CALL911

iTrader: (17)

Okay, for my 98 Formula WS6 in my sig, next year I will be installing the MS4 cam, LS6 intake, ported stock TB, Kooks (1 3/4), pullies, ORY, Magnaflow catback, 36# injectors, lid, and a tune. (Still will be using the stock heads, and stock 3.42's for the M6). What kind of RWHP levels can I expect from this?

I am guessing around 420-430 RWHP, but I may be off. Anyone have a guess? Or any other suggestions for simple mods?

'Trust'

iTrader: (24)

Sorry man, but I don't think you're gonna sniff even close to those numbers. The 98 806 heads are a joke and they will hold you back like crazy. It sounds dumb, but I say 380-400 max. Let us know what you get.

CALL911

iTrader: (17)

Really? I know the 98's heads weren't as good as the 99+ LS1's but most people agree that the HP difference is very minimal, and most wouldn't be able to tell any difference.

Here are the threads I am referencing this to;

https://ls1tech.com/forums/generation-iii-internal-engine/826950-were-heads-different-98-ls1-s-than-say-02-ls1-s.html

https://ls1tech.com/forums/generation-iii-internal-engine/826358-anyone-have-real-proof-98-heads-flow-so-much-worse-than-99-up-heads.html

streetassasin

iTrader: (30)

CALL911

iTrader: (17)

Thanks for the laugh streetassasin, but I am really trying to find out honest opinions here.

streetassasin

iTrader: (30)

400 give or take 15hp

CALL911

iTrader: (17)

Maybe I have been fed bad info. Everyone I have talked to previously about bolt ons and a cam with a tune all said 400+ would be easy. Given the MS4's level of performance above most cams, I figured a good 420+ RWHP could be attained.

Anyone else?

TheLS1Kid

iTrader: (12)

The MS4 is a top end cam and makes a lot of power up top.

I agree with streetassasin's with 400 give or take 15.

Now throw some better heads, even stock 243 castings on there and it would be a different story.

SweeTbone

iTrader: (8)

I would think 390-ish for the RWHP and 375-ish for the TRQ. Cam only is pretty hard to hit 420-430 RWHP, especially with an LS6 intake and not a Ported FAST 90. As stated, the heads could be your choking point. If you do that "math" this is floating around the interent, people say add 45 HP for heads, add 50 HP for cam and yadda yadda. Too many variables to put set numbers on a mod. I thought I'd put down 465, and was 20 HP short for a H/C/I car. I think you can hit 395-405 range.

CALL911

iTrader: (17)

Well, I am also not one to go off of "this cam makes this much power", or "with this combo you can expect".

I more or less based my original guess using other peoples similar setups with their numbers. Almost all made at least 400 RWHP, some made 430+RWHP.

But I am not stubborn, and I do believe I can be wrong (and am a lot of times). Does anyone have other results for power with this combo. I could post up all the guys I am getting my RWHP numbers from, but they all support 400-430+ RWHP, not 390-415.

cbra-klla

iTrader: (52)

405-415 hp

2002t/a06

iTrader: (2)

407rwhp 392rwtq!

'Trust'

iTrader: (24)

Stock for stock 98-02's are comparable, but you must remember why. The 98 heads are really the worst of the 3 castings for LS1 Fbods (806's for 98, 853's for 99-00, and 241's for 01+). The reason they are comparable stock for stock is because 98's, although have crap heads, had a bigger cam than all the years to make up for it, 99's had a better head but a smaller cam, 01 and 02's had substantially better heads, but again a smaller cam. Making them all comparable to each other. Now when you throw the same size cam on each, there differences will start to show more.

Simply put, better heads will yield better results given equal cams. Knowing the inside and out of my 98 for 3 years I can attest to it. My A4 98 TA with a lid, cutout and !CATs made 316/341. After LT's and a cam (TR224 w/XR lobes) it only made 342/248 tuned with a perfect 13:1 A/F and the stock locked stall. After putting some ported/polished 241's and adding a stall the car made 400/380, a gain of almost 60RWHP with just heads, and adding a stall! If I had done some ported/polished LS6 heads I'm sure it would have done 420RWHP on a TINY 224 cam with .563 lift. Us 98 guys love to know that our cars are equal, and honestly the only downfall in my opinion other than crappy rodbolts, are the horrible 806 heads.

GIVE EM' THE BIRD

iTrader: (1)

^Great explanation^ i actually feel like i learned something today and it wasnt even my thread!

CALL911

iTrader: (17)

Well, I think I have been proved wrong on my guestimates. Looks like I'll need to pinch a few pennies and get some heads with my upcoming combo.

While we are on topic about the 98 heads, does this mean with the different headbolts that I will need a specific type of aftermarket heads? Or will they all fit the same on my 98 LS1?

CranMaro99

iTrader: (10)

Should fit the same homie.

'Trust'

iTrader: (24)

The design of the headbolt holes aren't different, its the boltholes for the valvecover that are different. Any head designed for an LS1/LS6/LS2 will boltup just fine, what you will need to get that the 99+ guys already have are centerbolt valve covers and the coil pack brackets. Good luck with everything!

EDIT: TSP Stage 1's are a great head if you don't want to spend a chunk, then PRC Stage 2.5's would be a good upgrade from there.

HeapaShifter

iTrader: (2)

This is almost dead exact what I had. Mine was a 99 and still had the stock pully though. I even had the same brand headers and catback.

I put down 402 rwhp and 400 rwtq. That was with stock injectors at 92% duty cycle. I never got to dyno it again with the 36# injectors installed.

CALL911

iTrader: (17)

Thanks for the good info fellas. Anyone know how much and where I can find the centerbolt valve covers, and coil pack brakets?

TXws6

iTrader: (10)

i would definately think you can break 400