L98 options???

[351coupe]

OK,it seems like I plan out and work on other people's cars more than my own,but here goes.My brother has a L98 vette(the white one with the black ZR1's),he's ready to start making some power and I don't know shit about whats different about the L98's to the LT1's.Another thing is,were thinking about new rods and pisons for the bottom end,would that do?How strong is the crank?Were looking at the AFR 180cc heads,I don't know what to do about the intake.

Basically,were gonna do a h/c/i car with some good rods/piston and a supercharger.The $'s not really an issue but he don't want to spend a fortune on it.He's already got a bad ass exhaust(thanks Sammy :) )so he's got a start.

If you had his vette what would you do?This is a street car with a auto tranny that will be built too.Thanks for you opinions.

[Sneakin Deacon]

go with a set of nascar heads on a 383, and just a bit of juice. i've seen that combo put down 550+ a couple of times.

i havent toyed with my l98 though, hell havent even driven it in so long. i wanted to turbo it, plenty of room, toss a TH400 in there...be done with my tranny worries.

[trigger]

how about this?

twin turbo L98

[Sneakin Deacon]

calloway?

[BAMF]

Now he's building the L98? I thought he was buying an LS6 or somesuch? Damn, man's caught the racing bug, he doesn't know what to swap out first :)

[351coupe]

LOL,I think he should sell it and buy a stang personally.

[DaTruth]

Nothing wrong with building a L98.. They can be real potent.

[Rolling Thundah]

Swap the intake for a lt1's , they gain like 35 hp. Jeremy formato has one and it was stout. Maybe shoot him a pm on RX and ask what was done, he has alot of knowledge on that motor.

[BAMF]

LOL,I think he should sell it and buy a stang personally.

See, he doesn't want to be fixing it twice as often as he's racing it though. :-D

Naah, I wanna see that Vette ride out, Vettes are just plain sex, and no matter how fast the FoxBodies get, they'll still never be plain sex.

[Sneakin Deacon]

the intake, is from LT1intake.com or something similar. basically the back of the manifold is setup for an old style distributer setup.

[Dead Hooker]

The limiting factor of the L98 is the intake. It will make a ton of torque at arelatively low RPM (really long runners), but falls off to the point of uselessness at anything over 5K (assuming 350cid). So with that in mind, you will be more or less waisting money on fancy short block parts and/or heads if you are going to keep the intake.

If he is set on keeping the intake, your best bet would be a mild cam, ported stock heads (they should be the alluminium L98 versions if the motor came in a Vette), nice headers, and maybe a better piston - but only if he wants to spray a little. Otherwise, I doubt you would ever make enough power to hurt the factory shortblock as long as it's tuned correctly.

TPIS sells a replacement intake for the L98 called a "Mini Ram". It looks very similar to an LT1 intake. That opens up a hole new set of options for you...but you will still be limited to tuning it with the stock computer which is the next biggest limiting factor to the L98!!

The quikest, cheapest, easiest way to power would be to smack a Performer RPM and a good 750 on there. That would be my advice.

I have a completely worked L98 setup and believe me, I've been down this road. If you need more specific advice give me a call.

Brandon 813 3680685

[Gunslinger09]

Brandon,

Couldn't he swap to DFI with the Mini-Ram?

[Mars_302]

The cheapest route is the Lt1 intake though. that Mini ram is far from cheap. Doing your comob once and having it tuned once and leaving it alone is the cheap way to go too. No point in going stand alone except to get rid of the batch fire setup and wanting the ability to grow. My boss and a cutomer both have "L98 vettes"

The customer has a 400ci motor with a dart block and pretty much all the best internals too. It has the 225cc AFR, the Mini Rim, very healthy roller cam with AFRs hydra rev kit. BBK throttle body, 36# Accel injectors, long tubes with 1 3/4" primaries, Plus uses FAST for a tuner. It went 11.8 running outta fuel with 30# injectors witht he stock 2.73 gear and a the stock 2.25" rear y pipe. As soon as it gets retuned again and he has the money for it, hes going to do a NOSzle system witha 200 shot on top of it. shoulld net him low 10s easily.


My boss setup which has been sitting on a stand for a 3 years is a 421ci motor with AFR 255cc with the bigger valves and competition port job, Mini ram intake, 42# injectors, Any even healthier roller cam with the hydrda rev kit, plsu all the other goodies with FAST for a standalone as well. Hes going to the NOSzle system sometime but probably 150 shot. He is limited by his block. Its a factory 400 block with good internals.

Both will have good street manner and run a built 700r4 tranny with dana 44 rear ends

[351coupe]

Thanks guys,were looking into more of doing h/c/i car with the option of a blower down the road.Maybe a 9 to 1 motor,were trying to put together a h/c/i searching over the internet but it's pretty confusing trying to figure out what to go with.

