Seeking F-Body Tech Options

[GaryK]

My $.02:

I've had a couple LT1 Camaros, a '94 and a '95. I did quite a bit of F stock autocrossing back when I had them, and all I can really say for sure is that they were a blast to drive. I competed against LS1 Camaros many times, but can't really draw any conclusion on F Stock potential other than to say I didn't feel like I was at any real disadvantage to the LS1's.

I recently bought a 98 Camaro with the intention to do some autocrossing again. I did look around for LT1 cars, but with what I had to pay for one that was well maintained and in decent shape, I figured I might as well go for a newer LS1 car...this assuming I could get into a nice one for less than 10k, which I did. I'm prepping to ESP rules, but whether I was planning to run FS, ESP, or SM I'd have been just as happy with an LT1 car. If you find the right one you can save some money over an LS1 car. I think all the other pros and cons kind of equal out, so to me its nothing more than a question of money.

[shortbus]

I regularly compete againt LS1 cars.

In fact I am the only LT1 car in the area... And I do pretty well against the LS1 cars. One of them is a WS6 car and I go head to head and toe to toe everytime. It is a good match. He has more motor, tire, suspension and I am within a second (last week) of his times.

I do have the LS1 brakes all around. The LT1 brakes are horrible... and the biggest weakness of the LT1 car IMHO.


I need to look at the other LS1 cars from the last autocross.. Paul Williams (FS) beats my times on Kuhmos. (Not to mention a great driver.)

A LS1 vert I beat more then half the time. (He is on Hosiers.)

The LS1 WS6 (from above) is always a head of me (but behind Paul)- is anywhere from 1.5 to .7 seconds ahead.

A LS1 1LE SS gets killed by everyone. He is on decent streets, but less expreienced then I... But, my expirence is thin too.

So I end up being middle to upper ground and about the 3rd fastest FBody near me. Hopefully with these new wheels and tires I bump up a few.

So as far as competition ability the LT1 still has a big can of whoop ass.

[trackbird]

Otherwise is is a pretty strong motor. I believe is is more durable then the LS1.

I agree with that feeling. I've been somewhat afraid to start with the heads and cam on my LS1 due to the fear of it coming apart. I don't think I have that same fear with an LT1. I'm not sure why I don't think they are as durable, but I still don't quite trust them.

[LT4Firehawk]

What I was trying to say is that LT1's feel like they have more low end grunt to me and yet, I make more torque at 2500 than most of them seem to. Meaning, the LS1 isn't lacking low end grunt, but it feels like it is (compared to the LT1). I was trying to explain that the numbers say the LT1 does not have more grunt on the bottom (on paper), but they sure feel like they do. I'm open to explanations/suggestions as to why that is.

Depends on the LS1 I guess. My bone stock 2000 TA (M6) has the following dyno:
(IMG:http://www.lt1.net/images/evandynostock.gif)

As you can see, it doesn't hit 275 lb-ft of torque until 3300rpm and doesn't hit peak torque (304) until 4000rpm. I repeat, this was a completely bone stock 2000 TA that had 1750 miles on it. By comparison, my bone stock 95 Formula (M6) made 289lb-ft (table top flat curve) to almost 4000rpm. Also, the LT1 in my 92 Vette made 300lb-ft from 2000-4000rpm bone stock, again with that table top smooth curve.

FYI, the LS6 in the Z06 has a similar tq curve to the LS1, but with a more gradual rise from 300 lb-ft @2500rpm to 340lb -ft @4500rpm. The LT4, has the same characteristics as the LT1, just a higher level of torque (328lb-ft from 2000-4500rpm).

I've always said the LSx engine are stronger on the top end than an LT1, but that they lack the low end grunt. These figures back it up. The best is the LT4, torque of an LT1 and HP of an LS1, but of course you'd have to be ESP to run one of those, plus they aren't nearly as cheap as the LT1 (or even LS1) cars.

Anyway, back to the primary question, for FS I'd favor the LT1 for several reasons:
cheaper
no brake hop issues
better low end torque

For ESP or roadcourse use, I'd recommend the LT4.

