BRP/Hedman "Hedder" dyno and track results :)

[1st and goal]

On Thursday I went to the dyno and tweaked the tune slightly to accomodate for the "Hedders" as Hedman spells them.
I went with 1 3/4 long tubes, they are made by Hedman and sold through BRP Hot rods.
The motor is from a 98 Z/28 and has an LS6 intake manifold and comp cams camshaft, springs and pushrods. Otherwise the motor is stock. Tranny is a 4L60E w/ Vigilante t/c.
I did three baseline dyno pulls with exhaust manifolds and the first one was 322 @ 5850, the next pull was 312 and after letting the car cool I backed it up with another 322 RWHP pull.
On to the "Hedder" dyno pulls
On the first pull we only spun it up to 5700 and it made 338, we tweaked the tune a bit and it ran it up to 6200ish and it made 355.9 RWHP @ 6150 and torque went up from 273.8 to 304 @ the same 6150 rpm. Peak torque was 327 @ 5200, the previous peak torque was 303 @ 5200
I backed up the 355RWHP run with another 355 RWHP pull and spun it up to 6500. HP remained at 355, it flatlined from 6150-6500 @ 355.
https://static1.pt-content.com/images/pt/2008/09/BRP_hedders-1.jpg
https://static1.pt-content.com/images/pt/2008/09/BRP_hedders2-1.jpg
Of course with new found power a trip to my local track (New England Dragway) was required so off I went last night to make a couple of passes
My previous best was 12.730 @ 106.39, other pases that day was 12.781 @ 106.14, 12.794 @ 105.92 and 12.757 @ 105.55. Sixty foot times ranged from 1.821 - 1.848 on the above passes.
With the increase in power my sixty foot times improved to 1.782 1.792 and 1.755.
First pass I cut a .080 light and my sixty foot was 1.782, 7.842 @ 88.03 in the eight and then I bounced off the rev limiter a couple of times and as I ran thought the lights I looked up and saw 12.330 (well actually I only saw the 33) but you get the gist... so it was a 12.330 @ 109.60, next pass I red light by a c/h (.004) and sixty footed to a 1.792 and ran 12.384 @ 109.26 with again bouncing off the rev limited on the 2-3 shift. I decided to give it one more shot before I left and cut a 1.755 sixty foot (.102 light) and ran 7.790 @ 88.62 and again as I go through the lights I crouch down and lookup and saw a "25" :drive1: , drive around and get my slip and it's a 12.256 @ 109.96 with again bouncing off the rev limiter twice before it shifted into third. My buddy has the laptop with EFI live so at the time I was stuck and couldn't make any changes.

Bottom line I picked 34 RWHP, 30 RWTQ on the dyno and a solid 3+ mph and almost a half second at the track.

These "Hedders" are by far one of the best investments I made as far as dollar vs. performance gain. :git:

Uncle Marc

[meenaggie]

How much of the ~33 HP increase do you think were the "hedders" and how much was the tune? Could of you not made some gains on tune alone before the header swap? It sounds like you had the stock manifolds prior but just confirming, correct?

I ask becuase eventually I need to by a set of LS swap headers for my camaro and the BRPs are on the list. Also, what is the weight of your car? Is it a 1973 camaro?

[1st and goal]

How much of the ~33 HP increase do you think were the "hedders" and how much was the tune? Could of you not made some gains on tune alone before the header swap? It sounds like you had the stock manifolds prior but just confirming, correct?

I ask becuase eventually I need to by a set of LS swap headers for my camaro and the BRPs are on the list. Also, what is the weight of your car? Is it a 1973 camaro?

Hello,
We didn't have to tweak the tune much, we basically took a degree of timing out and left the fuel alone. It had 3* of knock retard on the first pull where we made 338 so we pulled a degree. When I did the baseline pulls I was not able to scan and check for knock. The tune was a little lean with exhaust manifolds at high rpm and when we checked the a/f ratio with the headers it was dead on (12.8ish) till 6K and then it fattend up a bit and was 12.4 from 6-6500. We could have leaned it out a bit but I'd rather leave a couple of hp on the table and have a safer tune.

I've weighed the car twice, once at the track where it weighed 3400 (no driver) and once at the town dump where it weighed 3350 (again no driver). At the track on Friday it weighed 3590 with me in it.

My Z is a 73 Z/28 (formerly a numbers matching car :) )

[cdoggy81]

Fantastic results!!!
I was about to ask the exact same question as meenaggie but you answered them with great data. I am very pleased with what you posted as I too have a set on the way. I did go for the stepped set (1 3/4 -to> 1 7/8) for my LS1 but I put a healthy cam in it (230/232 .595") & dumped the cash for a FAST 90/90 setup as well as ported & milled heads... :) Our cars are the same so I'm hoping to be high 11's when done! BTW what gears & T.C. are you running. I went with the Vigilante 3200 for my 4l60e (along with the trans-go shift kit) & 3.73's

[1st and goal]

Fantastic results!!!


