I need everyones help here in coming up with a round figure of what my HP and TQ rating SHOULD be.

Here is what the car has got:

The original 305 in the car went to Camaro heaven and I'm having another 305 from a junkyard (Same car and same year it was pulled from so an LB9) with 112,000 miles on it (I know not the greatest but I couldn't afford anything else at this point) dropped in.

So at this point, were talking a stock LB9. But here is where all the goodies come into play.

When I first bought the car the guy didn't know much about It's history or what had been done to it. It was pretty obvious from his sales pitch. "Edelbrock headers, B&M shift kit and rebuilt trans.

When I got the car home I found out that it not only had Edelbrock long tubes, but the ignition was MSD, the runners on the TPI setup were SLP high flows, the exhaust was flowmaster and I believe it has an aftermarket throttle body.

So here is the list we are looking at after the engine goes back into the car:

*Means this is a mod I will be having put it while the new engine is being dropped or after It's already done.

- Edelbrock headers
- SLP High Flow Runners
- MSD Ignition with MSD spark plug wires
- Flowmaster Exhaust
- Jet Stage 2 Performance Chip (This is negligible. As soon I get the car back It's coming out for a stock PROM because it is making the car run HORRIBLE!)
- *Comp Cams 12-388-4. 206/212 Duration, .425/.440 Lift.
- *Comp Cams Flat Tappet hydraulic lifters
- *Gutted MAF Sensor
- *Throttle Body Airfoil
- *Denso Iridium Spark Plugs



I was guessing around 260 - 270 HP and a little over 300TQ. Maybe in the 310 range.

Anyone got a second opinion on this?

 

stock LB9 made 195hp/285tq i believe... those headers arent the greatest but with the rest of the exhuast done u could pick up 20hp, msd ignition i would think 3hp max esp with the plugs, the chip isnt gona do anything really but with the stock chip there is no change... u should have a chip burnt for the new cam. the cam is mild and u could pick up 15-20hp but your heads are holding u back. the runners arent even needed bc your base/plenum arent upgraded and your not flowing enough air with the stock heads to really need a TPI upgrade. the SLP's might actually make u lose power... if u even gain anything. gutted maf isnt even needed for your low output 305, stocks are good for about 400hp.u wont see much of a gain there just more than 100cfm that your engine isnt using. throttle body air foil is ok really just smooths out air entering the TB, maybe 3hp max.

stock
195hp
20hp exhaust
3hp ignition
15hp cam
3hp air foil
235hp total... that would be my guess and it could be alil less or more
300-310 tq seems about right

if your going the cam, throw a 100$ mild portjob at the heads, port match the intake to the heads and the SLP runners to the base and plenum and u could pick up another 30hp. your not gona get alot from the cam with the stock heads, port the heads and u will reap more of the hp increase from the cam/head combo. once the heads/cam are done then the intake becomes a restriction... and the SLP's will be needed as well as sum porting to take advantage of the larger bore SLP runners/siamesed to the plenum part. u will see the most from cam/heads and sum intake porting. tahts just my .02$

 

you cant just add up factory/manufaturer's claims. first off, the 195 is at the flywheel, so knock off anywhere from 15-20% (parasitic drivetrain loss closer to the 20 if auto) off of that to get the stock approximate at the rear wheels. 165 to 155 stock if you are lucky and the engine is in decent shape and rebuilt. i dont know how many miles are on the engine, but i dont think you would even see that.

you wont see 20 from exhaust with those headers and catback even if you dont have a cat. i would say maybe 10.

ignition on a car that is that stock wont give you anything noticable. you would see the big gains on ignition from a significantly more built engine (bumped up compression, bit cam, high flowing aftermarket heads).

you will see a solid gain from the cam. maybe 15 hp if you are lucky, but if you were to do some port work you would see the 15 for sure if not 20+.



not to rain on your parade, but if i were you i would be jumping for joy if you hit 200 RWHP. but my guess would be in the 180-195 range.