Brandon,thanks for the good advise,seeing I don't know shit about these motors or cars I'm kinda stumped on what to tell him to buy.If you were to freshen the stock bottom end with forged pistons,what could we do for heads and intake?We were looking at a Lignfelter(sp)? intake online but I'm not sure what heads to get first?We like the AFR's but what size?I'll continue to search and if you could help any further it would be appriciated.Also,the tranny needs to be gone through and built,I talked to Marc Shakesphere,cool guy,it prolly will go there,any other opinions?

[Dead Hooker]

Just remember if you go with the LT1 intake you will have to address the reverse cooling issue. I have seen people who convert the LT1 intake to the standard cooling flow for the L98 stuff, but have no personal experience with it.

As far as heads, if he really wants to buy an aftermaket set I would recomend the Trick flow 23 degree head. It will make great power unported and leaves plenty of room for growth. The AFR is a fine choice, but is more expensive and I haven't seen that they make any more power than The Trick Flows.

Also remember that if he intends to go with any kind of boost in the futre, you will need to take the compression into account.

In order to be more specific, I would probably need to know just how much power he wants to make or how fast...etc.

Also, I would personally stay away from the Lingenfelter "Super Ram" as it's known. It has the potential to make more power than the stock piece, but is generally overpriced from what I've seen and is a real ass-pain to work with.

[Mars_302]

You have no idea how much of a pain in the ass it is to work with Super Ram...... An even bigger bare to deal with than the stock intake.

[Dead Hooker]

You have no idea how much of a pain in the ass it is to work with Super Ram...... An even bigger bare to deal with than the stock intake.



Absolutely!!!!

[351coupe]

Ok,so I looked at the Trick-flow23's,seems like a good choice,now do I tell him to go with a LT1 stock intake?How well will it flow to the heads?If we decide on a stoker motor insted of a blower,what can this block handle for power.He wants to make in the neighborhood of 500fwhp,again he's not looking to build a race car just to make this thing move out pretty good,whats the best,and I say best not cheapest way to that.Another thing,how much can these fuel systems and computers run power wise,it obvious he'll need injectors and a fuel pump,what else are we looking at?Thanks again Brandon for the help.

[myltwon]

the lt1 intake I believe flows equally to the top of the line after market ones and is EASY as hell to work with, having pulled mine off about 4 times I can say this honestly

[BAMF]

I'm startin' to get excited about Dwayne's Vette. Now if only I could get ahold of him to ask what he's gonna decide to do.

[Dead Hooker]

You will definitely need to use something other than the stock intake to make that power. Again, the LT1 intake is a good design but you will have to resolve the reverse flow cooling issues to adapt it to L98 duty. Then, I would certainly have it port matched to the heads to ensure the transition is correct.

GM also makes an intake that looks like an LT1 or TPIS Mini Ram. It's called the Ram Jet (part # 12489371)...comes on the Ram Jet 350 crate engine. You would need the throttle body for this intake also as it uses a single blade version (like the LS1 or Ford) verses the 2 blade deal on the L98. I don't know the price and you don't see them everywhere, but that would be another option for you in the intake department that should make the power he wants.

Speaking of throttle bodies, if you go with either the LT1 or the TPIS Mini Ram, plan on getting a 52mm (2 blade) version from BBK, Edelbrock or somebody.

The stock block will handle that power with no problems...assuming it's in good shape. You're only talking about 375-400rwhp tranny depending. No need for anything fancy i.e. 4 bolt mains and stuff.


My advice is still to slap the carb'd setup on that bitch....your talking less money, way less work and probably more pwer for your time/dollar.

[BAMF]

You will definitely need to use something other than the stock intake to make that power. Again, the LT1 intake is a good design but you will have to resolve the reverse flow cooling issues to adapt it to L98 duty. Then, I would certainly have it port matched to the heads to ensure the transition is correct.

GM also makes an intake that looks like an LT1 or TPIS Mini Ram. It's called the Ram Jet (part # 12489371)...comes on the Ram Jet 350 crate engine. You would need the throttle body for this intake also as it uses a single blade version (like the LS1 or Ford) verses the 2 blade deal on the L98. I don't know the price and you don't see them everywhere, but that would be another option for you in the intake department that should make the power he wants.

Speaking of throttle bodies, if you go with either the LT1 or the TPIS Mini Ram, plan on getting a 52mm (2 blade) version from BBK, Edelbrock or somebody.

The stock block will handle that power with no problems...assuming it's in good shape. You're only talking about 375-400rwhp tranny depending. No need for anything fancy i.e. 4 bolt mains and stuff.


My advice is still to slap the carb'd setup on that bitch....your talking less money, way less work and probably more pwer for your time/dollar.

Godo advice, either me or Bryan will relay that to him, but I've got to make one thing clear. Money isn't an issue (within reason). He wants the most streetable, clean, and efficent combo he can get, and really doesn't give a shit how much he spends on it.

[trigger]

Wow, thanks for all the help. I think I'm gonna go this route.

