TPI-Formula350-

Just had a quick run with a friends 87 Grand National. He showed up on slicks and running race fuel. It's a bolt on car, stock internals and stock turbo with 6 extra pounds of boost. We went from a dead stop, both heated our tires for 3-4 seconds. I have to say the G bodies hook nice, really plant the rear. He didn't spin at all on the slicks. My MT DRs felt like I was on ice, spun really bad. My converter flashing to 4400 is a bit to much. Anyway he had 2 1/2 cars on me right away. Of course I bounced the rev limited off the 1-2 shift(6400) and again the 2-3 shift(I was a mess). By the 1/8 mile I was pulling him, he was a car a head. Then I pulled him in just before the end of the 1/4. May have learned a few things tonight. Next time I'll let the car shift itself..lol. I'll also see if I can get him to run from a slow roll if he has the slicks/race fuel again.

zraffz

GN is an easy mid 12 second setup. Local guy runs water meth with bolt ons and turns low 12's on radials.

tpivette89

Close call! As stated, the GN should be a mid - low 12 sec car. Man those things respond really well to simple mods!

One of these days I will own another one... sigh

zraffz

Got one in my garage... read up on a tune only for premium fuel, multiple claims of something like 30hp and like 90 ft lbs.

Street Lethal

iTrader: (16)

GET AN LS1....!!!!!!!!!!!!!!!!!!!

Nice run...

Street Lethal

iTrader: (16)

Try to get the run on video if you can, as I'd definitely like to see the outcome from a slow roll. There's a member on the Buick boards who ran a GT-R from a roll, and pretty much cleaned his clock, which is surprising because they normally aren't known for being roll racers...

paul_huryk

That is the awesomeness of a turbo motor - lots of power and TQ with relative ease of adding more. When you consider the 3.8L motor was more a large V6 for mid and full size cars, never making 200hp NA in any form, the power of the GN is all that more impressive.

ZONES89RS

iTrader: (2)

You are over powering the radials big time, VS his power coming in smoother. At the track slick for slick you should murder.

TPI-Formula350-

I totally agree, my DRs were useless. When I suggested going from a roll next he wanted nothing to do with that idea. I'm sure he was surprised I caught him after him putting cars on me out of the hole. I'm sure I would have put 5-6 cars on him from a roll. I was still happy to catch him at the top of the 1/4.
I really need to figure out how to make the car hook better from the stop. I have MT DRs, Founders LCAs, and UMI LCARBs...The stall is an off the shelf Hughes 3000 converter but it's flashing to 4400. So with that converter and the engine making 517 fwtq the tires just smoke even after heating.
Any ideas on getting the car to hook better?? I'm looking to get a cross member mounted adjustable torque arm. I'm not really into the drag shocks.

Street Lethal

iTrader: (16)

Didn't see this part, and I find this pretty amazing that he had that much of a jump and lead on you at only six pounds of boost pressure. Why was he running such low boost, was it agreed before the run? Stock turbo is good for up to 15 pounds of boost before it starts heating up the charge, is he down an alky system and FMIC as a reason for keeping boost pressure low? From the sound of it, at 15-psi you won't be able to catch him whether from a dig or a roll...

TPI-Formula350-

Originally Posted by TPI-Formula350-
stock turbo with 6 extra pounds of boost...

read it again "6 extra pounds of boost" above the stock boost.... 15 pounds plus the extra 6 pounds = 21 pounds of boost

Street Lethal

iTrader: (16)

Don't have to read it again because you didn't say six pounds over what it is tuned for. Grand Nationals didn't come from the factory set to 15-psi, I said they were tuned for up to 15-psi, GM didn't need the owners killing themselves as they drove off the lot. LC2's are something that I am very familiar with being that I have owned a few of them, and part of the reason why I asked to see video I guess. At 21-psi, a "bolt on" (as per you) Grand National with stock turbo can and will see mid elevens, and there is no way you are catching that at the end of the quarter with that much of a lead from the getgo. Gotta call BS on this one to tell you the truth...

