Hey all, I want to see how much HP you guys got in your cars.
just askin..

My 305 TBI put out about 175hp

 

Did you dyno this Dave?

I'm at 207HP and 304 lbs-ft so far.

 

I'm hoping to get over 450 hp with the new motor I'm currently finishing up. It should be in the car by hopeful tomorrow the lastest.

 

Gm claims I have 210, but I think the wear on the driveline has deminished that over the years.

 

The factory specs say 230hp and 300lbs torque. Low mileage car (70k) and it feels like all the power is there.

Some simple mods, porting work (TPI), pullies, cold air and a Jacobs ignition if I could ever get the freaking wiring right. If you do the add-up-the-mods thing I will end up around 250hp and 330 lbs torque. Not a killer app but alot of fun to drive.

RP.

 

I have no idea what kind of numbers my car generates so i'm just going to say 235HP and 345LBs/ft.

 

Cool

IROCKER, I never dynoed but factory said about 170hp but with some new parts I threw on it must of added at least some HP.
And it was a quick car. so considering the HP was still there.

 

From factory LO3's are rated at 170 HP with 255 ft/lbs of torque. Depending on suspension and mileage, its more like 145 RWHP. LO3's suffer from being severely restricted with intake and exhaust. The duration for intake and exhaust of the cam's are probably the lowest of all GM cams. The differential they were mated with 2.73 is terrible for acceleration. A stock setup will make b/w 145 HP to 160 HP depending on condition. I'm planning on going to the Kitchener Dyno day to see what numbers my car puts out. I have a custom RAM air intake setup, underdrive pulleys, 3.23 differential, K & N filter, polished heads and intake manifold, strengthened 700r4, TCC lockup switch, 180 degree thermostat. Since most LO3's came with 15" rims, having the 16" ones make a big difference in traction.

It's all a matter of time...

Mods to come:

1le driveshaft
Flowmaster
eibach springs (sportline's most likely, but prokit if cheap)
LCA's & panhard rod
intake manifold (probably edelbrock performer EGR)
Hooker headers or TPS Edelbrock/Edelbrock 3" catback
matched cam and heads (still deciding)
335 stroker kit
Holley 650 CFM TBI
torque arm (edelbrock)
sub frame connectors

Each mod is in order of what I need and what each mod will cause me to need in succesion until I push well past 325 ft/lb of rear wheel torque, the suspension won't have to be reinforced.
I can easily imagine by the time I'm at the 650 CFM TBI, the setup should be getting to 1.0 HP per 1 Ci. By that time though torque should be into the 400 ft/lb range or close to it which will hurt the stock setup. At the moment, I'm probably making b/w 265 ft/lb to 280 ft/lb of torque at the engine.

 

I hate to be a pessimist here guys, but you can't rely on the factory specs and manufacturer's claim for HP increase calculations. And I'm talking the more realistic rear wheel horsepower (RWHP). Unless you've dynoed your car, you really can't know, you can guess but that's it. A dyno is not 100% accurate, but about as close as most of us will get. Keep in mind that any factory spec numbers you get are at the flywheel, same with most manufacturer claims...they advertise the higher of the two numbers for obvious reasons, marketing. That's why my car, rated at 225-230 HP factory, dynoes at 207 HP with my mods. For auto's you normally minus 20-25% and standard is usually 15-20% drive train loss. So really, from the factory my car is rated at 180 RWHP...and my mods have accounted for 27 RWHP gain.

Believe me when I say your mods are never worth as much as you think they are. K&N on their TV commercials claims up to 20HP gain...I'm yet to see this on any type of car. I know now whatever a manufacturer claims the gains are, except no more that 20% of that.

 

Some time back I had an '88 Formula with 305, TBI and 5-speed.
I started the perf buildup early on and found that it was alot harder to build torque than HP with the TBI. HP, as it turned out, came alot easier.

Here is what I did:

- 670 cfm Holley OEM unit with 80lb'ers that I always had to dial back as these were way too much, should have got the 70lb'ers in retrospect.
- Weiand 7525 single plane manifold with universal EGR attachment (still have this piece). Tried the dual plane but frankly liked the single much better. Had an adaptor made for TBI to manifold.
- Z28 L69 dual snorkel with T/A power bulge down draft unit from '84 T/A, this really worked great by-the-way. Never a problem finding cool air with that setup.
- factory roller changed out with 217/225 duration and .480/.505 lift. Way too freaking much cam for that engine I must have been nuts... well ill informed, there was not alot of knowledge on TBI buildups back then I was really on my own. But it SURE DID REV like a banshee. Pulled 6400rpm easy. Of course I toasted my bottom end.
- Comp cams 1.65 roller rockers, valve springs and push rods.
- Hedman headers to full 3 inch mandrel bend pipe through hi flow cat and flowmaster. Car sounded awesome.
- under drive pullies of course.
- Jacobs Ultra team -- really woke up the car.
- 3.42 rear posi unit.
- disk brake convert (waste of time, car came with aluminum drums and I never could tell the diff).
- KYB adjustables on 4 corners.

