So my new motor is in my car and running strong. I'll estimate on the low side and say the motor is putting out 425hp and around the same amount of torque.

It's a 355 with an XE 274 cam w/1.6 rockers, right under 10-1 comp., and Trickflow 23 degree heads.

The trans is a pro-built 700r4 with a vigilante 2800 stall.

Here is what I want to know, I will be swapping the rear out soon, but I'm gonna run it for a while.

My only suspension mods are IROC springs (stock height) a BBK panhard rod, and Lakewood LCA's.

Right now I have 275/17's in the back. My Dad is the only one to have driven the car so far (it's in Hawaii, I'm still in school) and he said the tires go up in smoke with a touch of the throttle but at least the car is going striaght.

So here is the question, since this is going to be a pretty radical street car (haven't installed the nitrous yet), I'm pulling the 17's for some 15x10's with drag radials.

The rear is the stock 10 bolt housing with a Zexel POSI and Richmond 3.23's.

Will this setup hook pretty decent with drag radials??? Or do I still need to get LCA relocation brackets and a torque arm??? If it does hook hard, how long do you guys think the rear will last until it blows apart???

Is it possible to run some low 60 foots with just LCA's, panhard rod, drag radials and SFC's???? I really don't want to blow the rear apart but I am gonna launch the crap out of the car after I put the D/R's on.

What do you guys suggest???? T
his car will probably get driven less than 1000 miles per year. It's gonna be radical and my goal is low 11's high 10's in the quarter in street form with D/R's on it.

 

I still have my stock rear with an Auburn Pro-Series posi and Richmond 3.73 gears and i have run 11.98 with it on Drag Radials. My engine is pretty stout, the numbers on the dyno were 321 RWHP and 486 RWTQ. So now i know you don't need gobs of HP when yo got crazy torque!!!! My best 60' time was 1.69 on the drag radials, of course i have all Spohn parts holding my rearend in, Adj. LCA's, PHB, and TQ arm, i have a set of Reloc. brackets i haven't put on yet.

 

Do you pull the front wheels up with that suspension setup and D/R's????

 

It fully extends it i know that for sure.

 

Nice launch...LOL.

I want to be able to heat the D/R's up on the street an maybe pull the wheels up in a street race. Improbable, Yes I know, Impossible, no.

Blowing my rear in the process, Highly probable.

 

I fyour not going to have more torque than me (486) then i don't see how you are going to blow it out? How much heavier can your car be than mine? Mine weighed 3600 with me in it.

 

Just because you haven't blown yours YET, doesn't mean I won't. Shoot, the last car I had probably barely put out 300lb ft and I blew the rear.

My car probably weighs as much as yours, I weigh like 195 and haven't stripped any weight off of it.

BTW- I'm going to put at least a 100 shot on the motor after it's broken in, so then I'll probably have a lot more torque than N/A.

I'm expecting between 435-455hp or so and at least 425lb ft at the fly. Add a 100 shot (nitrous is rated at the wheels) and I'll have about 550-575 hp and well over 500 lb. ft.

If that won't pull the wheels up, I don't know what will.

Nice setup BTW, do you drive it on the street???

 

Oh hell yes, it was my daily driver until i bought this little toy. But as for your TQ figures if you have 425 at the fly your only going to have about 360-370 at the rear wheels once you calculate in the 15-18% for drivetrain loss. SO even if you add 100 shot that is a HP rating not TQ. If you put some good stuff into that rear it will last. My has lasted me 6 years now and it shows no sings of distress.

Here's the daily driver.

 

Nice daily driver....wish I had a pic of mine over here in CA.

It's a 95' T/A. 390rwhp and 360 rwtq. It's fun, except at the gas pump.

Nice to know your rear has lasted that long. I think I am going to get a 4th gen rear for the disc brakes, then get an Eaton or Auburn POSI, with some 3.73's or 3.42's, and a T/A girdle.

My 95' Trans Am has the Eaton on it with 3.73's and 315 series rubber and has been great for almost a year now, but everyone over at fbody.com says I'm gonna blow it up if I hook and start running mid-high 11's.

How many passes would you say you rear has on it total???

 

probably about 200-300 but thats a guess, i have a huge pile of timeslips from it, and i started going to the track in 97. I did have to replace one set of gears becasue the stupid shop didn't locktite or stake my pinion nut and it backed off on my way to the track. Ate up a couple teeth on both gears and it was a pretty scary sound too, luckily it happened before i got there and not while i was running!!