TPI-Formula350-

there is no BS, if any thing a misunderstanding. I'm not a turbo guy, I have no idea how much boost a GN was set to from the factory. The reason I said from the start " 6 extra pounds of boost" is because he told me he was 6 pounds over the factory boost setting.
I just added that number to what you said the factory turbo was good for. So you tell me whats stock boost for a GN and add 6 more pounds of boost and that. he was running on bolton, slicks and race fuel.

zraffz

I'm pretty sure they only reach about 12 PSI from the factory. Have a low mileage bone stock one in the garage and I've never seen it go anywhere near 15 PSI.

Manic Z

iTrader: (1)

I'd argue that GM was more concerned with potential durability issues than owners 'killing' themselves.
But anyway, the race sounds legit. I would never count a car out even with a two car lead.

TPI-Formula350-

ok, so like I said he was running 6 pounds over the stock boost. 12+6=18 pounds of boost.

Street - there is a video taken from about the 1/8. In the video he is a car ahead of me, before I pulled him down...I'll see if I can get it..its a night time video so not the best quality.

zraffz

I don't doubt you can run him down. These cars are not known for top end power. His final drive ratio is a tad bit lower (numerically) than yours and I doubt he's making the same horsepower. However, as you sat you lost the race. You stated it yourself, the g-body suspension hooks very well.

Street Lethal

iTrader: (16)

My goodness, let me clarify something. I am not here to pull the "BS" flag without a good reason. I can assure you that in the Grand National world, Ed Brewer ran 11.37 with the stock heads, stock LC2 camshaft (192/196 .384"/.408" (w/1.55 rockers) @ 107 LSA), and the stock turbo. A camshaft like that isn't going to have great top end, but there are plenty of grinds that do though. It doesn't take much for the LC2 to dive into the elevens with the stock turbo, as members have been doing it with less than 400-RWHP. To analyze what was said above, we have a Grand National w/bolt on's and slicks running 21-psi. This would tell anyone that already owned a Grand National that the owner was ready to run because a Grand National "should" hookup fine running the stock turbo without the slicks, yet he felt compelled to run them, which tells me he launched hard. Not to mention, nobody would run 21-psi with the stock turbo without 93 octane and alky injection, or C16 for that matter, because above 15-psi the stock turbo will essentially cause detonation from the heated charge, and when we get into boost, every pound of boost above 15-psi is very substantial in terms of horsepower being added...

TPI-Formula350-

Yes, as my tires went up in smoke he launched hard. He had a few cars on me right away. I was def thinking I was in big trouble, like I said after he launched like that I was rattled. Once I hooked I hit the rev limiter on two up shifts. If I can get my hands on the video you can hear my car bouncing off the limiter. I agree the only thing that kept me from losing was I make more HP and was able to catch him just before the top end of the 1/4.

TPI-Formula350-

OK, but are you following that I said he was running 6 pounds over whatever is the stock boost. 6 pounds over whatever is the stock boost, 6 pounds over whatever is the stock boost..( I only said 21 before because I read your post saying 15 pounds are stock boost number +6 gave me the 21 number) . I now see that the other GN guy posting here says 12 pounds is what a stock GN makes(12+(6 pounds over he added)=18 pounds). I also said he was running cam 2 race fuel. My car is in the high 11's so I dont see why this seems like BS..This GN ran tight with a stockish C5 ZO6 when the both hooked(running mids/low 12s) This GN is not in the 11s

I know there are a lot of GNs in the 11s with little mods..This car has few boltons ,slicks,Cam2 race fuel, and 6 extra pounds of boost..This GN is not in the 11s and I never said it was.

Copperhead

Stock boost on an intercooled GN is 13 PSI, +6 = 19 PSI. 19 PSI on a stock turbo will run you around 350 FWHP. If it really is a stock turbo, it could be a mid-12 second car on a good day. If you have 467 FWHP, catching him by the end of the 1/4 should be about right. A stock turbo would need to be running 25-30 PSI to be near your HP level.

Bigger turbos are considered "bolt-ons." Unless you know FOR SURE the size of the turbo on that GN (several of them look stock) you can't be sure what you're racing. You can never tell what a GN will run until you've ran it, 10-second GN's look and sound much like 14 second GN's.

InfernalVortex

iTrader: (4)

This thread makes me want a turbo.