Various other mods and work done. I did as much as you could without changing the cubes and heads or remain NA. The car made about 275hp and about 300-310lbs torque. I don't think I could have made 1hp per cube on the 305 without worked over heads.

It did not make torque like a 350TPI car does which was my goal at the time and by the sounds of it the kind of power you are looking for as well. IMHO the 335 stroker is not going cut it either, not without some serious head work which leads you to the 350 more bang for your performance buck than the 335.

What I ended up doing to my '88 Formula was build a 350 cube motor to put under the induction system I had put together. I used the 305 heads upped to 1.92 and 1.6 and switched to a milder 208/214 and .460/.480 cam and found an excellent balance of hp and torque. This got me to about 320hp and 330lbs torque. I ended up selling the car before I could install the killer app -- dual TBIs !!! Now that would have built torque.

I'll be interested in seeing how your buildup works.

my .02cents worth,
RP.

 

Ok... next you'll be telling me my airfoil isn't worth 30rwhp !!!

RP.

 

lol you are kidding right

Irocker is right on. factory HP are always at the flywheel=less at the rear wheels. and never expect to get what the manufacturer said you will out of parts.

Acceld Z
I have no idea what kind of numbers my car generates so i'm just going to say 235HP and 345LBs/ft.
thats all? i thought you would have had more than that?
what are your 1/4 times and speeds

dave
by my math and test numbers i should be about the same as Acceld Z 235HP and 345LBs/ft. at the rear wheels.
after the 15th of june i will have the exact #s

 

Since dyno day is coming up soon, I'll have a better idea of the numbers for my car. I was pretty realistic though with my numbers for a standard LO3 engine. With a rated 170 HP at the flywheel, after tranny, suspension, diferential and traction you are only looking at somewhere b/w 145-160 RWHP. HP is easier to generate/free up than torque, that's true. But with the right modifications, torque can be generated greatly. I use the LS6 as example. It actually has less Ci 347Ci vs the previous gen engines with 350Ci. But Ci for Ci it generates way more torque than a 350 LT4. It does this by having much better flow characteristics in intake and exhaust. Compression is also much higher too thanks to more air taken in due to better flow once again.

The key for torque generation lies in the heads and cam. Just popping in cams will not help much, same with just putting on heads. They must be matched. There are some built up 305's floating around with the magic 1.1 HP to 1 Ci rating. The key is in the head/cam combo.

http://www.goingfaster.com/spo/325_h...chevrolet.html

I think the best thing to do is do it in proportions, you only lose your car for a few hours and each bit gives you a boost in performance that is noticable.

 

palric: If you put a "Type R" sticker on the back of your car I hear you can get an extra 50 HP...if the stickers yellow then it's good for 75 MHP (mental HP)...at least that's what the Civic owners are telling me! hehe

Just a side note: In all seriousness, I totally agree with the increasing of TQ being easier with some mods. Take my mods that I did over the winter (ported plenum, everything cleaned up inside, and bumped up FP) and the HP went up a little over 6HP from last year...but a nice gain of 12 lbs-ft of TQ. I would have thought it would be the opposite way around.

 

I'm just being conservative. You need to ditch those stock TPI runners and base plate. You probably allready know that though.

 

Numbers are in the sig

Trigger's gotta get some custom chip burning done to. Next drag event... I better see you kicking my *** trigger!!

 

I guess with what mods you have it will generate torque above all else, especially with the engine.

From edelbrock...

Horsepower comes from torque. Torque comes from the pressure of combustion in the cylinder because combustion pressure causes the piston to turn the crankshaft which is measured as torque. The trick is to generate high enough pressure on each stroke and to do it often enough (RPM) to produce the horsepower needed.

Increase the airflow into the engine, you have more torque. That's why cams/heads wakes up a lowly 305 so much as 35-50 HP and upto 50 ft/lbs of torque because stroke for stroke it has more air, more fuel and thus more power. Exhaust mods also wake up the lowly 305s much more than a 350 gets. I'm not saying a 350 doesn't gain or is less than a 305, that's just plain silly. I'm saying mod for mod, a 305 gains more because it starts with less. Most 350's are designed with performance in mind, save for the 350 TPI whose plenum and intake were designed for a 305. That means when putting an exhaust on a 350, you're not increasing the exhaust flow all that much over stock. Where as with the 305, you are freeing a whole lot and more. That's probably why GM put such restrictive items on a 305. They didn't want people to know that their 350 design for thirdgen's mind you were not all that much better than the 305 design. That's why an LS6 less displacement motor spanks the hell out of a L98. GM fixed the design flaw of the 350 for the LS1 and LS6 and that is representitive of the power of a true 350. If you've gone ahead and updated your 350 with better intake and exhaust, you won't be disappointed. The same goes for the 305. Mod for mod, a 305 will gain more, in the end a 350 will spank a 305 though when the equivalent mods are done to a 350.

