Lou, that's an interesting intake mod. Although what you did is much more involved, it reminds me of the old days where we would modify the divided plenum on V8 intakes to enhance top-end power.
It was an experiment. I threw caution to the wind and would never do this on the street but the benefits outweighed the drawbacks in this case. Giving up 10 ft*lbs for a larger area under the curve gain from 4600-6000 rpm seems like a big win here.
It was an experiment. I threw caution to the wind and would never do this on the street but the benefits outweighed the drawbacks in this case. Giving up 10 ft*lbs for a larger area under the curve gain from 4600-6000 rpm seems like a big win here.
Impressive results for what you have there. You gained more than 22 HP as a stock 2.8L on a dyno only puts out about 120 RWHP due to drivetrain losses.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
My motor is actually making >200hp but my larger diameter and much heavier wheels+tires and clutch spacer (1" thick aluminun disc) drivetrain are making it *look* much lower. I don't put on "dyno wheels" to tune. The 3.4 can make >200 rwhp in a Fiero pretty easily if you don't just do a low-ball "basic swap" that will only get you 135rwhp...
When I was using wheels near stock weight, this motor put down 187 rwhp and 249 ft*lbs on a Mustang dyno. That was using 99 Camaro 16" alloy wheels and 255 series tires that weighed 45lbs each. My current combo weighs 52 lbs each and most of that weight-gain is a the perimeter since they are 1" larger in diameter than stock and much wider (315/35/17). If you know anything about torque is that it's based on a radius arm and where the force is coming from. Since the force is coming from the axial point - If you shorten the arm, torque goes up...lengthen the arm and it does down. When you force it from the radius, then it's easier to apply force to a wrench, for instance, to loosen a bolt. I think we are talking about 1/2" but that's about 5% off the top already. So just taking that into account, I'm almost at 181rwhp. Perhaps if I decide to skip next year's racing season, I'll go back to street tires and work on fixing the body and maybe hit a dyno then... That's a big if. I love racing.
[This message has been edited by lou_dias (edited 07-06-2019).]
Disappointing results as I lost part of my exhaust in round 2 which pinched a brake line. Caused me to lose my balance in round 4 when I was coming into turn 4 hot and tapped my brakes... Looked like I would have been able to out accelerate John Feilding's Camaro coming out of turn 4 until then...
You can see my exhaust fly out at around the 12:21 mark...
[This message has been edited by lou_dias (edited 07-08-2019).]
Very nice results, Lou. Great to see some dyno evidence instead of the more common "I swear it had 100 bhp more...' we see so often. What is the intake you started with - 3.1 F body?
Very nice results, Lou. Great to see some dyno evidence instead of the more common "I swear it had 100 bhp more...' we see so often. What is the intake you started with - 3.1 F body?
It's a ported Firebird 2.8 upper intake. I had the neck bored to 59mm and all the ports were gasket matched on 3 sides and the inner wall was bored about ~3/16" on the 6 ports to increase flow to the middle manifold. The middle manifold's upper inner wall on the ports were similarly opened up as well. Again I feel I went a bit overboard with how much material was removed at the base of the middle manifold... Perhaps some angled cross-drilled holes would have achieved close to the same results without giving up so much mid-range...
BUT it does show that the main problem with making power > 4500 rpm is the middle and upper manifolds...
BUT it does show that the main problem with making power > 4500 rpm is the middle and upper manifolds...
Very useful information.
I used a late Camaro intake on the 3.4 I use and did a bunch of port work and manifold modification including boring and fitting a 62 mm throttle body.Worked very well. The engine runs cleanly through 6,000 plus with no falling off (Crane 272 cam).
It is sad that the GM engineers couldn't be bothered to eliminate bottlenecks that cost horsepower but could have been improved for a small amount of money. Relieving the stock Fiero exhaust manifolds is the worst example.
The more modern example is the Solstice. They had a tune that they made an option. It was approved for warranty, yet they didn't offer it as anything but an add on option. It added 30 bhp and 50 Tq and actually resulted in slightly better fuel consumption. If they had standardized it before submitting the cars to the magazines for the road tests, the car would have been better than the other candidates in terms of performance which would have sold a lot of cars. Wonder which bean counter botched that one....
[This message has been edited by BillS (edited 07-17-2019).]
Nice Im not suprised you gained HP, Its in line with my flow measurements of these intakes. It is intresting that no major loss of TQ in the mid RPM range occurs, you kind of moved the plenum down all the way to the LIM..
Originally posted by BillS: Very useful information.
It's about building the type of engine you want without breaking the bank. It amazes me how a little grinding here and there can make such changes to a motor. Ideally if somehow intake ports could expand and contract in a controlled manner, you could make an engine very efficient for it's entire RPM range.
My next engine will have much higher compression since E85 can handle it quite nicely. ;-)
So I just did this mod on my daily 3.4 Formula this week as well. Using stock 3100 roller cam and Sprint F1 Headers...and Camaro stock 9.0:1 3.4L pistons. (Yes I bored a 3100 to 3.4L...)
This time I grinded out less material. No dyno yet, however it feels like I didn't lose any torque but now the engine revs faster (as in more HP). Idle has gone up. This is on 87 octane fuel. I am probably running lean until the computer adjusts however the power gain is quite noticable.
Does anyone have an 88 V6 5 speed BIN file with the EGR disabled programming in place? I'd like to tune it using that as a base.
[This message has been edited by lou_dias (edited 02-18-2020).]
So I did this mod to my 3.4 last year and there was a noticeable difference in the upper rpm. Yes have now installed a vortech supercharger V1 S trim with a 2.8 pulley. My boost is only around 5-6 at 4500 rpm. I can’t push it as it needs another tune being lean and all. with the factory crank pulley and the small sc pulley I should be higher in the boost then showing on the gage right now. Im no engineer but im wondering if the boost is registering lower than it should due to the runners in the middle intake being eliminated?
So I did this mod to my 3.4 last year and there was a noticeable difference in the upper rpm. Yes have now installed a vortech supercharger V1 S trim with a 2.8 pulley. My boost is only around 5-6 at 4500 rpm. I can’t push it as it needs another tune being lean and all. with the factory crank pulley and the small sc pulley I should be higher in the boost then showing on the gage right now. Im no engineer but im wondering if the boost is registering lower than it should due to the runners in the middle intake being eliminated?
I was thinking Thst because the runners were eliminated between the middle intake and lower intake that pressure cannot be built up due to the disbursement of the air between lower and middle intakes.
the lower boost pressure means(in this case) each cylinder is getting more air in, this is typically a good thing. I would leave it.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
Im not suprised you gained HP, Its in line with my flow measurements of these intakes. 
