Before and After JM's Striker Heads - Not so creamy anymore!

[SEASNAKE]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Yes, I could have bought a supercharger for the same price and made a little more horsepower. I almost went that route, but decided to go with this setup instead. I'm a lot more comfortable with this package as a daily driver - occasional road track car. Maybe in a another 5 years I'll do something else.

The car is running pump gas. The A/F ratio (from the tailpipe was 12.9 for that run and 12.6s for the other runs not shown). This is with the stock O2 sensor in a primary tube - the only option on these headers now. NC has not been very smog sensitive until very recently. I will probably have to have it checked next year when my inspection expires.

If the A/F ratios are good and the engine runs well with the stock injectors/pcm why would the engine be in danger of grenading? I would think this would be the safest way to go.

The supplied rockers are not already installed. They have to been set just like any other rockers - although they are the nicest I've seen.

 

[KepRght]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

with SVS at 600/600 with computer&fuel, and now you here without computer&fuel these heads are looking very very nice. are numbers even close to greg goods porting setup?

are these #'s with the Race or Street version of the heads??

i heard the spark plugs are special and rare(back order issues?) for these heads, true?

i agree with your path of heads/cam 1st. i rather have a car with 600/600 NA that i can drive every single day and road race/auto cross on the weekends with 0 issues. then a blower car making slightly more power, with more gadgets, lines, belts, things to go wrong as well as putting more wear and heat on everything.

 

[1TONY1]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

I find it hard to beleive the stock PCM can handle the cam swap without any check engine lights. You should eventually throw P0300 which is a general misfire code.

Do you guys realize the the 708 cam is the stock cam that came in the forged piston gen2 cars. I wouldn't expect any issues with it. I'm not sure it would be worth the trouble to change from a cream puff cam to a 708 cam unless the engine was already apart.
So IMO he made these gains with heads/headers only. That makes it look a little better.

 

[Joseph Dell]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Sweet numbers! every time i hear about these heads I want them more and more. Not that I _need_ them, but they do sound pretty cool.

I suppose if someone made me an offer on my stellar 320+cfm flowing Greg Good heads, i'd look at some of these more seriously. *hint*

congrats!!!

JD

 

[1TONY1]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

with SVS at 600/600 with computer&fuel, and now you here without computer&fuel these heads are looking very very nice. are numbers even close to greg goods porting setup?

are these #'s with the Race or Street version of the heads??

i heard the spark plugs are special and rare(back order issues?) for these heads, true?

i agree with your path of heads/cam 1st. i rather have a car with 600/600 NA that i can drive every single day and road race/auto cross on the weekends with 0 issues. then a blower car making slightly more power, with more gadgets, lines, belts, things to go wrong as well as putting more wear and heat on everything.

This is not the place to debate a Roe vs n/a, but another thread with both dyno graphs would be nice to see. It would be nice to see the torque curve in the lower rpm range were we do our "street driving"

By the way, there are quite a few of us with >10,000 miles on our blowers on the street and in my case also on the autocross. No more issues than a 600/600 NA car
One of my favorite stories is when my tow truck broke down in Florida after the V10 nats where I had run just a 9.85 (stock motor) We unloaded the car and drove it the 400 miles home. The thought of not doing a drive like that never crossed my mind, no need for it to.

 

[ViperJohn]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

I find it hard to beleive the stock PCM can handle the cam swap without any check engine lights. You should eventually throw P0300 which is a general misfire code.

Do you guys realize the the 708 cam is the stock cam that came in the forged piston gen2 cars. I wouldn't expect any issues with it. I'm not sure it would be worth the trouble to change from a cream puff cam to a 708 cam unless the engine was already apart.
So IMO he made these gains with heads/headers only. That makes it look a little better.

His car did not originally have a 708 cam in it, he had the "creampuff" cam. While not as aggressive as most aftermarket cams, his PCM is not set up to run the 708 cam. It's also been proven that the 708 cam makes more power and responds more favorable to mods. Iam impressed the 708 cam passes under the PCM misfire radar so far.

 

[1TONY1]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

His car did not originally have a 708 cam in it, he had the "creampuff" cam. While not as aggressive as most aftermarket cams, his PCM is not set up to run the 708 cam. It's also been proven that the 708 cam makes more power and responds more favorable to mods. Iam impressed the 708 cam passes under the PCM misfire radar so far.

Where is that proof and how much more power ?? While I believe all that is true I still think you would compare it more to his stock cam rather than an aftermarket cam. Look at the cam specs.....there isn't to much difference between the stock cams. Those specs are on this site somewhere.

 

[ViperJohn]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

His car did not originally have a 708 cam in it, he had the "creampuff" cam. While not as aggressive as most aftermarket cams, his PCM is not set up to run the 708 cam. It's also been proven that the 708 cam makes more power and responds more favorable to mods. Iam impressed the 708 cam passes under the PCM misfire radar so far.

Where is that proof and how much more power ?? While I believe all that is true I still think you would compare it more to his stock cam rather than an aftermarket cam. Look at the cam specs.....there isn't to much difference between the stock cams. Those specs are on this site somewhere.

Six degrees of valve overlap is the main difference I can remember in the cams.

 

[SVS Turbo]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

i agree with your path of heads/cam 1st. i rather have a car with 600/600 NA that i can drive every single day and road race/auto cross on the weekends with 0 issues. then a blower car making slightly more power, with more gadgets, lines, belts, things to go wrong as well as putting more wear and heat on everything.

Amen brother!

I would like to see someone build the bottom, add the JM race heads, cam, fuel and engine management and go for 700rwhp N/A

 

[SSSSE YA]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Why did You use the 708 cam and not the JM cam ?