There is no replacement for displacement...

*****'s make me laugh... nothing gets a good laugh than spanking a sticker car...

So in theory if I stick my K&N filter sticker or say on the left side I'll have 25 hp... but if on the right side I get 30HP???

I dream of LS6 though when I think of 350...

 

What about those silly coffee cans that they attach to their 3/4 inch inside diameter exhaust pipes ? I hear tell they are good for BIG hp gains -- especially if the can was decaf...

RP.

 

Apparently too, if their ABS sticker falls off their car then they don't have any brakes!

 

OMG I should have used the decaf cans!

Me thinks me need to drive near the local high school and show off lmao... a car with real power...

 

I disagree with one comment made by the Edelbrock site... saying that upgrading the exhaust on a 350 doesn't improve horsepower much.... my engine made a huge increase with the exhaust, and headers should give me another 20 horse, 10 at least.

 

I agree with Nathan that exhaust does make a difference. But, at least on the TPI cars, the real big restriction is the intake design...for both 305 and 350. More so for the 350 though. Even if you go by just the improved sound alone, exhaust upgrades are feel worth the coin!

 

Ditto.

I read it and pashawed it. No dis to Edelbrock they know lotsa stuff. But I've had 3 f-bodies two of which I have sunk money into exhausts including a 305 and 350 and know it has BIG payoffs especially as you continue to add mods.

RP.

 

There was a comment made by Slade1, that the TPI on 350's were designed for the 305.
This may be possible, I'm really not sure, but I always thought the 1985 Corvette was the first GM TPI's and came with 350's.
Is that wrong?

 

yes... TPI was for the 305 at first. then just stuck on the 350 later

 

Here's the thing though.. EFI flows as much as it has to.. all you have to do is deliver efficient fuel, which is why GM upped the injectors to 22#/hr. So yes, intake was "designed" for the 305... but was it really? Maybe it was designed for any small block chev. Besides.. not like intakes and carbs were designed engine specific.

 

The '84 Vette inherited the TBI Cross-Fire design which was a disaster (unless you own one in which case it is the greatest thing since sliced bread). I have read of fundamental design flaws in this system that led to an enormous number of warranty claims for GM so they hastily dropped it.

When they did so the '85 Vette needed something usefull to fill the lifter valley and seeing as the f-body had a TPI for the 305 they borrowed it and put it on the 350 with (as Nate pointed out) larger injectors and a recalibrated ECM setup. I don't think the Vette got a purpose designed EFI intake until the LS series motors (excluding the ZR cars of course).

Last I read the 48mm 305 TPI setup flows 575cfm and the 52mm upgrade ups this flow to 650cfm. Wondering if anyone has done the 52mm thing on a 305 ? Did it do anything or do you have to do runners and base as well ? Does it do anything even with these ? More questions than answers.

RP.

 

What is the stock injector and throttle body sizes on the 350?
Is it the same as the 305?

 

I believe the TB size is the same for both...48mm. The injectors for the 305 are 19lbs and the 350 injectors are 22lbs.

 

When TPI was designed, it was originally designed for the 305. Where the TPI lacks is in airflow at higher RPM's which is where the big difference between a 305 and 350 is made. That is why the power difference between the 305TPI and the 350TPI is marginal.

 

What's the best way to correct the airflow problem. Intake, runners or throttle body. I have heard there is a larger MAF sensor avaible. Wouldn't that be a big help? Probably big bucks, huh?

 

I found that a little old airfoil was a great start and made a noticeable difference. Other than that, I didn't go any farther. My hatred for fuel injection grew, so I dumped it for CARB POWER.

 

The best improvement can be made by swapping the base manifold for a higher flowing version like the Accel or Edelbrock units. Runners are a close second. Changing the MAF or throttle body on an otherwise stock engine would be a great waste of money. The stock 48mm TB is supposed to be good up to 350HP but i've never seen any numbers that support that theory. The MAF sensor is capable of flowing more air than the ECM can calculate. After the MAF becomes saturated at 255GPM the ECM goes stupid and starts to fudge the numbers. The only aftermarket MAF available for our cars is the Wells unit. It uses "thick film" sensing tech rather than the "heated wire" method. It flows more than the stock unit, but again, the ECM can't see any higher than 255GPM.

