FlamedROC

Well I finally got a chance to get the IROC strapped to the dyno today with my local car club. I was hoping to see around 300HP/400TQ at the wheels. But unfortantly I fell really short of my expectations. But I like my TQ numbers, which really impressed me.

1 st run-
241.5 HP@4700
341 TQ@ 3100

2nd run-
243.2 @4600
343.5 @3100

I was also on the rich side, around 12.5 so I think that had a part of the low HP numbers

So I guess shes a Torque monster which Im very happy to see cause thats what I built it for. u can see all the specs on the motor by visiting my car domain site

Do these numbers seem a lil low to you? I think they do but oh well. I will be headin to the drag strip tomorrow to get som ET's so I will have all the numbers on this car figured out by the end of the weekend

NEEDforSPEED

good job man!

screaminformula

well, i can see you are a little disappointed with your HP numbers, but to be honest they both look pretty damn good...im gettin ready to put the 350 in my Z28 hopefully tomorrow...pretty much a stocker, but will do ok for now until i am finished with the 383...

Josh

88TPI406GTA

The numbers do look decent...but I would think a bit more should be in order when itn't so rich.

After looking at your combo, do you think that the "ported stock runners" are hurting you?

I would have thought that you would have been closer to 300 rwhp..with your great torque #'s too

What are the specs on your cam?

FlamedROC

I think that the ported runners would actually help me, and to be honest they are not "ported". All I did was radious the area between the plenum runners and smmothed out the lip inside the runners. But I havent made the tubes any bigger then the stock size. I wanna switch over to TPiS's big mouth runners, but I dont see spendin the money when Im goin to be ditchin the LTR system this winter.

As for the cam the specs are as follows--

Intake Exhaust
Advertised duration 280 280
Duration at .050 224 224
Gross lift .495 .495
Lobe separation 112

FlamedROC

Well after a decent turnout for power out of the IROC yesterday at the dyno day I headed to rock falls raceway this morning. I was hoping for a 13.5 but after seeing my dyno numbers I thought that was far fetched so I guess about 13.7 would be more like it. This was my first time EVER at a drag track so I had no idea what to expect, esseically the christmas tree

well my runs are as follows lets just say I was plesently surprised!

Best run was my 3rd run which was 13.512 @ 99.26

total of 6 runs

1st. Run-13.600 @ 99.30
2nd Run- 13.626 @ 99.40
3rd Run- 13.512 @ 99.26
4th Run- 13.57 @ 99.63
5th run- 13.63 @ 99.03
6th run- 13.56 @ 99.55

here are my bests times of each catagory, so this is not one specific run just the best of each catagory.

R/T-.059 (5th run)
60'-1.858 (3rd run)
330-5.514 (3rd run)
1/8- 8.571 (3rd run)
MPH-79.60 (5th run)
1000-11.245 (3rd run)
1/4-13.512 (3rd run)
MPH- 99.63 (4th run)

I think that these are some good numbers for the car. So yea but I loved drag racin such a friggin rush!!! I will be back there later thhis year hopin for 13.4 or lower!!

Jason

PS if u want me to post my time slips just let me know and i'll slap em up for ya...just thought I would save ya the headache of readin alot of numbers

vortec77

Man that sucks, I just put my engine in my car yesterday.Its pretty much the same set up as yours except mine is a 2000 L31 vortec motor with .480 .480 cam and 1.6 aluminum roller rockers adj. fuel pressure regulator, im thinking of getting high flow runners and a 52 mm throttle body. The only difference from ur motor and mine is the cam and i have a full roller motor.

FlamedROC

Yea I think a 52mm tb and better flowin runners would help but I'm goin to bother, I got the ETS i wanted so im satisfied till the TT385 is done

vortec77

what kind of exhaust do u have?

vortec77

You know, im really starting to get annoyed. Ive read about engines that have the same block and heads as i have with less Gross lift on the cam and they make around 330 to 350 hp. I dont see why i shouldnt make that much or even more Can anyone help elaborate on this? I know i dont have the exact same set up as some engines advertised but the only difference i see is that some of those engines have a ram jet set up on some of them and i know that is a much more aggressive induction system than TPI but by how much more hp is that gonna make maybe 30 hp? Im sure if im wrong someone correct me please.

