I'll be posting chassis dyno printouts of the Miniram-injected 409 small block I just built for my brother's 87 GTA.

Long story short: It makes peak torque at only 2700 RPM- the lowest recorded RPM on the dyno. And it's no weakling. How about 481 Ft/lbs @ 2700! 470 Ft/lbs at 5000, 430 Ft/lbs at 5500 and 401 @ 6000!!

I told my brother the engine would be a "billiard table of torque from idle to 6000" and it basically is. Not quite but pretty close. Traction in first gear with the 3.23s in the back is nonexistant. Sit-n-spin.

Nobody thought the combo would work well (not enough cam was the usual comment) but I had a few tricks up my sleeve for this one. I used a short rod 400 bottom end punched 40-over with "crappy" TFS Twisted Wedge G2 off-the-shelf heads (the same ones GMHTP couldn't seem to make any power with on their pathetic low buck project Firebird Formula) and a cam so small I'm embarassed to mention it: 210* @ .050, single pattern cam on a 110 lobe sep. Compression is right at 10:1 and for the test the stock restrictive air inlet system was in place (yes, we're replacing it as fast as you can say "SLP Cold Air Kit!!"). Exhaust is 1 3/4" shorty headers and an SLP 3" ehxaust from the y-pipe back.

Why it works: The short rods and long stroke help generate a wicked strong intake pulse when the intake valve opens which helps make the miniram "work" at a lower RPM than it was really designed for. Plus the cam is of short enough duration that it props up the low RPMs pretty well, too. The tight lobe separation is a proven way to make power through the midrange which is what I was shooting for with this motor, primarily. Up in the high RPMs where the cam starts to "fall off" the short MiniRam runners help keep the party going about 500 RPMs beyond what the cam is really designed for. Not too different in concept than a late model LT-1: short runner intake with short cam = flat torque curve over a large RPM range. No single part made it possible- it's the total COMBINATION of parts that's important.

Beware a tired looking 3rd gen GTA in the Norfolk, VA area! It's claimed about 1/2 dozen victims in only the last 2 weeks. I know becuase my brother calls me ever damned day with his "race log!"

[This message has been edited by Damon (edited August 30, 2001).]

[This message has been edited by Damon (edited August 30, 2001).]

 

That sounds like a pretty wicked torque curve, do you have any dyno sheets scanned?

 

My brother is scanning and emailing to me. I'll drop them on my webpage and post the link here soon.

 

For all the rest of you, THAT's what happens when you do your homework first, and plan for a SYSTEM instead of individual components. I think I recall having mentioned that once or twice before...

Cool, Damon! All on the "lowly" TW heads. And people wonder how any power can be made with stock heads. You gotta have a plan.

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Later,
Vader
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"Get UP - Drop the bombshell!"
Adobe Acrobat Reader

[This message has been edited by Vader (edited August 30, 2001).]

 

Well it is impressive, but not real useable in my opinion. Nomatter what you do, (unless u tub it) you will have traction problems with that much lowend.

In my opinion, that is one of the benefits of moving the powerband up. Not only can you get the car rolling before the torque peak hits, but wheelspin is easier to control.

I also have a theory that putting a lower rearend gear can reduce wheel spin under the right conditions. Look at whats happening now. You have about a 3.07 first gear and a 3.23 rear end. As soon as you push the pedal down, the motor goes straight to 5000+ rpm. Thats probably a tire speed of almost 40 mph. Well, since the car can't just jump to 40mph from a stop, the tire can't help but light up. But, if the powerband peaked slightly higher and the rearend gear was lower, the motor could be driven out of the hole and then hammered with less wheelspin.

My 4.10 rearend gear with a 2.95 first in a T5 was only about 35mph at 6200 rpm and at any speed more than about 10mph, the tires did not turn when you hammered it (with a 400 that had about 500hp).

[This message has been edited by jcb999 (edited August 30, 2001).]

 

Hmm... TFS TW heads... 383... sounds familiar. It must be a Hell thing.

Damon, post that bad Larry's chart once ya get it, it should open some eyes. Congrats!


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"Question with boldness even the existence of a *** ; because, if there be one, he must more approve of the homage of reason, than that of blind-folded fear."

-Thomas Jefferson

 

Having a lack of traction is a problem I'll take every day of the week! Sticky tires and some better LCAs (maybe some relocation brackets) on the back end should improve the situation dramatically. And with that much torque on tap there's no chance of ever "bogging" the motor off the line. You should feel a 1/2-throttle highway pass in this car. Very little noise or fuss, no downshift- just watch the digital speedo jump up in 3-5 MPH chunks right up into triple digits. It's a totally different animal than a high RPM-oriented motor.

