smitty2919

I just had my 95 Z dyno tuned to make sure things are in order for AutoX season. Put down 311/347 on a dynojet with following mods:

60K miles
Custom CAI
Pacesetter L/T's...no EGR or Air pump
Catless midpipe
Borla 3" Catback with Hooker Maxflow muffler
Dyno Tune

Tuner and anyone I mention these numbers to say that is pretty strong for a "stock" LT1. I am by no means a "number chaser" but if I can get some more out of the car in a simple manner I would be interested to do so.

I was contemplating picking up a 58mm TB, try doing a slight porting job on a stock intake, converting to a LS1 SLP lid style intake, crank U/D pulley and go in for a retune.

So cost invested I see as:
Stock intake "free" - I have a buddy that will give me a stock intake to port/use then I give him my stock one back.
SLP lid - $75-ish if new, can save if buying used.
58mm TB - $? undecided what one to go with
U/D pulley - $?
Retune - $125/hr on the dyno


Any opinions on how much these cars pick up with those mods? What TB are you running that is not giving you issues?

Thanks Guys.
Dean

93M6Formula

That IS abnormally high for a bolt on LT1.

Don't waste your money on a 58mm TB. You aren't making enough power to warrant any gains. I would just have the stock one ported.

I think UD pulleys are a waste of money

I'd like to see pics of your air intake setup, I doubt you'll see much gain going to a LS lid setup.

Porting your stock intake isn't a waste, it probably won't gain a whole lot but it will be ready for if you ever do H/C.

bowtienut

iTrader: (1)

Is that 311 SAE corrected? Even if so, that's not abnormally high for a M6 car. Definitely good though!
Porting the intake is worth nothing at this point. Don't bother to pull it off. I'm running an unported one making about 540 crank hp.
Aggred, the best TB option is a stock one re-bored to 52mm. The openings at the front of your manifold will accomodate that.
U/D pulley is worth 5 hp at most.

lt1-xjs

Strong runner for sure, for just cai, long tubes, cat back and a tune. I would be going for the bolt-on record. Should be sub 12.50's at that power level. For new mods, LS1 lid, ASP 945103 set, ewp, springs and rockers.
You need to run that car down the track.

smitty2919

Thanks for the replies guys. Yes I believe it is to be corrected. I'll have to upload the dyno sheet tomorrow.

I have no interest in 1/4 mile times...building the car for AutoX and RR. But I keep reading how well these motors respond to simple mode, so I figured I would make the best out of simple bolt ons and leave the motor untouched.

lt1-xjs: I forgot about RR's and springs. the tuner also recommended 1.6's for a simple easy swap to gain some power. I always heard that but forgot about it lol.

For now the WP will stay stock unless it starts giving me problems.

Here is the CAI I made. I may go to the LS1 lid due to the fact that my MAP dropped down to 92 at it's lowest point through the pull when the tuner said a Moroso CAI will keep steady at about 95KPa. I took a K&N CAI off to go with my custom setup. I have no dyno numbers or MAP readings from the K&N unfortunately so I don't know if my CAI is better/worse/same as the K&N.





It is a 3.5" pipe slightly dimpled at the bend to clear the stock 95 hood. It's the first version of it so it's not "pretty". basically did it because I can and wanted to try something different.

And now that I think of it...anyone think all the aftermarket 3.5" catbacks are a little small? Last time I built a catback for my 04 GTO I went with a single 3.5" to mimic a 2.5" dual setup from a cross sectional area standpoint.

On the flipside, I guess the only way to tell if the dip to 92KPa MAP reading is from the intake side of things and not the small exhaust side of things is to do a pull with only the MAF on the TB...

bufmatmuslepants

iTrader: (3)

Lid, 1.6-1.7 NSA rockers and good springs, and an EWP and spin the bitch to 6300 all day, you'll be surprised how fast it will be. 300-315 is typical through an m6 so your right on target. Add the above and you may get into the high 320s, the springs and rockers really just permit you to use more RPM, shifting g at 6300 instead of 5800 cut nearly half a second off my 1/4.

smitty2919

If all I'm looking at is 320's after EWP, RR's and springs I may just say screw it and go for suspension mods. The money for those 3 things would get ma a good way toward some Strano springs and swaybars. If those mods would get up to 340ish then I may entertain them.

It is not a max effort build. As far as I'm concerned where it is now is prob more car than I can handle for autoX needs.

It would be nice to eventually get back to power level of my 04 GTO at 340/356 with a CAI, full exhaust and a tune.

I'll look into porting the stock TB though as well as maybe cleaning up a stock intake and tossing on a SLP lid.

bufmatmuslepants

iTrader: (3)

The EWP doesn't belong on a road race car anyways. The springs and rockers are just to add stability in your valvetrain as you hold a gear a couple seconds longer before a turn. Stock you get float above 5800, and with SA rockers your at risk to sliding a rocker off a valve. With NSA you don't have to worry, and can spin it until you run out of power.

trilkb

iTrader: (4)

Your money would definitely be better spent on a set of springs and 1.6 rockers over the Underdrive pulleys, TB and ported intake.

1.6RR/springs, trickflow chromemoly pushrods, and EWP would be a good direction to head.


I dont know if you will gain much with the LS1 lid over the style of intake you have now, ls1 vs stock is an advantage in the higher rpms though, I am sure yours is aswell.

smitty2919

Well I found a SLP lid cheap online so I have that coming my way tomorrow. I have an idea to duct some air to the lid if I go that route.

Who makes a reliable RR/spring setup?

bufmatmuslepants why do you said a EWP does not belong on a road race car? (I won't be road racing for a while due to no car trailer and $$ to sign up for one of those events but anywho...)

