Jason E

Ok, well, because I was working on my house all winter and helping my fiancee with our wedding plans (getting married in May), I didn't fiddle with chip burning over the winter like I'd planned to. So now, here it is Spring, and I want to get the RS out and get the oil leak fixed, and I cannot tune my own chip. So, here are my options, as I want this car for driving throughout this summer...

1) Have the top end of the engine regasketed (RH head gasket is puking oil, despite no one on here believing me...I've seen it with my own 2 eyes), adding Edelbrock TES or Hooker shorties and Y pipe. I'll replace the cat with the proper 3" in/out cat to match my 3" exhaust and new Y pipe. I will keep the TBI performer intake, 3" Magnaflow, 14x3 open element and Hypercrap Stage 2 chip that came with the car. Anyone have an idea how much HP that will give me? Is 190hp out of the question? I've been told on here before I could get close to 220hp with that same combo with nothing more than a proper tune...is that true?

2) Do a crate LO5 swap, which is 210hp out of the box. Add the same headers, and lets say a tbichips.com chip, because I need one programmed for an M5. Where would I be now? 230hp or so? Would a tune net me even 20hp, versus the 30 I was told on a 305?

I'm curious to see what I'm dealing with here. I want the car on the road ASAP (the oil leak also needs to be cleared up because its coating the underside of the car, which I want to have sanded and painted, and have the SFCs welded on this spring), so I need something that will more or less plug and play.

Is it possible to get 250 net, flywheel HP out of an LO5 with a tune in my car? If so, that would be good for mid to low 14s with my M5 (not that this car will ever, EVER hit the strip), which is pretty much 350 IROC territory. I'd be thrilled with that.

Am I making sense? This is a cruiser, not a strip terror. Mid 14s with a 350 swap,would make me thrilled, to be honest. Any help is appreciated.

Jason E

BTW, has anyone here actually done this swap before? It seems like I see cars for sale all the time with 350s swapped into 305 cars. I know the swap sticky says the fuel pump may not handle it...what have people here experienced?

kdrolt

I'll skip question #1, and go directly to #2.

The crate L05 is 180 fwhp when using the L03 roller cam. Add the copcar the 9C1 cam (same pn as L98 cam, "773") and using the right tune, then it's 205 fwhp when using the copcar exhaust.

A NE neighbor had the copcar L05 in his '93 Caprice 9C1, so he started with the 205 fwhp engine. Stock it ran low 16s in the quarter mile. He added a CAI from the Caddy fwd v8, and altered his exhaust. IIRC he also tweaked the fuel pressure. He ran 15.7 @ 85+ mph in the quarter mile. If you do the math, he gained 20 to 25 hp from the mods. And his tune was porbaby not quite optimum (i.e. there may have been more there).

His heads were stock, and so were the rocker arms. He still had the mech fan) and he still had, at the time, the Caprice exh manifolds with the copcar Ypipe. So 230+ hp is easily attainable if you use the 773 cam (copcar, or TPI 773), or the LT1 equivalent.

Lo-tec ran 13.6 in the quarter mile using a Caddy L05 engine, by swapping in an aftermkt cam (over 210 degs IIRC), headers, and a carb+intake (simplifed tuning).... while still using the L05 longblock (a cheap fast car). You need at least 250+ fwhp to go 13.6 @ 101 mph, so yes --- if you can duplicate that effort with the TBI + tuning, then yes you can have similar performance (and power).

Note that technically you will void the warranty on the crate engine by installing the copcar/773_TPI cam even though it still meets GM specs for one of the versions of the L05.... because you'll be buying the passenger car version (non police). The ONLY differences in the engine, L05 civilian vs police, were the cam, ECM tune, exhaust (bigger Ypipe on the copcar) and possibly slightly larger injectors. Your 305 injectors will work if you boost the stock fuel pressure, or you could use 350-type (larger volume) injectors and keep the stock fuel pressure. HTH.

BronYrAur

iTrader: (1)

I would stick with scenario 1 personally. Swapping in that LO5 is going to be a lot more work than you think at this point, and if you can't tune chips you will be regretting it, believe me, ESPECIALLY with that M5.