[shortbus]

So what LT4Firehawk is saying....

I need an LT4 intake and a set of heads.... Where's my damn credit card!

[LT4Firehawk]

So what LT4Firehawk is saying....

I need an LT4 intake and a set of heads.... Where's my damn credit card!

Well, not exactly. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif) For ESP you'd also need a 4 bolt main LT1/4 block to make it truly legal under the update/backdate rule. Of course, how many people are going to be nitpicky enough to protest you for having a 2 bolt main block instead of one with 4 bolt mains? (IMG:http://www.frrax.com/rrforum/style_emoticons/default/unsure.gif)

[Tommy R]

Hey fellas,

Okay, Jason (Soma07), how do you know me? And how do you know my language? (IMG:http://www.frrax.com/rrforum/style_emoticons/default/tongue.gif)

Sammy, yes, 'tis me. I'm certainly not decided, but I'm considering a swap from co-driving the Scirocco in FSP to moving back into a pony car in F-Stock. And, yes, this means I'd be selling the (potentially STX or DSP) 325is I was slowly prepping. Of course, nothing is set in stone yet as I'm merely in the data acquisition phase at the moment. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

Anyway, on to the questions.........

'93 models: I'm still undecided. The gearing is better with the "old" T-56 and 3.23's. Second is effectively 6.9:1, whereas the later models are 6.1:1 which I thought was interesting. However, I'm not fond of a "single year production" vehicle with unique/troublesome concerns. Speed density and eventual mod-ability is a concern. And is batch firing true with this model? I didn't know the front brakes were different, too!

LT1 vs. LS1: Smaller steering wheel in the LT1, huh? Interesting. It sure appears that the LT1 has the stronger low end torque and obviously the LS1 has the horsepower. But, I'm not going the LS1 route. The LT1 is certainly cheaper, plus it's still very nationally competitive. A win/win. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif) And the braking issue with the LS1 is a serious one to consider, IMO. I've experienced and seen that wheelhop. It can be quite violent.

Weight: Does the LS1 carry a lack of weight compared to its iron block counterpart? If so, how much? For that matter, what's an FS class F-body weigh in at? Are theZ28's lighter than the Formulas? No T/A's for me, FWIW.

Suspension: Any differences among the years of LT1 cars? Obviously a 1LE isn't necessary to win. Any spring rate differences over the years? Sway bar/bushing differences?

Non-performance stuff: I know the Optispark can be an issue. And changing plugs/wires requires an act of Congress. But, what about the other "mundane" maintenance issues? T-56's and the rear ends seem to hold up well to anything, but drag slick launches. The LT1 sure seems plenty robust. What about steering racks, A/C compressors, window motors, electrical issues, fit-n-finish after 100k miles, etc.? I need to consider the whole package and potential repair costs and daily nuisances are a real consideration. I don't expect BMW interior quality, but just how bad does it get?

FWIW, I'm expecting the suitable candidate to have 100k+ miles. At that point I'm sure it'll be needing lots of maintenance, if not already done. Are bushings a PITA?

Diffs: Are all LT1's equipped with some sort of posi? Are they Auburns? I understand the LS1's came with Torsens, but even they have shown to be far from flawless. Do the Auburns wear and need replacement every few years? Suggestions here?

Thanks,
Tommy

[LT4Firehawk]

Suspension: Any differences among the years of LT1 cars? Obviously a 1LE isn't necessary to win. Any spring rate differences over the years? Sway bar/bushing differences?

All the same. Only suspension option was 1LE. Like you said, that's not really that big a deal, just get some Koni SAs or DAs and stick with stock springs.

Non-performance stuff: I know the Optispark can be an issue. And changing plugs/wires requires an act of Congress. But, what about the other "mundane" maintenance issues? T-56's and the rear ends seem to hold up well to anything, but drag slick launches. The LT1 sure seems plenty robust. What about steering racks, A/C compressors, window motors, electrical issues, fit-n-finish after 100k miles, etc.? I need to consider the whole package and potential repair costs and daily nuisances are a real consideration. I don't expect BMW interior quality, but just how bad does it get?

