millican

http://www.lt1intake.com/dyno.htm

Big Als Z

very nice. I am thinking about going to an LT1 intake now that I have evaded NJ's emissions laws. Has anyone done a dyno run on a 305? I know Ive heard of people saying they were gunna do it, but no end result. I might have to give it a go.

RedIrocZ-28

Hey John, anyone that you know of with a 355 shortblock, 10:1, AFR 195's, 228/234 cam, and an LT1 intake with a dyno sheet? I'm really still wondering if the Stealth Ram is all that its cracked up to be. I still dont feel the power I want. Perhaps its just tuning still but if its the fact that the HSR is crap unless you plan on spinning to 7500 I'd go with one of your LT1 intakes.

Damon

Yep, that looks good. I built an engine a few years back using the TPIS Miniram (very similar to a stock LT-1 intake) and it pulled like a freight train well past our self-imposed redline, even with a small cam. Very impressive, but WOW, DID IT COST AN ARM AND A LEG!!!

If I had it to do over again there is no doubt I'd start with a converted LT-1 intake system.

A factory TPI makes good torque, but you usually waste it blowing the tires to smithereens coming off the line. Once you get it hooked back up you're making the rest of the run in the 3500-6000 RPM range, where a short runner intake like the LT-1 or Miniram just KILLS the TPI setup.

I can totally believe the power increases you saw. We saw similar shapes to the torque/Hp curves but overall larger numbers on a 400ci small block with the MiniRam. Those short runners can really stretch the top end, even with a modest cam.

Marc 85Z28

Not to rain on anybodys parade, but there was an upgraded cam installed with the intake. I know they compliment each other, but the LT1 intake would have only been worth another 10 to 15rwhp TOPS on the previous setup.

millican

Got proof? I say the LT1 intake is worth much more then that. On my 383 I gained 5 mph in the 1/4 by intake swap alone. That mph is worth at least 35 rwhp.

His cam swap with intake swap wasn't from a stock cam either, it was a ZZ4 cam. His intake wasn't stock either, it was an Accel intake base and runners.

jzajac1

I've got to agree with Marc, the cam alone was worth about 45 HP. The ZZ4 cam is a nice cam but the duration doesn't compete with the duration of the cam upgrade, that's were most of the power came from. I'll give you a real example: I had a Fast Burn 385 GM crate engine, it comes with the ZZ4 cam. It makes 385 hp. I later upgraded to the GM hot cam kit which still has less duration (218/228) then the upgraded cam in the post and the hot cam kit (1.6 rockers) and nothing else gave me 428 hp (do the math). A nicely selected cam/intake/head combo can make some very nice horsepower. As a general rule, no matter what you read, intakes usually give you about a 10-20 hp increase....

millican

45hp at the rear wheels or crank?


Are your numbers from Desktop Dyno or a chassis/engine dyno?

Zepher

I'll probably be doing an LT1 heads/intake swap on my stock 305 TPI motor in the next month or so. What kind of power should I expect?
Car right now runs 15.7 @88mph with a race weight of 3590 with driver. I may even put the LT1 cam in there as well.

Marc 85Z28

No, I don't have proof. Then again, neither do you.

Gained 5mph from what intake setup? A stock TPI? That's believable.

I know his setup wasn't stock. Never claimed it to be. I could see a significant gain from a stock TPI, but a modded TPI?

With all the intake conversions you sell, the only dyno test came from some guy half way across the world, with a cam swap? Surely someone slapped their LT1 intake on with no other mods and dyno'd it...

That 50rwhp came from the extra 1000rpm of powerband the guy gained (estimated from 5000rpm peak hp to 6000rpm peak hp). BOTH the intake and the cam gained that powerband. Neither would do it alone. The LT1 intake would have seen minimal gains on his previous setup where the cam topped out around 5000rpm. Like robvas said: RPMs = HP.

millican

I sell to all countrys, I can't help it if no person from the United States hasn't dyno'd their swap before and after. I guess that the saying all Americans are lazy seems to fit in this one. The only customer that reported back with results was from Finland.

Oh and what's wrong with doing a cam swap while your in there. You know a stock cam won't do your conversion justice so why not change it while you can?

Marc 85Z28

EXACTLY!!!! The LT1 intake has the potential for HP gains with bigger and better components. But it cannot do it alone on smaller components, like his original cam.

There's nothing wrong with it. It would be wise to install a larger cam that would take advantage of the better intake.

But to claim 52rwhp "from an LT1 intake swap" is BS.

That's like claiming an LG4 will gain 73HP from just an Edelbrock Performer intake swap. Clearly though, the cam was the more important contributing component.

Dirt Reynolds

Hey Marc - I wouldn't be so quick to jump on millican. Holley claimed the Stealth Ram made something like 62HP @ 5200 RPM over a bone-stock TPI intake, so the intake design is lot more important than you are implying here. At higher RPM's (over 4500) the TPI system is simply out of its design element with those very long runners (21" from plenum to intake valve) and simply runs out of breath. An intake like the LT1 with its much shorter runners can supply the engine pretty much all the air it needs at the higher RPM's, as it is not tuned to any specific RPM range like our stock TPI intake is. Sure the cam is important, but only to allow the engine to breathe in the range of it's intended RPM application. Most TPI 350's when converted over to carb make a lot more power over 4500 RPM than they could with the stock Tuned Port intake, so its not unreasonable to expect a short runner intake like the LT1 or HSR to unlock some major power increases once the RPM's go over 4500.

Just my take.

Marc 85Z28

Flowmaster claims 40HP with just a muffler swap on our cars, so what?

I've never seen that claim. Could someone post a link? Besides, I'd bet the engine wasn't a stock TPI 350. Chances are it had high dollar aluminum heads, a cam with specs way out of the TPIs range, full exhaust etc etc. Holley probably built an engine with the HSR in mind, and then threw on the TPI knowing it wouldn't perform well, so it could boast about big numbers with its HSR to move its product.

So, does anyone have any real world numbers here?

Dirt Reynolds

Actually, it was a bone stock Z28. The only mod done was to remove the stock TPI induction and bolt on the HSR. That was it. They then put the car back on the chassis dyno, and recorded the results.

There was a lot of discussion about it over on thirdgen.org quite some time back when the HSR first appeared. The guy from Holley posted his initial results over there as I recall. It seemed the stock TPI really strangled the airflow after 4500, as all the gains from the HSR came at over 5000 RPM, where the TPI was really falling off in HP.

Third Gen Resource has a small blurb about the HSR power gains. Scroll down to almost the end of the page.