Thanks :yeah:

I was / am pretty stoked at the results as well.

Hoping to get a 12 flat in October on a weekend when the track is prepped and traction is at a premium and it's "brisk" out :drive1:

As far as the converter goes, it was a 3600 stall in my 94 Z with 383 LT1 w/19#'s of boost (650RWHP), the mechanic that did the install swapped over the guts from my LT1 tranny into the LS1 case and used a differnt input shaft to make the conveter work (it is a 5 disc Vigilante converter that cost me a grand so I kinda wanted to keep it), and he rebuilt the LT1 tranny with stock parts and sold it for me, now it seems to be more of a 2400ish converter with the lack of power as compared to my old ride. Don't get me wrong, I much prefer my current ride and I'm not munching through head gaskets like they were Pez candy as I did with the other car....

I'm most likely going to pull the tranny in the winter and send back the converter and have it loosened up a bit. I've got a Trans-go shift kit as well, hits em real hard :git:

Next time I get to the track, we're going to hook up my buddy's EFI live and log the run, then I'll get a truer picture of the stall plus get a look at how the tune is working in real world conditions.

Gears - another mystery...I was told they were 4:10's but I don't think they are and I just have been lazy about pulling the cover to check.

The motor revs 2200-2300 at 72mph so I'm thinking they're more likely to be 3:42's.

You should get easy 11's with that setup. My best runs with exhaust manifolds were back in the spring (12.73 run was on 5/28), when I ran the car in the heat, it would loose 2-3 tenths and 2-3 mph.

With the weather I don't think I'll be able to get to the track till next Friday so I'll keep you guys posted.

I'll see if I can scan my timeslips and post them.

Uncle Marc

[cdoggy81]

Cool & thanks for the info. Looking forward to hearing more results!

[1st and goal]

I'll see if I can scan my timeslips and post them.

Uncle Marc

https://static1.pt-content.com/images/pt/2008/09/scan0006-1.jpg

[meenaggie]

Thanks for the follow up and response. It looks like a should be able to manage mid 12's with my 68 camaro (when it is finsished).

[1st and goal]

Got a couple more passes in last night.

12.561 @ 108.91

12.311 @ 110.42

12.226 @ 110.37

Tweaked the shift points and adjusted the rev limiter so I did not bounce off it at the top of second gear. No ET improvement but the mph did go up another half mph.

So now I'm at a solid 4 mph improvement from the "hedders" :git: :git:

[cdoggy81]

That is sweeeeet! What cam did you go with BTW?

[1st and goal]

That is sweeeeet! What cam did you go with BTW?

The cam is a Comp Cams cam Part # 54-428-11
Specs are:
Dur @ 050 228/230
Duration 281 / 283
Lift 571 / 573

Going to the track on Wednesday.

As Scotty said to Captain Kirk "I'm givin her all she's got" :headbang:

[cdoggy81]

Cool, a very close cam to mine!
Report back on Wed. Looking forward to seeing good #'s again :)

[1st and goal]

Cool, a very close cam to mine!
Report back on Wed. Looking forward to seeing good #'s again :)

Thanks, the car ran pretty good last night but it was a bit warmer out and I could only must 12.3X a few times and a 12.40

On a positive note I won all five of my races and beat a Mustang on a holeshot with a 0.014 reaction time :drive: :camaro: :drive:

[cdoggy81]

"beat a Mustang on a holeshot with a 0.014 reaction time "
That's such a cool feeling when you leap out of the hole by just enough to never have to look back over!!!

[1st and goal]

"beat a Mustang on a holeshot with a 0.014 reaction time "
That's such a cool feeling when you leap out of the hole by just enough to never have to look back over!!!

Thanks, the stang was charging hard and had me by 4 mph so I needed every bit of the .014 reaction time I had

Will give it hell again next Wednesday and report back on Thursday:cheers:

[Moose]

What does your car wiegh, and which converter did you go with?

[1st and goal]

What does your car wiegh, and which converter did you go with?

I've weighed it a few times, once at the town dump and it weighed 3350 (without me), once at the track (again no driver) 3400 and I weighed it at the track with me in it and it was 3519 (-240 for me and that puts the car at 3380)

I am running a vigilante torque converter.

[1st and goal]

Well boys and girls, New England Dragway is closing tonight and I'm taking my three year old daughter out trick or treating so 12.25 @ 110 is as good as I was able to get the car to run :git: :drive: :git:

I have no major plans for power improvements over the winter, I do want to get some Patriot heads but I think I'm going to hold off till the following winter.

