dj haf

well... lemme make this as short as i can. ive been doing some research, searching around the msgboards trying to find what im looking for... ive found some things, but nothing solid enough for me to choose which intake to get.

im stuck between the lt1 intake, and the hsr. i have ported iron l98 heads, and a comp cams 503 cam (224/230, .537 / .544 w/ 1.6 rr), hedman 1 5/8 headers, an edge converter with a 2600-2800 stall, and all that good stuff. i also have a list of mods on my site (check sig). anyway, im trying to figure out which intake would get me down the track faster. i'd like some low end torque, and good top end... i plan on shifting at around 6k with the 08-503-8 cam and my ported heads. ive heard a lot of ppl complaining that the hsr has no low end power, which is what got me thinking about going with the lt1 intake instead.

basically, what im trying to figure out, is if i had an identical duplicate of my car, one with the lt1 intake and one with the hsr, both shifting at 6k, which one would go down the track faster. damn... so much for this post being short, lol

BadSS

The StealthRam on my 355 with a 218/228 cam and heads flowing 235 cfm on the intake at cam lift liked being shifted at 6400/6200 rpm – shifting at 6000 rpm cost me almost .15 seconds. Optimal shift point for your engine will depend on the level of porting on your heads. If they flow more than 235 cfm, your engine would more than likely want to be shifted higher than mine, if they flow less, it would more than likely want to be shifted lower.

Regardless,,, in general, longer runner intakes tend to be less sensitive to short shifting the car (from the optimal shift point), or said another way, shorter runners tend to be more sensitive to short shifting than longer runners. That being said,,, since you asked which would run better on your engine shifting at 6,000 rpm (not knowing how well your heads actually flow),,, my money would be on the StealthRam due to the longer runners (compared to the LT1) – even though they probably would run similar ETs when shifted at the optimal rpm for each intake.

dj haf

well, the reason i say 6k is because im not sure how well my bottom end will hold up. when i did the rebuild on my engine, i got a high performance kit with hyp. pistons, 10:3 to 1 cr, and a new crank. i also got springs that would hold up to .560 lift... i don't want to go solid roller, but i would like to know how to take my car past 6k without doing a lot of work to it. i think with my ported heads, my car would be good up to around 6-6200 rpm. if i decided to go with better heads, what would i have to do to my car to get the hsr moving to 6500, or even 7000 rpm without having problems? TIA

97WS6SCharged

I'd go with the HSR over the LT1 unless you already have a spare LT1 intake and fuel rails. It's going to cost you about the same amout of $$ in the end.

BadSS

The rotating assembly shouldn’t be a problem running up to 6500 rpm or so – if it was built within tolerances and ARP (or comparable) rod bolts were used. What usually give problems running up that high are the valve springs and / or hydraulic lifters.

For a high revving hydraulic, valve spring seat pressure needs to be between 105 – 130# and depending on the beginning seat pressure and cam lift, the spring rate could run anywhere between 350 – 420#. I use springs rated at 105 seat, 417# rate, with an open pressure at cam lift around 315#. I also run the pro-magnum flat-tappet hydraulic lifters. Recommended pre-load on these lifters are .002” - .004” (about 1/16 – 1/8 turn) to prevent “pump up”. I’m not having any problems running up to 6400 rpm (and have taken it close to 7,000 on a few occasions). They’re also available in a hydraulic roller lifter.