yamban

Hey everyone. I own a 1987 iroc-z and its almost time to take her out of storage! Theres a kid at my school that drives his dads 2009 GMC Sierra and claims it has the 6.2 vortec. He threw out the offer to race and I accepted thinking it shouldn't be too much of a problem. But, after taking a look at the HP rating on the truck I'm a little skeptical. Heres the stats of my car and his truck that I know of.


87 camaro
350 TPI with cermaic headers
Auto 700r4 trans w/shift kit
9 Bolt 3.27
full 3" Flowmaster 40's exhaust
at the most maybe 240-250HP?

09 sierra
6.2L Vortec 403HP est.
all stock
easily +4500lbs

Do I have the better power/weight ratio? Ive driven my dads 2006 Ram with 5.7L hemi, and that thing is pretty dam quick! what do you think?

Camaro Spectre

From what I know of the sierra I think the 6.0 & 6.2 models push the weight around 5200lb. Figure it will roughly be at about 350-360whp with roughly same for torque.

It should be a decent race in the end but the Iroc might have the edge. He may have more power, but he also has a lot more weight to be pushing off the line. As you forget the most important part is your hp may be tad on the low side, but its more then made up for in torque.

tpi305

I read that a Silverado with that engine can run 0-60 in 6.5 and do the 1/4 in around 14.9. Those headers would help you in the top end too. I think it would be close, but if you drive it right, I'd think you could beat him. Make sure you have a good tune.

Man, I've never thought of my '86 Iroc as "fast", running maybe a low 15 with headers, but when I see trucks and suvs that can out run it, it sure seems real slow.....or maybe the new vehicles are just real fast.....

J91

Unfortunately our cars are slow in stock form. You've got the headers, now I'd do some intake work, remove airbox baffles, K&N Filters, remove screen aon MAF, then have a real good tune put on it. Help the poor choked out bastard breathe! You might beat him? The shorter the distance the better chance you will have!!! Practice coming out of the hole, if you get him off the line, you could win....

tpi305

Agreed. At least he has a 350 over a 305!

I remember hitting 115 in my car and having it just crawl past that. After I put headers, I was doing 122 and it was still climbing (way better than before lol), but I ran out of road. Ok not climbing real fast, but not bad!

Anyway, those headers will help decently, as it's really close. But yeah, some airbox work would really do good. Does the maf screen really do that much?

J91

The screen removal helps, especially if you do the airbox work, hey it's a cheap way to squeeze a little more out of our cars I'd also do a coolant bypass on the TPI (in the summer months). I have a modified airbox w/ K&N's for sale if any body wants them, don't need that stuff anymore. Our cars were choked so hard from the factory, they need to breathe...

fly89gta

iTrader: (1)

Not really, would you risk damaging an important sensor for a possible 1hp gain? I wouldn't. The screens are also there for a reason.

yamban

thanks for the input guys. We'll do a 0-120km run on the local bypass in mid april. The iroc seems to be very peppy under 100 so it'll be good. If anyone is interested in the results I'll post 'em up along with a video! Later on this spring I'm going to race a 1996 cherokee 4.0L, 2003 sunfire GT, and a 2008 impalla SS probably at cayuga dragway. If anyone visits/races there keep an eye out for my car this year I live close

fly89gta

iTrader: (1)

Why would you waste your gas on a Grand Cherokee and a Sunfire?

Save your $$ unless they're putting $$ on the race

yamban

haha well the sunfire owner just wants to race for fun...drives that car ***** to the wall , and the guy with the jeep thinks that because my car is older its not as fast. He claims that since its a HO 4.0L it'll make up for displacement I never though about putting some money on it...

fly89gta

iTrader: (1)

Further proof that move Jeep owners are 'tards.

tpi305

Sorry to go off topic here, but what has been done to the airbox? I've been wanting to buy something for my airbox for some time now, I might be interested in purchasing it from you.

Yamban, that's a nice iroc!

J91

If you run a proper filter you do not need a screen, the screen restricts airflow across the entire rpm band, it's more about usable power not a 1 hp gain, do not knock it until you try it. Look up TPI hopup tricks, it's in all the books, on this site and many others, why because it works. You can modify airboxes, filter, etc. all you want, but it does no good if air gets choked up at the MAF. Thereason are cars are slow is that they do not breathe. Why modify an exhaust w/ headers if you are still gonna choke it on the intake. I ran TPI setups for years, they need to breathe like any engine.....

91 zeee

I know this is a couple weeks old now....but... went with my buddy to the dragstrip today. He has a 09 Sierra 4door 4wd w/ the 6.2L. Ran a 14.18 @ 98.4 mph w/ the cold air intake. At the end of last year I ran it one time, 14.30...bone stock w/ about 3000 miles on it.... very impressive. This truck pulls as hard at 80 as it does at 30.

KnottyBuoyz

iTrader: (2)

Bite me!

How well does your bird work in 20" of fresh snow?



Go get' em yambam! Only way to find out is to do it! Don't get caught though.

CamaroIROC88350

iTrader: (1)

I'm a Jeep & a IROC owner. I'm no turd!

