Nice numbers. Throw a set of 1.6 rockers and some LT4 Hot
springs and I'll bet you make 300.

 

Hey Dan...I thought all of us with MAC headers were supposed to run slow and not make any power?...LOL

Frank

 

You prove that wrong, that's for sure.

All I know is that I'm VERY happy that I bought the MAC's. I have nothing against LT's, but I just want to give unbiased results of what you can get without having to go with LT's.

Now I really wish I would have dynoed with an ORP so that I could compare directly to LT's. Like I said, I probably have at least 5 more HP in the system, so the numbers look very similar to what I see guys putting down with LT's, on a stock car. ( I know I sound like a broken record by now)

Now I do agree that once you go BIG with the cam and heads, forced induction, or nitrous, LT's or bigger primaries should be better.

Seeing that my TQ hovers between 310 and 320 from 1800 RPM up to over 4800 RPM has me thrilled. Bump that up another 5 TQ without the cat. I don't recall whole lot of LT guys running 325 TQ with headers and CAI.

Dan

 

great numbers, I just got my macs on. did the y pipe exit point a bit towards the passenger side of the car for you? I have to take it to an exhaust shop to get the y-pipe, cat, and catback to hook up. drove it open headers in the rain though. tire spinnage

 

My Y-pipe pretty much was straight back. Are the Y-pipe to Collector bolts tight?

Dan

 

yeah, they're tight. we left the header to y-pipe bolts a little loose, but that only allows us to pivot it up and down, not left and right. there was no way to point it straight back.

http://www.cardomain.com/memberpage/520908/7

theres some pics from it. I forgot to get a shot of the Y-pipe on there now.

 

Everything on mine bolted up perfect. The only problem I have is my #5 tube hits my steering linkage, but that's because of the weak motor mounts.

Frank

 

Since the end of the Y-pipe is a ball joint, it allows some misalignment and it will still seal to the cat.

Just make sure that you have the header to Y-pipe bolts tight and make sure the alignment is bad before you cut the Y-pipe. It surprises me that it's far enough off to make you cut it. Rem
Rember that you can move the catback a little left to right.

Hope it goes well.

Dan

 

DId you dyno your car at Hardcore Racing? Were you the first car to dyno?

 

Yes, that was me.

I assume you were there too?

Dan

 

I love my MAC's, they made a huge difference over stock and I can't complain. But I have a question...my car dynoed 279.8 RWHP (SAE) and 317.4 TQ. During the run the a/f was around 13.1 - 13.4 through 3800 rpm, from there it went to 14.4 at 5400 rpm.
My question is...what would cause something like this and what's the easiest way to correct the a/f?

Drew

 

I'm guessing that your PCM needs a slight adjustment/tune.

If you have a graph of what the A/F ratio did during the dyno run, I believe you can send that to www.madz28.com or www.pcmforless.com and they can help you get rid of the lean condition up top and get it running great.

Are you running a cat? If you are, and they put the wideband sensor in your tailpipe, it will read a few points high. So 14.0 is actually 13.7 or so. This is only if you have a cat though.

Dan

 

Yeah I have both cats still, didn't want to worry about pasing emissions test.
I have a graph of the run and I notice madz28 is somewhat local...that will help. Thanks!!!

Drew

 

Looks awesome Dan!

With that low end torgue your gonna need some stickier tires in back. If your car is anything like mine I'm sure you can break em loose in first gear at just about any speed

 

Thanks!

Yeah, I'm surprised that even with the 275/40-17's (Goodyear F1 GS-D3's), I'm able break them loose with ease. Almost too much ease.

Dan