CUTOUT or a dynomax Bullet Muffler!!

That B&B exhaust you have on the car flows like **** at your power level. **** isnt a strong enough word hehe

I'll even pay for the price of the cutout (not including install) if it doesnt give you a BIG gain!! (More than 20-30RWHP with tuning


Chris

 

You have a deal

the cutout is on my list and I'll get to it very soon. I need to get the other nit picky bullshit out of the way first and I'm pretty close now

I like the BB Triflow so a dynomax is not in the cards right now a cut out will solve the exhaust flow and I can cork it back up for street use.

Today was a major step in the right direction and I still have another couple of tricks to play with

= Chris/ARE360

Paul

 

You said you had and exhaust leak in the cross over pipe? Could welding and fixing that problem be the reason why everything is running great now?