Time to go Full PI?

[LI98GT]

I've done the PI parts in phases like you are. First I had the Intake, then added the cams and a few months later found heads cheap and popped them on until I went with the Fox Lake PI's and a few sets of Comp Cams.

The Intake was the single biggest difference to me just because the usable RPM range was extended. The cams also were a nice kick compared to stock. When I switched to the stock PI heads I did not notice a big gain but the premium fuel at the pump was difference in my wallet

If I had it to do it all over again I would have bought some NPI's that were ported by Renegade and stayed N/A with a 150 shot of Nitrous.
My opinion is if you are going to go through the effort of swapping heads save up for some P&P'd with better valves/springs etc and a set of mild street cams so you can still pass emissions if needed.

Hey, very much appreciate the info - got to check into some mild street cams that are more agressive than the PI cams, but still keep under the NY emissions laws. For me it was the other way around, although the PI intake raised rev range, it was slightly down on tqe where as the PI cams raised the rev range and felt power throughout, but then again I reverse the order of installation than you. PI cams 1st with PI intake 2nd.

 

[LI98GT]

101mph is good for LOW LOW 13s if not a 12.99... you have the power just need the balls to get it out the hole. what drag radials are you running???

is it your daily driver, are you scared to break? if not you should be leaving the line at atleast 4000rpm. i dont see how you leave the line at 2500rpm on radials without MAJOR bog unless you are slipping the hell out of the clutch. track time would do wonders for your times in my opinion.

get that 60' down to a 1.6 or 1.7 and you would be low 13s, very doable on the right tire.

also, shifting at 5500rpm is not short shifting with your mods, peak power is probably around 5400rpm, from what i've seen shifting at 5500-5700 works best with a bolt on car, after 5500rpm you are just wasting valuable time that could be used in the powerband if you had shifted. <--- especially true on an NPI car.

My meaning of "granny shifting" is not powershifting (leaving foot in gas while banging gears) or Granny shift=lift throttle, put in clutch, shift real quick, let out clutch then get back in the gas (again all real quick). I didn't mean shifting at a low rpm.

I was being coached by a knowledgable racer at the track to launch at that rpm, slipping the clutch slightly. DRs brand were brand new Nittos. I added LCAs post runs to hopefully help in that dept.

 

[sneakypete_ftw!]

heat them up really good and drop the clutch at 4-4500rpm's. when i ran the slobra on worn out nitto's i heated them up really well and dumped the clutch at 4200rpm's and it hooked really well, but then i missed 2nd that ran and messed it all up lol. i was nervous due to it being a grudge match against a rivals ls1 ss.

 

[Lee12609]

are you sure they are nitto drag radials, or are they just the nitto 555's??? 2500rpm launch is very low for a drag radial even the worst which is the Nitto. i pull 1.9 60' in an automatic with stock stall on nittos all day. your 5 speed on drag radials shouldnt have a problem pulling 1.7s atleast if you have the melons to dump it at that high an rpm. only problem is you'll find out where the weak link is if it hooks.

like me and sneakypete said 4000rpm and a clutch dump should get you going. the nittos like about 18psi and a good bit of heat (second gear burnout 4-5 seconds)....

 

[LI98GT]

are you sure they are nitto drag radials, or are they just the nitto 555's??? 2500rpm launch is very low for a drag radial even the worst which is the Nitto. i pull 1.9 60' in an automatic with stock stall on nittos all day. your 5 speed on drag radials shouldnt have a problem pulling 1.7s atleast if you have the melons to dump it at that high an rpm. only problem is you'll find out where the weak link is if it hooks.

like me and sneakypete said 4000rpm and a clutch dump should get you going. the nittos like about 18psi and a good bit of heat (second gear burnout 4-5 seconds)....

Thanks for the advice guys - as it was my first time at the track with DRs and 2nd time ever, I tried to listen to people with experience and that's the advice I was given. I did drop my 60' time down from 2.02 to 1.90 over stock Goodyear F1s. I will try more agressive launching next time out.

