2000Firehawk

iTrader: (248)

Ok, here are my specs...
1998 Camaro LS1, A4, 3.23, GSC's, ALL stock with bolt-ons...

LS6 intake,ASP crank pulley, Meziere street EWP, TSP lid/FTRA, ported TB, Pace Maf, JBA shortys/high flow cats, SLP y-pipe, SLP 2OTL catback, LS1-Edit...

Runs 13.0x's all day, 12.9x's on good air day, 106.5 - 107.5 MPH, 1.99 60' all day, shifting at 6,000rpm...

Now, what type of performance will I have with just swapping out the heads for a pair of stock 5.3 heads with the stock, SMALL intake valves, & 2001 LS6 springs with a slight clean-up cut of the head surface ...

It's a daily driver, so I think that it will have much improved super low-end tip-in/driveablity, because of the small intake valve & compression ratio going up 1 full point from 10.1 to 11.1...

At the track I think that the extra low-end grunt, will help the 60' by a full tenth, which should put me in the 12.8x's all day long at the same MPH...

What to you all think will happen ?? Will the small intake valve hurt me at all in this 1998 5.7 engine that will not be shifted over 6,000rpm ???

Thanks,
Dave

Nickn20

why do you want to do this? get a stall and run 12.50s with some tires. and/or get a 75 shot and have some fun, heads are a lot of work man, trust me I know, so many other ways to make power, I'm assuming you have the heads already, probably laying around and wondering what you could do with them.....

from a tuners prospective you will probably gain some TQ yes, which will help with a stock stalled A4, you will probably get your tenth of a second.

2000Firehawk

iTrader: (248)

Been there, done that...
Had NOS on a 1971 340 4sp Cuda vert, & on a 1974 440 A3 Roadrunner, way back when NOS was a hardcore gearhead thing...

Head swapping is no problem for me... My 1st head swap was on my 'worn-out' heads on my HEMICUDA back in the 70's, talk about a back buster...

I hook EVERY time with GSC's, & go 13.0s' all day... It is a daily driver, even in most of the winter, here in PA, so 1800rpm stock stall is a-ok...

I'm just about where I want to be with this car...
I'm having fun with it everyday...
With all the different heads out there, I was just thinking outside the box, with this setup...

Stock 98 LS1 Cam, shorty exhaust/catback, A4/stock convertor, 3.23 rear, GSC street tires, are all fine...

I'm looking for a little more 'LT1' type low-end grunt, & 12.9x's all day...

Thanks for your reply...

Dave

foff667

iTrader: (2)

first off its a 98 so youd need to get the new style valve covers and stuff so you could attach the coils to them since 98's were separate coils...also the stock 5.3 heads give no advantage over the 5.7's other than maybe a little bit of compression but the valves would be smaller and not give you the flow you need. If you just want more compression just get the stock heads milled...probably much less of a headache.

lata
Bill

boomcase

2000 firehawk what is your point about the stall and driving it all year long. I drive my car all year long here in CT , as many other people do everywhere and I even put snow tires on it in the winter, Torque converter will not affect your daily driving , once it locked up in D you wont even no you have a converter. Like Nickn20 said get the stall its the best mod for use A4 guys hands down, Skip on the heads for now. As you stated yourself firehawk you want low end grunt, well a torque converter will just do exactly that, there are many cheaper converters available that are worth every penny do a search read up on this.

offaxis

iTrader: (19)

Id go for the converter also.

Windy City

Listen to what's being said. By far, the biggest improvement on an A4 will come from a stall. You don't have to go crazy and get a TP4400 but even going to a 2200 will net you a good improvement.

If you are worried about streetability, don't sweat it. A stealth converter will drive near stock but improve your times better than what you are looking for.

Just to give you an idea, my '02 A4 is a daily driver, my wife takes it frequently to her work because she loves driving it and I'm running a 3800 stall. I even haul my kid back and forth to daycare in it. I don't drive it in the winter but that's only because I don't want any salt on it. If I had to, I'd just put a set of winter radials on it with some weight in the back. Been there, done that with my '99 M6. Oh yeah, my '02 does 12.1 @ 110 (1.62) with just bolt-ons and full weight.

critter

iTrader: (9)

Been there. Won't do it again in a street car.

2000Firehawk

iTrader: (248)

I love convertors, & have had many in my 50 years...