DSM

iTrader: (1)

That does seem a little low for your combo. Your numbers are almost identical to mine:
246 rwhp @ 4300 RPM (242 @ 4600, 239 @ 4700 RPM)
346 ft/lbs @ 3200
Except that my combo is a lot tamer than yours:
standard bore 350 4 bolt main block, 9.5:1 CR
L98 Vette aluminum heads, machined for springs but otherwise stock
207/213 @ .050 hydraulic roller, .476 lift and 1.5 stamped rockers
bone stock TPI base and runners
mildly ported plenum (EGR ridge removed)
48 mm throttle body, stock MAF (screens in place), AC Delco paper air filters, no airfoil
Edelbrock TES headers, test pipe, 2.75" intermediate pipe and a single 2.5 inlet/outlet Dynomax turbo muffler
stock 22 lb injectors, and its 11.8-12.0:1 A/F at WOT
stock ignition

It runs 13.50s @ 103 mph with 2.0 short times and the muffler removed. You are obviously hooking up pretty good to run mid 13s @ 99. With your traction I'd be in the 12s!

12.5:1 A/F is a little rich, but don't expect to see major hp improvements from leaning it out. I think the root of your problem is that your cam/heads/intake are a bit mismatched. Compared to my L98 Vette heads, your heads have more intake flow and less exhaust flow and a better balance of intake to exhaust - out of curiosity, why did you pick a single pattern cam? At any rate, a 224/224 @ .050 is a pretty healthy cam and is probably just starting to really make good power right about the time the TPI system becomes a major restriction. Your peak power should be up closer to 5300-5500 RPM. A Holley Stealth Ram would be much better suited to your combo and probably pick up way more than 30 hp...

DON 88T/A

I agree with DSM that the cam has too much duration on the intake for TPI...usually 212-218 is about right...the runners just won't support much more....even aftermarket ones...you say your ditching the LTR setup so I bet if you switch to a shorter runner setup you pick up bit....heads have any port work done to them?

FlamedROC

Thanks guys for the replies! I agree with you guys on my heads,cam, intake all being mismatched. The heads I think flow better then the intake can give em, but their werent many options for vortec heads. So I choose to go with the SDPC intake which I now relize was a BIG HUGE waste of my MONEY and TIME! I choose the cam because that what TPIS said to use with my motor. I dunno about single stage cams I just called them up and they said go with that one. Also On my dyno graph my car was still pullin power until it hit like 4500 then just fell on its face.

I really want a stealth ram to run with my heads but those wont be out for sale until sometime next year and by then I will have built my other motor to go into the car.

I guess my biggest regret is not portin the heads and buying the SDPC intake!

vortec77

Well since u didnt buy high flow runners or modify the plenum, its no surprise the engine pulled untill 4500 rpm, thats pretty much where the TPI Pulls to and then drops down.

FlamedROC

I was well aware of where the restriction is/was on the TPI when buildin the motor but I thought it would have peaked by then an started to fall before the restrction.

vortec77

Oh i see, I just purchased a set of slp high flow runners last night, they should be here by thursday. , You said u had a flat tappet cam with 1.5 rockers in ur engine right?

FlamedROC

Yea I have a flat tappet cam and lifters. The block is a pre roller block so its rally my only option.

vortec77

That might be another big factor to the low HP and Torque numbers. Not to sound like a D**k, but i have a full roller motor so i should have better luck.

DON 88T/A

Suprised TPIS would recomend a cam that big....
From what I've read /seen most 23* head setups like dual pattern cams....always a bit more on the exhaust....
The situation your in is exactly why I never liked the whole vortec head setup...ala that money for a manifold that can only run one kind of cylinder head...and an average one at that...
But you could get the heads cleaned up a bit..some bowl blending/valve job...a cam that suits your setup a bit better...with good tuning you could have a 12 sec capable car...
vortecs are okay for budget racers,I'm not knocking them...but you'll find the cylinder head is the one place you want to spend the money on a good setup...

RednGold86Z

iTrader: (1)

Just to ease your mind about the richness, 12.5:1 is NOT too rich. I'd consider you lucky because most stock calibrations are way too rich. I'm an EFI engineer, and would consider a WOT run that stays between 12.3:1 and 12.8:1 a near perfect calibration. Since you're probably MAF, it's not really surprising.
Runners AND base manifold will probably get you a lot more power over the stock manifold, assuming you have headers.