And yes, the Nittos are NT 555Rs Extreme Drags in 275/40/17s. Here's a shot of them.

 

[Willis_98GT]

nps do no have a flat top piston, tey have an 11cc dish as posted above.

A stock pi car with d/r's can run 13.7 ish, your going to have to hustle that car, AND get some weight out fo it for you to see another half second drop consistantly.

Appreciate the input so far - I want this to be a healthy discussion. So that is what I ran the last time out with DRs with mod list (again minus LCAs). Sorry, guess I used the wrong words as you are correct, the NPI pistons are not flat, but do have less of a dish than the PI pistons. From where I was at last time out, I'm trying to drop ~.5. Willis, I discounted the stage II cams due to cost an emissions issues .
Maybe it's too much for me hope for, which is why I was asking if anyone did just the heads on top of PI cams and PI intake with the increased flow and compression that they bring. Hoping that not just the extra 10-20 rwhp peak but additional improvements under the curve (if they exist?) might get me down to low 13s. I do have some mods to go along with this setup i.e. gears, upper intake, 70mm TB, pulleys, catted X and catback, DRs plus the aformentioned LCAs. Unfortunately, being on L.I., doesn't afford me the luxury of going to a track that often to improve on driver mod that much as there are none on L.I. and the closest track is several hours away. Maybe the heads plus a tune? I'm still on stock tune.

i drove my car for about 6 months after my piswap before i added my 270s and i loved the power beforehand.

i mean dont get me wrong my car pulls like jason stathams horse track sex scene in crank 2 from 4grand to red.

but what im getting at is the pi heads with just pi cams is a deadly combo, most people forget that stock pi cams are awesome all around cams.

 

[DropTopPony]

I've done the PI parts in phases like you are. First I had the Intake, then added the cams and a few months later found heads cheap and popped them on until I went with the Fox Lake PI's and a few sets of Comp Cams.

The Intake was the single biggest difference to me just because the usable RPM range was extended. The cams also were a nice kick compared to stock. When I switched to the stock PI heads I did not notice a big gain but the premium fuel at the pump was difference in my wallet

If I had it to do it all over again I would have bought some NPI's that were ported by Renegade and stayed N/A with a 150 shot of Nitrous.
My opinion is if you are going to go through the effort of swapping heads save up for some P&P'd with better valves/springs etc and a set of mild street cams so you can still pass emissions if needed.

Hey, very much appreciate the info - got to check into some mild street cams that are more agressive than the PI cams, but still keep under the NY emissions laws. For me it was the other way around, although the PI intake raised rev range, it was slightly down on tqe where as the PI cams raised the rev range and felt power throughout, but then again I reverse the order of installation than you. PI cams 1st with PI intake 2nd.

I remember a few guys saying they passed Cali emissions with the VT stage 1 N/A cams and they would be good for about 25rwhp over your stock PI's.

 

[duff daddy]

my car pass cali emmisions in ma with 270's

 

[sneakypete_ftw!]

are you sure they are nitto drag radials, or are they just the nitto 555's??? 2500rpm launch is very low for a drag radial even the worst which is the Nitto. i pull 1.9 60' in an automatic with stock stall on nittos all day. your 5 speed on drag radials shouldnt have a problem pulling 1.7s atleast if you have the melons to dump it at that high an rpm. only problem is you'll find out where the weak link is if it hooks.

like me and sneakypete said 4000rpm and a clutch dump should get you going. the nittos like about 18psi and a good bit of heat (second gear burnout 4-5 seconds)....

that's what i do with mine. 2nd gear burnout for about 6 seconds, pull out the burn out box and pop it in 1st real quick to see if it's sticking, then up to 4-4500 depending on the track prep and a dump to launch.

i have 275-40-17 nittos and i was on 16psi some runs and 18psi some runs.

 

[Willis_98GT]

1.9 60 for leaving at 2ish. man thats goood