TPI-Formula350-

I think I should be pretty much on the money(losing 15%-18%) but I'll def be sure to post after the dyno tune on 4/21 and let you guys know

1989GTATransAm

iTrader: (3)

I was figuring 20% loss. This will be one of the few times that we will have both an engine dyno and a chasis dyno. The results will be interesting.

VincentZ28

iTrader: (2)

I was basing your combo from our past Dyno results. There was a red 91 Z28 with the same set up as mine but the runners wasn't simeased But the manifold flowed 310cfms and it made 355rwhp at 5500 and the car is an auto. Another car with a 383 and stock Super Ram only made 330rwhp with longtubes, E-tech 200 heads fully ported flowed about 285-290cfms and Vortec manifold. So I'm taking a good realistic guess it will be somewhere in the middle. Not to burst your bubble but these are facts.

TPI-Formula350-

well those are the facts for those cars not mine...the "fact" is my engine/superram has made 467HP and 517TQ with the SuperRam on The engine dyno... So losing 15-18% would put me at approx 383HP and 424TQ(going to the high side 18%)...those are the facts. Unless for some reason my car loses more HP/TQ going from a engine dyno to a chassie dyno then everyone else does that you can explain to me? Like I said before I'll post my results after the chassie dyno tune on 4/21

VincentZ28

iTrader: (2)

Remember after all the accessories are bolted up it will be a big power lost close to if not a little more than 100hp. Don't forget that it will be turning a transmission, driveshaft, readend with wheels and the weight of the car.

TPI-Formula350-

yeah...thats why you get a 15-18% loss to the wheels after everything...15% to 18% lose is the approx formula going from FWHP to RWHP

VincentZ28

iTrader: (2)

Well how much do you think I'm making at the crank?

TPI-Formula350-

well adding 18% to your combo would put you at approx 467HP and 458TQ at the crank(auto and accesiories)...adding 15% if you had a (manual and accessiories) would put your crank HP at approx. 440 FWHP and 446 FWTQ

1989GTATransAm

iTrader: (3)

Regarding the engine dyno figures which exhaust system did you use on the enging dyno? Also how does that compare to the exhaust system that is installed in the car?

When I ran my new motor on the dyno I used the headers that were actually going in the car and compared them to the long tube dyno headers.

z 28 jari

iTrader: (1)

Is it right way to calculate power loses at presentage.Somehow it doesn't seem to realistic if you have two different engines behind identical powertrain.First engine makes 300hp and second 600hp.First loses are 54 hp and second 108hp(18% loses)

TPI-Formula350-

Yes, that's correct
http://www.moddedmustangs.com/forums...ower-loss.html

pwdbychevy

Pretty good numbers. Almost similar to mine.

Saabster

iTrader: (2)

Drivetrain losses measured as percentages are typically for ballpark estimates. And rather than talking about what stall the car has, we should be talking about how wide the tires are and what kind of rubber they have on them because they vast majority of drivetrain loss comes where the tires meet the road. The differential is the next biggest power waster, apparently changing the direction of the power (90 degree turn) wastes quite a bit.

z 28 jari

iTrader: (1)

That seems to be like that.If look at those rototest measurements(2xVettes -05,-06 and Shelby gt 500)loses are only 7% to 12%.
http://www.rri.se/index.php?DN=29&List=C-L

Orr89RocZ

iTrader: (20)

C6 vette rated at 400 will dyno around 340. 60 hp loss or 15%

C6 Z06 rated at 505hp will dyno 450-460. 45-55 hp loss or 9 to 11%

C6 ZR1 rated at 638hp or w/e it was now dyno's 550whp from one test I've seen. 88hp loss or 14% loss.

All manuals. 15% manual is conservative. Auto's usually stated around 20%

badgta

iTrader: (4)

a 327 making 530hp

http://www.chevyhiperformance.com/te...aft_specs.html

a 355 making 460hp

http://www.chevyhiperformance.com/te...ead_bolts.html

both using large cams 250* range, but what i cannot still seem to grasp is, the relative thinking to high rpm, is simply a mystery, where as above cams that are 250*+ peaking near 6500 on the 355, with a 220cc intake port..

that head was huge, and flowed near what the afr 195 eliminator does, plus has a larger port width, which would allow more rpm, or a higher peak rpm according to what i have seen and read here at thirdgen.

