Can a LT1 car be Nationally competitive? Options

[gunslinger]

quicker and to a higher amount. The LS1 cars will nose over at 5200rpm with stock valve springs in there.


Bret

Did you mean the LT1 valvesprings? I am pretty sure my LS1 doesn't float the valves at 5200, although it might, just not a noticible amount?

I know you have very intricate knowledge of ICE. Would changing to some new stiffer pushrods and LS6 springs be a good idea for my DD w/ 127K mi on it?

I am kinda worried about the valve springs getting tired and I mechanically over-revved my car once, but never checked to see if the pushrods were all still straight(never a ticking sound, happened 35K mi ago)....

[wdtiger]

Oh, i'm well aware that auto-x is not all about power. To that end, yes, an LT1 can be very comptetative. Heck, there's a guy up here running ESP in an '86 IROC that kicks everyone's tail. I'm more interested in getting as much power as possible to have fun during it's daily driver duties and still play with the ESP cars on auto-x days. But yeah, there's no way i'm spending that money for the little gains you're talking about doing as long as the motor is running. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif)

My LS1 doesn't feel like it loses much at 5200. It pulls pretty well up to 6k when it taps the limiter.

This post has been edited by wdtiger: Jun 29 2007, 12:03 AM

[pknowles]

quicker and to a higher amount. The LS1 cars will nose over at 5200rpm with stock valve springs in there.


Bret

Did you mean the LT1 valvesprings? I am pretty sure my LS1 doesn't float the valves at 5200, although it might, just not a noticible amount?

I'm sure he meant LT1 valve springs because my LS1 make peak HP @ 5700 rpm and only lost 3hp from peak @ 6,000 rpm.

[tjZ28]

Thanks for the advice! I'm leaning more and more towards building this car, so now I'm starting to look into the budget it'd take to get it competitive. Here's what I'm working with...

• '97 Z28
• Six Speed
• Hardtop
• Crank Windows Etc
• ~100k Miles
• A lot of fresh parts (clutch, u-joints, water pump, this and that sensor, oil pan gasket, intake gasket, etc)
• 18x11 & 18x12 CCW Classics (from Z06) w/ 315/30-18 & 335/30-18 A6s

So I'm thinking I need at least the follwoing to get in the ballpark of competitive:

• Good Diff (what's working these days? T2R, ???)
• Ground Control Setup in the Front (probably somewhere around 800-900#)
• "Weight Jacker" Setup in the Rear (probably around 300#)
• Shocks (I'm up in the air here, pretty much nothing off the shelf would work well w/ the spring rates I have in mind, maybe just have Strano valve some Bilsteins for me?)
• Sways: Strano Bars
• Brakes: LS1 Front Upgrade w/ HP+, SS Lines, Fresh Stock stuff in the Rear, Adj. Proportioning Valve
• APHR: Build my own AL/Heim
• Lower/Level APHR

To get the car to the top level of competition (even though I probably won't be there as a driver yet):

• Motor Work: The motor is healhty, but I'd need a CAI (actually might have one from another car), LTs + True Duals, Under-Drive Pullies, Roller Rockers, and a good Tune to get competative. If/when the motor dies a full LT4 build would be the way to go.
• '93 Trans
• UETA
• ????

-TJ

[Racer X]

Most (but not all) 4th gen ESP cars run a T2R (there are a few other not-as-good options).

Most (but not all) 4th gen ESP cars usually run a 500 - 600 lb spring in the front and 150s in the rear, But if you're going to mess with the PHR, then yeah, I guess you'll have to run it stiffer. FWIW since we're talking about being nationally competitive here, I'd hate to experience what a "stiff" car would feel like at HPT. I ran there on a warm day in May and my "soft" car never felt like it got hold of the surface. I'd think that the stiffer cars would really skate around there on a cold day in late September. *shrug*

I have absolutely no problems with wheelhop under braking with a comparable setup to your list. The adjustable prop valve would be an unnecessary waste of time IMHO.

Roller rockers are not legal for an LT1 in ESP trim.

An LT4 build would have to *exactly* reproduce an LT4 right down to the smallest detail.

[tjZ28]

Most (but not all) 4th gen ESP cars run a T2R (there are a few other not-as-good options).

Most (but not all) 4th gen ESP cars usually run a 500 - 600 lb spring in the front and 150s in the rear, But if you're going to mess with the PHR, then yeah, I guess you'll have to run it stiffer. FWIW since we're talking about being nationally competitive here, I'd hate to experience what a "stiff" car would feel like at HPT. I ran there on a warm day in May and my "soft" car never felt like it got hold of the surface. I'd think that the stiffer cars would really skate around there on a cold day in late September. *shrug*

I have absolutely no problems with wheelhop under braking with a comparable setup to your list. The adjustable prop valve would be an unnecessary waste of time IMHO.

Roller rockers are not legal for an LT1 in ESP trim.

An LT4 build would have to *exactly* reproduce an LT4 right down to the smallest detail.

Hmm, I guess I hadn't considered the surface @ HPT. I'm spoiled with Castle Airforce Base out here. I'm still a long way off from specin' my spring rates, but it doesn't hurt to start researching now. I had 500 or 550s (don't remember off the top of my head) in my '99 Z/28 and they were certainly too soft for the surfaces out here.

