johnyIROC

I went to the track yesterday, and I picked up 3 tenths with my new exhaust:

NEW:

Hedman Shorty 1 5/8" Primaries
Hedman Y-pipe
Cut-Out
Best ET: 14.8@91MPH


OLD:

LG4 manifolds
LG4 Y-pipe
2.25" I pipe
Best ET: 15.1@95MPH



I don't have posi, so some of the gains went into wheelspin. If I had posi, I believe the drop in ET would be even more dramatic.

Here's a pic of the setup:

johnyIROC

Apparently no one cares....

darbleinad

heheheh........gotta love the exhaust mods......i picked up almost 4 tenths with my true dual setup. it was a good night for both of us at the track

old best ET: 15.69@88.39 MPH

new best ET: 15.32@90.71 MPH

new best MPH: 15.34@92.95 MPH

the true duals was a good investment. my old exhaust was a dynomax 2.5" mandrel bent system .

1989camarorsrs

iTrader: (-1)

how come u dropped in mph?

TRAXION

I think nobody cares because why would you be happy with losing 4mph??? What was your 60ft in both circumstances? A loss of 4mph is huge and is an indication of LOSING horsepower. I would be very unhappy with losing 4mph. MPH is more important in terms of total power than ET. ET in many cases just shows how good you 60ft.

Tim

johnyIROC

That was with a 2.5 60'. I think you missed the part where I said the new exhaust made my wheelspin WORSE. I do not have posi yet.

Mark A Shields

Is that an Edelbrock emblem on your car on the gfx?

I'm surprised you went with header wrap, heard bad things about that stuff. Oil collection on the wrap can be be fire hazard.
Plus it will trap moisture for faster rusting.

darbleinad

Mark A. Shields,

it doesnt trap moisture when you seal the header wrap with a water proof coating. also when you remove the shipping paint and paint the headers with a high temp VHT paint and bake them in the bbq they wont be rusting anytime soon. the header wrap also keeps under hood temps down. also i am not sure why you think the header wraps will become soaked in oil...........when i put oil in my car i put it into the engine through a hole in the valve covers, the one marked OIL, not on to the headers. perhaps you do something different than me.

also motor oil is no where near as volitile (i dont think thats spelled right) as gasoline. i have accidentily spilt a few drops of motor oil on to hot headers.......it smoked off........it did not burst into flames. the header wrap keeps the heat in the headers adn by keeping the heat in the headers, the outside surface of the wrap is not as hot as bare headers and therefore there is less of a chance of motor oil actually starting on fire .......and if you have enough oil on the header wrap to cause a fire in the first place, you have a serious oil leak and should be running the engine to begin with.

Black 91 Z28

Hey,
I'll congratualte you on improving. I went to the track after redoing my exhaust and ran slower. I also couldn't get hooked up well but I think that had a lot to do with the track conditions cause no one seemed to be able to. Never the less, When I ran after the exhaust the weather was drastically different, hot and very humid as opposed to when I did my "before" runs where it was cooler and dryer. Weather plays a large role in results from what I've heard (unless I'm wrong and then someone can correct me). So take that into consideration if it applies.

David

Mark A Shields

Fine by me, but I believe there's a reason why most header manufacturers will void the warranty if header wrap is used.
Just ask on the tech board, I'm sure you'll get the same answers.
Oh, and engines produce oil leaks, it happens to all of us.

darbleinad

i agree header wrap can cause problems, but if you prep the headers and the wrap properly first, you wont have any problems with rust.

Mark A Shields

Very good point.

TRAXION

Dude - if your wheelspin got WORSE then your MPH should be GREATER than previous ... not less ... IF you actually gained any power. Something just isn't correct with this data. A slower 60ft time with MORE power will always result in a higher MPH if all other factors are the same. I am not necessarily saying that something is wrong with your car ... could be the track, the altitude, the weather, the track timing device ... but, in any case, something isn't kosher.

t

johnyIROC

Instead of working from memory, I figured I'd just post the actual slips:

I circled my car number in green







Someone please explain to me what's going on with my MPH

johnyIROC

I think if I remember correctly I blew the 2-3 shift (700R4) on the pass with the low MPH. If you look at the 1/8 mile MPH compared to the last pass, I should be able to get under 14.8.

TRAXION

Ok - I was right. There WAS something wrong. You indicated the wrong times in your first post

You said the old mph was 95 and the new mph was 91. That's not true. The old mph was 94 and the new mph is 96. So, instead of losing 4mph you actually gained 2mph. That explains everything. Good gain.

Tim

johnyIROC

Thanx.... .any idea why my MPH varies so much?

johnyIROC

Serious question:

Is the waranty voided if you ceramic coat?

craig

iTrader: (1)

i noticed you have a cutout. did you run the car both awys to see if being uncorked helped?

redbird_400

Screw the wrap! My Brother had that on his 81 Camaro. The wrap frayed off and was hanging on the ground. + when You get oil all over that wrap it really looks bad. Hope your not one for appearance. Why not get the Jet hot ceramic coating? Now there is something that looks good and works!:rockon: Decressing temp by as much as 25% I beleive.


Check it out...
<img src=http://www.jet-hot.com/gif/headers.gif>
http://www.jet-hot.com/direct.html

johnyIROC

I'm not paying $500 (Canadian) to have a set of $250 (Canadian) headers coated. I will just take that money and buy two more sets of headers when these rust out in 5 years.

The wrap claims to decrease temps by up to 70%

They've only been on for a few weeks, but are still looking great. They coated in VHT underneath the wrap, baked, and sealed with Therma-Tec on top of the wrap. On the other hand if you just wrapped them straight out of the box, your headers would be fubar ASAP.

A fraction of the price of jet coating, and my plug wires and starter will still live. Your brother must have prepared his wrong because mine are never coming off.

This is a budget racer... NOT a show car.

You guys read too many magazines.

johnyIROC

I haven't tried it yet, but I will next Saturday. I am quite curious to see what will happen as well. I suspect the cut-out helped as much if not more than the headers.

craig

iTrader: (1)

if you remember post the results or email me. i ordered the cutout for my setup , looks like yours,and would like to hear your results

Rob116

cermakrome.... :hail:

383backinblack

wow do i love my ceramic coated hooker supercomps......i mean close to 6 beans for headers is kinda rough but i dont have to worry about them, cause they warranty the coating for life.

They seriously reduce underhood temps too...5 min after shutting the car down you can grab the header tubes with your hands.....you can grab them while its running with gloves on (for a few seconds anyway)

CraZ-28

Ok, here is some information on wraps for the masses.

Exhaust system wraps, which are popular among racers, do a better job of containing heat withinb exhaust pipes, particularly inside header pipes. The problem with wraps are that they are too efficient--they trap so much heat inside that the metal from which the exhaust pipes are made changes structurally, and literally becomes so brittle that it breaks apart like glass, requiring frequent replacement of exhaust headers.

Basically the way I see it, wraps are good for tack runs but not that great for everyday street use.

383backinblack

well put

25THRSS

Ever find out what the gains with the cutout open versus closed were?