 

Wow! That's incredible, congrats Damon. Hey, quick question: What's the lift on that "cam" and are you running the stock ratio on the rockers (basically more details on the setup). I was hoping to use the Mini Ram in my setup in the future, until I found out it has no EGR provisions , I gotta pass smog you know. I think that is an excellent (FI) manifold design. Any plans on getting track times?

------------------
George P. Lara
1984 Z28
2001 SS #0391
SCCA, SCFB, SC3GFB

 

It's all about the combination of parts--looks like you got it right.


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350 with stealth intake, holley carb, 470 lift cam. 700r4 with .5 boost valve, vette servo, tci lock-up kit, B&M megashifter. Richmond 3.73 gears, powertrax locker, timkin bearings, synthetic lube. Custom 3 inch single into 2 2.5 pipes. 1 1/2 drop springs, 1 5/16 solid front sway bar, 1 inch rear bar, custom subframe connectors, custom LCA relocation brackets. Kobel ground FX, currant red metallic paint. Lots of other stuff...
82camaro

 

Now thats what I call an engine!! Some people just dont seem to understand the benefits that low end torque can provide. That engine seems to have torque EVERYWHERE! Let us know what he is running when he gets to the track!! And for the carb guys...lets see ya get those numbers with a qjet.
peace

 

What did you have to do to get the twisted wedge heads to work with the pistons? Are you using regular pistons or the special pistons?

Of course you've got a ton of torque, you've got a 400 cubic inch engine. Try that with a 350.

------------------
1991 Camaro Z28
5.7L 5-Speed (originally 305)
317 RWHP, 418 RWTQ
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Member: SoCal F-Bodies
-=ICON Motorsports=-

 

What kinda hp numbers is it hitting?

And is this rear wheel numbers we're talking about or what?

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited August 31, 2001).]

 

well its probably 250 HP and 400+ TQ big deal from a 4 cyl cam profile and a 409 engine.

 

Man, that really makes me wish I could use a miniram .

 

eeeasy there killa. damon, for entertainment purposes, what kind of mileage do you get from that size FI engine? It sounds like an awesome motor, and I am all about engines that have hp lower in the rpm range.. when i drove my friends 93 RX-7 (two sequential turbo's) it was really fast.. but i mean dam, you had to get it above 4k to make any power, other wise it felt no faster than my 89 honda accord, no lie. have fun chewing up some new SS's

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83 Z28--not a pretty site, sold thank goodness

74 Z28-- 383/400, green on black. pretty clean. FOR SALE!!!

 

Somebody had to bring a carb into the discussion. With good carb and good intake and the rest of the parts the same you would get about the same power.


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350 with stealth intake, holley carb, 470 lift cam. 700r4 with .5 boost valve, vette servo, tci lock-up kit, B&M megashifter. Richmond 3.73 gears, powertrax locker, timkin bearings, synthetic lube. Custom 3 inch single into 2 2.5 pipes. 1 1/2 drop springs, 1 5/16 solid front sway bar, 1 inch rear bar, custom subframe connectors, custom LCA relocation brackets. Kobel ground FX, currant red metallic paint. Lots of other stuff...
82camaro

 

Lesee here........

Cam- lift is .440 and we're using Crane Gold 1.5 rockers (we had them laying around). Yes, 1.6s would help, but we didn't have them available at the time. The cam is a Crane Energizer 266 cam- you can look up all the specs on their website if you want. It's a carb cam with a sharp profile and tight lobe sep. It's installed "straight up" but the cam has 1* of advance ground into it from the factory, probably to account for timing chain stretch more than anything. Pistons are a set of Federal Mogul Hypereutectics with about 12cc worth of dish (d-dish) to them for a C/R of right about 10:1 with the 67cc TFS heads. The cam is so mild we're no where near hitting the valves into the pistons- no modifications required. The block was decked to bring the pistons up to about .015" in the hole versus their stock .025" dimension. I didn't WANT to deck the block but it was warped .006"!! Head gaskets are standard rebuilder Fel Pros for a 400 SBC with a .039" compressed thickness and requisite steam holes.

Horsepower? Well, if you throw the torque numbers into the old (Tq * RPM) / 5250 calculation you'll see we're nudging up against 450, ALLEGEDLY. I think the dyno is reading a little higher than reality, however (how often do you hear someone say THAT?!?!). Even if we were talking readings at the flywheel it seems a bit high.