 

425HP would be on the high side

Anyway I'm running a similar combo, just tad milder though. I'm running WP S/R heads.

I used to run sub 2.0 second 60' with my 15" Radial TAs. Now with more power, better gear, and more traction it launches a good bit harder. My 10 bolt, while not stock, has held up fine.

However it definately will not hold up to your combo leaving on the juice Mid 11's is REALLY pushing it on these rears, low 11's/high 10's is near impossible.

 

You kidding about 425hp on the high side or what???

The differences I see between our motors is the heads and intake. I went with the CNC heads for a bit more flow and while my intake is a dual plane it peaks at 7200 rpm, not that it matters cause this motor won't even get close to spinning that high.

Do you have 1.6 rockers with the XE274???

What kind of times/hp + tq figures are you seeing with the setup you have???

I also noticed you have a 2400 stall, is that a bit low for your setup??? I went with a vigilante 2800, I hope it was a good choice.

 

Mine is still kickin!
best 60ft 1.54, Hope to be sub 1.5's if I can get it to hook with this new converter.,.

 

No, I'm not kidding about that 425HP comment. Didn't realize you had the CNC heads. 425HP might be possible I guess.

Regardless of what others say, you won't find any dual plane intake that outperforms the Performer RPM. Weiand does make a nice piece, but IMO its overrated. I've seen flowbench tests where the RPM outflowed both Weiands dual planes.

Yes I run full roller 1.6s.

No numbers yet, either dyno or track. But comparing it to my old setup with track numbers (see my reply in the CompuCarb post)and cars I've run on the street its an easy low 13 second car, with mph in the 104-106 range.

I bought the 2400 stall TC many years ago when I put in the trans. It stalled around 2200 with the old cam. Now its 2400-2500rpm. Perfect for street use with the DRs, but its still a little low for the powerband. I won't upgrade till in get my AFRs in.

 

Well, I bought these heads because they flow the most for the money and for the cc size. I wanted a pure bolt on set of heads.

I was going to get AFR's but they are 68cc, and I wanted 64cc as to not drop the compression.

As far as what you say about the performer rpm, whatever, I could care less. I wasn't trying to say there was a difference.

Thing is you said you have World Heads S/R model. Stock Vortecs outperform those by about 10hp. The heads I have when placed on a 400hp 350 in place of the Vortecs yielded over 20hp.

I am figuring the motor should put out right around 425 horse, I'll almost put money on it.

I also think the machine shop decked the block a little, but I can't remember. It was so long ago when I had it done. If they did then my compression is higher than I think it is.

My Dad has had some really radical cars and he seems to think it has enough power to pull the wheels up.

Thing is, those Vigilante converters really get the torque to the ground. In studies/tests they been proven to multiply torque by a large margin. I think that is why my Dad is saying it is so radical.

You'll be up around 425hp when you put those AFR's on, if you swapped the converter out for a Yank, Vigilante or similiar in like a 2800 or 3000 rpm stall, you'd easily run low 12's/high 11's on drag radials.

 

Chevy Hi-Performance did a Goodwrench 350 buildup where non-CNC TFS heads outperformed fully ported and worked heads by 7hp.

The cam in this motor was an XE268 with 1.6 rockers. The motor made 416hp with the TFS heads. It had a compression ratio of 9.4-1.

I'd say the steup up from the XE268 to the XE274 is worth 15hp, at least 10.

I also have 5 extra cubic inches. Not a dramtic increase but it is worth something, that's why we do it.

I just wish there was a dyno where I live so I could just stick it on there and be done with it.

 

I'll be a little over 425HP

I got the Competition Package 195s. They flow a good bit more than the standard 195s. The XE274 will be pulled in favor of the XE284 grind with 1.6s. PI recommended a 3200rpm stall for this application, but the $750 price means it will be put off for a year or so. I have an interior I want to address first

For what its worth I went back into my car rag archive and pulled out Car Crafts September 2000 issue. They bolted on a set of TFS 23* (30400001) onto an 8.7:1 355 with a Comp XE274 with 1.5 stamped rockers, Performer RPM, 750cfm Speed Demon, and 1 3/4" LTs to a true dual setup.