 

were talking about FLYWHEEL hp... not rwhp.... so most cars still make close to there stock rating with usual flucuations of about 10-5 hp less due to carbon buildup, used sensors, worn drivetrain, compression loss etc... ive seen stock 350tpi with over 130,000 make 190 rwhp with no mods, stock is 225.... given the 24% which is more likely for a auto drivetrain loss for a AUTO trans, its still making way more than the rated HP.

now the exhaust were talkingt about 20hp at the motor! so it would be alil over 13hp at the wheels... remember that these cars usually gain .4-.5 sec in the 1/4 with a good complete exhaust upgrade... and has been proven many times... a .4-.5 sec decrease in 1/4 mile times usually equates to about 40-50hp... since it takes 10hp to usually drop a car .1 sec.

"ignition on a car that is that stock wont give you anything noticable." same that i said...all i said was about 3hp... due to better efficency of burning the fuel mixture more complely...including eliminating weak spark in the upper RPM ranges... increased of 3hp are not uncomon, also increased mpg can be a reward of a ignition upgrade... so not sure wat ur saying there

"you will see a solid gain from the cam. maybe 15 hp if you are lucky, but if you were to do some port work you would see the 15 for sure if not 20+." again.... same as i stated.

so like i said with my expected hp of ABOUT 235hp... with "IMPALED's" rule of only 20% drivetrain loss (i would choose 24%) it comes out to 188hp... which is exactly wat he just stated... so im not sure what hes getting at but hes stated everyting i just said but telling me im wrong...

basically to get more hp to get closer to your 260hp goal u would have to port/polish the heads decently... to take full advantage of that cam, then your intake becomes a restiction... which there i would have to be ported, and portmatched to the SLP runners... i give u as a ROUGH estimate of about 235hp at the CRANK... and about 180-190 at the wheels.

 

In the end I'm shooting for 400HP/400TQ rwhp minimum.

Torque is higher on my priority list though so if i can hit 400TQ without quite reaching 400 HP thats acceptable. But I'd prefer 400 minimum for each. I know It's not easy and the going trend are 350cid engines, but I'd like to stick to my 305 setup if this is accomplishable.

TBH, I'm rather afraid to build upon the longblock assembly itself because the 305 being dropped in has 112,000 miles on it and I'm not sure if it will want to last. Bear in mind this isn't going to be a strip only car, nor will it drag race on a daily basis. My goal here is the 400/400 as a daily driver. A car that I can drive everywhere constantly getting the satisfaction of knowing I created what It's packing, as well as burning a honda here and there and not having to drive like a grandpa without fear of spinning another bearing.

My last 305 took a serious dump unexpectedly at approx 140,000K and all I had the money for was a visit to the junkyard.

This 305 was pulled from the exact same car. 1985 Z28 with an LB9 TPI. BTW, the rating for the LB9 in 1985 was 215/275.

These engines were 2 bolt/2 piece correct?

What would you guys suggest?

 

u wont make 400hp/tq let alone 400rwhp/tqwith a 305 unless u have a power adder. a 350 would need to be created. i would think the 305 max hp output would be around 330-350hp and alil more on the tq side at the crank. to get 400 rwhp u would have to make over 500hp at the crank, this would be a serious 350/383 to accomplish this. the blocks up until 1987 were all 2 piece real seal and all the blocks in camaro/firebirds 305/350 were 2 bolt mains. now as far as the 1985 305 making 215 that was brand new and with an auto behind u have to factor in 20-24% drivetrain loss puts u at 40-50hp loss so ur really only making 167-177 hp at the wheels.

to get 400rwhp i think ur outa the relm of a 305 with a big cam/big heads and a turbo/supercharger, dont even think u could pull it off with all that. my 383 has a 230/236 cam with ported 195cc aluminum heads, ported HSR etc and i'll be lucky to make 470-480 hp at the crank which with 24% drivetrain loss through my 700r4 and i'll be looking at 370 rwhp/tq... still not making 400rwhp. mines a alil tame but mine will also be a daily driver.

i vote for 400rwhp u need at least 550hp at the crank, thats a mean @ss 350/383

 

So from what I've gathered, basic mods to do a 350 swap include a 350 specific knock sensor, new injectors, an ECM tune, and a new flex plate for a 1 piece rear seal?