true the 327 peaked at 7100rpm, but a 355 is 22ci larger, surley that would make up for a 500rpm or more differnce? im just dumbfounded, i cannot figure out why cams with 250*+ duration, are peaking near what everyone here says a 230* cam will...

i think the package you have put together is very nice, but do you feel there is a simple cam just slightly larger than can put you at the 400whp mark without revving over 6500? i would love to pick that perfect cam for my 355, im down 2 3 choices now, one is the xfi292 i already have, other from the xe line.. any thoughts?

adam

Orr89RocZ

iTrader: (20)

IF you have a 250 duration cam in a 350 and are not peaking ove 7000 rpm, then you dont not have enough compression/intake/heads to support the rpm. Heads/valvetrain will be needed to support those rpms.

the 292xfi in 350 LT1's drive around nicely, about the same as a CC306 if not better but it still revs to 7000+. Some guys noted it hasnt peaked yet by 7000 on a 350. I think its a big cam. Comp's rpm range for those cams are wayyy off.

skinny z

Do you suppose drive train losses are even higher than the generally accepted 20% when the convertor has no lockup?
My (modest) 285 rwhp from the dyno doesn't quite jive with my 1/4 mile et and speed. At 12.7 @ 105 (3 in a row with excellent air altitude density) indicates that I'm making closer to 375 chp rather than the 345 chp that you get from adding 20 points to the dyno numbers.
Incidentally, good call by 1989GTA TransAm regarding the dyno headers vs street headers. A lot of power can be left behind when the headers are less than optimal.

Orr89RocZ

iTrader: (20)

OH YES its drastically different depending on the stall speed. I picked up 15whp just by locking up the converter on a mild 240's whp L98. Just a 2800 stall.
87_TA's car on this board I believe dyno'd near 370whp but that car ran 10.8's at 126 on motor alone. His was near 3500 stall thru a Th350 I believe, so no lockup. That 406 motor of his would probably hit 450whp on a locked up 700r4 setup. Considering my 383 made about 400whp and only trapped 118-119, his times are about what my 150 shot times were and I anticipated 500whp easily but never dyno'd. I went 127-128 on the gas. His car may be a touch lighter but you get the point.

Thats why alot of drag racers say they dont race dynos because the numbers are not true with open converters

skinny z

I see the point. I suppose the numbers are useful from the standpoint of evaluating your own mods. Then again, the track does the same.
(have to thank VincentZ28 for the use of his thread). I see he has a manual trans.

badgta

iTrader: (4)

http://www.chevyhiperformance.com/te...der_heads.html

355ci
compression 10.5:1
heads, 220cc intake that flowed 280cfm
Camshaft 255/263 at 0.050; 0.540/0.534; 106 LSA
Valvespring diameter 1.55
Valvespring seat pressure 135 pounds
Valvespring open pressure 360 pounds


yes they wound it up to 7000, but it peaked at 6400 rpm, and it didn't show valve float as you can see the power number didn't drop significantly after peak either, which it is a solid flat tappet, but still had all the things needed, compresiion, heads, cam etc.. i just can't figure it out orr, why a xe288hr-10 or a xe294-10 or the xfi292 would peak any more above a cam several degress higher? just don't make since... im not saying i disagree with your staments, i am just trying to understand why the laws of physics and probabilaty is changing all of a sudden..

yes the xfi line has faster ramp rates, but you would think that would mean better lower rpm hp, due to the faster ramping, and around the same characteristics of the xe line at max lift so to speak. faster ramping would mean quicker cylinder fill at lower lifts correct? killer on valve springs, but near same at the same given lift of a same degree, lift cam of another type?

damn i should have kept my learning up over the years, i am way behind on valvetrain tech.... man i have been out of the loop way too long.

1989GTATransAm

iTrader: (3)

Comparing my new motor to the one listed above in CHP. Mine has a much smaller camshaft of 233/233@ .050". Slightly more cubic inches at 369 versus 355 yet it had peak power at 6500rpm and peak torque around 5000rpm. No dyno headers either. Using the ones that will go in the car. Something to ponder.

badgta

iTrader: (4)

exact cam specs, heads?

Orr89RocZ

iTrader: (20)

Hard to say exactly but they did use a factory 302 DZ carb, which may not have been able to deliver good quality fuel control at higher rpms like modern day carbs. may have been a reason for power to drop off.

Roller cams always seem to peak higher than a flat tappet at the same duration. Its just a smoother running setup with more aggressive lobes and sometimes much higher lift than flat tappet.

