Hey guys.

Has any tried a Tpis 90mm ls6 intake or had their ls6 intake modified with 90mm opening?

Dyno time?

Good experiences? Bad experience? Decent?

 

https://ls1tech.com/forums/generatio...sxrt-more.html

 

The link to my flow testing above has a lot of LS6 intake manifold testing, including a TPIS/LPE 90mm snout LS6 intake. I have two of them. One is on my 91 RS Camaro and another one for my 02 Z28.

See post #18 - pictures of ported 90mm LS6 intake manifold

I had a dozen or so dyno graphs from two different DynoJet's of the 91 RS's 383 LS1 with a 102 mm Fast LSXRT, 90mm Fast LSX & the ported 90mm LS6 etc however when my LG phone died all of them were lost. I had been so excited that massive LSXRT fit under the 91 RS's hood

The short version is the LSXRT had severe drive ability issues in my application despite over a half dozen attempts by one tuner to sort out. Another tuner managed to improve the drive ability to a fair degree but the RS still had issues.

Ended up doing a drive ability and DynoJet dyno test with the LSXRT, 0mm LSX & 90mm ported TPIS LS6. The trick LS6 had the best drive ability basically stock, surprisingly better than the LSX which was also very good. The LSXRT was marginal. The expectations were the trick LS6 would be down 15-25 whp vs the LSXRT. To everyone shock the trick LS6 made the best peak hp and torque and had the fastest horsepower & torque curve. Tests were same engine temp, water temp, and same weather conditions on a calibrated DynoJet. 465 whp & 442 wtq.

I've been told the old 229/229 cam costs at least 15 -25 whp over the bigger new state of the art split duration cams. I'm not sure how much additional hp the tweaked LS6 intake would support.

The LS1 383 has a small 229/229 cam & TEA LS6 Stage 2.5 head that Tooley hand finished etc. I'm sure sure with a bigger cam spinning more rpm the LSXRT would have made more power. Ported the LSX would make more power with a bigger cam and more RPM.

The LS6 intake runner appears to be maxed out around 275 cfm based on my testing and others.

The Fast LSX has a bigger runner and can flow 275-280 cfm with porting.

My unported LSXRT flowed 278 cfm and it's reasonable to expect expert porting to add another 10+ cfm so probably 290+

Max airflow thru the intake manifold with the cylinder head attached is a fair predictor of hp results. So the 90mm LS6 can do pretty well with the ~6,500 rpm and done sorts of engine builds. For spinning above 6,500 the other intakes will have major advantage with the correctly matched cam. They also have more plenum volume to help support more rpm.

I like the TPIS 90mm LS6 intake. Several friends that have rode in and drive my 91 RS are pretty amazed at how mild mannered the car. A couple have even offered to buy the trick LS6 intake if I upgrade to a big cam and MSD or LSXR etc.

The 90mm LS6 intake is also very Stealth. I've been told several times I need to upgrade my "stock LS1" and at least get an intake and put a cam in the car. Folks that like to pop the hood and get attention for having an aftermarket intake would probably not be happy. Likewise hardcore street / racer types won't like it because it's not suited to 7,000+ rpm

 

Thanks for taking the time in supplying your info. This helps alot. My max will be 6500 rpm really wanted it to 6k.

Im building a 5.3 bored to ls1
ls6 intake
243 heads I plan to get worked to tea ls6 stage 2
maybe summits ghost cam with supporting bolt on mods & rear end. All going in 86 camaro
Sounds like this will work for me best

I was just looking for 400-425 rwhp, easy drive to take trips with and still have some fun

 

86Camaro, sounds like a good build. Looking forward to seeing the details. Most folks on LS1TECH will say sell the LS6 intake for $350-$400 and use that toward a used Fast 90/92 for $575-$700 that has more potential if you upgrade cams later for more rpm. I tend to build daily driver type cars that have good manners and really liked the results with the 90mm LS6.

There's a lot of nice header choices for LS engines in 3rd Gen's these days! Good times
Back in 2002 when I started planning the LS swap for my 91 RS it exhaust manifolds or JBA "shorties"

Very similar to Mavn's and he had excellent results with the Ghost Cam. I'm planning a Ghost Cam in my 02 Z28 with my old set of TEA S2 5.3 heads later too and shooting for ~425ish whp with my other 90mm LS6 intake.

