TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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I'm toying with the ideas of a 383 for my iroc.
i wanna know what you have?
383's only
what intake, heads, cam, compression and bottom
NA,N20, FI
what kinda power are you making
I'm thinking about a 383 w/
AFR 195's
cc305 or cc306
HSR or superram
I'm looking for around low-mid 300's at the wheels
something that has a nice power curve and is somewhat steetable
__________________ 89 iroc 305tpi
best et 14.676@92.02 w/a 2.008 60'
best mph was 92.21 and best 60' was 1.989
Originally posted by wyclefsirocz I'm toying with the ideas of a 383
I'm looking for around low-mid 300's at the wheels
something that has a nice power curve and is somewhat steetable
You can do that with a 350....
hsr
195 afr
lingenfelter219 or zz9 cam
9.5 comp
See - the 383 you have in mind would probably make more than that! You would have to use more restrictive stuff and/or lower compression (7.5 - 8.5). So, you would have big displacement but it would be held back. Less gas mileage than a 350 making the same power too! I could say more, but I think this is sufficent information. Constructive of course, just pointing out better interest maybe. So, the question now is, 350 combo or MORE power ?
For a good balance of power and driveability. My recommendation is to use AFR 190 heads with the LPE 74219 cam and either a HSR or a MiniRam. The car will have excellent driveability and will be able to hit the HP numbers you are looking for.
The CC305 and 306 will work better in an application where the cylinder heads do not flow as well on the exhaust side. The AFR's tend to have an intake/exhaust ratio in the 75-80% range.
Some may disagree with my choice here but I have assembled this combination of parts and the car ran 11.60's.
Here's my 383 combo:
Actual displacement is 385
.040" overbore
Cola 4340 crank
Eagle 4340 rods
SRP dished pistons
9.3:1 CR
AFR 190s fully ported/polished
Comp Cams valvetrain
Comp Cams bumpstick(blower cam to go with blower motor!)
Hooker long tubes
HSR, ported
No blower yet
Stock rear end for now
TH-350
Go for the 276HR from comp. I think it specs out to 230/236 @.050". Many are very happy with it. I have a similar cam but it is ground different due to the fact that one day I should have a blower on this engine. Right now the car runs very well...
I would say you can always go bigger if you are still looking for more, but as a starting cam I think you will be very happy. I will probably go bigger one day, but only time will tell...
BTW, is your car going to be daily driven or more fun than function?
Go with the one where the description uses fuel injection talk. I think there is mention on TPI in it. Its been awhile though since I skimmed there catalog...
Just got the new Walbro 255lph fuel pump in (factory unit could not keep up with demand) and had to replace the distributor. Now I will be able to start tuning.
As far as power, Harold (cam designer) said that this combo should be 460 'real' horsepower. We have our annual dyno gathering at the end of January so I will be able to get empirical data at that point.
I will hook the n2o up after we get the tune right n/a.
Yeah I have been driving her for a while just haven't been able to tune it yet due to all the normal little gremlins that occur. We did some data logging last night and I am sending it to Jesse (ski_dwn_it) who is helping me with the tune. I am still using the chip that we took a stab at to get her running. Needs WAY more fuel up top Harolds cams usually like that.
It runs great. To be honest after researching everything I was concerned that I was going a bit too big on the cam. I went with the 114 lsa for several reasons but one is that the computers seem to like it better. The car is extremely driveable. As a matter of fact, this car is still my daily driver. Idles real good. Drives around town like it was supposed to be this way. But get on it and she really comes alive.
I will reserve my comments about my complete lack of torque with the miniram until after the dyno
One thing that I've found when tuning a MiniRam'd motor is that it likes advanced ignition timing and all in by 3000 rpm. My best ET was with 38 degrees total timing on a 11.5-1 motor.
389 CID
2 bolt main.
Main Studs, Head Studs.
Eagle crank,
6 inch eagle rods
KB pistons 10.3 : 1 Comp.
Ported Vortecs with 1.6 exhaust valves
Comp Cams XR276HR
Crane Golds 1.5 RR's
SDPC Vortec base
Ported SLP semi-siamesed runners
Ported plenum
52 mm TB
Coated Hedman Headers
__________________ 1989 Pontiac GTA Nighthawk, 389 CID TPI, 448 HP 485 TQ. Vigilante 2800 stall Converter and TCI Steetfighter Trans. Spohn Suspension. 4th Gen. wing and hood, 92 GTA GFX front wheel back.