My 383 peaked at 6300 rpm with 230 deg cam. A custom grind for 6500-6600 rpm peak I was told would be 240/243 duration. It takes a good bit more duration to start pulling more rpms once you get up in the mid 6000 rpm range

3rd gen Will

iTrader: (8)

Thats awesome info Orr!

My old 84 Camaro I had the GM 350 HO Crate motor Rated at 330hp 380tq Dynoed 272 RWHP (310 rwtq IIRC) through a 700R4 w/ 2200 stall non lock up converter 3:73's. If you run that back it comes out to about a 21% loss for Drivetrain/accessories. That is saying GM was spot on with the 330hp rating.

badgta

iTrader: (4)

the pic is crackys dyno graph (dyno sheet xfi292)
as you can see in the pic, power drops slightly after 6200 mark, right were comp advertises, he said it would wind to the moon, but he always shifted at 6500, hence why the dyno stopped there.

video of car
http://s16.photobucket.com/albums/b3...urnouts033.flv

2nd video
http://www.streetfire.net/video/crac...ust_131247.htm

Orr89RocZ

iTrader: (20)

without knowing what cc those heads are ported too and also what the intake was ported to, its hard to say why that XFI cam would peak before 6500.

Given my cam had more overlap than the xfi and peaked at 6300 in a 383 with 12 deg less duration on the intake than the xfi, there is no reason for the xfi to peak below 6500 in a stock 350 cube application. I'm wondering if he was having valve float issues. Power didnt drop off much but started to flatline, it could have been lack of valve spring control. I'm willing to bet it was a combination but more so the lack of intake/head flow/size to support the cam.

6200 peak at 350 cubes with that cam dont make sense. I have seen 224 cams peak there. He has some restriction.

The only thing is I havent seen any other dyno tests with that cam. I dont know many people running it other than Cracky on the Z28 board. That was years ago too, and he makes GREAT numbers. I just dont understand why it wouldnt hold rpm out to 7K based on duration numbers alone and with that wider 113 lsa.

you can find many LE2 and LE3 graphs that peak later than that cam and those cams dont have near the duration but do have tighter lsa's for more overlap

badgta

iTrader: (4)

see thats what puzzles me man, he had crawford ported heads, plus a lt1 intake, and i agree that i don't think it's valve float seeing as how the numbers didn't take a dive after peak.

do you think the 195 eliminators will flow more than those race ported heads he had? i plan on boosting mine in the future, wonder if that will drop peak any? 9psi + will have about 9.2:1 compression, shooting for a .040 to .045 quench. i live about 90 miles from cracky, so i will probably get him or the local dyno guys to tune.

im just trying to figure it out man, i want to get to that magic 400whp mark like the guy above also, but i don't want to stuff in the wrong cam in the process. everything i see says im on the right track, but i see dyno graphs here that say other wise, im am completely lost here.

there just has to be a way to squeeze 400whp out of a 355ci engine without revving it past 6500 rpm... there has to be.

thanks for taking the time to help and talk it out with us, i am enjoying this mechanical and power talk emminsley!

adam

skinny z

http://www.popularhotrodding.com/eng...der_heads.html

Yes I'm aware it's a "magazine article" engine however this a representation of how it can be done.
If you maximize the torque production of a little 350, helping low rpm cylinder filling, then the horsepower will fall inline once you start to wind it out.

badgta

iTrader: (4)

thats flywheel not rear wheel

skinny z

Whoops. Didn't read your post well enough.
Aren't there people here that make 400whp though?

Orr89RocZ

iTrader: (20)

Its possible no doubt. MANY LT1s doing it which means a miniram AFR 195 car should hit it. Or a single plane/HSR type car could do it.

Key would be to get compression up close to 11 to 1 if you can, and run a 230 deg type cam. I do not think you need a 236+ cam to hit 400rwhp if the heads are good.

Intake has to be ported to match head flow or exceed head flow to make sure no restrictions.

Typical LT1 packages with 200 cc heads will flow 280-290 cfm at best. They will run slightly shaved heads 54-56 cc chambers for near 11 to 1 compression. They are about 10.5 to 1 with 58cc i believe. Then you need about a 230-234 degree cam with around 108-110 lsa/.600" lift and your set if the valve springs are strong. AFR 8019 springs shimmed to 160-170lbs on the seat are perfect for this. Now you can also have cams like AI's 226/232 cam i think it is that runs very strong on a 110 lsa. Also capable of near 400whp without the need to rev that high if you have good heads.

