Hi guys,

I have an 83 notch back mustang, and am putting a 4.8 ls in it with hopefully a gt 45. I am planning on pushing the limits of this build to see what the block will take, everyone local around here doesn't think it will make much power and will blow up early, but obviously I believe different. The car will mostly be a street drivin car, with a trip to the strip every 3 or 4 weeks in the summer. I plan on putting a th400 behind it with a 3500 stall converter, and a relatively high gear (2.73 or 3.23). I am wondering what cam and springs to use with this build? what head gaskets should I get? does anyone have any experience with the ebay head studs? also I am wondering if the gt45 will work well, or if it will be to big? I have heard good things about the master power turbos, but don't know where to buy them (somewhere in Canada would be great) did a quick google search and nothing came up immediately.

like I said I am going to try and get whatever I can out of this car, I would like to see above 700whp, but maybe not gonna happen (shoot for the stars land on the moon sorta thing). The most local strip to me runs 1/8 mile drags, and I would like to knock off a mid to hi 6 second pass before the end of next summer.

Thanks for any help

 

Search for Denmah and his builds, he has a few different builds, and has run that same combo.

 

I see you have a couple of sleds in your sig.....do you have a build post of the them? more curious than anything. might be a fun winter project.

 

I seen 1000 out of those...

 

No build threads, but there may be some pics here somewhere. They're a blast to ride. We've been running strictly asphalt 1/4 the past 7-8 years, but a nhra rule change has made it only legal to run 1/8 mile, so it maybe time for some 1000' speed runs this winter.

 

Anyone have any more info? I tried to search for some of denmah's post and there were 75 pages come up!! must be the guy that knows

 

:lol: Everyone local must not have access to the internet! Must also not get magazines where CarCraft took a stock 4.8 and made like 1200hp on the dyno.

http://www.hotrod.com/techarticles/hrdp_1109_stock_gm_ls_engine_big_bang_theory/

 

I have defiantly read the big bang theory, and I believe in it completely. keep the rpms lower and the rods will hold, keep the air cool and the motor wont detonate, and the crankshaft in these ls' is bolted in far superior than any early model block. most guys at the local strip are running n/a, a couple of guys are spraying, I don't think anyone is running a turbo on an 8 cylinder.

I was going to get the same cam as in the big bang theory, but I am going to run the truck intake, stock unported head (unless I get ambitious with the die grinder), and the turbo didn't look like it spooled until around 4500. I want to keep the cam small so I can run a smaller converter (from what I have researched you want your stall speed to be 700rpm less then where the motor would make peak torque n/a), I think running a converter any higher than 3500 would be a pita on the street. Also I don't plan on spinning it a whole lot higher than 6000rpm, I think the rods would hold but I feel I am better to sacrifice a couple of hundred rpm than make a mess.

what about good head gaskets and ebay head studs? the studs say they are made from the same material as arp's, but I was wondering if anyone has actually had any success with them.

what about master power turbo's? who sells them? is there anyone that is local to me anywhere I am in Ontario.

thanks for the help guys

 

The ebay head studs are being used, I have a set for my current build. I have my doubts as to them being as good as the arp, but havent heard anything bad about them yet. Ls9 head gaskets seem to be the latest gaskets guys are running. From what I understand Master Power has changed directions with their turbos, and you dont see much of them anymore. The Magnum brand has taken their place.

 

I run a 4.8 and gt45. Stock cam, stock valvesprings, stock head gaskets, untouched cylinder heads, untouched bottom end. Only "mod" is an LS1 intake for hood clearance. My 3600 lb car went 11.67 @ 123 mph on a 2.0 60 ft. Calculator says over 520 RWHP. Shift rpm was 5700. I finally burnt a couple pistons.

 

Where in Ontario are you? I live in Prescott just south of Ottawa. I have a master power 70mm for sale in the classifieds. It made 587rwhp on my 5.3 at 12.8lbs of boost. I've been running the ebay head studs for almost 2 years with no issues. Call PTC for the converter, 3.55 gear or lower and I would run the stock cam. Your going to be limited by the turbo anyway. A mid 6 pass will be easy in a mustang.

 

I live in perth, and I know your car, I have seen it on kijiji and a fellow I work with has talked about it several times, and that's what pushed me in the ls direction. Why not throw a cam in it? im gonna have it apart that far anyways, will the power gains not be substantial?

I thought that car has made a couple of 9 second passes?

 

You can throw a cam in it for more power on less boost but here is what I found with my car. Big cam made less torque, made a ton of valve train noise (needed longer pushrods), made 13" of vacuum, idle at 950ish pulled hard after 4500rpm or so and got 22-25mpg at 55-60mph. Stock cam will idle at 500rpm if I wanted it too, no valve train noise, makes 20" of vacuum, will blow the tires of from idle and for the limited time I have driven it gets about 30mpg at 60mph. I don't have a truck now so my car will have to be driven to the track now and I don't go much anyway so I'm thinking of throwing a 4l08e in it with a shift kit. I think the stock cam will work better off the footbrake. I will be driving it to the track on Saturday so I will have some mileage and quarter mile numbers. A guy on ls1 tech made 50 or 60 more flywheel horsepower will a cam at 16psi of boost. Not really worth the $350 to me when a manual boost controller cost $10.
My car did run a couple high nines when I was at Shannonville but there printer was down or some bullshit like that so I didn't get any slips or video. I haven't told too many people though because I don't have proof. I will hopefully have some on Sat.

 

what about opening up the gap on the top ring? what does it do? is it worth doing it?

I agree with you if its not going to be a substantial gain, i might as well just turn the boost up, how much for the t70?

 

depends on the milage, a friend ran a 120k 5.3 a whole season without touching it, i have also heard of low milage motors butting rings.
https://www.theturboforums.com/threads/360220-project-Mullet-Hairdrier?highlight=mullet

 

If you have it apart check them. I never touched mine it had 100,000kms on it. 400 for the t70.

 

is it still necessary to upgrade the valve springs if I keep the factory cam? I would like to run as much boost as I can.

 

Most swap springs even with a stock cam, and you will want to if you're going to up the boost.

 

does anyone have any suggestions on what valve springs to run?

 

Pac 1218's are common, and reasonably priced.