FWIW, I'm expecting the suitable candidate to have 100k+ miles. At that point I'm sure it'll be needing lots of maintenance, if not already done. Are bushings a PITA?

Window motors can be somewhat problematical, but that's just because of the design. They'll usually start slowing down long before they fail and give you plenty of warning.

Power steering pumps can also be prone to failure under heavy abuse, at least with roadcourse use. I'm not sure how true that is to autox, I'll let some of the others give feedback on dedicated autox PS failure.

Timing chain will probably be getting very weak by 100K miles. If it hasn't been done, plan on doing it immediately and going with an upgraded unit. While your in there is a good time to go ahead and replace the opti and waterpump. You should be able to go ahead and upgrade to a vented opti too, I know there's at least one place out there that sells a wiring harness adaptor to fit the late model opti to the early harness.

Really there shouldn't be a lot of issues if the car was well maintained. I sold my 95 at 97K miles and it was still in very good condition and fit/finish.

Diffs: Are all LT1's equipped with some sort of posi? Are they Auburns? I understand the LS1's came with Torsens, but even they have shown to be far from flawless. Do the Auburns wear and need replacement every few years? Suggestions here?

The LT1s (other than SLP cars) all came with Auburns. While they aren't as strong as the Torsen used in the SLP/LS1 cars, it is still a decent unit. I never replaced the stock one on my 95 and it had probably 200 quater mile passes, several autoxes, 10 track days, and 97K miles on it. It was still working like new when I got rid of it.

[y5e06]

Batch fire really isn't that much of an issue. Only real problem w/ '92-'93 LT1's (including vettes) is you need to burn a chip instead of having the flash prom in the ECU. Lots of guys eak out tons o' power in the batch fire corvettes. Window motors tend to slow down and wear out. Straight forward enough fix. Seems to be common GM problem. Never had a compressor issue w/ my AC camaro, although I've gone through 2 on the Vette, one on the caprice, and need a third for the truck.
139K miles and I've never had a power steering pump problem.
I R&R'd the timing chain on my 114K mile Corvette this past spring (same engine), It looked great for wear. Didn't appear to have excessive slop. I don't think its much of a concern unless you already have the wp, opti, & timing cover already pulled off. Opti sparks suck, I've replaced at least half a dozen. Do the WP while your there too. Fit n Finish of F-bodies is absolutely horrid. It may be a big turn off for you, especially if moving out of the BMW quality. Want to get a good look over of a prime example of the higher mileage LT1? Check out mine at the next event (A&M).
Auburns do wear out, they are a clutch type of posi. You'd probably want to replace it each year just prior to nationals. If you buy a new one, you can have it rebuilt/exchanged for <$100. Karen can fill you in more about that.

[y5e06]

oh, At the April national tour My car weighed 3450 w/ 3/4 tank of gas, a drawtite hitch, stock salad shooter rims, V710's, power drivers seat, PW, PL, hard top car, 35mm solid front swaybar, and spare & jack removed. Driver not included.

[ESPCamaro]

Expect eventual problems with optisparks, diffs, and to an extent power steering pumps.

My recommendations. Take FWIW and call Sam too, DO NOT use Mobil 1, and keep the oil level topped off.

Expect an FS car to weigh mid 3,400's. In general the Camaros are lighter than Firebirds.
No weight saving advantage to an LS1. I've seen Jr's and Sam's car put on a scale when they were both FS.


As far as ESP the LT4 is definately the best choice. I'll tell you right now though, that there are no more. Try buying an LT4 longblock.......

You need more than a 4bolt block for an LT4 conversion. ALOT of parts are required. In fact almost every part is a little different.

In extremely rare instances where someone finds a complete LT4, or finds all the parts necessary, all NEW ESP LT4 cars are illegal.

[2manyfbods]

Expect eventual problems with optisparks, ........

By ESP rules - Wouldnt an ignition system that allows multiple coils retrofitted to a LT1 be legal? (Delteq or LTCC)

My recommendations. Take FWIW and call Sam too, DO NOT use Mobil 1, and keep the oil level topped off.

