Header dyno #'s?

[Wolf Spyder]

Has anyone got any dyno numbers compairing stock, Pacesetter and sprint headers?

[RallyBob]

Originally Posted by Wolf Spyder Has anyone got any dyno numbers compairing stock, Pacesetter and sprint headers?

None that I know of, especially with a comparable combination. Exhaust diameter, carburetor type, camshaft, early engine?, late engine?...lots of variables. I wouldn't expect much from just a Sprint manifold on a stock engine...remember the 1975 Opels were only rated at 5 hp more than the '74 Opels, and this was with the EFI system and the Sprint manifold installed. Same goes with a Pacesetter on a stock engine...they usually feel lethargic below 4500 rpms in fact, far worse than even the stock exhaust manifold. On a modified engine, the Pacesetter starts to make a difference however.

I am currently working on a 'street' GT tubular header, and hope to dyno a bone-stock late-model (low compression) engine with the standard exhaust manifold and exhaust system, plus a 32/36 DGV Weber on a stock intake.

Then I want to pull the stock manifolds, and bolt on the header with another stock intake.

Then I'd like to bolt on a ported intake.

Then a larger diameter performance exhaust system.

Of course, this will require jetting between each dyno session, but it would be interesting to see how each mod affects power and torque. When the header and exhaust are done, I'll be looking for someone in the New England area willing to have his car tested for posterity (dyno shop is in East Hartford, CT).

Bob

Link to dyno shop map: http://www.mapquest.com/maps/map.adp...maplink2&name=

[baz]

form a que only 1 entry per member

[namba209]

Originally Posted by baz form a que only 1 entry per member

Hope you don't mind Baz, but "que" isn't a common word here in the "Colony".

Form a line, only 1 entry per member, is more appropriate, at least on this side of the pond.

[baz]

dont mind at all just wish i had my cay in NE with a stock motor in it

[Travis]

Originally Posted by RallyBob When the header and exhaust are done, I'll be looking for someone in the New England area willing to have his car tested for posterity

Do you have an estimated date?

-Travis

[RallyBob]

Travis, this will be a small tube header for a stock engine. Probably not the best thing for your engine's state of tune.

[Travis]

Yes, I understand it will be optimised for much lower power motors then mine. However, it would still be interesting to see how it compared to my current sprint manifold.... and a good reason to take a day off from work

-Travis

[Opel1_9]

I'll volunteer my bone stock 72 GT as a candidate. No doubt I'll be one of many volunteers.
Ron

[RallyBob]

Thanks guys. I'll post back here when it's ready for fitment. Maybe we can try both cars.

I expect Travis will lose some power due to the smaller tubes and a full exhaust system with two mufflers, but on the other hand some low-end torque gain is entirely feasible. I want to make it pretty quiet too.

When I build the second design (slightly larger tubes for larger displacement engines and/or built-up 1.9/2.0's), then I think Travis will see more benefit. But I'm strictly speculating. The dyno will tell all...

[Gary]

My stock '72 wagon with Solex is available.

[baz]

quick gary do some editing and you will be the only one

[jeff denton]

Oh, man, how I wish there were a chassis dyno near here! Just to play with fuel octane and ignition timing and valve timing...

[calvin]

when I switched from the standard opel header that is always for sale on ebay to the Rhonet (spelling) system that I got from BOB I think I lost some low end however it goes faster and there is more oomph in the middle and I think it breathes better should I by oversight chance to exceed the speed limit

On the other hand now there are weber 48ies and not 40ies (if you pull the manifold off why not change the carb and headers at the same time? Same amount of bolts and you have them off already) of course the cam is different too.

[opelwasp]

Bob, as you perform each dyno run, could you please documrnt and post the setup for each run? Especially jetting and cam profiles.

[Wolf Spyder]

Originally Posted by namba209 Hope you don't mind Baz, but "que" isn't a common word here in the "Colony". Form a line, only 1 entry per member, is more appropriate, at least on this side of the pond.

Tis legal in Scrabble!

[RallyBob]

Originally Posted by opelwasp Bob, as you perform each dyno run, could you please documrnt and post the setup for each run? Especially jetting and cam profiles.

That's the plan. Stock cams only though, that's the whole idea of this test, to see the results on a bone-stock engine. Too many variables will skew the results.

Of course, air temp, humidity, gasoline brand/octane/chemical composition and altitude will mess the jetting up for other parts of the country. You really have to tune for your specific region.

[RallyBob]

Originally Posted by Gary My stock '72 wagon with Solex is available.

Sorry, GT's only on this one!

[namba209]

Originally Posted by Wolf Spyder Tis legal in Scrabble!

True, but the key phrase I used was "common word". I too have used "que" playing scrabble.

Now getting back on topic, I would really like to see the numbers that will come from the dyno runs. If nothing more than to see if what I'm doing with Willit? has really been worth all the time and money expended.

[hrcollinsjr]

Originally Posted by namba209 If nothing more than to see if what I'm doing with Willit? has really been worth all the time and money expended.

To quote a great movie line, "You can't handle the truth". But it has been great reading for the rest of us and a real journey for you. So, yes it's probably been worth it because you would have always wondered, what if?

So Ron, keep up the good work and updates on Willit.

Harold

[Paul]

Bob,

You can use my 71 GT. It has a stock low compression engine and stock exhaust. I'm gonna send it to you via UPS ground. I building a box for it now. Heck, I'll even pay ya for the header when you a done.

[RallyBob]

Originally Posted by namba209 Now getting back on topic, I would really like to see the numbers that will come from the dyno runs. If nothing more than to see if what I'm doing with Willit? has really been worth all the time and money expended.

I suspect you will see about 135 hp (to the rear wheels) from your V6 conversion Ron. That's far more than any low compression 1.9 with bolt-ons will ever see. I recall the Texas club had a dyno day not long after we had the Carlisle dyno day, and the stock 1.9's there varied from 47-55 hp at the rear wheels. I think based on this you'll find your V6 conversion appealing, especially from a torque point of view. But it has certainly tested your patience getting to this point!

I'm not sure what people are expecting to see, but I'd be extremely happy if I could get a ~50 whp low compression Opel up to 54-55 whp with just the header. That would be a 10% increase! Maybe another 3-5 with the exhaust system. Proportionately, those are huge gains. It's like adding 30 hp to a 350 hp Chevy V8 with a simple bolt-on.

With a Weber carb, ported intake, electronic ignition, the header and exhaust, and some tuning, it would be nice to see 70 whp. That would be a fat 40% increase over stock. You will certainly feel that! Of course, these same mods done to a high compression/solid lifter engine should yield still more power, and other changes will likely compliment it further. But for now, small steps. You could spend 10 hours a day for a month testing combinations to see what makes the most power, but it gets expensive fast.

Bob

[neuropel]

Any idea how much gain you get with changing to a sprint manifold under these same scenarios?

[namba209]

Originally Posted by RallyBob But it has certainly tested your patience getting to this point! Bob

Not to mention my finances,too. But I will finish this project, I'm too close to having the engine running in the car to quit now. 135 HP at the rear wheels, WOW. I'm glad I got the posi installed. With the 5.7L in the monza, it was spin one tire all the time, after I got the Auburn posi installed it IS spin both tires half the time.

Thanx a lot for the input Bob, I really do appreciate it.

[jeff denton]

But, why the "stock cam only" rule, Bob? Seems anyone wanting a serious power gain would be changing the camshaft anyway. Probably would have done it before the header even.