Outa curiosity, how much Flywheel hp do you think a stock L98 would make with just a Vortec Head and base swap. The 350 TBI motors went from 210hp to 240-250hp, would you think it would be roughly the same increase on a TPI 30-40hp at the crank? Or better yet anyone ever do this swap, just cause the had a damaged cylinder head or something?

 

The TBI motors got a 30+hp increase because they weren't TBI anymore . They were a whole new set-up. If you are going to go through all that work I would also at least swap in a cam. You will then see your 30+ hp increase.

 

If you did everything you said plus a cam and runners and some porting I would say 50 hp on the high side.

 

Were the trucks MPFI for 96-98?

 

Yes.

I would guess you would add 20-30 with a cam. TPI engine are not limited my the L98 heads they are limited by the intake itself.

 

 

look at my sig,

probably 70-90 rwhp over stock, seriously changed the whole car, feels like it should have from the factory. but really needed to upgrade the brakes withthat much of a power increase. just heads probably 20-25 rwhp , and that is after it would be tuned, untuned you will be diappointed with the head swap.

To be honest, with my vortec set up the power is so fun to drive I like it better than my mild bolt on LS1. You just need to get your combination of parts right and get it tuned to have a good vortec set up. they are great motors!

 

Kennerz,

is 1/4 time in vortec, Do u have stock tran? or shift kit?

Thanks

 

The trans is a probuilt/ w a 2200rpm stall speed. I don't have any 1/4 mi times, but assume it would be low 13s ~ high 12s - have beaten low 13sec cars on the streets ( evoIII, M3, STi) This is still not a high top end HP set up . TPI will never have a peak much over 5K. It will pull cleanly over 6K but the peak HP is just at, or slightly above 5K rpms. This is a awsome torque combo though.

Let me know if you have any more questions..

 

Thats because you gained a huge amount of low-end torque and power, not hp. Tons of low-end power will always be more fun than high rpm power on the street.

Theres no way you gained 90 hp.

 

Think about it.

a stock 5.7 in 88' made about 230HP- most of them dyno between 195~220 rwhp stock


Realistically, a vortec / hotcam car, with full 1 3/4 slp ehxhaust, 3.5 catback, AZs&m runners, 52mm holley TB, ported plenum, 24hr injectors, tuned properly will easily pull 320~340 fly wheel hp trans lating into 280~290 rwhp, this is not unrealistic - vortec/ hotcam motors with a 750 carb made 400 fwhp - unported heads-


suposing you made 210 rwhp stock , and now you're at 290 rwhp that's 80Rwhp or close to 100 fwhp, there is a guy on here with a very similar set up to mine making 304rwhp if the guy has a 700r4 means it is very close to 360 fwhp - this is not a joke.

that guy with the sdpc mule motor , had crappy edlebrock runners and 1 5/8 exhaust in the car and I believe on the dyno it made 269 rwhp. with much lesser cmponents and tuning than my car. Untuned with open 1 7/8 dyno headers when they supposedly got the 357 fwhp # - I'm not saying I believe that #,

But , I have a maxed out bolt -on (including an asp pulley)- vortec hotcam car that is tuned well - what are you saying - my car is making 250rwhp, I don't think so - it would not beat an M3, or sti with that kind of power, it has run with a stock C5 on the freeway, I stayed ahead of a convertible SS (2002) to 120 ( he could not catch me)

I'm sorry- every indication is that my car makes HP very close to what I claim

and why you can't believe that a full effort car ( with unported vortec heads, and a hot cam) can't make that kind of power - I don't understand that

my car has the best of the bolt - ons , and was tuned by an unoficial vortec tuning expert who totally understood the fuling and timing requirements of vortecs inside and out.

I hope you're not one of the poeple who think just because it's a tpi you can't make any HP at all... a stock LS1 z28 is out matched by my car.

Just realize that vortec's with out tuning or being fed air in ( fully modified TPI) or air out ( fully modified exhaust) aren't very impressive,

They need to be set up right to run right, and when they do run right, they are excellent street motors- trust me ( you don't have to ) but trust me on this

If you are strictly drag racing, this probably isn't the motor for you- and honestly I don't think you could get much more than 310~315 rwhp out of one of these vortec tune ports with a full race set up, unless you get a super ram or a stealthram( no stealth in CA)

1bad91Z supposedly made -guessing- over 350+rwhp with a highly modified vortec - is it possible? you tell me.

 

Stock L98 short block
Stock L98 Cam
untouched used Vortec heads, 1.6:1 RRs
TES Headers, no cat, Dynomax IPipe and '02 Camaro SS Muffler
Shift Kit, stock TC stock gears 3.23:1
Boxed LCAs, PanHard and TQ Arm
SLP CAI, Stock MAF, Ported Plenum, Ported OEM Runners
Custom Tune by me!

Car runs 13.6-13.9 @ 99-101 MPH with a best of 13.34@103 MPH.

On street tires with good track prep I get 1.91-1.94 60ft

Race weight 3750 with me in it.

Bone stock the car ran 15@89 MPH.

So basically stock Vortec heads, SDPC base and full exhaust was worth over 100 HP.

Vortec heads make good power.

 

Hope poncho's reply helps some of the readers, a 13.3 on stock cam and runners - is pretty impressive. I'm not saying you will go out and blow away an 03' cobra, or Z06 , just that the vortec combo is turning out to make pretty fair power for the investment, ( people are consistently getting low 13 sec cars without major mods) and people who are getting 250~260hp are either running stock parts, or not tuned well.


Look at poncho- with stock parts and tuned well the thing runs respectable times - 100fwhp is not out of the question - you just have to remember 100hp doesn't make these cars twice as fast.

I'm sure if you hopped from a stock 5.7, and got into a modded vortec you would realize that there is a world of difference, but because of the TPI the power delivery is similar- there is just more of it
- I like my vortec and have no regrets in doing it- but I will admit it was a pain in the butt to get to run right, and took me about 6$months to get it right ( replacing old sensors, fixing wiring, air leaks, getting it tuned,etc..) now I look forward to driving it, and look for excuses to punch it. People in new cars are always suprised that the old car is so fast, the thing is fast enough to get thumbs up from challengers in cars that 'Should' beat it, but can't- the thing sounds great to.

Again if you want more top end buy a stealth ram, or some thing - but us CA people are pretty limited when it comes to smog legal mods- my car passed a visual, and a sniff test, the technition noted how clean my car was ( emissions wise).

big cams and non egr intakes can't be used out here.

 

gotta agree with Kennerz, I LOVE THIS MOTOR.

like him, my ol' girl has shown her azz to MANY cars that were shocked to watch her pull away.

one of the best was the AWD twin turbo audi s4 she walked. guy drove down from virginia to try it out. he wasn't pissed, just suprised.

bomp, bomp, bomp.........another bites the dust.

 

again hopefully people will read this and believe. Of course you will need some additional heavy (another intake, or power adder)mods to get these things into the low twelves. And no, I really isn't turnkey. It takes some work to get them to run right. but the satisfaction of being ahead of an Sti , or evo III, or neck and neck with a newer M3 makes it all worth the effort. People really get Big eyes when you beat them.

This really would be a awesome combo with a t56, maybe not off the line , but for high speeds the 700R really kinda sucks, the gap between 3rd and OD is so great. Newer cars really have the thirdgens beat when it comes to efficient gearing. I have to give the 700R credit for the stoplight to stoplight action though. I pulled a WRX launching at 5k, with my 700R and 2200 rpm stall converter, and my suspension is stock except for sub frames, on mediocre Kuhmos.


Vortec- hotcam =