As for the Rockers thanks for the heads up. It looks like I need to read the rule book again.

What all is involved in "exactly" reproducing a LT4? I have access to a true LT4 block/heads/intake if the internals are only modded to the ESP rules would that be enough?

-TJ

[Mojave]

Most (but not all) 4th gen ESP cars run a T2R (there are a few other not-as-good options).

Most (but not all) 4th gen ESP cars usually run a 500 - 600 lb spring in the front and 150s in the rear, But if you're going to mess with the PHR, then yeah, I guess you'll have to run it stiffer. FWIW since we're talking about being nationally competitive here, I'd hate to experience what a "stiff" car would feel like at HPT. I ran there on a warm day in May and my "soft" car never felt like it got hold of the surface. I'd think that the stiffer cars would really skate around there on a cold day in late September. *shrug*

I have absolutely no problems with wheelhop under braking with a comparable setup to your list. The adjustable prop valve would be an unnecessary waste of time IMHO.

Roller rockers are not legal for an LT1 in ESP trim.

An LT4 build would have to *exactly* reproduce an LT4 right down to the smallest detail.

Hmm, I guess I hadn't considered the surface @ HPT. I'm spoiled with Castle Airforce Base out here. I'm still a long way off from specin' my spring rates, but it doesn't hurt to start researching now. I had 500 or 550s (don't remember off the top of my head) in my '99 Z/28 and they were certainly too soft for the surfaces out here.

As for the Rockers thanks for the heads up. It looks like I need to read the rule book again.

What all is involved in "exactly" reproducing a LT4? I have access to a true LT4 block/heads/intake if the internals are only modded to the ESP rules would that be enough?

-TJ

You would need a complete, factory LT4. There are a lot of little details about the LT4 that are over-looked.

http://www.grandsportregistry.com/lt1vslt4.htm


Also, do anyone know if the f-body LT4's were 2 bolt or 4 bolt mains?

[BigEnos]

Also, do anyone know if the f-body LT4's were 2 bolt or 4 bolt mains?

I've asked around and the consensus from those who've torn them apart is that they are 4-bolt, identical to the 'vette motors internally.

I've gotten as far as an estimate for the cost of building one (IMG:http://www.frrax.com/rrforum/style_emoticons/default/blink.gif) , then I got skrrrd. Engine builder swears he can get crank HP numbers that start with a "4" though (IMG:http://www.frrax.com/rrforum/style_emoticons/default/ph34r.gif)

[tjZ28]

So this would be fully legal, correct: http://www.sdparts.com/product/12534776/19...vroletYLT4.aspx

Also, would a LS1 (and LS1-era T56) swap be legal in a '97?

-TJ

[Racer X]

So this would be fully legal, correct: http://www.sdparts.com/product/12534776/19...vroletYLT4.aspx

Well, here's a problem that I see...

Notes: Does not include Inlet Manifold, Exhaust Manifold, Starter,
Flywheel, Water Pump, Ignition or Attaching Parts

GM no longer has the intake in production. Good luck finding one.

Also, would a LS1 (and LS1-era T56) swap be legal in a '97?

I believe so but why would you want an LS1 vintage trans?

[tjZ28]

GM no longer has the intake in production. Good luck finding one.

I already have the manifold lined up, besides aren't intake manifolds unrestricted?

so but why would you want an LS1 vintage trans?

Sorry if my wording was confusing. I meant to swap in a LS1 motor + the appropriate trans for the LS1 (since as far as I've seen there is no legal way to run '93 gearing behind a LS1 due to the different input shafts).

-TJ

[Racer X]

I already have the manifold lined up, besides aren't intake manifolds unrestricted?

Yes, but I'm not sure how that would play into an engine swap. I *think* since the rulebook reads that any swap must be done as a unit, you would be required to use the LT4 manifold. Besides, is there an aftermarket intake that will fit the LT4? The new Edelbrock might. I don't know.

I don't know if a modified LT1 intake would work since there are some restrictions on porting as well.

[BigEnos]

You can put on any intake manifold you want.

[Mojave]

I already have the manifold lined up, besides aren't intake manifolds unrestricted?

Yes, but I'm not sure how that would play into an engine swap. I *think* since the rulebook reads that any swap must be done as a unit, you would be required to use the LT4 manifold. Besides, is there an aftermarket intake that will fit the LT4? The new Edelbrock might. I don't know.

I don't know if a modified LT1 intake would work since there are some restrictions on porting as well.

What he said. You can do whatever you want to the intake. Port it, use an aftermarket LT4 intake, or even a carb'ed LT4 intake if you really want to.

Edelbrock does make an LT4 Airgap; some guys on LS1Tech actually have one.

[ESPCamaro]

LS1 swap into a 97 would be a complete waste of time and money. As we've been over the LT1 IS competitive. Regardless of dyno numbers the LT1 has more torque. Especially an ESP LT1.

I'm not even sure that an LS1 would fit into the bodywork of an LT1 car.

If I were to swap in an LS1 to build an ESP car it would be into a 93 or 94 hardtop V6 car with no options.

[SLICK1851]

What is the issue with the car? Ive been looking for a stripper Z for a good amount of time, and they are hard to find.....



Looking to sell it?