 

Hummm... that's interesting.
Having an airfoil is an obvious help. Will removing the screens from the MAF sensor do much? I'm just looking for some free power for now. Need to put money into a traction problem before I spend more on hp. and as bigga pain in the a$$ as injection can be, I'm gonna stay with it.

 

I say save your money on the "traction problem" for now. A little more practise with your launches can help this and it won't cost you anything. Your money spent on performance would be much more worthwhile...unless you're pumping out like 300RWHP+ then some drag radials would be an easy solution.

 

IROCKER what are your 60' times

 

Thanks for the advice. Your probably right, but you guy's gotta be spinning badly on the line. Either that or I'm doing something wrong. ( or maybe cheap tires ) My worst times were bringing the RPM up to about 1600 and just nailing it off the line.
What are you doing on the line?

 

Trigger: My best 60' time is a 1.99 with an average of 2.2 which is not great, but not totally bad either. I'm still working to improve it and at least have an average of 2.0

16th: It requires a lot of practise and even though I've got better at it over the last year I am still far from happy. With our cars having so much bottom end torque, it is hard to do, especially with an auto. The best way that I've found is to launch at a very low RPM, which means barely loading up the convertor. Anything over 1000-1200RPM without drag radials and you're gonna spin if you just mash that pedal on the last yellow light. It's hard but you really need to ease in on the gas pedal...easy but quick. I know this sounds stupid but that's how I got my 1.9 and a bunch of 2.1's. If I get jumpy at the light and just put my foot down I'll spin for sure....Also, one question...are you auto or stick? If you're auto I strongly suggest that you manually shift it to second when the time is right. If you let tranny do the work it will prematurely go into go into second and bog you down. I hope that helps.

 

Yeah thanks, that does help.
That's what I did when I ran my 2.1 60 ft.
My car is an auto, but
I never did manual shift thou. That was something I was going to do next time out. It does shift early. Unfortunatly, I won't have my sfc's on yet.
Makes me a little nervous about running it.

 

375

 

Its still possible to go easy at the start and prevent an early shift into 2nd. It takes some practice with a 700r4 auto, but its possible. I adjusted my TV detent cable a wee bit off full to achieve this. I can go easy at the start and prevent spin, still mash the pedal down once its in motion and get it to shift at around 4500 RPM into 2nd gear. It'll then shift at 4300 RPM and leave me dropped to about 3500 RPM in third and I hold that to the end. I haven't done a TCC lock launch yet though as I'm still working on the launching part, but basically I keep the chirps to a minimum.

Irocker, do you run the the standard cold 30 PSI for your norm driving? Since we got the same tires and rims, I'm trying to figure out a balance b/w traction and ride and was wondering what your comfortable pressure was and give that a shot. Also u have any clue what the min PSI is so I have a base to start with?

 

Slade: I've had sucessful runs while letting the tranny shift itself, but I decided rather than risk a premature shift into second it's best to do it yourself. As far as PSI, I use about 32-34 cold on the street and about 25-27 at the track.

 

You lucky bugger. MercMarine under rated those things ya know. Did you get a good deal on it? I've never seen one in Canada for less than $35,000. Is it stocK? In case you havn't guessed my favourite cars are those "special" 'vettes they made from '90-95

 

My best 60 foot time was a 2.3. My car is a little difficult to launch Maybe I should let one of you guys drive.

 

OK

 

I'm serious.

 

Why is your car a little too hard to launch?

 

AcceldZ is, by my guess running like 400-450 lb ft of torque. His car just spins through 2 gears. Even when he feathered it for 100ft and then mashed her down it still spun like crazy.

Paul I think you have to gradually bring it to WOT. Your one case that definately needs some SFC and then try again. I found mine made a huge differnece in planting the tire. Oh, and replacing the defenders with those TA's would help too.

 

If you haven't improved upon the stock system, no sfc, no torque arm, no lca, no springs.. just all stock even with a posi, if 350 ft/lb of torque gets passed to the rear, it won't grip well. that's assuming your tranny can even generate that amount of torque. Remember when all is said and done, the power goes thru the tranny to the drivetrain to the rear with power loss at each point and it doesn't take much to get the rear to spin. Even a lowly LO3 TBI with its 255 rated ft/lbs makes the stock setup suspension look like crap. Unless he went all out on the engine, 350 + intake, cams, heads, headers, exhaust ie the works, 400 is a conservative number to say the least. Two guys can have radically different setups and still both spin like they were the same. He's guessing 345 torque from the engine.. not a far cry from the stock numbers of a typical 350 tpi. The question is his suspension built to even handle the stock engine?

 

Well, he has enough ponies under the hood of that thing to smoke probably everyone here on the Ontario board. problem is he can't hook it up a bit.