Street Lethal

iTrader: (16)

Grand National's come with 28 pound injectors from the factory, and their duty cycle is essentially pegged at 15-psi, and nobody will run more than that with the stock injectors. They are tuned for 15-psi through the MAF scaler which is why GM went with 28 pound injectors, and if the above Grand National was running more than that, it is a safe bet that he was running more injector and a Turbo Tweak chip as well, which uncorks additional horsepower that GM detuned out of it from the factory as to not embarrass the Corvette. 15-psi will double the horsepower of an engine so long as the air charge temperature is not detrimental to the spark advance, and if the 3.8 is making 175-FWHP naturally aspirated, it should see 350-FWHP at 15-psi, and way over 400-FWHP at 21-psi. But that only tells part of the story because one, stock Grand Nationals will make just as much, if not more torque than horsepower, and when we get into bolt on's that changes absolutely everything. Also remember that this is average horsepower, not peak, which is why it makes a world of difference with a turbo charger. Here is my old bone stock '87 running a Turbo Tweak chip and 2800 stall speed at 15-psi, nothing else. Upping the boost to 21-psi with the stock turbo would easily get me into the elevens even with the same 1.76 sixty foot, and every tenth of a decrease in sixty foot after that will give you a two to three tenth decrease in ET. Bolt on's will give me an even quicker/faster ET/trap...

TPI-Formula350-

Poor quality video made from 1/8 or about 7 seconds into run. At this point he was a car a head. I don't have any video from the end of the 1/4 but had him by then.

rx7speed

GN isn't that great, same with the TTA.

Remember there is no replacement for displacement

TPI-Formula350-

I don't agree with that, the TTA, GN and GNX are some of my favorite cars.

Street Lethal

iTrader: (16)

Of course not, their 3.8's are no match for the Century 3.1's...

Back to the topic though, I remember when this one was sold way back when, it sported a stock turbo and psi was upped to over 20+. Even the guy who uploaded the video doesn't remember the details regarding the upgrades, but I do remember that this TTA was running the stock turbo, block and heads at the time it was sold. The rate of acceleration with these little motors is unreal, and the Buick guys have it down to a science...

fasteddi

iTrader: (2)

I've only had the priviledge to race one GN before and I know I was no competition at all considering he car was not far from stock. I went 13.50's to his 12.40s(IIRC) and he didnt do much to the car but jack the boost a little.

The T-type, GN, and TTA's are truely amazing cars produced in the 80's!!

fasteddi

iTrader: (2)

Yes there can be for us "normal 8-13 sec" racers Boost and n20, take your pick. IMO

Z28FAST1

You would have murdered him from a roll. Get some better footage next time!! Cool race though, I'd be honored to run one of those unicorns.

zraffz

Too bad only homos race from a roll

Z28FAST1

You must be confusing homos with people that make over 300 hp at the weels. You probably don't know about that...

TPI-Formula350-

Hey Street - spoke to the GN guy today and asked him how much boost he was running when we raced. He just told me 21 pounds, I'll find out his other mods Saturday, He's my auto body shop guy and I have to drop my car off for new door hinge pins then. I told him you turbo guys online were saying that was good for low 11's, he said he is slower then that. So as of now all I know for sure is he had slicks, Cam 2 race fuel and 21 pounds of boost. I'll ask him about his bolt on but I don't think many. I'm not looking to BS anyone so I'll just tell you guys what he tells me.


edit..spoke to GN guy... 21 pounds of boost, larger down pipe, MT STREET slicks, 116 octane race fuel.

zraffz

Nope... only ever owned a 454 punched .040" with oval ports and a mildly built vortec 350 with a 100 shot in a SCSB S10. Doubt either of them even broke 300 crank horses.

paul_huryk

Racing from a roll is a much more equitable way of showing how fast a car is. It also takes out the traction bogey and puts "area under the curve" in the forefront.

TTOP350

iTrader: (8)

Make sure your rear lower control arms are downward 1-2degs and your front swaybar is off of the car...

HI85WH1

Racing from a roll also takes the science of launch and traction out of the equasion.

Its more a means of racing for those that dont know what throttle control is.

My Fox Mustang (383W/PT78 turbo)made 500WHP at 6.5 psi, now up to 11 psi (not dyno'd since) but figure thats over 600 at the tires in a #3000 car. .... and like a GN, (wish I still had mine) can be as docile as it needs to be, or be as much of a hooligan you want it to be.... all based on your right foot.

Thats the beauty of turbocharging...