The 230 degree cams can get up to 6300-6400 rpm and carry rpms out further. This is a typical LE2 type setup from Lloyd Elliott. generally considered the max rpm package for stock LT1 bottomend. 380-400whp is common for these setups but most are in the 390-410 range. Slightly less with an auto naturally. LE3 revs higher, take it to 6800 or so and the cam is usually in the 236-238 deg range on the intake lobe, 3-4 degrees split, tight lsa again. Not quite XFI292 size but more overlap so it still pulls good rpms.

There are several members here on this board in the 370-380whp range with 350-355 motors with fairly small cams. Anywhere from 218 to 230 deg on the intake.
400 can be done with either abit more cam or abit more head flow. More revs make it easier I think if you have the valvetrain to support it. To ask for 400whp by 6000 rpm on a 350 just seems abit optimistic. 6500 peak should be attempted, just get good rod bolts, longer rods/lighter pistons. Should have no problem pulling that rpm.

skinny z

Don't forget that when your talking about a 20% drivetrain loss, that's 20 points off the crank horsepower value. 400rwhp takes closer to 500chp to achieve.

VincentZ28

iTrader: (2)

One of the things I need to do is find a better set of lifters. These Elgin Lifters bleeds down when the car sits for five minutes engine off then tap after starting it back up. They just don't stay pump up long at all. I might be losing power there. I'm going to use what I already have to make over 400whp.

Orr89RocZ

iTrader: (20)

As long as they get filled with oil again while running you should be seeing max valve lift and making the best power you can. If oil squeezes out from valve spring pressure during operation then you may not be seeing max valve lift. I dont think they should bleed down that fast but certainly will bleed down over time.

LS7 lifters are popular for a good quality lifter at a nice price. Morells lifters are some of the best I believe but you pay a premium for them. I've been using LS7's in my last 2 motors

badgta

iTrader: (4)

i bought a brand new set of oem gm roller lifters... afr 1038 elimanator heads out of the box, xfi 292 cam, arund 9.2:1 n/a but will eventually have the supercharger with 9psi boost. hence why i like the 113* lsa for the supercharger.

i think all of that with tha eagle all 4340 forged bottomend will handle 6500, thats where i am setting the rev limiter on the 6al2 box... personally i think people who ran the xfi 292 to 7000 was people who just wanted to rev that high but didn't need to, we have now a dyno graph to look at, which shows it peaks near what comp advertises. a 6200 peak with 300 rpm more shift point will be winding like a mother, with a set of 4.56 gears in a 9", hell of a 1/8 mile car. which is exactly what i want with the 6 speed.

1989GTATransAm

iTrader: (3)

My new motor has the LS7 lifters. Best bang for the buck out there.

Orr89RocZ

iTrader: (20)

I think you will be surprised when you run the 292 cam. I bet it will peak near 6400 6500 on the 383. Power should hang on til 6700. The duration is there to support it. Its not revving out because people want to its because it pulls some rpm. Not a bad thing since your bottom end if balanced well should hold 7k rpm. I took my 383 that high and had eagle forged internals. You will need strong springs to handle that cam. 160 lbs on the seat atleast

badgta

iTrader: (4)

why would tht cam peak near 6400 6500 rpm when a dynograph of a 350 lt1 peaked at 6200? im running either a 350 or 355, 383s are too much of a headache to me, clearancing etc, just not enough for me to go through when i can assemble a 350 and push for 500hp. it has to be possible, especially with afrsand a prt matched stealthram.

if it peaks at even 6500, i would be stisfied, any more then no.

Orr89RocZ

iTrader: (20)

1 case of that cam peaking at 6200 does not mean they all will THere are many guys that say it will go over 7000 rpm. 1989GTAtransam has a 233 cam that goes up over 6500 and should shift near 6800. And thats on a 370 small block.

I dont know why the LT1 case peaked near 6200 but I'd be nervous with that cam on a 350

1989GTATransAm

iTrader: (3)

The camshaft is only one part of the equation as to when peak power will be made. The heads, intake system and exhaust system also play a large role. As has been said many times it is the total package that counts.