F0x Slaughter

Rockers the standard is Comp Pro Magnums.
If you run NSA you need guide plates and hardened pushrods.

ahritchie

iTrader: (1)

What he meant was the stock WP technically does flow more GPH at high RPM stock on flows about 20gpm at 2000rpms through the restriction of the system and 66gpm at 6000rpms, where as an electric WP always flows the same 43-50 GPH CONSTANTLY, so if you are constantly at 5000K RPM+ a stock one would actually flow BETTER. Most people don't drive at high RPM for extended amount of time though which is where the electric WP shines is better low-mid RPM flow and more HP. I have an electric WP and highly recommend it however!

ahritchie

iTrader: (1)

+1 Comp cams does make very nice rockers, can somebody tell me the difference in "Pro Magnums" and the "Ultra Pro Magnums" I honestly forget, I just bought the more expensive "Ultra Pro Magnums" as they were the most expensive, therefore they must be the best! lol I do remember they had a lifetime guarantee and are rebuildable which is hard to beat!

96capricemgr

iTrader: (1)

The electrics are FREEFLOW RATED many of us have documented a 2200rpm cruise is all it takes for a 30gpm electric to run hotter than a mechanical pump. By 3000rpm the mechanical is going to be moving more than even the high flow electrics.

The electrics free up power by DOING LESS WORK. How much time does an engine spend below 3000rpm making power that really needs cooling?

The electrics are ADEQUATE for most street and drag cooling, but they are a downgrade it true cooling capacity.

bufmatmuslepants

iTrader: (3)

+1 to caprice and richie, for drag or street duty I think an EWP is great, but on long tracks like road racing, stock is better since it flows more at higher rpm. Check out frrax.com, that's the big road race f body forum. Another thing you'll see over there is the hard core guys stay with the stock k member and lower control arms due to them being over engineered (heavy too) vs tubular k members and front LCAs. I changed my suspension towards road racing from drag, havnt gone yet, but did a bit if research before the changes. Other things are going to at least 1 side rod ended rear LCAs, new front blue timkin hubs (I think thats what it was), a power steering cooler, ls1 front brakes or c5 front brakes, the lt1 radiator is better than the ls1 radiator, strano and BMR have the same spring rates, don't oversize your rear sway bar, OEM (from the gm factory) wheels are stronger than OE aftermarket wheels, etc. C5 wagon wheels are hands down the cheapest way to get 18x9.5 wheels all around, I paid $100 for a set of 4. There's a ton of info out there.

On the NSA rocker topic, standard guideplates don't fit LT1 heads perfectly, a couple of my rockers are not perfectly centered, you need adjustable guideplates from isky or trickflow or another. Doing rockers and a good spring now that will work with a future cam upgrade is a way to do things in steps, rather than dropping $1000 all at once on a cam swap. I got my pro mags, Howard's springs (good if I went as big as a 503 but not going to work on the .600/602 lift cam I ended up buying), pushrods, guideplates and 7/16 studs for $300 by shopping around used parts.

smitty2919

Awesome info guys! I would like to lean toward reliability than performance to tell you the truth. Which will be difficult when adding performance parts but you guys had a good point on the EWP running hot. Since my WP is not causing issues I will stick with it for now.

And thanks for the heads up about the RR. I may start searching around for prices etc and see what I can come up with.

The C5 wagon wheel, while not the prettiest wheel, will be good to serve a purpose lol. I have chrome (but crappy chrome) staggered 17" ZR1 wheels now. I would rather a square setup to be able to rotate wheels (reliability purpose again).

ahritchie

iTrader: (1)

Do some suspension work for a LOT more fun per $$ IMO, and not affect reliability Lowering springs, big swaybar, boxed control arm, panhard bar, poly bushings/trans/motor mounts, good shocks, and even subframe connectors make huge difference in how well the car puts the power down effectively, and handle like a very large Miata!

Oh yes, do not shop for rockers by price! I tried that a long time ago and it didn't end well! "You get what you pay for" rings very true here, get the best ones (or maybe one step down) that either Comp cams, Lunati, or Crane cams sells. I like a company that stands by it's product for LIFE!

smitty2919

Sounds good. I already have bolt on SFC's, front shock tower bar, adj. PHB and boxed stock rear LCA's. I bought the car that way.

Here is the dyno sheet from the other day:


I may not mod ANYTHING this season as far as suspension goes. With the exception of LS1 front brake swap that I will be doing this weekend. I would like to approach autoX in a systematic manner. As I get to be a better driver and "out drive" the car, then I will want to mod.

I wanted to bring this up since it was fresh in my mind from the dyno and to start planning future mods.

Honestly, first step would be to dump this staggered ZR1 wheel setup. It's proving harder than I thought to find a simple 17x9.5 wheel all around. Vette wheels always seem 17/18 staggered. I've looked into the "wagon wheels" and even "sawblades" LOL. It won't be a fashion show with the car. It needs to be effective and sawblades are cheap allowing me to run a 275/40/17 tire.

bufmatmuslepants

iTrader: (3)

Saw blades and wagon wheels are cheap, the VW guys use the front 17s all around on their gtis and sell the 18s, that's how I got mine. You actually don't want boxed LCAs, you want tubular with at least 1 end with a rod end and the other poly, the poly isolates the vibration from the chassis, I had double rod ends and it transferred alot of vibration and noise to the body, so I went to poly/poly again, but I will get rod/poly eventually. You need the rear suspension to articulate as much as possible with no binding, and poly binds.

As for your dyno sheet, where you see it to drop off at 5500 is where your valvetrain is holding you back. Springs and rockers will take it farther to 6000.

smitty2919

If I was to spend money on worth while rear LCAs I would go double heim joint ends. I would deal with the noise. It's no Caddillac right now anyways lol