FlamedROC

Really! Hmm everyone I talked to says I wanna be in the 13-13.5 area. Yea IM MAF but not for long as I want to switch to SD. also I do have headers hooker 2055's.

as for my heads, the reason I went with em was I got a heck of a deal on em so I went with em. At the time it was better then spendin a good coin to get some good heads.

What head intake combo would u think this cam would like? fast burn/HSR? AFR/Mini-ram? others?

Jason

vortec77

Hey Fbirdta878787, did u do anything to ur Vortec heads in order for them to accept that much lift from ur cam?

nick418

hey great #s Fbird

FlamedROC

other than springs, no i didnt which I really regret. i thought the heads would flow plenty enough stock w/o porting. I think more focus needs to be on the intake system more then the heads. Really these heads should be able to flow enough till I think I heard 350-385 HP before needing port work. I may end up selling my whole system from the heads up, and starting over

Jason

vortec77

Not Good, Ive read that on vortec heads u have to have the valve guides machined for valve guide to seal clearance if ur going over a lift of .450. and the pushrod holes should be elongated, Thats what i did to mine before i had them installed

vortec77

I mean before I installed them myself

FlamedROC

Again I went with what TPiS said to do and they said it was safe to use the springs I used cause they are stock diameter but tolerate the higher lift (up to .575) Plus there are no problems at all. I have kept a close eye on the goins on under my valve covers and all is well with not interferance.

Kennerz

Fbirdta878787

If you think about it, your probably @ 300HP at the crank or more. Your stock runners are probably hurting you alot; and if your car hasn't been tuned for the vortec's you will be off. I can tell you the timming curve is almost inverse on vortecs of what they would be for an iron head L98. I have a similar combo with unported heads and intake( I wish I would have done the home port on these too) But I have azs&m runners, and a 52mm tb , I know this helps with the breathing. Once I had my car tuned the low end came on so much stronger, along with a much stonger top. I was running the ARAP bin, the car seemed to run well, until I had it tuned, and it was a entirely different motor; again the vortec fuel requirements, and spark tables are VERY different, seriously you could be giving up 25-40 hp in your runners and tune, I'm sure fully ported and tuned these vortec engines will put out close to 300RWP on a modified TPI, just needs to be maximized, and All of your related compoenents need to be in good order(injecters, ignition, no air leaks(SDPC has alot of opportunity for leaks)) The SDPC vortec's can be a great street motor, just needs to be sorted out (A little bit of work) I can hang with most things on the street ( including M3's, turbo'ed imports, mustangs you name it) these things will never have the top end of an LS1, won't happen with this combo. but they can produce enough overall power and torque to beat stock LS1's. I'm not saying the hotcam is the best, but that's a little large of cam with stock runners. Get runners, fully port your intake, and get it tuned and I'll bet you'll find that missing power. 280rwp+, over 300 rwp think super ram on SDPC intake.

Good Luck

Kennerz

Fbird

looks like using a 20% driveline loss calc puts you @ 290 FWHP
and 410 FWTQ, so yeah your HP is alittle off you shoud be fish'in for about 40 more hp. Again could very well be hidden in your combo. What I'm saying is you did almost hit your 300hp/400tq goal with flywheel #'s. Rear wheel HP is a different game. If you want a real 12 sec combo wait for the vortec HSR, you will still have to tune alot though. To fully change your current combo will $$$ and if your looking for 400FWHP aboout 320RWHP or so it will cost and maybe not be as streetable.IMHO

Matt87GTA

He is running a very slightly tweaked ARAP.

I think you are selling that SDPC intake a little short. I certainly am no fan of LTR setups unless you are planning on towing, but I think your setup could make quite a bit more useable power if you did a few things to it. First would be the PROM tuning. I would call what you are running for AFR a bit rich but who knows what the car really wants until you start moving it around and seeing what happens. So tuning should release a bit more power....

Then, as others have pointed out, there is the TB and runners.... The intake base is good to go for more air but those stock runners are killing you.... A set of larger runners along with a 52mm TB and some more porting on the plenum should unleash a few more ponies and allow that base to do what it is designed to.

The cam is large-ish but I think with the better flowing parts on the intake side to compliment the headers and fairly good flowing heads it should work well. I certainly do not see the cam as a huge mismatch for a fully upgraded TPI system with good heads. That cam is very similar to the LT4 Hot Cam except a lower intensity since it is a flat tappet and not a roller.....

