I have a Crane Compu-Cam (Grind 2030) with the 1.5 ratio Gold Series Roller Rockers installed on my Fiero. Has anyone tried the 1.6 ration rockers with the 2030 cam? I called Crane and they said that my power range would rise and I would lose some bottom end. He was unable to say how much. Since the factory computer's rev-limiter is 5800rpm, he felt my power band would be rather limited. I can get a new prom with a rev-limiter at 6400rpm (max rpm of the valve train supplied with the cam) but will this be enough? Thanks for any info supplied.
Mike Nichols

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The 88 Fiero V6 ECM does not have a rev limiter (disabled in code), a cheap solution to your problem..
The Fiero V6 ignition system is weak (IMO) so I would be for installing an MSD 6AL, and then you can choose an appropriate rev limit quite easily. The 6AL also uses a better method to limit rpms then does the stock pre-88 ECM.

quote The 6AL also uses a better method to limit rpms then does the stock pre-88 ECM.

No joke. If I remember correctly, the pre-88 ECM actually shuts down the engine when you hit the rev limit.

I have a question about rev limiting, also. I'm planning to get an aftermarket PROM chip for my 1986 2.8 engine, probably Hypertech or ADS unless someone has a better suggestion. The question is: on the Hypertech and ADS performance PROMs, do they keep the factory rev limiter setting (i.e. 5800RPM) or is it increased? And if the rev limit is increased, what is the limit?

Thanks

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Tweaktech

If you are going to 1.6:1 full roller rocker arms, be aware that they will probably hit the stock valve covers.
Some solutions to this are to find different valve covers, or you can put 2 valve cover gaskets on each cover and that should give you enough clearance.

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quote No joke. If I remember correctly, the pre-88 ECM actually shuts down the engine when you hit the rev limit. I have a question about rev limiting, also. I'm planning to get an aftermarket PROM chip for my 1986 2.8 engine, probably Hypertech or ADS unless someone has a better suggestion. The question is: on the Hypertech and ADS performance PROMs, do they keep the factory rev limiter setting (i.e. 5800RPM) or is it increased? And if the rev limit is increased, what is the limit? Thanks

No kidding. Nothing like doing about 130 when the freaking engine just dies! Only happened once... that was enough for me!

I do have the ADS chip, but not sure if the rev limit has been raised/removed because I don't rev my engine that high... it starts to suffocate long before then.

I've got the ADS B series (strip) in my '85 GT 4spd. I believe this chip eliminates the rev limiter. I've only had the motor above 5800 a few times though, so I'm not completely positive.
Scott

quote Originally posted by 00lE: The 88 Fiero V6 ECM does not have a rev limiter (disabled in code), a cheap solution to your problem.. The Fiero V6 ignition system is weak (IMO) so I would be for installing an MSD 6AL, and then you can choose an appropriate rev limit quite easily. The 6AL also uses a better method to limit rpms then does the stock pre-88 ECM.

I already have a MSD6AL. The Fiero ECM is before the MSD system as you know the MSD plugs into the cable harness coming from the ECM. I have an very modified 86GT and it would be cheaper to just get a new custom PROM. But price here is NOT the object. What I need to know if the power band is too narrow for practical use. Thanks for your input.

Hypertechs Thermomaster chip in my 87 5spd GT adds more punch than stock. I believe your running an automatic or somethings wrong with your chip. Dont bother buying the other Hypertech chip or ADS. I've never had that brick wall effect. I believe a 2030 cam and 1:6 rockers would be pushing some computer controlled functions. Also-You could get adjustable CRANE True Roller RADI ARC VARIABLE RATIO ROCKERS with 1:5 1:55 1:6
in case computer freaks out-

quote Originally posted by rmcmsw: I already have a MSD6AL. The Fiero ECM is before the MSD system as you know the MSD plugs into the cable harness coming from the ECM. I have an very modified 86GT and it would be cheaper to just get a new custom PROM. But price here is NOT the object. What I need to know if the power band is too narrow for practical use. Thanks for your input.

My suggestion was to actually replace your existing ECM with one from an 88 since the 88 ecm does NOT have a rev limiter. Your 6AL will have "no effect" on increasing the rev limit, since your existing pre-88 ECM has the limit set lower in code.

Practical use is quite subjective, if you have the capabilty of obtaining the full RPM range of the cam by removing the limitations of the pre-88 ecm, then what is really the issue? You are certainly not going to narrow your powerband significantly from that exhibited by the 2030 cam, just by increasing the rocker arm ratio.
There are emissions related issues that may be encountered from the lowered idle vacuum caused by the increased ratio, but other than that I would say its not a big deal. :-)

[This message has been edited by 00lE (edited 12-28-2001).]

the ecm prom has no fuel mappings above 6000 rpm so no fuel= no power. basically the injectors shut off on pre 88's

I don't see how 1.6 rockers will make you lose some bottom end. it's just like installing a higher lift cam

Is the 2030 the one with .423/.423" lift? It's just a torquey cam with not much hp above 4500rpm. you are better off with the GM performance cam or Crane's equivalent that's advertised with .427/.455" of lift.

To all who responded to my query:
I called Phil at FOCOA and asked him to ask Keith (his son, Fiero Doc) about using a Crane Compu-Cam 2030 with 1.6 Gold Series Roller Rockers. THE ANSWER....Yes! No, they won't hit the top or sides of your valve covers. No, they won't push the valves into the top of pistons as long as they are stock. Yes, you will lose some bottom end but it is hardly noticable. Yes, the increase in power is very noticable above 3,000 rpm. Keep your Red-Line at 6400 rpm because the supplied valve springs are not designed for use above that. And last, most people do not use them together because of cost. Retail on the rockers is $351.00 but I have found them for less than $200.00. FOCOA is still the best place I have found for knowledgeable and reliable answers to any problem you might encounter with the cars we so dearly love. Got a problem, Phil is still the answer man.
Happy New Year to all,
Mike Nichols
Master Chief, USN, Retired