Need feedback on my future plans.

[devilfish]

Hello

COuld you give me som feedback on this please?
Im on a tight budget,so keep that in mind. And Im from Sweden so many thins is hard to get "over here".

And its for my 1991 6spd vette.

here is the list:

LPE219 cam
LT4 springs, reatiners etc. ( im not going abow 6000rpm, so it should be enough)
accel superram bas ( ony base )
as+m runners.
ported stock plenum, to match the as+m runners.
Stock TB.
Going to cheap port the 113 heads myself, match it to the accel base.
manley vavles ( stock size )
Increase the comp using a diffrent head gasaget then stock.
heddman headers.
1,5rr, i dont think the stock heads can flow abow .500 in lift, so i stick to 1,5.
no egr
no airpump.

And to add in the future..

superram plenum and runners
hooker headers
AFR heads
1,6 rr
stronger springs
bigger vavles

Does this sound like a good "cheap" top end for now?

Is 370hp possibel with good tuning?


Thanks

devil....

 

[Vettelt193]

I am not familar with the LPE219 cam, but I would suggest you check it out to see if it specifies a certain ratio rocker arm... the rocker acts as a multiplier for lift, so many times the cam will give rocker specs.

The combo, with a guess on specs of the cam, will basically bring your peak HP rpm up... I wouldn't suggest you go over 6000 RPM with a stock bottom end, but I am guessing your peak HP will be pretty close to 6000 if everything is tuned right.

A stock Throttle body will be a huge bottle neck, and all the other intake/head work will be a waste without a new one, (or port your stock TB)

Before you go waste any money I suggest you develop a final plan, then work backwards... for example: it is a real waste of money to buy 1.5 roller rockers if you want to go to 1.6 in the future.... I think it is better on your wallet to have a slightly de-tuned car for now, as long as you don't re-purchase parts.

Another thing to keep in mind is the low-end grunt is easily lost in the L98 with high flow, high RPM mods like you are planning.... If what you enjoy most is that off the line low-end torque, you are not headed in the right direction IMHO... but, if you like High RPM high HP... you have the right idea for sure.

 

[devilfish]

well the cam spec is with 1,6rrs.

And the lpe219 cam is "made" for the superram.

I keep the tuned port desgin, i just swap out the parts for better breathing once, like the as+m runners. If i would go the miniram or lt1 intake route, the lpe cam is "wrong" and a zz409 or simular should work better.
Also going to miniram i will loose the low rpm torque the tpi design gives me. With this combo I will use, I still get a low end torque and topend power ( i think). Not as much topend like a miniram/lt1intake and zz409 combo, but a good compromise between top and lower powerband.

I agree on the 1,5rr, i could use the stock non rollers for now, and save the money to get 1,6 with my nyew afr heads.

I think this combo will make power from 1500romp to 5700rpm.

My goal is set. A mid/low 12sec car, with good higway preformance..

 

[Vettelt193]

ok... sounds like you have a good idea of what you are doing... I think your power band will be a bit higher than you are expecting though, because the porting of the stock intake, plus the new runners will shift things up a bit...

I know once you get a superram, headers, and your whole plan is 'finished' you will have a really high revving engine.... you may have problems with the bottom end, because your HP curve may force you to go above 6000..... Whatever you decide, good luck... and, of course, tuning is the most important part of getting more horsepower... do you have a good place to dyno-tune your vette where you live?

 

[devilfish]

yep we have som places that have good dyno jets.

I will never take the stock bottom end abow 6000rpm.
Some people have good results with this combo. I think the use of a superram will take the power band 800rom higer them the use of as+m runners.

 

[Vettelt193]

i agree with 800 RPM higher.... I am guessing 800 over stock will come out the as+m and porting the intake though... start adding in the headers, porting the heads, 1.6 rockers... you start adding more and more RPM to the mix...

I hope one of the dyno shops has experience with Corvettes... it will be much better for you if they do

 

[devilfish]

there are most turbo guys here in sweden.

 

[-=Jeff=-]

Devilfish, with the following combo.. I still have 340ft lbs of torque @ 3550rpm a VERY Streetable combo. I am also going to swap cams in the Spring from the ZZ9 to the ZZ409

My current set-up:
- 350 CI
- CNC Ported L98 Heads
- ZZ9 Cam
- 1.6intake /1.52exhaust Rockers
- 1-3/4" Long tube Headers
- No Cats with an LT4 Stock Cat-Back
- Miniram
- 52mm TB
- 6spd
- 3.45 Rear gear

 

[Vettelt193]

there are most turbo guys here in sweden.

uh oh well, I am sure they can figure out a good ol' 350 if they have to!


Jeff, did someone tell you to run the mixed set of rockers with the ZZ9 cam? I haven't had any personal experience with the ZZ9 with a mixed set.... any troubles tuning etc.? I absolutly love the mixed set on LT1's... it makes for, what I think, is the best combo of torque and HP.

 

[-=Jeff=-]

Jeff, did someone tell you to run the mixed set of rockers with the ZZ9 cam? I haven't had any personal experience with the ZZ9 with a mixed set.... any troubles tuning etc.? I absolutly love the mixed set on LT1's... it makes for, what I think, is the best combo of torque and HP.

Vettelt193,

I had read in the TPiS catalog that the 1.6 rockers on the intake gain a little more power..

Keep in mind the ZZ9 specs are:
112 LSA
212/226 Duration @ .050
.483/.520 Lift with 1.5 Rockers

So I opted to go with the 1.6 in the intake for that little extra HP.

In the Spring I will be changing to the ZZ409 which is:
112 LSA
226/226
.520/.520

I think I may go with 1.5 rockers all the way around, if I go to 1.6 I will have to swap springs.. I am not sure what I am going to do yet.

Jeff

 

[Vettelt193]

thanks Jeff...

What kind of power gains do you expect by going to the 409 cam? If you switch down to 1.5's, all you will really gain is intake duration, unless I am missing something?

 

[-=Jeff=-]

thanks Jeff...

What kind of power gains do you expect by going to the 409 cam? If you switch down to 1.5's, all you will really gain is intake duration, unless I am missing something?

I am not sure what I am goign to gain with this Cam.. A friend of mine who really knows his stuff says I will see 114mph out of this cam (I run 110 with the ZZ9)

You are correct as I am only going to gain intake duration and a small amount of lift with 1.5 rockers.. I am considering the 1.6 rockers, but I will be doing this at a friends house when we do the clutch (he has a lift) and I will need to decide before if I want the 1.6, if so he will need to keep my car there while I order the springs for my heads.

Jeff

 

[devilfish]

i talked to a guy in thirdgen.org, he said that my combo whas only good for aroud 320-330 hp at the crank? Sounds littel to me..hmm...

 

[-=Jeff=-]

i talked to a guy in thirdgen.org, he said that my combo whas only good for aroud 320-330 hp at the crank? Sounds littel to me..hmm...

Which set-up? the first one? or the final one?

The stock heads are going to be the choking point

 

[devilfish]

the first one.

Im going to cheap port the heads my self, port match it to the accel base.
Huw much hp will this hold me back vs a fully ported 113 head by a machin schop?