Now... if the Mustang still had AC... LOL

TPI-Formula350-

The lcas are angled slightly down towards the back of the car, installed in the bottom hole of the relocation brackets. I need an adjustable tq arm next. I won't remove the front sway bar because I won't sacrifice handling.

Z28FAST1

Not too much science for launching/traction: slicks, stalled, geared with some suspension mods. However, not everyone likes to drive on the streets with slicks, etc. Also, there are less chances of getting busted when you don't risk stopping, prepping street, warming up the tires, and having someone flag a street race.

These guys are so homo, I'm sure they wish they had a bored over 454:

TTOP350

iTrader: (8)

If you want to go fast straight line, take it off.
If you want to bang out some hard cornering put it on.
I take mine off an put it on all the time, depending what I wana do with the car that day.

HI85WH1

Not so much science?... think about that.. "some suspension mods" is a little deeper than you allude to.

Geometry for the lower arms is key (and a science the g-body guys have gotten down pat. F-bodys have to deal with torque arm (trans mount) failures. All can be overcome, but most dont want to put the time into thier cars to make them launch right.

Slicks?... try DRs with proper air pressure. A well built car on DRs will do fine, considering its built for it and the driver can drive with DRs.

Once you dial in suspension.. the biggest problem is the loose nut behind the steering wheel. Make a drag car a drift car at the touch of the throttle.

It takes far more skill to know how to let off rather than to hold it to the floor.

Interesting though... you post a video of on a roll racing.. and the guy in the firechicken has DRs (or maybe slicks) and he held with the car next to him.

GenX'Motorsport

How old are you bro? Because it seems like you just tuned into the whole performance car thing about 2 weeks ago. No offense but I keep seeing youre posts and..... well. IDK...

Eric. Keep up the great work Bro. You know I love reading these threads with one of my favorite Thirdgens of all time.

zraffz

Cool youtube video bro.

I've stated it many times before, I don't consider a car that traps a higher speed with a slower ET to be faster than a car that turns a faster ET with a slower speed. Your car is a total package, not just a motor. It isn't my fault that you dumped all your money into your motor and forgot about your suspension. No need to get all bitter


Edit:
And I forgot about all the science that goes into building a motor... stupid me! Any moron with half a brain can assemble a motor using expensive aftermarket parts and make big power numbers. What separates the morons from everybody else is ridiculously high trap speeds with terrible ETs.

fly89gta

iTrader: (1)

That easy eh?

Z28FAST1

I agree. At least someone gets it.

How old are you? Did you just discover the internet gramps?

I see what you are saying but some people like street cars and not high stalled, DR/ET Slick car with skinnies with powerglides in their cars. Maybe I'm just jealous because my 6 speed will never be as fast as a stalled auto from a dig but from a roll...you get the idea.

Yes that easy...When you see a stock suspension f-body pull 1.6's on stock suspension, I consider it pretty easy

zraffz

I understand but everything is a trade off. You chose a nice local driving 6 speed setup to make your power; your trade off is you ultimately put more power to the ground and it will show on a highway pull against the comparable car with an automatic trans. You'll have a nightmare of a time having the consistency off the line of a stalled automatic. From a dead stop you'll be chasing him but from a roll you'll walk away.
It's almost like at what point is sacrificing low end torque for top end power on the street.

The only true way to race in my eyes is from a dead stop. Just like you have edge when it comes to running from a roll (and ultimately less drive train loss), it is only fair to give the other car their advantage as well; which more than likely leaves you chasing and relying on top end to run them down anyway.

rx7speed

oh yeah but if that 3.8 had a 305 in it we all know it would make more power. ie there is no replacement for dispacement


[QUOTE=Street Lethal;5382639]Of course not, their 3.8's are no match for the Century 3.1's... QUOTE]
Yup if I put a 3.4 in my car it would be mad fast cause it has more displacement.

GenX'Motorsport

Im in my early 30's Jr. Been on TGO since you were in diapers..

fasteddi

iTrader: (2)

[quote=rx7speed;5384815]oh yeah but if that 3.8 had a 305 in it we all know it would make more power. ie there is no replacement for dispacement


I still dissagree. The only replacement for displacement is who has the most $$ and knowldege in a specific engine. BOOST

fly89gta

iTrader: (1)

Oh OK, thanks for dropping the knowledge on me.