anyone have a near stock zr-1 with the secondaries removed?

[Kevin]

and is going to be at carlisle? i'm kicking around the idea of pinning the secondaries open on my stock 90 and having a chip burned for it but before I do I want to see what the around town performance is like with them on all the time. I understand there maybe some loss in mpg but i'm more worried about throttle response and down low power. can anyone help me out?

also does anyone have a copy of the under plenum dvd that mark sells that I could barrow? I've pulled the plenum a few times before but I'm going to have to dig into the injectors next year and would like a refresher before I do.

[sammy]

kevin ,hi i did one on a totally stk zr1 ,except for flowmaster exhaust . we used mark prom and boy did john like it .the car was a 10k mile original car except for ficinjector replacements and the exhaust. if you would like to talk with him direct pm me your ph and i will give it to him

[sammy]

to me it had better throttle responce and a little more midrange power .by the seat of the pants meter

[Kevin]

Originally Posted by sammy

kevin ,hi i did one on a totally stk zr1 ,except for flowmaster exhaust . we used mark prom and boy did john like it .the car was a 10k mile original car except for ficinjector replacements and the exhaust. if you would like to talk with him direct pm me your ph and i will give it to him

incoming pm

[XfireZ51]

Originally Posted by Kevin

and is going to be at carlisle? i'm kicking around the idea of pinning the secondaries open on my stock 90 and having a chip burned for it but before I do I want to see what the around town performance is like with them on all the time. I understand there maybe some loss in mpg but i'm more worried about throttle response and down low power. can anyone help me out?

Kevin,

Before my recent head and cam upgrade, that's exactly how I was running. Had ported top end, took secondary throttle plates out and tie wrapped throttle shafts open. Burned a chip for secondaries on after idle tip in. I was getting about 23mpg at 75-80 and making ~ 400rwhp like that. Ran great, no bog. Takes a little work on the tune. I also believe having a Fidanza also helps in mitigating any bogging.

[Kevin]

Originally Posted by XfireZ51

Kevin,

Before my recent head and cam upgrade, that's exactly how I was running. Had ported top end, took secondary throttle plates out and tie wrapped throttle shafts open. Burned a chip for secondaries on after idle tip in. I was getting about 23mpg at 75-80 and making ~ 400rwhp like that. Ran great, no bog. Takes a little work on the tune. I also believe having a Fidanza also helps in mitigating any bogging.

this will be my first my first big mod that the car will see. everything on the car is stock except this....if I end up doing it. still not sure if i will but a little pre mod research never hurt anyone

[VetteMed]

My ZR-1 has been running without secondary butterflies and hardware for about a year now. Only other mods are headers and exhaust, FIC injectors, and a swap to the later style injector housings. Essentially a stock motor. I think it runs great this way, I do not perceive any loss of low end or throttle response. If anything, I think the throttle response is improved over stock.

[Paul Workman]

Originally Posted by VetteMed

My ZR-1 has been running without secondary butterflies and hardware for about a year now. Only other mods are headers and exhaust, FIC injectors, and a swap to the later style injector housings. Essentially a stock motor. I think it runs great this way, I do not perceive any loss of low end or throttle response. If anything, I think the throttle response is improved over stock.

Overall drivability is better now w/o secondary hardware - prolly due in no small part to Marc Haibeck's chip. IMO, parts that don't exist don't break, and they don't cost much to repair! I'd never go back, as long as I have a choice.

But, let's say I relocated to where emissions testing of OBD-I was still done. What then, sez me? I think I would make up a IH gasket with the secondary port blocked off, install my stock chip, and leave the power key in "Normal" for the duration of passing the emissions testing, at least.

Just a thought.

P.

[Kevin]

I had a nice conservation with a gentleman who did this to his stock zr-1 today and i'm 96.75% sold on it. It looks like I have to do injectors next spring anyway so while i'm there I'm going to do a few other things I want to do, TB coolant bypass, IAT relocation. does anyone have the part numbers for the FIC injectors for both the primary and secondary? And does anyone have a copy of the Haibeck dvd I can barrow for a refresher course before I dig into the motor?

[gmonsen]

I don't know what types of injectors are used and what their flow rates are, but there could well be problems with this approach, because the secondary injectors should have more flow than the primaries and some injectors don't work well when the duty cycles are very low, which they would need to be down low in the rpm range. The whole premise of the motor was to make a lot of torque down low and yet have the air flow and fuel to make max power at the high end of the rev band. The approach you are thinking about will probably reduce torque at the bottom end and might add some to the mid-range. The top won't change at all. I would think trying to open up the secondaries a little sooner and retune would be a better approach.

Gordon