I have an M5 in my car and after I put on a Holley intake and full exhaust, headers back, the driveability was not great. It bogged a little when I first got into the throttle, it would often die if I was coasting and put in the clutch. These stick shift cars are much more sensitive to changes, more so than even what people say in general about changes to a TBI system.

You put full exhaust, headers 3" all the way and throw in some gears/posi in the rear end you will be much happier with it. It will wake the car up a ton and you won't have all the headaches you will definitely have if swapping the 350. If you're willing to learn the chip burning, put in the time, and deal with a sloppy car for a while, you will like the final result with a more powerful 350, but if you aren't going to the track and want a fun car to drive all summer, it won't happen with the 350 especially with a chip from tbichips or anywhere similar.

Jason E

Thanks for the responses so far. Bron, you say your car was bogging...I see in your profile you only have a 305. Did the Holley intake cause that? If I do a full exhaust on my car (which as I said, I am planning either way with the Edelbrock TES setup), will I have any issues like that? Most people on here seem to do a full exhaust and not have issues like that. What did you do to cure your problem? How much speed will gears give me? I have some old Hot Rod articles where they hopped up an 89 M5 TBI RS, and swapping gears barely added any speed, but they did say it felt better...should I add 3.42s? 3.73s? How will my MPG be affected at a normal cruise?

I will say, when I first added my Edelbrock TBI intake, the damn car kept stalling for the first 2 days (when I'd push in the clutch, like you said), then it was almost like the computer adjusted, and its been fine for months. I think I pissed off the computer while it learned the SLIGHTLY fatter air and fuel curves the manifold provided!

Indeed, this is a summer fun car, not a 1/4 mile stormer. I have the Z28 for that!! I cannot afford to create headaches, because I work 60 hours a week...a tech will fix this car, not me. If an LO5 is more than a "simple" swap, I shouldn't try in the first place. Even at a reduced labor rate of $45/hr, it'll get expensive quick if I have a problem. I already have $8,500 tied up in this car with the bolt ons and a gorgeous paint job, and it needs chassis and interior work this year. I need to keep it simple...

Jason E

If someone could help me with one more question...

What would the ESTIMATED HP be of my car with my Hypercrap Stage 2, fresh tune up, 14x3 open K&N, Edelbrock TBI intake, Edelbrock TES with 3" outlet, 3" cat and 3" Magnaflow be? Could I get to that 190hp # I quoted above? Would I be a bit higher? I know it seems kinda rice-ish, but I added '83-'87 silver "5.0 Liter H.O." stickers under my RS rocker logos and on the rear bumper, where L69s have them. I'd love to at least be putting down L69 levels of HP, so my buddy with a genuine L69 will shut up I just didn't want people thinking my car, when sitting still, had a crappy V6 in it I endured 4 years of 2.8 hell when I had my old '89 RS...no more!

kdrolt

Your profile says you have a 305 w/LT1... which I assume means you have, or will have, an LT1 cam. The cam itself is good for at least 15 hp over the L03 cam, so that's 185 into the stock exhaust. A very good exhaust will boost the combo by another 15-20 hp, so that's 200-205, Finally, if you skip the open element (great sound,great look, but a power robber) and use a cold air ducted air cleaner, you can add 5+. So 205 to 210 fwhp is very reasonable.

The big IF in all this is the EPROM tuning, and the Hypertech chip isn't going to get there. The factory stock chip is OK for an exhaust mod, but once you get into the cam swap, you really need to do something more. The band aid solution is raising the fuel pressure, or even better using a vacuum-referenced FPR that only raises the FP during WOT. Depending on your skill, you might get one of these to run well.... but both are poor man's excuse for proper tuning in the EPROM. FWIW.

Jason E

Sorry for the confusion, but the LT1 cam is currently attached to the LT1 in my Z28 I have both cars listed in my profile...

So if I deduct 15-20hp from your totals, then I guess I end up around 190, which was my estimate, right? I guess that's where I'll end up, then. Any other input is appreciated.

Jason E

Anyone else? Anywhere? Any regulars have any input?