those with out the secondaries?????

[Hog]

Mr Workman, do you notice the torque drop during low rpm cruising/driving? Looks like around 20-25 rwtq at 2000rpm. Does throttle response feel soggy down there?

peace
Hog

[sammy]

his 2 dyno sheets were stock and after his porting . i don't think he had the secondaries removed on the first sheet . on my car it seems that if anything there was better low end performance

[Paul Workman]

Originally Posted by sammy

his 2 dyno sheets were stock and after his porting . i don't think he had the secondaries removed on the first sheet . on my car it seems that if anything there was better low end performance

The first is graph is stock. The second is w/ the secondaries removed AND full porting. There is no reduction of torque anywhere across the rpm range, comparing the "after" to the stock graph.

Not mushy or boggy at 2000 rpm at all, after the 500 hp mods. Absolutely love the way it handles/drives now - with the mods, w/o the secondaries.

P.

[Paul Workman]

Originally Posted by Hog

Mr Workman, do you notice the torque drop during low rpm cruising/driving? Looks like around 20-25 rwtq at 2000rpm. Does throttle response feel soggy down there?

peace
Hog

I think you're swapping the graphs? Wheel torque for the stock motor at 2000 rpm was about 275-280 (top graph). After the mods torque was at 300# @ 2000 rpm (bottom graph) and climbs from there.

[rkreigh]

marc pulled my secondaries when I had some troubles and the plenum needed to come off. he also cleaned up the injector housing porting a bit.

net result, no more HP but a noticeable difference in mid range and a bit better throttle response. real opportunity is if you pull the secondaries and open up the secondary ports in the heads.

not a good idea if you need to pass emissions. Graham told me that this is one of the reasons they are there. more port velocity, swirl, and less HC.

sure enough, with the secondaries (big cams and valves) I could previously get the car down to 98 HC, after the secondaries were removed, 140 was as clean as I could get

didn't really notice any difference in mileage. running at 14.7 stoich should be the same with one injector or two

definitely think it helps the car keep the secondary valves and injectors much cleaner as they are running all the time except for dead idle when the calibration cuts back to 1 injector as less than 1% throttle.

[Paul Workman]

Originally Posted by rkreigh

marc pulled my secondaries when I had some troubles and the plenum needed to come off. he also cleaned up the injector housing porting a bit.

net result, no more HP but a noticeable difference in mid range and a bit better throttle response. real opportunity is if you pull the secondaries and open up the secondary ports in the heads.

Yeah, buddy! The secondary runners going into the secondary throttle plates are are approx 36mm, but just past the throttle plates, the dang things cone down to much smaller than that in about the distance of 10mm before just as abruptly straightening out. Far as flow dynamics go, that's one area that can benefit from some time with a die grinder (and the heads don't even have to come off to do it either! Wow! What a difference removing some metal there made!

"Coning" the runner from the entrance to the valve guide @ ≈ 4% taper. this gets rid of two rather abrupt changes in angle to air flow past the port throttle area: Smooth taper.



I'm digressing a bit, but here's and example of some "FBI" IH runners on a 90 - as part of a top end port&polish - well on it's way to 400 rwhp.

Originally Posted by rkreigh

not a good idea if you need to pass emissions. Graham told me that this is one of the reasons they are there. more port velocity, swirl, and less HC.

sure enough, with the secondaries (big cams and valves) I could previously get the car down to 98 HC, after the secondaries were removed, 140 was as clean as I could get

didn't really notice any difference in mileage. running at 14.7 stoich should be the same with one injector or two

definitely think it helps the car keep the secondary valves and injectors much cleaner as they are running all the time except for dead idle when the calibration cuts back to 1 injector as less than 1% throttle.

I often wonder what affect a special gasket - one tha blocks off the secondary runner - would have on emmissions tests. (Just asking out loud)

P.

[Hog]

Originally Posted by Paul Workman

I think you're swapping the graphs? Wheel torque for the stock motor at 2000 rpm was about 275-280 (top graph). After the mods torque was at 300# @ 2000 rpm (bottom graph) and climbs from there.

Yes Paul, thats what I was doing, I crossed up the graphs. Thank you.

Sounds like other than emissions there really arent any downsides to removing the secondary throttles.

Some have stated their desire to retain the "power-key" function. Is there any way to accomplish this. Can the throttles be removed, and still have the primary injectors do all the fueling when in reduced power mode?

As Ron states, it is good to have the secondary injector firing in order to keep the valves clean. I'm not the type that would drive a whole lot without the secondaries firing.

peace
hog

[rkreigh]

Originally Posted by Paul Workman

Yeah, buddy! The secondary runners going into the secondary throttle plates are are approx 36mm, but just past the throttle plates, the dang things cone down to much smaller than that in about the distance of 10mm before just as abruptly straightening out. Far as flow dynamics go, that's one area that can benefit from some time with a die grinder (and the heads don't even have to come off to do it either! Wow! What a difference removing some metal there made!

"Coning" the runner from the entrance to the valve guide @ ≈ 4% taper. this gets rid of two rather abrupt changes in angle to air flow past the port throttle area: Smooth taper.



I'm digressing a bit, but here's and example of some "FBI" IH runners on a 90 - as part of a top end port&polish - well on it's way to 400 rwhp.






I often wonder what affect a special gasket - one tha blocks off the secondary runner - would have on emmissions tests. (Just asking out loud)

P.

putting in a gasket blocking off the secondaries would be an ez way to pass emissions, turn off the power key and away you go

my problem is that with the 234 cams, my hc were up at 98 even with the secondaries. VA cut the emissions standard to 48. very tough with cams

I actually want to try getting a chip burned for E85 (or pure alchy)

warm up the car on gas, drain it out, swap the memcal, and go through like a breeze.

I haven't found anyone local that can help me burn the chip. wouldn't be all that hard as I'd only need to run part throttle up to 30 mph (no wot ever)

the VA emissions standards are pretty tough