Just curious, Why not Mobil 1?

[patred]

DO NOT use Mobil 1, and keep the oil level topped off.

Ut oh, where's Karen? (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)

[robz71lm7]

I regularly compete againt LS1 cars.

In fact I am the only LT1 car in the area... And I do pretty well against the LS1 cars. One of them is a WS6 car and I go head to head and toe to toe everytime. It is a good match. He has more motor, tire, suspension and I am within a second (last week) of his times.

I do have the LS1 brakes all around. The LT1 brakes are horrible... and the biggest weakness of the LT1 car IMHO.


I need to look at the other LS1 cars from the last autocross.. Paul Williams (FS) beats my times on Kuhmos. (Not to mention a great driver.)

A LS1 vert I beat more then half the time. (He is on Hosiers.)

The LS1 WS6 (from above) is always a head of me (but behind Paul)- is anywhere from 1.5 to .7 seconds ahead.

A LS1 1LE SS gets killed by everyone. He is on decent streets, but less expreienced then I... But, my expirence is thin too.

So I end up being middle to upper ground and about the 3rd fastest FBody near me. Hopefully with these new wheels and tires I bump up a few.

So as far as competition ability the LT1 still has a big can of whoop ass.

You can't really compare the two engines between cars that are setup differently and driven by different people-especially at local events.

Heck some people have good and bad days. For example I've beaten Greg Cudnick (slightly faster than paul williams) by over a second and Paul has beaten me by over a second at times.

LT1 brakes really aren't that bad for FS if you use good pads (w/o they suck). I could consistently lock up my 275 victo racers with LT1 brakes and HP+ pads. I just switched to LS1's for open tracking.


Trackbird, I'd feel more comfortable putting heads and cam on a stock bottom LS1. LS1's are just plain stout. A lot of LT1 owners are experiencing spun bearings after heads and cam. Some of that is due to age and sloppiness and people revving too high, but not all. A lot of people are finiding the front cam bearing looks like crap at the time of the cam swap. I think some of it might have to do with the LT1 water pump.

FWIW, my 10 year old LT1 dyno'ed 300+ ft-lbs from 2000 rpms up with cai and a catback. I don't think there is a significant difference between either. In esp I feel the LS1 is a better choice, however in FS it's about even.

Of course LT1 r&d is not dead by any means. There are stock heads/bottom end cam only LT1's dynoing 350-360 rwhp and running in the 11's. There are some heads and cam 350 ci guys making 420-440 rwhp.

[Soma07]

Tommy,

I recognize you from CC.com (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif) I am a frequent lurker/occasional poster there. A few months ago when I was semi-looking for an E36 you posted some good info so I wanted to try and return the favor.

A few random thoughts:

93's are the redheaded stepchild of the 4th Gen F-bodies but they don't differ from the other LT1s by that much and most of it is trivial crap. The brakes use different pads but they are really no better or worse than the 94+ cars. Sam probably knows better than I but I don't think its that big of a deal to find decent pads for them. I'm almost sure Hawk HPS & HP+ are available.

Don't sweat the timing chain, I just replaced mine at 190k and it really looked no worse than the new one.

Fit and finish is typical GM, in other words not that great. With nearly 200k and 11yrs on mine it has more squeeks and rattles than I would like but its far from falling apart. As long as you find a car that isn't beat to shit (which can be a challange) I don't think you'll have any problems.

Power steering pumps can and do die but its not that common. Mine will start to whine if I have to do more than 2 back to back runs or if its really hot outside. No damage so far but it does make a little fluid leak out of the resevior.

If I had my choice of a year to pick it would probably be a 95. It had the vented optispark (cheaper & supposedly more reliable) but not OBDII. That said I would probably buy the cleanest car you can find regardless of the year. IMO the differences from year to year are very minor when you consider the big picture.

Good luck and let us know what you decide!

