[Bomber '67]

Today I booked three hours on the chassis dyno - money very well spent!

After http://www.chevelles.com/forums/showthread.php?t=105713&highlight=pics I knew that the carb would need some serious reworking to keep up with the newfound exhaust flow.

The results far exceeded my expectations: new bests of 564 rear wheel horsepower and 562 rear wheel torque! Along with changing the air bleeds it also responded quite well to larger jets.

This Saturday and Sunday I plan on racing at Fontana with the PSCA.

It will be very interesting to see how it runs - because it now has 100 more rwhp than when it posted the times in my signature.

Thomas

 

[Bad Rat 414]

Since I'm planning a 496 how about telling me your engine specs. to get that kind of RWHP. :thumbsup:

 

[69 Ratt Vette]

Wow, 560+ hp at the wheels through an automatic is impressive, good luck Thomas

 

[Bomber '67]

Oh yeah, it runs and races on 91 octane - even gets 11 mpg on the highway!

Top to bottom:
Dominator 1050 #8896
1/2" four hole plywood insulator spacer
1" open spacer
Vintage Edelbrock C454 dual plane, port matched to Fel-Pro #1275
Carter 172 mechanical fuel pump
Brodix BB-2 heads, 2.25" x 1.88" valves intakes ported to flow between 375 to 383 cfm exhaust port flow I'll have to look up
T&D shaft rocker system 1.8:1 ratio on both intake and exhaust.
Manley NexTek springs
10.72:1 static compression ratio
Mallory HEI (I like HEI's on street cars) 37 degrees advance.
Chet Herbert 6K solid roller cam 248/255 duration @ .050 net lift after lash .675"/.700" 110 degree intake centerline installed straight up.
Hooker #2455 headers, 2" x 30" primaries, 3.5" collectors, 3.5" out to an X crossover, then 3" out of the X into MagnaFlow straight through mufflers, dumps off the mufflers.
Mechanical water pump and parts store clutch fan

The rest of the story:
200 4R Trans built by Bruce Toelle http://www.ptsnctb.com/index.asp
Billet 300M input shaft, billet forward drum 11" x 9" lock up torque converter
4.11 12 bolt, Tom's Kick Ass axles
M.T. E.T. Streets 11.50 x 28
Car weight with full tank is 3,380 lbs, 1,820 lbs on front 54% front 46% rear
Add 185 lbs for me

Thomas

 

[-SS454-]

Im stunned again. You sure u arent forgetting to mention a 100 shot of nitrous? I cant believe those gains you got from fixing the exhaust and doing some carb tuning, incredible stuff. Looks like you got a gem of an engine.

 

[Bomber '67]

Actually the kicker is that the engine was built with nitrous in mind on the ring gaps (should be safe out to a 250 shot). I'm waiting to get the whole car and chassis more dialed in before any juice flows.

The transmission will have to be rethought before any nitrous, I'm probably within 100 hp of where this trans will max out. The lock up converter by my reckoning is worth perhaps 8% of the rear wheel hp, but I'm not sure that I would want a lock up with this engine and a 250 shot.

Thomas

 

[Ron454]

Jesus H K-rist!
I bet you pick up over a half second.
Pretty amazing Tom......do post the new numbers and have fun with the PSCA folks!
Now wasn't that a nice job someone did with your old exhaust?
Ron

 

[66rat]

Thomas, holy crap that's a huge increase. We will be waiting to see what she does at the track. Good luck

 

[Dave Kaveshan]

Also curious about your suspension set-up front and rear, if you don't care.
You told me earlier that you were going to add an anti-roll bar, but I missed the details on the rest of it.

R/ Dave Kaveshan

 

[Bob West]

I'd say its worth .03-.05 in e.t. I'll be curious as to see the results, go get em!!

 

[artmalibu]

I'd say its worth .03-.05 in e.t. I'll be curious as to see the results, go get em!!

Why so little? 100 hp at the wheels not worth a tenth.

 

[Bob West]

.30-.50.....oops!! big TYPO up to a point 100hp is worth a second in e.t. after that the gain becomes smaller and smaller, most say my 150shot when I get it adjusted right MIGHT be worth a second in my car.

 

[1hot67]

the 100 new-found hp should be worth .8 easy imo.

keep us posted! What dyno shop did you go to?

 

[Slowpoke70]

If you race tomorrow, I should be out there watching you. :thumbsup:

Gonna be rooting for my "friends" at Hye-Tech with their Buick GN, although its been having problems lately. Not really my friends, but they're usually the closest people that I can bug with questions whenever my car isn't quite right. They were a Big help after breaking in the engine.

 

[70_FathomBlueMalibu]

What dyno were you on for the prior testing? Is this the same one with the same operator? Just hoping it's a true apples to apples comparison.

I saw the exhaust butchering pics and have to say that there should be some significant gains there. Of course, re-tuning for all that is a nice bonus.

I'll say .55 pickup in E.T. and 7 mph. Just a WAG.

 

[Harold Sutton]

Why so little? 100 hp at the wheels not worth a tenth.

Since this is RWHP i'd say low tens or high nines will certainly be possible as the car's weight is low at 3380. My son's Chevelle had about 561 RWHP and weighed 3540 lbs. quite a while back and his best was a 9.98 @ 133.9 MPH. It ran a 134.8 with cool weather and a 5 MPH tail wind.

 

[Bomber '67]

Harold, the dyno operator said the same thing - that this was 130 mph type of power. Alas, my day in the shade did not back that up http://www.chevelles.com/forums/showthread.php?t=106638 . But I should have it better sorted out and ready to run a better number soon.

I'm shooting for mid 10's just because so much of the car is street biased: smallish tires, street suspension, 3,200 stall. I know that if I had a race converter, more tire and suspension, then it would really rock.

Thomas