those with out the secondaries?????

[sammy]

i went to coreys in dec to remove my secodaries, get retuned and his headers,instead of the stainless works . didnt get a chance to do headers, his brother was getting married that sat . but did get the secondaries done and a new tune . when i had it tuned after putting on the stainless works 3 yrs ago she made 383 on the dyno . car also had a corsa on it . this time with my 3in x pipe then 23/4 factory tubing into 3 in super turbos with dual 21/2 in exits made 399.plus my highway mileage seems to improved by about 2 mpg. .the runs were 3 yrs apart and figure the exhaust might have made some of the improvement .car also seems to have alot better midrange .what are your guys experiences ..please tell me your thoughts on your cars . can hardly wait for the first weekend in feb to try at the strip .

[Kevin]

i've been trying to drive a stock cid non ported car without secondaries for years. I've been kicking around the idea of pulling mine via tune for years

[Blue Flame Restorations]

Before I bought a ZR-1 to drive, I joined the Registry and read everything I could here. At the time, it seemed that there were several people with vac leaks. Chasing leaks, pulling plenums, etc.

When Pete did my motor, I decided that I wanted the secondaries removed at that time. It just made sense to me. Still does. Haven't chased any vac leaks either.

Love my car. Thanks, Pete!

[scottfab]

Originally Posted by Kevin

i've been trying to drive a stock cid non ported car without secondaries for years. I've been kicking around the idea of pulling mine via tune for years

Same stock cid and non ported here.
Fixed a plugged check valve and hole in the tube in 99 and the
secondaries ran fine until last year when the pump got a rebuild.
Secondary works fine and I LOVE being able to take the power key out. It's a great conversation piece.

[WARP TEN]

As part of Marc's 510 package he removed my secondaries, pump, hoses etc. Since we are adding headers we also removed the AIR pump and pipes (it was born a California car). I am keeping all the parts in case the next owner (after I am dead and gone!) wants to restore the car to stock. Removal seemed like a good idea since we no longer have emmisions testing in Illinois for our cars. Marc said it doesn't adversely affect the operation of the car, keeps the secondary valve clean, is less work to put back together and means fewer future headaches. Seemed to make sense to me. I look forward to trying it out next month--weather permitting. --Bob

[Paul Workman]

Originally Posted by sammy

i went to coreys in dec to remove my secodaries, get retuned and his headers,instead of the stainless works . didnt get a chance to do headers, his brother was getting married that sat . but did get the secondaries done and a new tune . when i had it tuned after putting on the stainless works 3 yrs ago she made 383 on the dyno . car also had a corsa on it . this time with my 3in x pipe then 23/4 factory tubing into 3 in super turbos with dual 21/2 in exits made 399.plus my highway mileage seems to improved by about 2 mpg. .the runs were 3 yrs apart and figure the exhaust might have made some of the improvement .car also seems to have alot better midrange .what are your guys experiences ..please tell me your thoughts on your cars . can hardly wait for the first weekend in feb to try at the strip .

Dyno results:

LOTS of varibles there...

The accuracy of the atmospheric parameters entered into the dyno is a factor
Air temp and engine temp contribute subsatially to dyno results,
Tire pressure, types of tires too, for that matter
Temp of oil in the transmission
(etc)

All of these things can increase the % of ambiguity in test results. There's no getting around the possibility for some of the change being due to some (or more) factors mentioned. However, a 17 hp change would appear to reach well beyond the normal delta one might anticipate in comparison due to common errors in instrumentation etc.

Pete did some recent dyno comparisons of a Corsa vs. other schemes (On Dave Johnson's car, if I'm not mistaken) and found the Corsa to cost an amount of rear wheel hp amounting to a significant portion of the gain you experienced by (as I understand what you're saying).

Bottom line - a 17 hp lift is significant. Congratz!! The X-pipe no doubt is contributing to some gain, but the trail starts growing cold, far as comparing results by others, as the number of variables changes (pipe sizes and especially changes in diameters throughout).

Gas mileage:

Changing the tune can have a significant effect on mileage either way - OR NONE, depending (again) on the specifics of the tune. In my case, before and after my "500" package (including removing the secondary port throttles), mileage was still within the margin for error; about 26.5 on cruise control at about 72.

