hey guys. ive bought a few things off the board for my father inlaw's car. its a 96 z28, auto, with slp muffler and tipps. ive bought him a set of bbk shortie headers w/y pipe, moroso cai and a trickflow elbow. now, the headers are for a single cat car, which his isnt. but because we dont have emissions here, both cat are going to be deleted. so, will i have to get a tune? as in, will the car not run properly, or will the check engine light just come on? and also, what would be the next bolton mod for his car? it wnot be drag raced or anything, its just a cruzing car for him, and he doesnt want to open up the motor. i was thinking gears, but its an auto and like i said it gets all highway use. and would a set of rollr rockers make a noticable difference? thanks guys

 

With the things you bought you shouldn't need one. But deleting the CATS on a OBDII car you will need the post-cat o2 sensors "shimmed" I think is what people call it so they don't through a DTC code. I'm not 100% sure though, I'm a OBDI kinda-guy.

 

You replace the after-car O2 sensors with "simms" = O2 sensor simulators. Hard to find since Casper got fined $70,000 for making them, but they are available.

One thing to keep in mind.... even a STOCK engine will pick up more than 10HP with a simple tune. With the headers and CAI you might even pick up a few more, and the tuner can eliminate the after-cat SES light. Don't "need" a tune, but there will be benefits.

 

thats what i was thinking too. i should just send it to pcm4less and have it tuned for the cat delete. i was hesitating though incase i get him some other small mods before the winter is gone. i doubt he will want to change the gears. so what would be left as a basic bolton that wouldd need to be tuned? thanks

 

i just checked out madz28.com. he is the first guy i used when i did my first blower tune. it was great. and i searched, and its seems that he usually gets more power out of his tunes, and hes the cheapest! so i will just ship him the pcm when i figure out all the mods to be done. so heres what i have in mind:
1-moroso cai
2-trickflow elbow
3-bbk shorties w/y-pipe
4-cat. delete ( this requires deleting the rear 02's?)
5-descreen maf
6-slp exhaust (already installed)
7-gears???? (i still have my stock 10bolt w/3:42s and i believe he has 2:73s. is it worth giving him my gears? and how will it affect his rpm's on the highway?)
8-160' thermostat??? (worth doing?)
9-new plugs & wires. (which plugs and gapped @ what? 0.35 is typical no?)

 

Don't descreen the MAF. All it does is make the tuner's job harder, since it screws up the MAF calibration table in the PCM. Its not a major obstruction on a bolt-on setup. Leave it alone.

3.42's will make it feel like you increased the torque available at the rear wheels by 25% compared to the 2.73's. But it will also increase the RPM at any fixed speed by 25%.

160*F thermostat is good for 10HP, with the PCM fan on/off temps reprogrammed lower, and a bit more ignition advance in the program. Also consider bypassing the coolant that is piped to the throttle body.

For the mods you described, TR55 Iridium, gapped to stock 0.050"

 

I'm about to sent off my PCM to get tuned. I just bought my car and it already has a MAF with no screen. Should I go buy a MAF with a screen before I get a tune?

 

Unless you replace it, you have to tell the tuner that it is missing. Then he has to guess at what effect it has on the MAF calibration table. That's not as easy as is sounds, because the specific CAI configuration will change the calibration from stock, without the screen.

 

ok so i should defenitly get him a 160' thermostat then. i was only going to descreen the maf because its an option on madz28's order sheet(so i assume he doesnt mind) but what ill do is put a note with the pcm and let him deside if its worth it or not. so i wont touch the maf till then.
for the spark plugs, i wasnt sure but i always thought that 0.035 was the standard. is there any benefit of going to 0.050 instead?
and for the gears, 25% more torque! thats seems like a lot. that would definetly be worth it then. im not sure on the rpms of the car on the highway cause its an auto, but i would assume that @60mph its in the 2000rpm range, so going to 3:42s would bring that up to 2500rpms?
anything else guys, its all very appreciated

 

The factory spec for the stock platinum plugs is 0.050". The iridium plugs offer the same long-life advantages as platinum, so you would use the same recommended gap. The advantage of the larger gap is a more open spark, better ignition of the A/F mixture. The wide gap becomes an issue when you use a non-platinum (or non-iridium) plug, and the gap slowly opens up as the plug wears. Hence, if you use a standard plug, you use 0.035" so they last longer before the gap gets so large the plug won't fire.

The larger gap also becomes an issue with a very high HP application, particularly large hits of nitrous, or high boost, where the extreme cylinder pressure will "blow out" the spark and cause misfires. Again, in those applications you want a standard plug, and a gap of 0.035" or less.

 

thanks for the spark plug lesson. very helpful. on my setup in my sig i have mine set to .028 as i will be running 13-15# of boost.

well thats about all need to know. oh one more thing. would it be worth getting a set of 1.52 sa rr. this way i wouldnt have to change the spring and add guide plates and pushrods, and it would gibve me the effect of a small cam? i know that when madz28 tunes he raises the rev limiter to 6000rpm. would that be too high for 1.52rr and stock springs? thanks