TPiS Mini-Ram Intake Manifold w/fuel rails
58mm Throttle Body
?# Injectors
Fuel Pump
Ported L98 Stock Aluminum Heads
TPiS Hydraulic Roller Cam
Stock Crank
Stock Block

...but I'm not sure about the pistons yet.

[Dead Hooker]

Wow, thanks for all the help. I think I'm gonna go this route.

TPiS Mini-Ram Intake Manifold w/fuel rails
58mm Throttle Body
?# Injectors
Fuel Pump
Ported L98 Stock Aluminum Heads
TPiS Hydraulic Roller Cam
Stock Crank
Stock Block

...but I'm not sure about the pistons yet.


I think you are on the right course. The stock crank and block will be fine. The heads will need to be worked nicely, but if done well will be fine for what you want. (remember the heads will make or break the entire combo...so make sure you have them done by someone who knows their shit) 30# injectors should be plenty and give you some leg room. Be carefull with the 58mm throttle body. You can probably make just as much power with the 52mm version, but have better throttle response, drivability....etc. Something to think about along those lines; a 70mm factory LS1 throttle body has less cross sectional area than a 52mm twin blade like you need. And you know how much power guys make with the stock LS1 TB!

Just get some off the shelf flat top .030" over pistons from Ross or JE. When you have the machine work done on the block, make sure it is zero decked with the pistons, rods a crank you are going to use. Then have the heads milled (or opened up, whichever) so that you get around 10.5-10.75:1 with a .040" thick head gasket. Don't get greedy with the compresion ratio. The head/chamber design of the L98 heads won't allow you to get away with compression ratios like that of the newer stuff. (not to mention the older batch fire computer system with knock sensors that aren't as good)

One more thing. Within reason, the bigger the header primary, the better. Either 1 3/4" or 1 7/8" primaries (or a stepped version of both sizes) would be great. Don't settle for 1 5/8". And put a good true 3" dual exhaust system on it - preferably with an x pipe. You will be glad you did all this down the road if nitrous comes into the picture.

[Maite]

With the L98, I would do the LT1 intake swap with long tube headers. If it's an automatic, get a good stall and put TCI or yank, baby 100 shot and decent tire combo... maybe some Mickey's. That should put you at a decent power/ET range.
:)

[trigger]

The LT1 Swap is a pain in the ass with all the cooling changes. I did a little research and you have to use a remote thermostat and something about reverse flow.

[trigger]

I did some more research, but it's still a sloppy converstion. Check out this guy's site.
http://www.lt1intake.com/swapping.htm

[trigger]

I'm trying to decide what to buy

SuperRam
MiniRam
or
just large tube runners and a high flow lower manifold and a ported upper

ps - it's a L98 TPI Corvette in need of some O2.

[Dead Hooker]

I'm trying to decide what to buy

SuperRam
MiniRam
or
just large tube runners and a high flow lower manifold and a ported upper

ps - it's a L98 TPI Corvette in need of some O2.


SuperRam = pain in the ass

Large tube runners...etc = going to be hard to make your HP goals with that setup...it's not that big of an improvement over stock.

MiniRam = no brainer chioce of these three options

[trigger]

what about all the stuff I read about the loss of low-end torque?

[trigger]

this is what I might buy

http://i3.ebayimg.com/01/i/03/db/1f/7f_1_b.JPG

[trigger]

any comments on this?
http://i10.ebayimg.com/02/i/03/e9/ee/f7_2.JPG

[351coupe]

Now your talk'n Dwayne,do the Holley system and the Trick-flo heads.You only live once bro.They have a nice ATI procharger or Vortec kit for your car too:naughty:

[Mars_302]

I do the holley or the mini ram. anf fuck low end torque loss. You ahve 350 CI of it. Toss a 383 stoker kit in it to make up for it.

[Dead Hooker]

what about all the stuff I read about the loss of low-end torque?


You are going to lose low-end torque when you go to anything beside that stock intake....that's the only thing it does well. But your car will be faster if you trade in some of that low end torque for some of a high end variety. And your car being faster is really the goal here I assume, not just numbers.

[trigger]

what about this...
made by Martin Motorsports
www.haroldmartin.com


http://www.haroldmartin.com/images/Ram_Jet_502_Engine_4.jpg

[???]

this intake


http://static.summitracing.com/global/images/prod/large/hly-7540.jpg

http://store.summitracing.com/default.asp?Ntt=stealth+ram&x=39&y=21&Ntk=KeywordSearch&DDS=1&searchinresults=false&N=0&target=egnsearch.asp

52 or 58 mm. doesn't really matter.

best heads you can, like afr's 210 and give them to brandon to touch up. along with the biggest cam tpis sells and a 4.10s to match.


jermey can burn a chip to make almost any tpi combo run nicely.


add a small 175 shot and have fun.



dont waste your time converting a stock lt1

[trigger]

everyone I've talked to said stay away from the Holley Stealth Ram (HSR). They said it's an old ram jet converted for fuel injection and has poor flow. Air gets trapped in the ass end if the intake and causes turbulence.