I did that check last summer before gassing up before going on a mild spirited cruise through some twisty roads in NW IL. There was many WOT spurts and a sizable amount of third gear stuff through the twisties. At the end, some 200+ miles later my mileage was still above 24, which surprised me a bit. Around town with stop and go traffic, I get about 18. (You can see my setup in my signature at the bottom of the post)

Midrange torque:

My stock 90:



After the 500 package:



I picked up approx 97 hp and approx 40# of torque, but not sure if that answers the quesiton. But, far as removing the secondaries goes, I like the improvements; the throttle response, and the fact both intake valves get constantly cleaned. I can't say what (if any) difference there is in hp or torque following their removal, but their not being there to impede the air flow at the core of the column, can't be bad. Plus, parts that don't exist seldom break, and they don't cost much! I saw no need to have 'em and was one of the first things I got rid of, and never looked back.

P.

[Paul Workman]

Originally Posted by scottfab

Same stock cid and non ported here.
Fixed a plugged check valve and hole in the tube in 99 and the
secondaries ran fine until last year when the pump got a rebuild.
Secondary works fine and I LOVE being able to take the power key out. It's a great conversation piece.

Well, that's two plenum pulls at least, and coupled with an external pump issue, that's 3 good reasons to eliminate 'em

With the SPTs eliminated, the smart thing to do is bypass the switch - read: hard-wire it through to prevent the FULL POWER mode from intermittently or accidently being turned off. So, the switch becomes nothing but a conversation piece at that point...which is ONE LESS PIA deal with, far as secodaries go.

Just tuggin' on yer tail in fun, thar Scott!

P.

[XfireZ51]

If you don't want to rip things out, then tie wrap the secondaries open and have the memcal burned for secondaries "always on".

[sammy]

Originally Posted by Paul Workman

Dyno results:

LOTS of varibles there...

The accuracy of the atmospheric parameters entered into the dyno is a factor
Air temp and engine temp contribute subsatially to dyno results,
Tire pressure, types of tires too, for that matter
Temp of oil in the transmission
(etc)

All of these things can increase the % of ambiguity in test results. There's no getting around the possibility for some of the change being due to some (or more) factors mentioned. However, a 17 hp change would appear to reach well beyond the normal delta one might anticipate in comparison due to common errors in instrumentation etc.

Pete did some recent dyno comparisons of a Corsa vs. other schemes (On Dave Johnson's car, if I'm not mistaken) and found the Corsa to cost an amount of rear wheel hp amounting to a significant portion of the gain you experienced by (as I understand what you're saying).

Bottom line - a 17 hp lift is significant. Congratz!! The X-pipe no doubt is contributing to some gain, but the trail starts growing cold, far as comparing results by others, as the number of variables changes (pipe sizes and especially changes in diameters throughout).

Gas mileage:

Changing the tune can have a significant effect on mileage either way - OR NONE, depending (again) on the specifics of the tune. In my case, before and after my "500" package (including removing the secondary port throttles), mileage was still within the margin for error; about 26.5 on cruise control at about 72.

I did that check last summer before gassing up before going on a mild spirited cruise through some twisty roads in NW IL. There was many WOT spurts and a sizable amount of third gear stuff through the twisties. At the end, some 200+ miles later my mileage was still above 24, which surprised me a bit. Around town with stop and go traffic, I get about 18. (You can see my setup in my signature at the bottom of the post)

Midrange torque:

My stock 90:



After the 500 package:



I picked up approx 97 hp and approx 40# of torque, but not sure if that answers the quesiton. But, far as removing the secondaries goes, I like the improvements; the throttle response, and the fact both intake valves get constantly cleaned. I can't say what (if any) difference there is in hp or torque following their removal, but their not being there to impede the air flow at the core of the column, can't be bad. Plus, parts that don't exist seldom break, and they don't cost much! I saw no need to have 'em and was one of the first things I got rid of, and never looked back.

P.

i understand that there was 3 yrs between dyno sessions looking at the sheets the temps and humidity were very close 2% difference .i do feel that the corsa does cost some power compared to my current set up as my ets went down from a before best of 12.48@114.89 to a best of 11.94 @117.81 these results wee all at famoso dragway in bakersfield ca.i realize to some that may seem like a big difference for just an exhaust change but it was the only change i made .maybe the tune was a little rich with the corsa and going to my current setup brought it in line better . i had the same tune on both passes

[sammy]

i havent run the car at the strip with the secondaries removed .will report when i do