Here's a comparison that DOES make sense to me: the dyno operator said the motor was putting out about 50 more HP TO THE ROLLERS on that SAME DYNO than a stock LS-1. So we've got a pretty well known quantity there to compare against. So if an LS-1 is rated at 345 flywheel, add 50 on that and you're right around 400HP, give or take. Seems reasonable to me. 450 seems a bit too high to be believed although I'd love to claim the bragging rights. Whatever, I don't race on a dyno.

ET? I figure mid-high 12s at around 110 or so, best guess, with just a smidge of traction. That's on street tires with stock converter and 3.23 gears. SLicks, gears, high stall converter I'm sure it could jsut squeak into the 11s, but it would ruin the whole character of the car.

MINIRAM vs. QJET. Interesting point. Funny you should mention it! This is the EXACT same motor I had in my 79 Malibu last year that had (TA DA!!) a Qjet carb on it! Same cam, equivalent heads, very similar bottom end components. That version of the motor ran 12.99/13.01 @ 108 for me in a 3600lb Malibu with stock converter, 3-speed auto trans, 2.92 gears and street radials on the back. The only changes to this version of the motor, other than the MiniRam, is the compression is a smidge lower, the engine is now bored .040 over versus .030 before and it has slightly better heads on it now than I had on it (TFS vs. my Iron Eagles). But the GTA has much steeper effective gearing, less weight (3500 vs. 3600- verified on a scale), and MUCH better aerodynamics.

Yes, the engine makes maybe a smidge more power than the Qjet setup did, but not much. If any. Track times will tell the real story there. We'll see. Certinaly, it isn't $1500 faster (cost of the Miniram + injectors)! They're jsut 2 different ways of mixing air with fuel. Tune either one well and it's gonna make good power.

Mileage- it knocked down 22-23 MPG in OD during the drive from my house (Philly) to his (Norfolk) a few weeks back. I used to get about 18 on the highway with it in my Malibu with QJet but NO OVERDRIVE. Over Drive accounts for about 1/2 of the mileage improvement over the carb setup (500 RPM less on the highway) but the rest is probably due to the benefits of EFI and a computer-generated ignition timing curve.


[This message has been edited by Damon (edited August 31, 2001).]

[This message has been edited by Damon (edited August 31, 2001).]

 

Thats ****ing incredible. To all the naysayers, don't forget HP = TQ * RPM / 5250. He was just sorting out the posers by not doing the math for you. He's making 450 HP from 5k to 5500, and 401lbft @ 6k = 458 hp.

Hey Damon, think he's interested in swapping to a 2.73 to displace some of that torque?

 

450 RWHP with that setup??? I had forgotten the formula but with torque readings like that at those rpms I thought it was going to be high. I just can't believe that setup is good for that much at the rear wheels.

The operator said it was putting down 50 more hp than stock LS1s on that dyno? They run right at 300 rwhp normally so you'd be looking at 350ish rwhp, 100 hp shy of what it read. Whats the disparity here? I guess this dyno was calibrated alot differently than your average Dynojet? 350ish rwhp, 400ish crank seems about right for a 400 with that mild of a cam to me...

Damnit, you might as well of not posted these numbers since we can't even bench-dyno-race with them, lol.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray


[This message has been edited by Ray87Z (edited August 31, 2001).]

 

Damon...Whats size injectors did you use? Who burned the prom for it? Sounds like alot of fun,I just bolted my 406 in the car today! I still have alot to do though. I hope it turns out as well as your brothers.

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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

 

I agree, 450HP sounds way too high to me. I think the dyno is out to lunch in terms of the raw numbers (and I have no idea if those are rear wheel torque numbers or if the dyno is extrapolating back to the flywheel by taking drivetrain losses into account). My brother doesn't have a scanner so it's going to take him until Tuesday at least to get the printouts to me. I'm as anxious to read them as you all are.

Like I said, stock LS-1s ON THE SAME DYNO were about 50HP down from what this motor laid to the rollers, so I figure an honest 400HP at the flywheel is probably a lot closer to reality. Also, TPIS (who made the Miniram intake) estimated we'd be right around 400HP, and they were right about EVERYTHING related to their intake and chip tuning at every step of this project. TPIS gets the big "attaboy!" pat on the back for their invaluable help and advice.

I think I posted all the info about the motor already in my previous 2 posts but the injectors are 30# SVO units. Little more than we need but, hey, they're dirt cheap!

 

I love torque monsters!!!! They are sooo much more fun in a street/strip car. Good job on engine planning!!!!!!!!!

