So apples to apples 13.63 TPI vs 13.60 HSR, my only concern is the stealth ram is NOT cheap and then you have the cost of re doing the fuel lines. It's a good intake, I have one, I just can't see putting it on a stock L98 unless you planned on doing quite a few mods.

 

idk, under $400 for a brand new, unpolished plenum and intake isn't bad. $180 for the rails..you can raise your power band a bit, for under $600..my wallet says it doesn't sound too painful.

 

Ya gotta remember that it really doesn't increase hp by that much. A small peak gain, but big gains up top. Hsrs are really best when paired with a set of heads and a matched cam.

Right now though I'd rip any sbc out of the third gen and go straight for the 5.3 swap.

 

While the 5.3 swap would be great, for the time being I don't have too much to dump into the car so for now I'm just looking at doing 'mild' mods to it. (i.e. exhaust, intake).

Like I said the overall peak gain is not what I'm worried about, but I'm not saying it's unwelcome either lol. I want that boost up top, car pulls like a raped ape at low speed/low rpm's but that's it. Straight up falls on its face past 4. But for now I gotta get my cat fixed, the core was clogging up but I managed to blow it out on the freeway..but there's still some blockage because there's a tin-y rattle/sound my car makes when building revs. And that is reeeeeally annoying.

 

Not quite apples to apples. I ran on a hot summer day and ran 13.6's I think with the HSR with no other changes..no tune/nothing. Similar day with stock TPI was 13.8-13.9's. Trap speed went up a consistant 2mph.
Winter air got me to 13.63 with stock TPI which is darn good. Similar air basically pushed my HSR only swap car to 13.4's I think, i'd have to go back and re-read my posts. ITs been along time. Then I added wheels/pullies and got 13.2's I think. 1.6 rockers later I think I got down to 12.95.

IN either case, the HSR is a big gain in performance on a stock L98..... but so is full aftermarket TPI. ANY intake on a stock L98 picks up useable power.

TPI is nice, but you'll spend more money in upgrading TPI components unless you get used. 350-400 in the base, 300-350 for runners, port your plenum to match...it adds up.

 

I say buy the peripherals first. Things like headers, catback, etc. when you have Those installed get the hsr.

Remember a stock l98 hits the traps in the 4500 range. A hsr will move the power beyond 5k. It's possible you could go slower unless you get something like 3.42s

Not saying don't do it. I had one and loved the powerband.

 

Yes, I was assuming you do the normal supporting mods like headers/catback, CAI type stuff. Maybe even advance base timing 2-3 deg. Throw in a set of 3.42's and a 2800 stall. Put the HSR on that and you will like the combination.

 

Exactly the answers I was looking for. I'm getting some 2055's put in with a 3" test pipe. Has flanges so when smog time comes around I can throw the cat on and pass the sniffer with flying colors. So I'll have a 3" exhaust from the headers to the exhaust tips (or electric cutout). Finishing the exhaust, got the home made ram air intake, now I can add me an HSR to the list.

Um does anyone have a dyno graph showing the amount of hp gain on the top end over the stock tpi? Not looking for peak hp but the overall top end gain.

 

I don't, however I remember the gain being nearly 60hp by 5500rpm on a stock car, only about 10-20hp peak gain though. For what you lose down low, the HSR extends the powerband to an easy 6,000rpm on a 350. If you have ever been in an LT1 car that is pretty much like what a Vortec HSR + Vortec heads and a L98 cam would run like.

My B-body LT1s cam is 191* @ .050" lift and the car still sings to 5500rpm easy. Heck its still pulling good at 6000rpm. I ran my 13.3 time with the transmission shifting at 6000rpm. It has trans problems, gets hot, shifts high. I've been limping it for 2 years cause I have a T56 already on the side and ready to go in. Just no time to do it right now.

 

I built a budget L98 for a kid with a HSR, OE LT1 Cam, Hooker LT's, 1.5-1.6 Roller Rockers and very mild touch up work on the stock heads. Ended up making a lil over 300whp once tuned on a Mustang dyno.

 

That's pretty impressive numbers on a mustang dyno a.k.a. heartbreaker dyno lol..

 

Nitrous? Timing too far advanced? Just curious - I'd like to learn teh easy way not the hard way to avoid this kind of thing...

 

just wanted to throw my 2 cents in. dynoed my car today with stock l98 with stealth ram, headers and 3in exhaust and put down 289rwhp and 388rwtq on a mustang dyno. all my ignition (cap,rotor,plugs) are msd. i had a msd coil but it cooked so now i can only rev till about 5800. took it to 6500 with the msd. i think the stealth ram is great for the price and amazing power top end. im going to be building a 383 for it in the near future.

 

What did it sound like when you blew the junk out of the cat? Did it sound like a bunch of large stones? cause i ran mine hard the other day and heard something like that.

 

sorry but I call BS on those numbers, ESPECIALLY on a mustang dyno

 

What did it sound like when you blew the junk out of the cat? Did it sound like a bunch of large stones? cause i ran mine hard the other day and heard something like that.

 

i suppose it could of been some long lost tools or something.LOL

 

 

Call bs all you want. Don't really care. I have the pictures and video for myself.

 

Much like radar guns, dynos need the right information entered to produce accurate results.

There is no way in hell a HSR'd bolt on L98 will make that kind of power without at least a cam. Could it be done on stock heads? probably with the right cam. And it could be done with a stock cam if the heads are ported.

