So here's the deal.

Mods I have are in my sig.

I have bought thus far:

-AFR heads
-Crane 109831 cam
-Superram
-Double roller timing chain
-New lifters
-NSA roller rockers
-head gaskets
-intake gaskets

However, I'm in college and with classes and my job, my hours have basically been cut in half. I still need to get pushrods, gaskets, exhaust, injectors, etc.

So what I'm wondering is how much time can be shaved off of a bolt on L98 by just switching the intake only? Like I said, I already have 1.6RR on the car, along with LT and exhaust.

Anyone have before and after 1/4 mile times with basically the same setup, and only switching the LTR design to the superram?

I figure it might be beneficial to switch the intake out, sell the stock one to start recovering some money, then 5-6 months later do the heads/cam build.

I know, I hate to have to pull the intake off again 6 months, but its only the intake, its not like I'm doing heads and not the cam.

However, what would you guys do? Wait 6 months and do it all at once, or get the nice improvement of the superram now, and just spend the extra time (I'm doing all the work) down the road when I do have all the parts (and still be able to fund my college expenses)?

 

If you do the Superam intake only you will get some minor increase in performance. The stock TPI will not let a L98 breath.
But

The Superam is a major pain to install. I have had mine off about 4 times and it's still a pain.

I would be patient and do it all at once.

P.S. I just looked at your mods. You have a ported intake and base. You may not see any increase in performance with the SR.

 

I'd wait and do it all and then have the chip made.

But I figure if you play with tuning what you can, AFPR, timing, then the SR would shave off a couple tenths....not much more.

 

Well, the chip also isn't an issue as my tuner would basically pre-program the one he gave me earlier for about 40 bucks.

I guess I was under the assumption that people were getting 30+ RWHP and an extra 600+ RPMS with just a swap. I wasn't sure as to the validity of that statement, as the stock cam is small, but negligible gains?

So best case senario...I'm only getting, what, .2-.3 off my 1/4 times? I would've thought we even just a 25 hp gain, the extra couple hundred RPM increase in powerband would help to knock off a few more tenths...especially with my 4.11's

 

For what its worth

my L98 TPI in my 89 Irocz went 13.6's at 97mph

with underdrive pullies, tune and holley stealth ram, i went 13.2's at 101 in similar weather.

1.6 rockers and drag wheels in better air, i went 12.90's

Big difference with the shorter runner intake. Helps the motor breath but gives you RPM range to rev up, making more power under the curve everywhere throughout your 1/4 mile run, so you will be faster.


My buddy had a 89 formula L98 with SLP runners/ported TPIS base, stock everything else but with full exhaust. he would do 13.63's to my 13.90's when i was stock TPI. I had a 2800 stall on street tires with 3.27 gears i think, but he had 3.73's and stock converter.

I'd say his aftermarket TPI was worth a solid .20 gain on a stock L98. I dont think the 3.73's helped him that much, proby a tenth.

superam on a stock L98 should be worth .30

 

I did this in 2003. Only mod at that time was Lt 5/8 headers and magnaflow catback, and open lid. Actually felt like I lost low end tqe on the street. Please keep following track times as a guide only, as I am not the best drag racer. 60' average about 2.3. I went from a best (after about 10 runs trying) of 14.6 @ 98 w/ stock TPI to ( and this was the next year, again after 6-8 runs of trying) 14.2 @101 with the Superram change only. In retrospect, I don't feel it was worth the effort to change out the superam alone. Hope this helps, Tom

 

Yeah, but keep in mind you're comparing a SR to a stock TPI.

That's why I first said he would see a small gain. I thought he was running a stock intake.

Look at his profile. He has basically stock heads and cam with a ported base and plenum. The Superam will make a big difference with new heads and cam. I'm thinking that with his 6 speed and 411 gears that Vette will get the RPMs up fast. That's when you need a superam.

 

in my opinion if you already have ported base and/or runners, then hold off on the superram install and just do the heads/cam intake mods 5-6 months from now

 

.2-.3 is about 20-30hp at these power levels. You think .2 is negligible?

Were you expecting a full second?

 

Well, yes and no. For an intake, I was expecting a .2 time from the larger runners and base, but I also figured on a bit more just because of the fact I would extend the powerband at the same time. I was thinking half a second was more reasonable going with a larger runner base and shorter runners.

The ported base is very lightly ported. No extrude hone job or anything. More, its ported enough to get rid of the casting flaws, same with the runners. Nothing to extensive.

Edit: I also figured a 25 or so HP gain was reasonable, but I wasn't sure as to if the 40+ HP you gain when the TPI falls on its face would account for anything.

 

It will wake up the motor, thats for sure. Your peak now is probly at 4400-4500 rpms with the stock TPI with your mild port work. Superam will extend that to 5000 rpms. thats where my L98 peaked with the HSR

you'll gain a flatter torque curve and a higher hp peak which all help reduce your ET's at the track

.3 seconds in the 1/4 when your talking about a 13 second car is a good increase for just a intake swap. I'd be very happy with that

 

I experimented with a Superram with a stock cam in the past. Much better breathing past 4000 rpms and no noticeable loss of torque down low. Heads were factory 113 castings with the stock rockers. My stock TPI ran 14.00 @ 97 mph but with the Superam, it ran 13.44 @ 102 so that means it is about a 50 hp gain over stock. The only problem with them is that they are a royal bitch to install and take off.

 

Hmm....it's tempting.

The superram is studded, so it should go a bit easier. I might just get a second set of gaskets and make the swap.

 

I have surfaced this thread from the depths!

Well, I got the weekend free, and don't want to try doing the heads/cam/intake all at once, so I'm going to wait and do the superram now, rest over the winter.

My new question, how bad would it be to run a superram on a modified (PCM4LESS) tune? I mean would it be harmful to run the motor to 5500 on a TPI checked tune....am I going to lean it out too much?

Basically, is it safe to do the install without doing the tune or anything else?

 

If I was you, I'd just go ahead and put everything you already have on the car right now..... as far as not having exhaust and injectors yet, just run the stock injectors, they'll be fine on your car and you can always upgrade the exhaust later.

Not sure what the specs are on that cam, but as typical, with a Superram, good cylinder heads and cam as you have, even with stock exhaust, you should see a gain of literally somewhere around 100 HP..... Ie: 240 HP to 340 HP...... add on headers/exhaust later on and that can quickly become 375+ HP and even over 400......

I agree on the others in this thread who said approxmiately a .2 improvement with "just" the Supereram changeover..... but if you also loosen up the converter at the same time you'll see 3-5 tenths et improvement.

One last note, in my opinion the Superram is "not" hard to put on..... it really isn't. I've installed the Superram no less than 10 times and it just isn't hard..... if somebody has trouble on anything, its the innnermost plenum belly bolts, which are actually easy. I can put on a superram within 1 hour..... so can you, albeit your first time might take an extra hour, but you do want the right tools before starting and at least notch the plenum screws. But, the tools are cheap over the counter tools you can get at any Sears.

 

Well if it isn't ahrd...I just might do it...