I am working on a 350 right now for my car and I'm shooting for torque. I plan on using the stock 2.73 gears, or maybe jumping to 3.08s (for gas milage). My cam is only a 214/224 @ .050" with .443/.465 lift. I have it advanced to 104 IC for more low end grunt. I am expecting at least 380lb.ft. from 2500 to 4500 RPMs with the peak of 400lb.ft. at around 3500. HP will peak at 320-330 @ 5000 RPM.

I plan on using the Vortec heads because as we all know, they were designed for a truck engine. More low end grunt!!! BFG Drag Radial will be needed I'm sure!!!! Plus a 2000 RPM TC should work great.

Everyone keeps telling me (my "bottom of the page" friends) that I should get a higher lift cam. But that's not what I want. I don't think they'll be disappointed after I get it done. This was all recommended to me by a local engine builder who builds drag cars and engines for dirt track stock cars. He knows what he's doing. Plus it's nice to see that someone else is happy with the torque motors.

Again good job.
AJ

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92 RS w/t-tops 305 TBI Auto.
170K miles and don't burn a drop o'oil
-K&N Truck filter #1500 w, open ele.
air cleaner
-Dynomax 2 1/2" cat-back
-B&M TransPak
-Jet Stage2 Chip
-180* T-Stat w/ 185* Fan Switch
-JVC CD--Alpine speakers & 4ch. amp
Rockford Punch 100. 1 - MTX 12" sub

 

I've got the exact same cam in my IROC. I installed it straight up because dispite my best efforts, every single engine builder in my area looked at me like i had 3 heads when I mentioned degreeing the camshaft. Long story short, I had no idea how to do it and no available resources for help. Anyway, back to my original story. Dispite the many, many tuning and drivetrain issues that I've got with my car, it can still chug up very steep hills at 30mph in Drive. My car has some pretty sick amounts of low end torque. Once I get it running properly, I expect greatness.

------------------

The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
Custom Thirdgen Subwoofer Enclosures
"I didn't know a bored out Ford could go so slow" -Shenandoah

 

[This message has been edited by Damon (edited September 10, 2001).]

 

Okie Dokie. A little explanation here. Forgive the lousy scanning job, please. And posting it correctly was a chore for a non-internet guy like me. THis was one of 3 runs and not even the strongest one, but it was the run with no "hiccups" throwing the curves off and scewing the results badly.

Here's the scoop: I have NO IDEA what a "Mustang Dynamometer" is.

The torque numbers I DO BELIEVE (top line), but the HP numbers I DON'T believe (bottome line), since HP MUST EQUAL torque x RPM / 5250 and it's not even close here. Since there is no relation of ENGINE RPM to torque I can't imagine how they calculate HP. Anyone familiar with this type of dyno I would like to hear how these things are set up.

AGAIN: The HP graph is "out to lunch" and everyone including the dyno operator agreed it was not to be trusted. Torque graph seemed to be reading accurately, however.

IMPORTANT INFO FOR THOSE NEW TO THE HIGH PERFORMANCE GAME: THis is why you don't compare HP readings from one dyno to a different dyno. You don't know how any given dyno was calibrated!!

All runs were done in 3rd gear (1:1) at WOT. Since they only indicate MPH, and not RPM I hand wrote in the approximate RPM readings at each MPH in blue pen. Now run the torque numbers back through the old HP = TQ*RPM / 5250 equation and you get APPROXIMATELY 400 HP out of this combo. That's a lot of assumptions given I have no idea what his dyno is actually reading, but 400 HP I can pretty much BANK ON. My own expereince tells me it's 400HP. TPIS tells me it should be around 400 HP. My rough calculations from this printout tell me it's around 400HP. If it walks like a duck and quacks like a duck, it's probably a duck.

If anyone can help decipher "Mustang Dyno" readings and what they mean in the real world I would love to understand it.

THat's it. I wish I could give some no-questions-asked kinda proof but the real world doesn't always work like that. THis is what we got, WARTS AND ALL. I'm not afraid to lay out the naked data, even though I don't totally understand it all myself.

Just keep one thing in mind: This car hauls A$$! WAY faster than my stock LT-1 Formula. Way faster than my 383-powered Malibu (which ran 13.4 @ 106 recently). It's a REAL HONEST-TO-GOODNESS 400+HP street car. No question about that!



[This message has been edited by Damon (edited September 10, 2001).]

 

Yeah, the darn Mustang Dynamometer results aren't comparable to "regular" dynojet results we're all used to seeing. The numbers are always pretty different between the two. I don't see why anyone would actually want the power@mph readings of the mustang dyno over the dynojets power@rpm readings anyway, but hey...

Oh well, we still don't really know how the setup is performing with these screwy results...

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray