Cam with stock computer and chip

jdawg454

Registered User
Hello everyone. This is my first post on this site. I have been reading up for a while and figured out most of what I need to know by searching, but this one is beyond me. All you guys seem to know quite a bit about these cars so I figure maybe someone can help me out here.
I have 2 90 SC's, one auto and one 5spd. The auto ending up being a parts car for the 5spd. I am having my eninge rebuilt. Bore it .20 over and all the usuall stuff. nothing too fancy. Im trying to build it on a budget like im sure you all have heard before. lol. My question is about the cam. I would like to put in a decent cam, but for lack of money, I cant afford the supporting mods. Meaning injectors, headers, and computer tuning. For now that is. Does anyone know what cam specs are within the tolorences of the computer so that I will not have to get a tune right away. I
n the future I will have the money but I need to get it going before the "Giant Laser" (Plymouth Laser) takes a crap. So Im at a time battle with that aswell. Thank you all for your help! :)
 
Re: Factory Tune

jdawg454 said:
Does anyone know what cam specs are within the tolorences of the computer so that I will not have to get a tune right away.
I have a Coy 1 cam & used it with the stock '89 5-spd computer. Course I also had #36 injectors & 70mm MAF (with #36 sample tube). I had no problems at all.

68COUGAR
 
68COUGAR said:
I have a Coy 1 cam & used it with the stock '89 5-spd computer. Course I also had #36 injectors & 70mm MAF (with #36 sample tube). I had no problems at all.

68COUGAR

That seems like a pretty decent cam. I will look into that one. Does that one "lope" pretty good at idle, or is it more of a smooth idle. I cant remember which makes more lope, higher or lower LSA.
 
everyone on here says that coy miller is the only one making cams for this car when my friends 95 5 speed has a NASTY crane grind in it. he didnt send off a core, just specs, and what he got WASNT what he wanted. well, it is what he THOUGHT he wanted. this car chops EXTREMELY hard and sounds very aggressive, but it hasnt been tuned and runs okay, but not like it oughtta. this car is in jacksonville fla by the way. i would definately get a tune right along with the cam, and i would do a ton of other things while i was in there, but thats just me and is also probably the reason my SC motor is on the ground right now lol
 
I know there is others out there. Right now Comp has a few different grinds available, new, not a regrind. Which is nice. Give more choice in other aspects. Basically what I'm looking to do is build the internals up enough to withstand some abuse down the road as I add other stuff on. Right now i just need a good car to drive and not that much money to do it with right now. I can do more later, just not at the moment. i know thats a bad way to do things, but i dont have a choice.
I already had a chip from a few years ago, it is a JET chip. The other question would be, would that chip give me a little more tolorance with a cam selection as far as not needing a tune for now?
 
Don't take this as gospel, but here's my $.02:

You should be good with the mild cam from Comp Cams, maybe even the next step up from their "entry level" cam. It'll be a little off, but the ECU should be able to correct for the majority of it after being reset and 10 drives around the block.*

* Start the car, drive it normally for about 15-20 minutes, then shut it down. Repeat. This let's the ECU adjust itself according to average driving conditions/driver habits. In the process, it should also help it adjusting to the new cam. It won't be perfect... but it will be better than nothing.
 
jdawg454 said:
, Right now i just need a good car to drive and not that much money to do it with right now.

With that said, I'd recommend forgoing the cam for now. If you don't have the money for a tune along with a cam, then you definately don't have the $$ to replace the HG. I'm a firm believer that when you do anything, you get it tuned ASAP. Excessive heat causes HG failure...that results from a rich/lean condition, which is directly related to the tune. It's been shown that even a BONE STOCK SC can be running dangerously lean at WOT just because of the age of the components involved.

I've seen too many people be off on their tune and end up blowing their HG as a result. I've got one buddy who had his engine completely rebuilt with heads/cam etc and even with a chip that got him in the ballpark, it wasn't enough to keep his HG from failing again...He had about 2k miles on his rebuilt engine...

Just me to you, I'd suggest that you take that money that you'd put towards a cam, and put it towards something that will keep you within safety margins... i.e. a tune, 2x IC, exhaust, etc. You can make some good power without a cam. I don't have one yet, and I'm making 250/340 at the wheels on stock injectors through an auto. I'm going to push it a bit farther too on the stock heads an cam. I don't think that 300 is out of reach by any means at all. So if you're just looking for a little something to do so you can build up from there, go a different route than straight to the cam. Take it for what it's worth. I've been around a while and have seen a few combinations that have worked out well and about 25x more that didn't work out nearly as well.
 
007_SuperCoupe said:
With that said, I'd recommend forgoing the cam for now. If you don't have the money for a tune along with a cam, then you definately don't have the $$ to replace the HG. I'm a firm believer that when you do anything, you get it tuned ASAP. Excessive heat causes HG failure...that results from a rich/lean condition, which is directly related to the tune. It's been shown that even a BONE STOCK SC can be running dangerously lean at WOT just because of the age of the components involved.


Just me to you, I'd suggest that you take that money that you'd put towards a cam, and put it towards something that will keep you within safety margins... i.e. a tune, 2x IC, exhaust, etc. You can make some good power without a cam. I don't have one yet, and I'm making 250/340 at the wheels on stock injectors through an auto. I'm going to push it a bit farther too on the stock heads an cam. I don't think that 300 is out of reach by any means at all. So if you're just looking for a little something to do so you can build up from there, go a different route than straight to the cam. Take it for what it's worth. I've been around a while and have seen a few combinations that have worked out well and about 25x more that didn't work out nearly as well.

Well that makes pretty good sense. It kinda sucks that im going to be in there and not do anything with it, but oh well. Theres always a lot more to be done to it down the road. On the bright side, thats a few extra hundred I dont have to spend to get it back on the road. :) I would hate to rebuild the motor and have it get trashed right away. The machinist is doing as much to the heads as he can so that will help, and the SC i just bought already had some exhaust work done. ( no more cats, hehe :D ) Its gonna be a work in progress, but I miss driving my old auto so much, the 5spd i just bought should be even more fun. thanks for all your help.
 
jdawg454 said:
I already had a chip from a few years ago, it is a JET chip. The other question would be, would that chip give me a little more tolorance with a cam selection as far as not needing a tune for now?

I can't say 100% for sure on this one, BUT you may want to get rid of that JET chip with a modified setup. From everything I have read here, JET is just NOT a very good way to go. Especially if you have any mods. Some have reported no problems with a JET chip and NO MODS, but with mods the air fuel ratio gets pretty lean. Would hate to see you trash a new motor because you had a bad tune/chip.

As already suggested, I would say skip the cam for now. Instead, use that money to get a proper tune with an SCT chip. Contact Dave Dalke (XR7Dave) and he can hook ya up. It's likely gonna cost ya more than the cam would have, but IMO it is a very necessary thing to have if you want the most from your motor and want it to last. You can always get a reburn on the chip later on if you do more mods.

At the very least.... do some searching/researching on these forums for different opinions on the JET/Hypertech/SCT/Diablo chips. I have checked it all out myself and found very little good about the JET and Hypertech.
 
XR7inWI said:
I can't say 100% for sure on this one, BUT you may want to get rid of that JET chip with a modified setup. From everything I have read here, JET is just NOT a very good way to go. Especially if you have any mods. Some have reported no problems with a JET chip and NO MODS, but with mods the air fuel ratio gets pretty lean. Would hate to see you trash a new motor because you had a bad tune/chip.

As already suggested, I would say skip the cam for now. Instead, use that money to get a proper tune with an SCT chip. Contact Dave Dalke (XR7Dave) and he can hook ya up. It's likely gonna cost ya more than the cam would have, but IMO it is a very necessary thing to have if you want the most from your motor and want it to last. You can always get a reburn on the chip later on if you do more mods.

At the very least.... do some searching/researching on these forums for different opinions on the JET/Hypertech/SCT/Diablo chips. I have checked it all out myself and found very little good about the JET and Hypertech.

I'd second that...most of it. A cam is tricky though...you can get a regrind, but it's not guaranteed to be degreed properly...so you could spend $150 on the cam...who know how much on getting it degreed...or the tools to do it yourself...then, if it turns out that it's off...then you've got another $150 or so in parts to get everything to line up properly... So you've got $300 + the cost to degree the cam...or a new cam is $350~ or so...(you don't have to degree a new grind). Or you can pay $300-$325 for an SCT chip, plus the cost of dyno time ($75-$100 per hour). So an SCT chip will cost slightly more than a cam very well could.

I'd suggest though that you get new sensors all the way around...O2s, crank, cam, etc if you don't have new sensors. Those are a factor in why stock SCs after a while run out of tune. And it's very difficult to tune a SC with bad sensors and keep it in tune. You really want a solid operating engine to start with. That's my advise...especially if you don't have a lot to spend. I'm perpetually in the tight budget group!
 
It's in the exhaust system

jdawg454 said:
Does that one "lope" pretty good at idle, or is it more of a smooth idle.
I guess that depends on how YOU define "lope". I would say that my Coy 1 lopes pretty good, BUT the sound depends on the exhaust system used. I have Headers, 2.5" down pipes, No Cats, No Resonator, 3.5" center, 2 Turbo muffs.

Another guy I know used a Coy 1 with a stock exhaust, & his sounded almost the same as the stock cam.

68COUGAR
 
New vs. Regrind

007_SuperCoupe said:
A cam is tricky though...you can get a regrind, but it's not guaranteed to be degreed properly
What makes you think that a new cam is more accurate than a regrind cam? If they are both made on the same machine, isn't their degree of accuracy the same? OR are you suggesting that an OEM cam is less accurate, than an aftermarket cam?

68COUGAR
 
68COUGAR said:
What makes you think that a new cam is more accurate than a regrind cam? If they are both made on the same machine, isn't their degree of accuracy the same? OR are you suggesting that an OEM cam is less accurate, than an aftermarket cam?

68COUGAR

This is based upon some conversations with people who have built these engines...

They have found that the advance timing on oem grinds are not as accurate as an aftermarket grind...a regrind is stuck with the oem grind...wherever that is...where a new grind can be right on (at your standard 4* advance). That advance that is built into the cam is also built into the computer...so if your grind is off, so is your tune and you're leaving power on the table so to speak. To get it back, you have to degree the cam and get a different cam sproket to get the timing where it should be.
 
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