THe Vortec heads have a pretty balanced flow intake to exhaust and I think it is just fine to run a single pattern with them. There are lots of 23* heads on the market that flow enough on the exhaust to run well with a single pattern cam.... Like my Brodix ones for example.....

I think that you could get very low 13s or even a high 12 out of it with a few more tweaks to the PROM and finishing off the intake system. But if you are going to just scrap it in the end for a different combo, it is probably better for you to just let it be and have fun driving it the way it sits.

FlamedROC

Matt- really my plan was to go Twin Turbo HSR 383 but seens how no word yet on the HSR for vortecs comin out soon I'm goin to keep and use my current TPI set-up. (I just decided this today) I think at the next club meeting if ur there I would like to talk to ya about tweakin the prom a lil more to see if anything can be squeezed out of the motor.

In the mean time im goin to try and find myself a set of SLP runners and 52 mm TB. I would really like to get the TPiS big mouth runners to keep my TQ sky high but im not payin close to 500 bux for runners.

In ur opinion should I do runners first then TB or vise versa? I want my new year end goal to see very low 13's by the end of the year.

Matt--i'll PM ya over at MNFBC...

Jason

Matt87GTA

We can definately tweak the PROM a little.... If you can show me your dyno graph I can adjust your WOT fueling to lean it out a little. I can always just blanket the whole table and drop it down but if I can see the graph and see what it really wants that would be best. Do you know if you were seeing any knock on your dyno runs? I forget if you have sanning equipment or not.... We can always put my laptop on it and go for a drive and check for knock too.... What I am getting at is that there may be some timing adjustments we can make as well.....

I think the runners would help free up more power than the TB.... Do you have an AirFoil in your stock TB right now?

I also have a 52mm TB I have up for sale though ......

I'll await your PM .

Nice work BTW, it performs pretty damn well all things considered! And if you could get a 12 out of it with a true LTR TPI on it you would be in a very small group of people from what I can tell. And with stock (upgraded springs only) Vortec heads too......

Kennerz

When you tune your prom, A have alittle tuning info. Vortecs really like alot less timming on top 35* or even less. When I ran the ARAP all the timming actually killed power, so lean it out + alot less timming. also they like more timming early on. experiment with this and you will get a vortec motor that runs the way you expect it to. There is so much hidden low end torque, when I ran the ARAP the mid range was great, but it was really off everywhere else, compared to where it should be. Your top will improve alot once you kill all that timming. the ArAP in my car would pull like 50* + deg of advance on top this will work on an iron L98, but not on an fast burn style chamber. You will want to keep the car once it runs right, spend the time and $ to get it right and it will be what you expect.

RednGold86Z

iTrader: (1)

ARAP is for aluminum headed corvette L98s, which can handle the timing at light loads from extra heat transfer out of the head slowing the burn (that's how I figure it anyway, or else it's just a combustion chamber design thing). Many people who start tuning with ARAP on iron head L98s have found the light load timing way too high. But yeah, Vortecs (so I've read) like around 31-32 degrees total timing at WOT.

FlamedROC

We'll keep that in mind when we tune the car!! keep the info comin. As of right now I'm looking at SLP runners and 52mm TB for now...

Kennerz

Remember, and they like *ALOT* early on in the 2-3K range,(give it way more than you think you would ever need, until it pings, then back off 3-5*) then have it ramp down really quickly to your total timming #; at idle leave it at the typical 15-20*total including the base timming.(6*base+9*ecm=15*total) this will restore the low end you're wanting back. Vortec's don't use the normal tuning conventions. My car's not a tire burner, but I can kill a reved up wrx on the launch, with stock Iroc suspension. WRX's are know for thier strong pull out of the hole.

chevymad

For the guys wondering about the hp potential of vortec heads, here's a link to a guy runnin unported(but heavily milled) vortecs in an 84 camaro.

Quick 3dgen

And even better, this is its first time to the track!

vortec77

Cool too bad its not a TPI making those #'s

DON 88T/A

A cam with 270 duration at .050...launching at 5200..12.1 compression..not very streatable...you could spin a set of LB9 heads to 10,000 rpm they would make power too...
Plus a stock crank at 7400 rpms...yikes