I too agree that a convertor is the best thing you can do for an A4 LS1. Also a cutout is the BEST thing to do for a stock exhaust, without going to a catback... And a lid is the best thing for the intake...


No convertor for this comb, as it is just right for the hills here, in Western PA... + with street tires I have no spin off the line with 1.99 60' times all day long...

The 5.3 heads will give a FULL 1 point increase in compression ratio, not just a little...

I was just hoping that someone out there has tryed just swapping a set of 5.3 heads onto a 5.7 engine... just to see 'what if'...

Kind of like GM going to a smaller cam for 00-02 for that little extra low-end grunt...

I'm thinking that the smaller intake valve and 1 FULL point increase in compression ratio should make for a super sweet daily driver that turns 12.8x's all day long...

Right now I can drive to the track, & turn 13.0x's all day long with A4 shifting at 6,000rpm, without doing ANYTHING at the track. Don't want to change tires, don't want D.O.T. tires. Don't want Nittos. Don't want to open the exhaust. Don't want to remove weight. Just want to drive & fly & have fun with this setup...

My car will be 6 years old in a few weeks... got it new in October 1997. Started racing it in November 1997, so this is my 7th year racing it, & still loving it...

Don't want to do this if someone has done it, & it didn't work... I was hoping that a tuner or head porter could say yea or nay on this...
If not, I will give it a try, as it will be neat to try...
Still crazy after all these years...

Thanks for all your answers,

Dave

offaxis

iTrader: (19)

ok back to the heads I would say you would get 10-12 hp from 1 pt of compression . Without porting or larger valves Its really not worth it.

If you want more hp and want to be like stock i would install a ls6 cam it idles like the stock one and that would give ya 20-25 hp

YOu could always do the heads and the LS6 cam as long as the heads are off its easy and still idle like stock and add around 35 rwhp

2000Firehawk

iTrader: (248)

Don't want to change the cam on this one... I do have a LS6 cam sitting on the shelf...

That's what I was thinking, approx 10 HP for a 1 point increase in compression ratio...

Now, will that small 5.3 intake valve really hurt that much on an A4 shifting at 6,000rpm ??

In the street driving range of idle to 2,000 rpm, where 90% of the time we are all at, the small valve + 11.1 compression should be wonderfull...

Thanks offaxis, for your reply...

Dave

CHRISPY

I would not use small valve 5.3's.

Mill your stock heads to 11:1 compression, install ARP head studs, good gaskets and a cam kit while everything is apart. 11:1 stock heads and a 224/224 114LSA XE-R cam should give you another 4-5 mph easily. If you decide to spray down the road you are all set

2000Firehawk

iTrader: (248)

Hi Chris,

Will the small valve intake 5.3 heads hurt that much ??

The low-end street tip-in throttle response & driveablity should be SUPER...

I just can't see this hurting the top-end that much...

Kind of like the smaller 00-02 cam didn't hurt the 00-02 cars one bit... 00-02 are just as strong if not stronger than 98-99 with the bigger cam....

Dave

CHRISPY

The heads in stock form do not flow as well as the 5.7 or 6L AFAIK. I would not use them without port work

2000Firehawk

iTrader: (248)

Chris,

Don't the 5.3 & 5.7 heads have the same ports ??

Dave

2000RATA

Chris ARE 360 is right. I know because I am a head porter. The loss of flow would be worse on power than the gain in compression. Don't fall victim to the small valve equals more torque saying. You will lose power.

If you are going to change heads get some that have been worked over.

2000Firehawk

iTrader: (248)

Hi 2000RATA,
Ok, that bad dream won't be happening...

Thanks everyone for stopping me from madness, I see the light now...

Dave

VINCE

iTrader: (1)

Lets back up.. How much would you have to mill to get 11.1:1 compression on a 5.7L head? I think a lot..

Tin Indian

Casting Number 241
LS1 / 5.7L Passenger Car and Corvette
97-00 P/N 12559853
01-03 P/N 12564241
Material: Aluminimum
Combustion Chamber Volume: 66.67cc
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 706 or 862
99+ 4.8L Truck P/N 12559852
99+ 5.3L Truck P/N 12561706
Material: Aluminimum
Combustion Chamber Volume: 61.15cc
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 1.89 inches
Exhaust Valve Diameter: 1.55 inches