But stock L98 with boltons and a HSR? No way.

If your car was TRULY making 300rwhp your trap speeds would jive, but I bet they don't. I'm willing to bet there is some headwork going on that you aren't talking about. Or a very mild custom grind cam.

My LT1 comes with better heads, the intake flows like an HSR, and I have all of the bolt-ons too. Oh, and a custom tune. Based on my 1/4 mile trap speeds I'd expect anywhere from 250-270rwhp, and the 270rwhp would be if I was lucky.

 

Not sure what to tell you. L98 .030 over stock heads stock cam. Holly stealth ram 58mm tb exhaust ignition and custom tune with a t5 tranny and stock clutch made 289rwhp 388rwtq at 4000lbs on the dyno.

 

Manual will put out more power than a auto. I got to 254whp running lean with an auto. Good tune could have hit high 260's I bet. Manual, add 10-15 more. happy dyno add 10-15 more. All dynos vary.

.030 over isnt a stock L98 anymore. new pistons may have given you some compression if they were flat tops. Fresh ring seal gives a few ponies over a stock high mileage L98 thats typically seen.

289 sounds optimistic especially on a mustang dyno but I suppose thru a manual trans it could be possible. The torque sounds extremely happy...mine only made 315wtq.

 

lets see um

 

Here's 274rwhp at 160* I let it warm up for the other pull. This was the only one I had filmed

http://www.youtube.com/watch?v=SnTUY...e_gdata_player

 

good thing no one races dynos that is one happy mustang dyno

 

Do you have 1.6 rockers? Try some if you dont, they picked up power on my L98

 

Sounds like very reasonable numbers to me. I don't see where that's hard to believe.

 

Yeah large stones in like..an empty coffee beans can lol. All good now though, I've got test pipes until I save up the coin to bolt in some new cats.

 

Does that mean you put in your car weighs 4,000lbs??
If I remember correctly that will screw up your numbers.

I'm just a hr north of the STL, which shop are you going to?? Is that Ranken ??

 

Oh yeah, inputting more weight than the car and driver actually weighs will screw with the Dyno results! Especially on a Mustang dyno that figures in more variables over a E.C. Dyno.

 

Your on the same page as me. HP seems very possible with a .030 motor. However I didn't pay much attention to the TQ number when I briefly looked at this last night. TQ seems way high from where it should be and just doesn't jive.

 

I dont know how a mustang dyno works but I never had to input a vehicle weight when I ran mine on a mustang dyno.

What does weight have to do with turning the dyno drum?

 

My bad, I'm thinking of inertia based calcs. Weight has a great deal to due with HP estimations with those.

 

the weight thing is sensless to me too. Our shop had a dynojet chassis dyno and it didnt care about weight, its just an inertia wheel. I will say that strapping the car down loose would give higher numbers, thats just a friction thing.

 

I'd be more interested in what the actual correction factors were and the shop air conditions that day. I've seen alot of dyno places use unrealistic correction factors.

 

It is worked in with the drum loading somehow for the correction along with the weather. Its supposed to give a more realistic number. So I'm told..

I've seen dynos where the straps were loose and tight but there wasn't really much diff in the numbers at all...
Anti-Venom has used a Mustangdyno but I have not, he may know more about the hows and whys.

 

Correct, the mustang dyno calculates the load (weight) and the aero of a car as if it were driving down the road with input on the air.

 

there are tons of dyno tricks to get big numbers, where you position the car on the rollers, correction factors, doing a wrong gear pull and tricking the dyno computer, etc...

 

a few years back one of the shops here had a dyno day that i went to.
some of the numbers for thirdgens.
the numbers are the best of 3 runs and were made on a dynojet.
the first car had full MSD ignition, Super ram, headers, under drive pulleys, tuned chip, it put down 244 hp and 283 tq
another guy put down 259 hp/259 tq, no air filter and exhaust cut outs open, mini ram, headers,
mild cam, head work, MSD ignition and chip tune.
the tunes weren't perfect, but not bad either.
the numbers from the dyno matched up pretty good with track times.

289/388 at the tires from a "stock" motor with just an intake, i think that dyno was snortin the laughing gas.
just get the important numbers, track times.

 

If a Mustang Dyno does factor weight into the calculation then having the wrong weight could affect the results. If the car is listed as heavier than it actually is the power will be higher than it should be. If the weight is too low, then the HP would be lower.

Exactly, Dyno's are cool to watch, a great tuning tool, and can give comparative gains for mods if done back to back. But honestly the drag strip is more fun.

 

They use a massive electromagnet to load the drum according to drag coefficient and car weight to simulate the car actually driving and not just spinning a set weighted roller.

It helps tremendously with tuning and troubleshooting to be able to apply a simulated load on the car as you can imagine. They are only as accurate as the operators inputs however. So say if you have performed weight reductions but the operator didn't scale your car and just put in the default weight from the database then your going to get slightly skewed numbers. Again if you have changed your aero say with a splitter and cannards then obviously the factory drag numbers don't apply. In that case unless you have wind tunnel data then you have to ballpark it.

Same with correction factors. They can be fudged also as we all know. A dyno is a tuning tool with a ton of calibration parameters, trust me I've installed one, the install manual is a little more than what's included with IKEA. The only way to compare nut's to nut's is to compare two cars back to back on the same dyno. Otherwise all your doing is pissing in the same ballpark.