I know I'm forgetting a couple things...

How hard is it to go a 400sbc?

 

neither flywheel nor RWHP were introduced by the main poster.

yes, FWHP does matter, but i really doubt that he would get a used 305 engine dynoed, that is not being fully rebuilt and heavily modified.

for that matter i didnt even know if the poster realized that the difference is as big as it is.


""which is exactly wat he just stated... so im not sure what hes getting at but hes stated everyting i just said but telling me im wrong... ""

i wasnt necessarily saying that you were wrong, i was stating the difference between your apparent flywheel figures and the more realistic RWHP figures.

the numbers that really matter are you trap speed and E.T.

then would come the RWHP figure. i will still stand in the 180-195 RWHP figure.

 

i am going to be taking the 400 route in the near future, new Dart little M block, AFR 227's, forged/billet internals...

most will say to just go to a 383 instead (depending on how radical you choose to go). due to various factors and opinions of others. also on most (if not all) of the stock production 400 blocks have thinner cylinder walls, limiting the overboring and potentially causing premature block failure. there are also significantly less 400 blocks sitting around than 350 blocks, and stroker kits are pretty cheap for the 350's, but as always the sky is the limit.

whatever you do choose to drop in, if i were you i would go carbed. it would save you alot of headaches involved with the swap, especially ECM/PROM burning/reburning as you choose to mod and remod. plus the TPI injection is not very strong in the higher RPM bands.

 

I know the difference bwteen bhp and rwhp, I just wasn't entirely sure whether the ratings on TGO tech articles were of rwhp or bhp. Thanks for clearing that up.

This car will be a daily driver, so TPI is out of the question.

I've been reading up on PROM burning and plan on getting into the trade, so that isn't an issue.

I'm sure with some heavy modification, my TPI setup won't have too many problems.

 

i believe that you meant Carbed instead of TPI where i bolded above.

in terms of streetability, if you are shooting for 400/400 RWHP/TQ, i dont think it would have the best street manners, regardless of induction.

if you mess with a carb enough and get familiar with carb tuning the gas milage wouldnt be any worse. i emphasize the tuning process.

i am by no means an expert on TPI nor will i claim to be. i suggest hitting up the TPI forums, alot of people know alot about that as well as the prom burning forums.

my extent of TPI knowledge is that the power tends to fall on its face past 5000 or 5500 RPM, unless it is highly modified, which again is beyond my scope of knowledge on TPI.

all of my Camaros have been carbed although i am decent with the OBD2 and tuners on my Stang.


this is an excerpt from hardtail.com which is Steven87IROC's personal site about horsepower ratings... SAE NET is basically the current standard, but neither methods account for drivetrain loss


SAE Net Horspower In 1972, American manufacturers phased in SAE net horsepower. This is the standard on which current American ratings are based. This rating is measured at the flywheel, on an engine dyno, but the engine is tested with all accessories installed, including a full exhaust system, all pumps, the alternator, the starter, and emissions controls. Both SAE net and SAE gross horsepower test procedures are documented in Society of Automotive Engineers standard J1349. Because SAE net is so common, this is the standard we will use to compare all others.
SAE Gross Horsepower This is the old process that American manufacturers used as a guide for rating their cars. It was in place until 1971. SAE gross also measures horsepower at the flywheel, but with no accessories to bog it down. This is the bare engine with nothing but the absolute essentials attached to it; little more than a carb, fuel pump, oil pump, and water pump. Because the test equipment on the engine is not the same as in SAE net, it is impossible to provide a mathematical calculation between SAE net and SAE gross. As a general rule, however, SAE net tends to be approximately 80% of the value of SAE gross. SAE J245 and J1995 define this measurement.
http://www.hardtail.com/techtips/hpexplained.html

 

My apologies. I meant Carbed was out of the question.

Not that I have anything against carbed. I like the idea of the old mechanical feel. Someday I swear I will own a 1970 Dodge Charger. That's when I goof around with carb setups.

But for now, I want to keep my Camaro TPI, for a number of reasons. Partially because I like the way TPI looks the best. Partially because I want to keep the car with It's original setup. Partially because I want the added economy benefits of TPI. Partially because I've already researched all the modifications I want to do to my TPI setup. And partially because computers are my number one fortae at the moment. I really like the idea of having to tinker with an ECM in order to tell the car how to run right.

Well, I'm sure you catch my drift. my 400/400 goal was a bit optimistic TBH. If I can get away with 300 - 350 HP and TQ at the wheels, I'll be happy. Not sure if this can be accomplished on a 305, but building a 383 Stroker does sound like fun.

 

the tpi will limit the max hp of the engine u decide to build. i would go with at least a 350 a 383 tends to make more tq bc its a longer stroke. the tpi cuts a stock 350 off at about 4200-4800 rpms... and then its dead. u can modify the tpi to make good power but this cost alot of money and u still have to do alot of custom work. new high flow base=400-500$ high flow runners=300-500$ TB=300-500$ and after all this u still need to port it ALOT! most go with extrude honing everything which will just about double everything i just stated except for the TB. but if uhave alot of time and patience and can hold your own with a carbide bit then u could do it yourself with sum help and preplanning. there are other systems out there like the HSR, super ram, miniram, LT1... that will also work, depends on wat u like as far as looks/performance/and budget. modified TPI's can flow 5000-6500 depending on your porting and how creative u get, i would do sum searches to see wat has to be done. bc i kno wat u have to do but its hard to explain. 300-350hp/tq is not hard to get there are plenty of 350's/383's that are putting that out and have good street manners.

the TPI is a nice induction system for the street, real fun goin around makes tons of tq. problem is your power band and max HP. also TPI's dont like cams above 220 degrees... and ive asked a few tuners to tune my cam which is only 230/236 and they say they wont even touch it. a smaller duration cam will also limit HP and rpm. so its a toss up. go with sumthing with shorter runners like the LT1 of HSR or superram and u can throw bigger cams. and make more HP, increase ur RPM range and do it for less $$.

the TPI does look mean tho im gona be selling my TPI, intake plenum/runners are polished but aslo (ported plenum, port matched to high flow SLP runners, port matched to TPI base. with fuel rails 22lb injectors, and BBK billet adjustable fuel pressure regulator, and 48mm TB with SLP air foil) if your interested...

 

How much are we talking?

 

for wat?

is your plenum portmatched to the SLP runners? if not ur leaving alot of RPM breathability on the table not to mention a good bit of HP... id say if its not porting and idk wat base u have u havent increased much overs stock, everything needs to be matched to get the benefits... id say ur still in the 4200-4800 max RPM room. if the plenum is ported to the runners and the base then i would think ud be in the 5200 range. port the runners and the base extensively and u could get 5500 with the TPI setup on a 305/350. ive seen a vortec headed, GM hot cam, 1.6rr with high flow vortec TPI base, high flow edelbrock runners and stock plenum with 52mm TB make 354hp and 432 tq. i believe max hp was around 4800-5000. the stock SLP's and all the portmatching will give u alil more RPM say in the 5200 range depending on your port work and a lil bit more HP than the edelbrocks. get alil creative with the SLP runners/base and u could be making 360-370hp range with the high flow TPI. not sure max hp of the TPI bc ppl do alot of creative stuff usually custom to get the flow#'s and HP they need.