jturkel

what does the butt dyno tell you? how much faster does it really feel?

Velociabstract

My butt hasn't been in the seat yet. I've been scr@wed at every turn. Now no one local has any stainless pipe to finish the exhaust. Dang GTR's ate all the supply. Now I'm hoping to get the car back before the weekend.

Les

C_DirtyTwo

any update?

Velociabstract

Let's get this over with. The shop did the open header and after dyno with the settings for 4wd parasitic losses so the numbers were no good. The pre instal was correctly done. When they realized what had happened I showed up at the shop and we did 10 more dynos more or less. In the end I made around 4 hp. As you can imagine, I've hardly left the bathroom or a full bottle since.

At the 1/2 mile event I managed 1.39 mph faster than my previous best which confirms a small gain. (140.62 mph)

Because I'm still in denial, yesterday I changed the intercooler pump and have new manifold gaskets on the way to rule out a boost leak. Boost dropped 2 psi with the headers. I have the erroneous dyno graph but was so disgusted I left without the correct ones. The difference between the open header and with full exhaust was 7 hp. Even with the erroneous settings on the dyno, the delta is reliable.

Tonight I'm off to a 1/4 mile drag rental. My personal best is 12.04 at 117 mph. As all of this forum knows, dynos are for tuning and the track tells the true story.

As disappointed as I am, I imagine the manufacturer of the headers will be more distraught. They are beautiful. The welding is the best I've seen on headers. My fabricator that finished up the headers to exhaust was inspired, his welds are beautiful too.

I haven't sent the final results in yet because I want to be positive my car is 100%. I'm pretty sure it is but a lot is at stake. When the gaskets come, I instal them (with copper spray this time), log the boost, find out if I had a leak or not. Then I'll feel comfortable and confident, beyond a reasonable doubt, exactly what others should expect from these headers.

Les

Gramma_Benz

My boost dropped about 2 lbs with my shorty headers.

Velociabstract

The rental was rained out. 1 1/2 hours each way. Fck! Next event is a track day, then another 1/2 mile the 28th of april. I'll check the calendar for the next drag rental. They're expensive but happen regularly. This 1/2 mile coming up is different. They're going to have 1/4 and 1/2 mile times and drag radials are allowed. I may up the boost, we'll see.

Les

GT-ER

Sorry to hear Les. How is the A/F ratio IN THE STREET before and after? If the car lost boost it could be very possible that the car just needs a retune. Still have no way to check for knock? I've been suspicious of you running out of injector a long time ago but don't know what you did with that.

Velociabstract

AFR's are fluctuating more than normal. Perhaps because the upper O2 sensors are in a single tube and not a shared collector? The car is still running lean at WOT so I keep a high concentration of 100 in the tank. I think we need to do some street logging, whens your day off?

Les

GT-ER

Thursday/Friday

Kreuzfeuer

Subscribing to this, Les.

I'm on your other thread as well on our home forum, so consider this subscription a "morale boost" LOL

As mentioned on the XF forums, a boost drop isn't that much of a concern. 4hp gain... that's what has me... confused

Those things are too dang pretty for that nonsense.

C_DirtyTwo

wait, so what happened to the original claim of 40whp??

really its only 4?

Kreuzfeuer

Sadly, yes...

macbryanie

This is heart breaking stuff, I was certain headers are certain HP makers.

Velociabstract

I'd never given it much thought before but now I'm thinking that our one exhaust valve is the culprit. Time for some of Rob's heads!

First things first. New gaskets (plugs are new BTW) find a way to meet up with Daniel for some real time logging and not get arrested. A revised tune would be nice.

Les

C_DirtyTwo

have your furthered your search for the culprit stealing your horespower?

Velociabstract

This truly has been FUBAR, not at all how I planned to do things. You know, clear and concise ...... professional.

Gaskets replaced saturday. The back 2 cylinders on the passenger side were leaking. I participated in a track day yesterday and the car ran flawlessly and fast. Talking about times won't work because I ran with R-compound for the second time in my life and first at this track. A new dyno session is in the works.

Based on the on track comments and people coming over to ask WTF I'd done to the car, I believe more than 4hp. If I can extract my self from FUBAR land, some decent information could actually be posted. Nah, I don't know for how long the gasket was leaking. A real shame, letdown, FUBAR.

Les

Kreuzfeuer

For the sake of research, you can send those headers up to TN and I'll do a baseline run and then install them, and make another dyno run. Headers may or may not make it back down to PR

Velociabstract

Next drag rental is the 21st of april and I'll run the car as is. Next 1/2 mile event is the 28th but I plan on changing a couple of details for it.

The headers were difficult to instal so they won't be coming off the car. Whatcha drinkin up in them thar mountains?

Les

Kreuzfeuer

Apple Pie 'shine, brotha

Hey, if you don't ask, the answer is "no" LMAO

Remove the mirrors this time, and see if that adds a MPH or two

Velociabstract

All I've tried is Kentuckee shine. After that my tonsils didn't need removing. If my data logs look good from yesterday I'll be adding my Code 3 pulley for the 1/2 mile. Hoping to squeeze 5 more mph out of the ole girl.

A photo after applying protection at the track and the header connections.

Les

Kreuzfeuer

Dude, you weren't lying. That's more protection than I used in college

The C3 pulley will be stacked with the 178, right?

320 dreamer

les indulge me. pull the grill and the lower grills before you run at the track. to much restriction. idea is to go fast not look good!

Velociabstract

The lower grills are already off the car in the picture ...... you missed that. The upper grill, well, I've run with it and without it. When I had a single intake it made a difference but with the double it doesn't seem to so I leave it on to deflect rocks. When you share the track with racers on Hoosiers you need all the protection you can get. The blue tape and road wrap aren't getting the job done the way I'd like so I ordered some collision wrap for future events.

I'm running a 178 ASP pulley now. I started with a Code3, switched when it started rattling but I still have it in the closet. With the headers I'm seeing less boost so I think I can run both without a problem. I guess I'll find out sooner than later.

Les

C_DirtyTwo

Did you ever get some real numbers on the headers?? Or at least some gains at the track?

Velociabstract

I never went back to the dyno but the 4 hp is about right. I picked up 1 mph at the 1/2 mile event. (140.62) At the 1/4 mile I ran .03 faster with a slower trap speed. (12.019 @ 115.70) It was warmer with a slight head wind. I've replaced gaskets, taken everything apart, inspected and reinstalled and the engine is perfect. Heck, I even did a compression test and have only 1 psi variance between all the cylinders. I've run with water/meth and without it. With 93 octane and 100 octane. I can't explain it. It is what it is. To be clear about my car, I had Needswings downpipes with the cutouts. The downpipes (no cats) gained around 15 hp and with the cutouts open another 10 more or less. The pre install numbers were with the cutouts closed. It doesn't add up but it's what I got. I put some black injectors in this week that I bought and had serviced. My blues are at Marren being checked and flowed. I should get some good info on the differences between the older blacks and newer blues. A new fuel pump and filter go in the weekend too. If any of these changes make a difference I'll post it up. I installed new plugs before the headers and gapped them at .039. During all my searching for a problem I gapped them down to .035 which is where I had the old set gapped. Next rental is the 15th of June, barring rain.

Les