BTW - soon I will have an update for the intake manifold flow test thread. The reference heads have been upgraded for better mid-lift flow by Brett at Land Speed Cylinder Heads and we'll retest a couple of intakes.

 

Good deal. I plan on running long tubes but I see Hawks is the only vendor with a matching y-pipe. How did you run your exhaust?

 

basically build it to stock ls1 specs if you only want to spin it to 6k. Even if you used stock 243s, stock ls6 cam and a opened up ls6 intake it will make the power you want but it will spin to 7k.

 

I'd check out the BlackHeart True Dual exhaust. It's 2.5 and fits well. On a ~600+whp set up, it cost 14 whp vs a 3 inch true dual according to a dyno graph I saw on here.. I think they make a BlackHeart for 3rd Gen's. It might be a little hassle with an LS swap. The BlackHeart stayed under 80 dB in my 99 TA in normal driving. Usually around 70-75 dB on interstate.

Y pipes & twin cut outs off the headers work nice together. Otherwise, not a Y pipe fan.

My 91 RS was LS swapped & restored by Hawk's. Exhaust is Hawk's Motorsports Stainless 1 7/8 long tune headers with 3 inch primary. The headers fit very well and spark plug access is good, better than my 99 TA with Kook's. I like the headers.

The RS has the matching Hawk's Y pipe, which I really don't like the Y merge. It's a compromised 3 inch into 3 inch Y and the Y is 3 inch out. However in fairness the Y pipe tucks up tight and doesn't rattle. Due to the Sinister Subframes, cross-brace and short torque arm attached to the subframe etc Hawk's put a one inch notch in my Y pipe due to the suspension set up so it all tucks up nice and tight. This gets more ground clearance. My RS has Eibach Sportlines with one full coil removed, so the car is sits low and ground clearance is at a premium.



The RS scraped occasionally in North or South Carolina with the tucked Y pipe where I used to live. Moving north to cold weather Indiana and getting on poorly maintained roads ravaged by winter and full of potholes quickly made me realize the RS is too low. Without that tucked & notched Hawk's Y pipe the exhaust would have been crushed probably a dozen times over.

A pair of electric cut outs off of the headers bypassing the notched Y pipe takes care of the restriction issue when it's time to play

 

Where’s that link to the Dyno graf of the blackheart 2.5 vs a 3” dual?

 

Saw it here on LS1Tech a while back. I didn't save the link or dyno graph.

 

I’d probably lean toward a dorman ls2 over a TPIS ls6

 

The dorman ls2 intake can be ported also... I wonder if anyone compared on dyno a ported dorman unit vs tpis 90mm ls6 unit? Food for thought

 

https://ls1tech.com/forums/generatio...sxrt-more.html

 

Has anyone attempted doing the 90mm snout conversion on an LS6 themselves? It doesn't look like there is much do it from some of pictures i have seen. Been going back and forth between the 90mm LS6 and the Dorman intake and trying some mild porting and smoothing.

 

FWIW, i think they were simply epoxied together. This made sense a decade ago as a cost effective alternative when the FAST/Wilson manifold just hit the market, but there's really no need for that anymore. The 102 is a better manifold than the original FAST/wilson, and far better than the LS6. The dorman LS2 is also better than the LS6 when ported, i believe.

if you have the dough, fast 102 or msd intake all the way.

if you don't, i agree with big hammer. just do an ls2 dorman and port it yourself.

the cost of the LS6 used and a new dorman are actually comparable. if you have an ls6, sell it and buy a dorman LS2. save yourself the trouble of hacking up two manifolds to make one.

 

That is my exact thought process. TPIS charges 350 just to epoxy the 90mm snout on. The Dorman you can get for about 375 on Amazon. I figured you clean up the Dorman and you have something probably better than a hacked together piece.

 

The FAST 102 is the only one that flows significantly better out of the box. The others are within a couple cfm of each other.

 

I love FAST 102's. It's so choice. If you have the means, i highly recommend picking one up.

 

I think WS6 store was developing a ported Dorman ls2 to surpass the LS6 and compete with the Fast 92. If it delivers it seems good value.

 

I would tell you to do a search, but if you reply to an old thread....well I can't talk about that....