1/4 mile 11.742@117.8 on Drag Radials 12.22@118.0 on street tires, top speed over 180 mph.
did some DD2003 and found the crane cam i'll be using makes more power after 4000 rpm over the hr276-14 some of you are suggesting. the graphs are here:
If directed at me, here it is. I like torque and hp, and according to DD, this cam gave a better balance of both. I threw about 30 cam profiles at it, and some gave more hp, but less tq, others had radical curves, and that's not what I'm after. This cam gave me a smooth curve, with a nice balance. That's why that cam.
Originally posted by wyclefsirocz i don't know how to post my dd results.
Here's how I did it (not a computer genius here)
open the DD and your profile.
hold the shift key and hit the print screen key
open Power Point
hold the control key and hit the letter V
once your pic is in there, you have to crop it and make it fit the entire slide. ( I cropped 4" from the left, and 1" both top and bottom.
Save as a jpg,, and you're in there..
Hope it helps!! There is probably an easier way, but I digress.
ok the motor as o now wll be a 383 forged pistons, LPe219 cam AFR 195 heads and HSR kit. this is the intake kit i will most likly be getting for two rearson. i wanan stay FI and my father will be getting my old motor and trans.
i will be ordering a level III 700r4 and 2400 stall converter from 700r4.com
and this from summit. what do u guys think? HSR kit
My motor is in my sig. It's a 12:1 comp. engine with a 4340 ESP crank, Forged Eagle H-beams, Wiseco pistons, AFR rev kit, AFR 210's that flow 300cfm, 58mm tb, and everything else you can upgrade in one of these motors. The car just put 375rwhp and 375rwtq, without adjusting the timing. My AFRatio started up at 11.8 at 3500 and ended up going to about 12.7 at 6500, which is good. I didn't have time to play with the timing, so I might get another 15hp or so. I think these #'s are good but I was hoping for 400+rwhp with this combo. Auto trannies are known to cost you 25-27% of your fwhp though, so that would put me at 500-525fwhp. By the way my buddy who owns the dyno races ASA stock cars with stock Ls1 blocks and stock heads. It crazy though, cause with a bigger cam, manual trans, and a killer exhaust, those engines put out 400rwhp. His happens to put out 430rwhp after he's tuned it on the dyno a zillion times. It's a dynojet by the way.
__________________ 2002 SOM ws6 M6, the 91 never was ressurected after the fire...
Old cars:
91 Z w/383 , all forged bottom end, miniram, TPIS ZZ-X cam, Ported AFR 210's, Pro-built trans, Vig 3200 stall, Hooker LT's, drag susp., 17x9 ROH Snypers, and quite a bit more. 375 rwhp 375 rwtq.
89 Iroc, SuperRam, 219 cam, AFR 190's, sold to the old man, now has 406, runs 11's.
CrazyHawaiian originally I was just going to rebuild my 350 then found out that the parts cost about the same for a 350 vs. 383 and the only real price difference was $200 to clearence the block.
I like it. No complaints. I only have about 40 miles on the new motor so no WOT runs, but it idles kinda smooth thump thump thump thump. Drivabilty is great. pulls 17in vacume at a 850 idle, but I plan on lowering the idle. I did get ansy once and chirped the tires but that was all lol.
I am doing a "budget" 383. I am going to be running the following
89 350 truck block 4-bolt mains (.030)
Scat 9000 3.75 Crank
Powder Metal 5.7" rods
Speed Pro 10.3:1 coated pistons
228/234 .480/.494 lift 110LSA
Ported 083 heads (budget part)
Melling HV pump w/ pickup welded on
Moroso oil pan with all the goodies
Ported TPI (other budget part)
I have no idea what power I am going to be putting out but it is going to be nice to get the 305 out and put a 383 in. If I have over 280rwhp I will be jumping for joy although coming from a little over 200 anything is going to be nice.
Mkos1980 - When I originally built my 383, I had pretty much the same combo as yours. The car ran 12.0's all day long with mid 1.6 60ft times. That was a great combo on the street.
I think I've read so many posts here on the 383 combo that I'm convinced there may be no correct answer, only opinions as to what combo works best.
I am already commited to going with a totally forged bottom end assembly, I want to spin to 6500 and have a history of beating small block on daily basis (they're cute when they scream).
BUT!
1) Can anyone explain in simple terms the pros and cons of a 5.7" rod vs a 6.0" rod ?
2) Can a 1988 350 roller block accept the H-Beam rods with the 3.75" stroke ?