Back to horsepower for a moment. The power that a motor can develope depends on how much cfm the motor can process or flow through it. The more cfm the more the power potential. That is why you have to wind up a smaller motor to a higher rpm to make the same power that a larger motor will make at a lower rpm. It is all about air flow.

badgta

iTrader: (4)

ok, heres that 327 i posted above that makes 530hp at 7100 rpm with the following cam specs.

CAMSHAFT SPECS
Manufacturer Comp Cams
PN 12-773-8
Grind number XR292R
Type solid roller
Valve lift 0.582/0.588-inch,intake/exhaust
Valve lift
(with 1.6:1 rocker arms) 0.621/0.627-inch,intake/exhaust
Duration at 0.050 254/260 degrees,intake/exhaust
Lash (hot) 0.016/0.018,intake/exhaust
Lobe separation 110 degrees


surley the xfi 292 with less duration, and with the afr 195 heads and a engine with 33ci more than that one, could muster that much and peak near 6500, what 33ci isnt enough for a 500rpm drop in peak power? i know the afrs will handle it, so that will only leave the cam shaft, and if the cam specs posted above made a 327 crank that much hp, surley a 350 with slightly less duration can do it at a lower rpm.

Orr89RocZ

iTrader: (20)

Doesnt sound like you will believe any of us so why dont you go run it and find out for us? I"m curious to see a xfi 292 combo other than that LT1. I havent seen many.

1989GTATransAm

iTrader: (3)

"i know the afrs will handle it, so that will only leave the cam shaft,"

Speaking in general and no particular motor you also have to have an intake system that is capable of the correct amount of cfm or you will choke the motor. Same with the exhaust system. If it will not process the cfm the motor will be constipated so to speak.

badgta

iTrader: (4)

i look at it like this, all i have heard is so and so revved to 7000, or this guy did this, no proof at all nowhere. then i found those 2 dynos that showed small cubic inch motors that ran bigger cams that peak way up there, with more duration. plus crackys dyno put it right were comp advertised.

guess i will just put it in when it's time and try it, if i am right fine, if i am wrong oh well, i will have a big im sorry when its time, but you have to look from my standpoint, so far all i have heard is inuendos or rumors on this cam, nothing factual, only factual thing i saw on this cam is crackys dyno sheet.

yeah those 230* cams your talking about are strange, maybe its the way they are specd is the reason you have to rev at x rpm. idk, i cant figure it out for the life of me really, but until another piece of paper or dynosheet shows up, then i have to stick with whats fact for now, if i see more, then i will change my mind.

Orr89RocZ

iTrader: (20)

I really dont want to take up this thread but here are some examples. Have you seen what the GM847 cam does in a 350 LT1? its a 234/242 cam.

LE4 cam which is abit bigger. This is in the low 240's duration since i've seen an LE3 spec out at 238/240 once. I'm guessing the LE4 is 242 ish intake. This is on a ported heads 383.




Just saying, The 292 cam is big.

1989GTATransAm

iTrader: (3)

"CAMSHAFT SPECS
Manufacturer Comp Cams
PN 12-773-8
Grind number XR292R
Type solid roller
Valve lift 0.582/0.588-inch,intake/exhaust
Valve lift
(with 1.6:1 rocker arms) 0.621/0.627-inch,intake/exhaust
Duration at 0.050 254/260 degrees,intake/exhaust
Lash (hot) 0.016/0.018,intake/exhaust
Lobe separation 110 degrees "

That is a large solid roller camshaft that was used on the 327. I have no doubt about the ability of that camshaft to peak at 7100 rpm with that motor.

badgta

iTrader: (4)

true, but image 33 more cubic inches and alot less duration, say the xfi duration, surley the added cubic inches and lower duration would drop the rpm peak while keeping power number near the same.

i cant figure out why the elliot cams rev so high. or others. it's like you read one thing one place, and when you think you have it figured out, then somthing new pops up, my question is why? when all nessasry steps are taken to squeeze the most out of a specific grind, then there should be a half level playing field.

i get what you guys are saying, i have an idea.

if i were to get a custom xfi cam, say using the xfi280 ehaust lobe of 236* for the intake and the 292 intake lobe of 242* for the exhaust that would put me in the middle of both cams, correct?

1989GTATransAm

iTrader: (3)

I think Comp lists the 236XFI lobe in their catalog. Also I believe a 242XFI exhaust lobe. If not they have other lobes that will work on the exhaust. They will grind it up for you and it may take an extra day. You just need to call them and check. I would look into a custom cam myself.

Orr89RocZ

iTrader: (20)

I would do that