KnottyBuoyz

iTrader: (2)

Amen brother! Jeeps are just as much fun as a flashy sports car!

yamban

Thats pretty impressive! I have yet to run the IROC but it would be around that maybe a little higher. He will also have the truck packed with people like usual so we shall see..

darkhorse91

THis isn't first hand experience speaking ( I have speed density) but here's an excerpt from "How to Tune and Modify Chevrolet TPI Engines" by Motorbooks

"Screens on the housing's inlet and outlet added further protection against debris damaging the sensor (they're very, very fragile), but the screens created quite an airflow restriction: According to TPI Specialties' tests, in stock form the MAF could flow 529 cubic feet per minute, but with the screens removed, flow increases to 711 cubic feet per minute- an increase of 182 feet per minute!"-page 88

like i said this is second hand information but i just read that chapter last night and had it handy. decent book but goes too far in depth about LT1s and LS1 without actually focusing on TPI like the title entails. decent info though

CamaroIROC88350

iTrader: (1)

2 things guys.

1.) Do not descreen a MAF if you want to prevent some potential problems that are expensive to fix. Why? They're there for a reason, let's just leave it at that. In fact below I have a link to a 3rd Gen. tech article about MAF screens/descreening. Read the WHOLE article like I did. There really isn't that big of a pants off the seat difference anyway. I do alot of my car work, modding & fabrication & one thing I had to consider while doing some mods was do I want to descreen that MAF? After doing enough research I came to the conclusion that doing so could ruin my car, at least make it run like crap. Plus I don't have the kind of money that flows like water to go replace a MAF for my 88 IROC-Z.

2.) On the part where they touch up on LT1's & LS1's alot, yeah, I can concur with that. I have lot's of respect for those motors but I can't stand it when someone tells me why don't you just go put a LS1 in your motor? And I tell them I think that the TPI is a great motor with lot's of potential & it's a great platform to build up on into the low 400 horsepower/gobs of torque region. While I admire guys who have the money to pour into a LS1 project I just don't consider that to be as wise as an investment as investing into my TPI which can beat a LS1 when souped up enough. That with the proper suspension upgrades or even the stock IROC-Z package is more than capable of out-handling a newer model Camaro/Firebird. How do I know that? I know because I've out-handled a LT1 WS6 and I've kept up with a LS1 SS Camaro. I didn't beat it but I was up on his butt.....

So in conclusion while I like the aluminum LS1 & I respect the LT1 cars, I just love being able to show up one of those cars with my TPI because most just assume it's a stock car or a stock 305. Anywho, thanks for reading guys.

http://www.gmtips.com/3rd-degree/dox...maf-screen.htm

yamban

Ok folks! I'd just like to let you guys know the results. We did a 0-120km. Right off the line the iroc had a small lead. Once I hit 2nd I pulled about a cars length on him and it pretty much stayed that way to the finish. The truck hauls *** non the less!!!!! Overall it was a pretty good race.That 4wd could of easily changed the results of this race if I had traction problems.. but lucky I didn't (225's in the rear too!)

ShiftyCapone

iTrader: (7)

Sounds like a good run. Basically the L92 makes 2X plus the power of an L98 but that truck is also 2X the weight. If you catch a single cab 2WD truck with that motor stay clear. They will weigh 1000 lbs less and can ruin your day. Heck my 4500 lbs sierra with the 5.3 is enough to beat most cars. By the way, although rated at 420hp to 430hp, an L92 makes near 500 on an engine dyno through stock exhaust manifolds. A 3rd gen with a stock L92 motor would run 11's with a novice driver.

ninetyone

iTrader: (2)

Look, I am a guy that grew up mainly in the 80's. All we had back then if you wanted a fast car was a Mustang, or a Camaro. Those were really your affordable "fast" cars back then. Any car that can do 0-60 in the mid seven second range is really, really fast. Yes, cars nowadays are really fast. It is rediculous. Standards have changed I guess. You can thank the Japanese for the technology. Don't get me wrong though, a Honda is still a slow car, and a true hot rod has 8 cylinders, RWD, and is supposed to suck up a lot of gas! My 91 bird basically still beats anything on the road though. I have never lost to any Honda or import car. The only thing our F bodies should have a problem with is the newer 8 cylinder cars like the new camaro ss, or 05 and up Mustang GT'S

J91

Guys like you crack me up. Ruin your car? Ever hear of a Quality Air Filter, instead of some paper junk. I ran no-screen on my MAF for years on two different cars. It helps, the numbers quoted above prove it. Unless you try something and know better, how can you come to these conclusions?
I work on cars daily and there are plenty MAF sensors out there w/no screen on them for many different brands of cars. Any car that runs worse from breathing better has serious problems. Combustion engines need airflow to run, the smoother and better the airflow, the better they run..

fly89gta

iTrader: (1)

Right. Not sure where this even ties into this thread but OK.

Go race an EVO or STi in your "true hot rod" and get back to us.

fly89gta

iTrader: (1)

Just because it worked for you doesn't mean it works for everyone. It's a topic that will be debated until people are blue on the face, most people don't have problems but there are cases that no screen=death to the MAF.

I personally don't risk it on my cars, the risk for maybe a 1hp or 2 isn't worth it. Others have had success...I never really saw any gains when I did it.

tpivette89

I descreened my MAF in my old 89' corvette. After a few months, the car developed a slight hesitation intermittantly while under load. The problem slowly got worse over the next few months til eventually the car drove so bad I had to park it. One day, I got lucky while I was testing a few theories, and the check engine light came on. After scanning the code, it came out as a bad MAF. Replaced it, and the car ran fantastic

I've never descreened a MAF since