Combo made 407.4HP@6000rpm and 415.2lb/ft@4500rpm

That should easily be enough to pull the wheels. But its gonna need chassis work, a higher stall converter, and some nice sticky tires to do it.

So I guess 425HP is reasonable with your CNC'd heads, more compression, and 1.6 rockers...

 

Cool man, hope your setup works out. Maybe we'll both be pulling the wheels up one of these days!

 

i have a pretty much identical combo to yours, 9.7:1 comp, TFS heads, XE274, rpm air gap, 750DP. Dynoed 321 hp/ 381ftlbs tq. This was through a t-56 and a 9 bolt. Temp was about 80*.

Combo ran 12.91@109, car weighs 3500lbs with me in it.

Your 425hp figure may be just a tad on the high side, but none the less, your gonna love it. Mine absolutely ROASTS street tires. I drive around on 275/50/15 bfg drag radials just to keep it under control on the street. Don't even dream of pulling a wheel with them though, ESPECIALLY on the street. They do work pretty well for street use though, i can pretty much stab the gas from a stop and it'll hook. might spin for a couple feet but thats about it.

Eric

 

Yeah, I'm not saying in the car it will produce that kind of power. I talking 425 hp on an engine dyno with LT's and true duals.

However with a 15 percent loss, You have approx 375-380hp at the crank and sweet 450 lb ft. of torque. That's pretty good.

I don't know what kind of exhaust you have, but I thin the configuration most of us run on our cars hold it back a bit. In other words I bet you could clispe the 400hp mark easy if you were to tune for hp. I.E. single plane intake, carb tuning, True Duals, etc.

Do you have 1.5 rockers or 1.6???

Is the motor punched over at all??? 355 c.i??? 360??

That is WAY more torque than I expected.

What is the rest of you setup?? I.E. gear ratio, suspension setup, were you running D/R's on the 12.9 run????

Do you think it would be worth it in your case to switch over to a single plane intake???

 

Zupman, only diff i see is the 1.6 rockers and the Catco Cat. The rockers may be worth only 10rwhp or so. I think you probably had your cutout open when you did the dyno run though so the cat is irrelevant. Did you have the cutout open?

I still have to upgrade the rear gears to 3.73 from the current 3.23's and then I'll have something.

I am currently working on the suspension too, I'm gonna go all out with drag bags, relocation brackets, LCA's,Panhard, SFC's, and a Jegster shortened adjustable Torque arm.

I think I'm going to go with a 275/50 drag radial on a 15x10 rim.

I have a single exhaust setup, with hooker shorties and a single 3 inch. I think I might run true duals with the shorties and dump it before the rear tires.

I'm going for that 425hp figure if its the last thing I do, before the nitrous.
If I can't run mid-low 12's on the motor I'm going to be pissed.

I guess I'll go home and drive it first, see if it needs more top end and go from there. Single plane intake may be necessary.

 

Did you get the CNC version of the heads or just the regular ones????

 

I bought the normal versions, since those times, and those dyno numbers, i've hogged them out just a little bit. As for the rest of the combo, i can't remember what rockers i had on there at the dyno, right now i'm runnin comp 1.52 pro mags. And yes the cutout was open. Biggest bottleneck i have right now is those POS edelbrock headers.

As for everything else, it's a 355, PM rods, trw forged flat tops, T-56, spec stg 3, and now i have a 9" with 3.89 gears. it's running 12.95's consistant as is on DR's. the 12.91 was with the 9 bolt which had 4.10's in it(and was about 120lbs lighter). The car should be going faster than it is, but the motor is breaking up at like 5700rpm due to tired valve springs. I got the 1.47 singles with the heads, which i'm pretty sure have just about had it. In the past the thing liked to scream right on up to 6500.

With the springs fixed, and on ET drags, i'm hoping for some 12.5's or better. then comes the n20

Oh yeah, suspension wise, it's got no sway bars front or rear (rear wouldn't fit with the crossbrace on the 9", working on fixing that now). Has a spohn tq arm, lakewood lcas, boxed Panhard bar, 50/50's in the back, 90/10s in the front. All times listed were with the 275/50 dr's on 15x10 weld prostars.

Eric

 

I was tempted to get the cheapest heads, TFS, but knew I needed the double valve springs to handle the lift, and I figured for a little extra cash i could get the CNC heads for more flow and perfomance.

You'll run mid 12's with that setup, just get 100 percent of that torque to the ground.