O.K. guys, I need help! I've just purchased an 89 Iroc with the following setup: 406 with super ram, trick flow 23degree heads, SVO 24lb. injectors, don't know what cam It does have a decent lope at idle. It's running stock computer with a prom from Ed Wright. Hogged out stock MAF meter. Tremec TKO 5 speed, moser 12bolt with 3:73's. When I got the car it ran like poo! I bumped the fuel pressure, and timing and it ran pretty decent. G -tech showed high 13's. I was not impressed So now I have taken all the smog crap off, did the coolant bypass on the throttle body, and don't have a clue where all of these vacuum lines belong! Car really runs like poo now. Assuming I get the vacuum figured out, what kind of times should this get me? This is a brand new motor, Do I need to pull it and take it apart just to figure out what cam is in it? Do I need bigger injectors? Bigger MAF sensor? Do I need to switch to speed density for this set-up? Please help!!!

 

You said the motor is "new". I don't know what you define as "new" but if its new new, you shouldn't be driving it hard anyway and let it break in. Fix the vacuum lines (a Haynes or Chiltons will show the routing), check the plugs, maybe give it a tuneup, mess with the timing, check for trouble codes, check for vacuum leaks (both visible and with a vacuum guage), just make sure everything is the way its supposed to be. First things first, that stuff is basic. Hell i'd even do a compression check to make sure the rings have seated, even if its a new motor. Yeah, definately find out what kind of cam you have in there and what kind of compression its running.

 

You really need to scan it and see where it's at-it sounds like some major tuning is in order-I have a simialr combo and burn my own-I had to do significant tuning and am still not done!

 

406, TF heads & a good roller cam should get you solidly into the mid 12s, maybe faster. 24lb/hr injectors might be a tad small, so bumping the fuel pressure was probably a good place to start. Get the vacuum lines figured out, then get a scan tool on it. Ed Wright is about the best there is for chips, but nobody is going to get the chip 100% right without having the car at their disposal to test.

 

30 lb injectors would be better for a 406. You should get a scan tool on it & see if it is running lean. I have a 350 Super Ram & it ran 13.19 with the stock MAF & an Ed Wright chip. With a 406 you should be kicking my butt.

 

are you sure its a 406?

If you let g-ma go pick up her depends in a thirdgen with a 406 she'd make it to the store in under 12 seconds...


But then again, i wouldn't evne use a Gtech for a paper weight.

They do however make good skipping stones

 

A g-tech is a great tool for those of us that don't live next door to a drag strip. Sure it's off by a couple tenths, but in my book, that's pretty good, and it's a lot more accurate than the butt-dyno for determining the effectiveness of mods.

 

I've run my gtech while running at the track quite a few times...and it's never been off more than a tenth....better than GUESSING what you run! I also love the fact that it gives you 0-60...where else you gonna find that out? And like he said....for those people that dont live next door to a track, it's a good thing. Hell even if you live close to a track doesn't mean anything....last year when the track was only open for TNT on thursdays, (now it's open tues. and thur!!) it rained 5 thursdays in a row!

 

 

I'll agree that a g-tech is not as good as a time slip, but it is a helluva lot better than seat o the pants feel. I didn't need the g tech to tell me my car should be pulling harder, It just confirmed it.

According to the seller, the engine has about 3000 miles on it. I do know it is not a roller cam. The car has an intermitent miss and surges badly. It pings pretty bad also, not so much at wot, but at part throttle. Thanks for the help guys! Is there anyone out there close to north central oklahoma? Later!

 

just out of curiosity, how much did you pay for the car? Did you buy it from a friend or just some guy?
The G-Tech might not be the most accurate but it is pretty consistant. I think that makes it pretty nice.

Brian

 

I traded my bike for the car. I was asking $7200 for the bike. Car is not a show car by any means, but pretty good shape overall. Everything works on the car other than the hatch pull down. That includes a/c, cruise and everything. Does this sound like a fair price? Car has 97,000 miles if it makes a difference. It also has a brand new set of Weld pro star rims all the way around. Trying to trade them off for something else right now.