I'm going to finally get the A/C working again and install my Morris classic seat belts, might get some new carpet too but otherwise I need to bring it to the body shop to get the dent removed in the right from fender that I've been driving around with all summer. Back in the spring when my mechanic was driving it a deer came out of no-where and rammed the car, he told me he had to pick fur out of the turnsignal. Apparently both car and deer survived as the deer staggered for a minute and then bolted back into the woods. My mechanic said to fix it and give him the bill.

Marc

[cdoggy81]

If on a budget you should just send your heads in to PP or TSP & have them CNC port it ($400) multi-angle valve job ($175) & mill them ($75). If you ever plan on a new cam in the future you can add springs at the same time for $150 or Dual gold w/ Ti retainers for $250 :)

[1st and goal]

If on a budget you should just send your heads in to PP or TSP & have them CNC port it ($400) multi-angle valve job ($175) & mill them ($75). If you ever plan on a new cam in the future you can add springs at the same time for $150 or Dual gold w/ Ti retainers for $250 :)

Thanks, I appreciate the ideas....I put new springs and pushrods in when we did the cam. I'm going to hold off until I do the heads, who knows I might even do the motor over at the same time.

My mind changes like the wind so who knows where I'll end up

[cdoggy81]

High lift springs & chromemoly - hardened pushrods?

[1st and goal]

High lift springs & chromemoly - hardened pushrods?

This is what I used
COMP Cams 54100

Brand:COMP Cams (http://store.summitracing.com/egnsearch.asp?N=400114+115)Product Line:COMP Cams Gen III LSI/LS6 RPM Valvetrain Upgrade Kits (http://store.summitracing.com/egnsearch.asp?N=400114+315956+115&autoview=sku)Part Type:Valvetrain Upgrade Kits (http://store.summitracing.com/PartTypeRedir.asp?PartType=Valvetrain+Upgrade+Kits )Part Number:CCA-54100Valve Springs Included:YesValve Spring Style:BeehiveOutside Diameter of Outer Spring (in):1.055 in.Retainers Included:YesRetainer Style:StandardRetainer Material:TitaniumPushrods Included:YesPushrod Material:ChromemolyTubing Diameter (in):5/16 in.Wall Thickness (in):0.080 in.Locks Included:No

[cdoggy81]

yep, those will work :)

[4086D9]

Great job man she runs sweet! I may go that way sometime down the road. Im pretty happy right now how mine runs but I am always changing my mind..:banghead: . I saw you used to have a boosted car before this and you seem pretty happy to get away from the head aches. I just picked up a procharger awhile back and was planning on putting it on my sbc and going blow thru. But I am having second thoughts...

My car is super drivable and reliable and I dont want to be worried everytime I hit that gas about "its it gonna live". My motor has a cast crank/rods/forged pistons so its not quite "ideal" for boost. My track is 1 hour and like to drive to the track and back. With the boost I think I would always be worried about a headgasket or something....

[1st and goal]

Great job man she runs sweet! I may go that way sometime down the road. Im pretty happy right now how mine runs but I am always changing my mind..:banghead: . I saw you used to have a boosted car before this and you seem pretty happy to get away from the head aches. I just picked up a procharger awhile back and was planning on putting it on my sbc and going blow thru. But I am having second thoughts...

My car is super drivable and reliable and I dont want to be worried everytime I hit that gas about "its it gonna live". My motor has a cast crank/rods/forged pistons so its not quite "ideal" for boost. My track is 1 hour and like to drive to the track and back. With the boost I think I would always be worried about a headgasket or something....

Thanks, I enjoyed "the Tomato" as it was called.
http://www.geocities.com/marc94z/

To be honest the best times I had with the car was when the motor was stock and I had a P600B on it and it had 8#'s of boost. It ran high 11's, the A/C still worked, I could hot lap the car, drove it to the track with drag radials on it. No muss, no fuss.
It did haul the mail when I had the 383 in it w/ 19#'s of boost and it was driveable but it had a cage, no back seat, no a/c, still a street car but not much of one. Of course if I could swing another race car I'd build the same damn thing but make a couple of changes to make it better, not necessarily faster but less prone to muching head gaskets.....

You could run a blower on your setup, what is the compression? You need to be careful of how much boost you're planning to run and watch the timing....that was my downfall. I had a FAST system that I tuned myself and it made more power with more timing but once I popped its cherry (head gasket), it was never the same.

Once I decided to part the car out, my intention was to get a 70-73 Z/28 and put an LS1 into it and get it to run mid-high 11's and I'm almost there. I'm going to just enjoy the car next year and the following year I'll throw some Patriot heads on it and get it into the 11's. I will not put a cage into my 73 so I don't need (can't belive I'm writing this) any more power.

Marc
P.S. I live 7.1 miles from my track :usa: