my car is a 90 tuneport,has all the work done on the tuneport,heavely modded,i want to change cam shaft (for the third time)im running PBM brand circle track cam for tuneport,yes they make one ,if ya didnt know that.it is a small lift ,long duration,good cam,but limited to only 5000.i need more rpm,the cam is a 472/465-288/284 with a 110 LSA,with 1.6 comp rollers.
the new cam i want is a 510/503-281/276 with a 112LSA.i was told by comp it was the best cam for the modded tuneport,lots of rpm to 5800,with 1.6 rollers they said it would be 544/537 lift,and be a 224/230 @50.the one i got is 215@50.they said it would be better for what i got ,tpi,heads gear,so on.but they said i might need to burn a chip.DO you guys know if this is so?the cam i got now ,didnt need one burnt,i had the hypertech stage 2 chip with it ,worked good.with 411 gears ,i was running out of rpm to quick,and i need the gear,because of all the suspision work ive done,adding subframe conectors,roll cage,and so on adds weight,so you got to get it else where,lol.any help ide be greatful!!!!!!

 

unless you guys can name a cam ,that will go to 6000 or 6500,with a stock computer,with a burnt chip.i like comp cams,lunati,dont like crane cams.gm peformance is good,have heard of accel,but havent tryed trhat cam.any way ,need something 224/230@ 50 or better.dont care to have to up the idle,as long as the knock senser dont denate the crap out of the motor ,cause that causes problems in a tuneport.

 

Reprogramming of the ECM can benefit even a bone stock car. Personally, I think it is one of the best things to learn as you can not only gain in performance but also fuel economy.

As you start to modify the engine further, such as with longer duration/high lift cams, the more important getting a correctly tuned eprom becomes. This is especially true if you have SD. SD would most definitely need a new eprom for that cam you are spec'ing.

MAF is a bit more tolerant, but it too benefits from a properly tuned eprom. Basically, if you want the most from ANY setup, it is always best to retune the eprom.

 

Speed Density systems do not adapt or "learn" your new mods. Simple things as changing to a full exhaust with headers throws the stock tune off. The HUGE increase in volumetric efficiency is enough to warrent a new chip. The tune on these cars is just enough to maximise what the car came with out of the showroom.

 

Very few fuel injection systems "learn".

I was tinkering with electromotives TEC-3 the other day. That does. I don't recall any OEM setups (even OBD-II) that do, but I'm sure theres maybe 1 or 2.

 

Pcmforless.com

 

It'll run without the cam change though. Believe it or not, I still have the stock California spec prom for the original TPI 305 when I transplanted my Corvette's old 355 into it. I didn't think it would run well, but it runs superbly. I'm sure a new chip will optimize everything better, but $400 for a custom chip...that's a lot of bones!
I'll just wait until I stroke it to a 383, and then I'll go with the custom chip.

But yes, it'll work. If I can do it with my dismal chip, you can!

I'd be cautious about the 224/230 @ 0.050 cam, that's a lot of duration for a smog motor! I use an Isky 221/221 @ 0.050 cam (their 270 "Mega Cam") and performance is great, but emissions are always tough to get through.

 

Yup indeed. That was the point I was trying to get across. I use that term to dispell the common notion that EFI systems "re-learn" when mods are added. Soon enough digital systems will be out that will in fact learn and reprogramming ecms and proms will be a thing of the past after cam swap. Cool stuff.