[CamaroFS34]

In terms of what "goes bad" with a higher mileage car, there is a thread floating around on here with all the stuff I've replaced on my 300+K green car. Of course, I'm crazy about maintaining stuff, and despite hammering the car around the autocross course (and letting people like Dean Sapp and Kevin Dietz do the same), I've never (knock on wood (IMG:http://www.frrax.com/rrforum/style_emoticons/default/unsure.gif) ) replaced an optispark. I've done bushings by way of replacing the entire control arm (it's just easier, and in the long run, probably cheaper).

Karen

ps., yeah, Lonnie, why not Mobil 1? I don't see any problems with it, and neither did the guys at F-Body Central when they pulled the heads for the head gaskets....

[robz71lm7]

Mobil 1 is a decent oil, but it's not the best for 350 sbc. It tends to be on the thin side for our engines. The wear results from it are decent, but could be better.

[Sam Strano]

ps., yeah, Lonnie, why not Mobil 1? I don't see any problems with it, and neither did the guys at F-Body Central when they pulled the heads for the head gaskets....

Oh boy.... Probably has something to do with his blown up motor on Mobil 1. Or maybe Kevin Howell's blown up motor on Mobil 1..... Or maybe Beecher's blown up motor on Mobil 1. Or any of the little things I've had happen with Mobil 1 like excessive usage that lessened or stopped when the brand was changed.

Come to think of it, the only LT1 or LS1's I've seen pop were on Mobil 1. I don't know what McGeorge runs in the MR2, but I'd bet it was Mobil 1 and Tim had the same problem in Peru that the V-8's did...... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dry.gif)

The fact the engine is clean means the oil has detergents. Good, but not protecting the engine per se. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif) Basically, you've been luckily (like most of us) to not have a problem that really would stress the oil film. Synthetics are about protection (and a little power too <g>). I don't expect you to have a problem just because you on on Mobil 1. But I'd expect any problem that might occur to be more serious than it should be. MHO and only based on my experiences, which are numerous. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif)

[rmackintosh]

ps., yeah, Lonnie, why not Mobil 1? I don't see any problems with it, and neither did the guys at F-Body Central when they pulled the heads for the head gaskets....

Oh boy.... Probably has something to do with his blown up motor on Mobil 1. Or maybe Kevin Howell's blown up motor on Mobil 1..... Or maybe Beecher's blown up motor on Mobil 1. Or any of the little things I've had happen with Mobil 1 like excessive usage that lessened or stopped when the brand was changed.

Come to think of it, the only LT1 or LS1's I've seen pop were on Mobil 1. I don't know what McGeorge runs in the MR2, but I'd bet it was Mobil 1 and Tim had the same problem in Peru that the V-8's did...... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dry.gif)

The fact the engine is clean means the oil has detergents. Good, but not protecting the engine per se. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif) Basically, you've been luckily (like most of us) to not have a problem that really would stress the oil film. Synthetics are about protection (and a little power too <g>). I don't expect you to have a problem just because you on on Mobil 1. But I'd expect any problem that might occur to be more serious than it should be. MHO and only based on my experiences, which are numerous. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif)

....yeah...I have a similarly low opinion of Mobil 1....and I have taken a lot of S#%T for it around here... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/tongue.gif) ....but I used it for 2 track days and it came out THINNER than water if you can believe it.... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/blink.gif) .....don't use it anymore.....

[sgarnett]

Mobil 1 is one of those periodically-debated topics. I've used it (and still do) in a lot of different engines. The two exceptions are:

1) My 96 Dodge 5.9. These engines tend to build up crud at the intake manifold gasket, which allows it to dry out or otherwise develop a latent leak. Synthetics tend to clean out the crud and expose the gasket, allowing oil into the intake manifold. If I'd bought the truck new I'd have used M1 from the beginning, but since I bought it at 100K it gets conventional Castrol.

2) My oil-fired LS1 needs all the viscosity help it can get. It gets Redline 10W-40

Other than that, I run M1 in everything - generator, tractor, mowers, the built 350 SBC in my former truck, the venerable MGB (which cruises at 4000 rpm on the interstate).

In other words, I don't think there's anything wrong with M1 per se. However, I do think the M1 10W-30 grade is too thin for some applications.

OTOH, for the only engine I use in competition, Redline is a very small part of the total budget (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)