 

[SEASNAKE]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

I didn't want to have to have the car tuned or the PCM reprogrammed.

 

[SUN RA KAT]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Were you able to get your car tuned to run right using the PCM only, or did you also use a VEC2, or did you need the AEM system?

 

[Camfab]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

I didn't want to have to have the car tuned or the PCM reprogrammed.

So, just to go over what you already said.

1) You bought the heads and cam, headers, gaskets etc.

2) You removed the stock heads and headers, and cam.

3) Bolted the new stuff in place. Welded the exhaust and put ALL the rest of the stock parts back on, including the original injectors.

4) Fired the car up and made those numbers.


Now my questions, did you use an adjustable timing chain? Did you degree the cam? Did you do the work? If so, did you pull the motor to make the cam swap easier?

 

[SEASNAKE]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

The stock timing chain was used and the cam was timed using the normal timing marks per the manual. That was what I was told would worked best by Jeff (timing wise). The motor was not pulled, but in retrospect it might have been easier to have pulled it. The transmission and engine were broken loose of their mounts. The trasmission had to be dropped and the engine raised to get enough angle to get the cam out over the radiator mounting bracket. There is not enough room to get the cam out straight without removing the radiator and a/c evaporator.

I'm still using the stock '01 PCM without programming changes.

 

[rcdice]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Ok, for all you prognosticators out there: Lets say you took another 01 car, hypothetically this time in yellow, and did the exact same mods. However, you left in the later Gen II stock cam. So, the only difference is this car does not have the 708 cam with it's additional 6 degrees of overlap. How different would the HP/TQ numbers be? SeaSnake achieved 529/547 RWHP/RWTQ "with" the 708 cam.

Would be interesting to know. Basically pulling the motor for the cam swap is one h*ll of a lot more work on top of the head swap. Any guesses?

 

[REDSLED]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Basically pulling the motor for the cam swap is one h*ll of a lot more work on top of the head swap. Any guesses?

You don't have to pull the motor to change out the cam.

 

[SVS Turbo]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Pics of the JM Striker "street" heads can be viewed here:

http://www.svspower.com/case_study_detail.aspx?id=30

 

[SEASNAKE]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Just a quick update for those interested.

I've put on over 1K miles since the mods. No check engine lights to date.

I had one trip to a poorly prepped drag strip and ran 11.84 @ 123 - that's .4 sec/7 mph better than before the mods. 11.6/125 should be achievable for me at a decently prepped track.

City gas mileage is down about .5 mpg (probably from the occasional acceleration tests) and highway mileage went up significantly (from 21 to near 25 - [*****]?).

The car is not quite as smooth at low RPM's (reminds me a little of my old Gen1), but still very drivable.

 

[KepRght]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

nice work on the setup & thanks for posting the info

how did the highway gas mileage go up significantly? can someone who knows why chime in.

low speed cylinder filling pulls less fuel with these heads? low speed meaning low revs in 6th on the highway. trying to figure this out.

 

[ViperJohn]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Great to hear everything is going well. I have two questions:

What was your 60 foot time with your 11.8 time?

What exactly do you mean by not a smooth at low rpm? Does the car buck a little? I have noticed this happens in Gen 1's and early Gen 2's.

 

[SEASNAKE]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

I ran two 11.84s. The 60' times were 1.99 & 2.02.

Yes, the car bucks a little - that is what I was referring to. Not near as much as my Gen 1 did though.

 

[LETHAL GTS]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

How much of these gains do you think the cam contributed?
Just wondering. My 2000 dynoed at 436 rwhp and 475 rwtq before I installed my Harland 1.7's. I know it pulls harder since the RR's.
I've been looking at these heads as well and this is very exciting news.
Thanks for sharing.

 

[Joseph Dell]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Well, your RR dont' work if you goto striker heads. they use their own rockers. different design.

it is the heads AND the cam that make the power. just heads will make some power, but add cam and it is a huge difference.

JD

 

[FE 065]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Your 60' times don't reflect a strip that's that poorly prepared. Meaning with an extra 112hp under the hood, it'd seem you should have seen a little better drop in ET. Unless your were spinning when you hit second gear, or granny shifting a bit.. Are you on street tires? I'd imagine street tires would be spinning on the 1-2 shift.





----------------------------------------
1999 GTS / 11.80@120

 

[LETHAL GTS]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Well, your RR dont' work if you goto striker heads. they use their own rockers. different design.

it is the heads AND the cam that make the power. just heads will make some power, but add cam and it is a huge difference.

JD

Yes, I realize that my RR's won't work.
But more to the point, the cam is a stock cam pre '00. So I didn't think there was that much difference between the two in lobe duration. So my thoughts were that it wouldn't really amount to that much of a gain over a stock '00+ cam.
Changing cams is a pain in the asp.

 

[KepRght]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

what is the best overall cam for use on the street version of these heads? JM makes a cam right? 708 or JM cam would be the question

 

[SEASNAKE]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

Just off the line the track was OK (for a short time- too many guys with street tires rolling through the water box), but after that I could not hook up 1st gear at all. I'll go out sometime when the real drag racers are out putting some rubber on the track. 1-2 spinning is not terrible with a good shift. I'm still running michelin tires w/ 10K miles on them.

 

[SammyV]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

rcdise, I was wondering the same thing?(How much power with heads only?) At a local dyno session my 2001 with filters,smooth tubes and corsa catback made only 400hp. Wile a fellow members car (1997) with same mods made 434hp. I now have bellangers and Harland Sharp rockers and my car still only makes 420hp.I do not think the cam is is the only internal differance in the two engines.(pistons,lifters etc.)My guess is heads only 80-90hp. 708 cam may be worth 30hp. Sammyv

 

[Russ M]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

I didn't want to have to have the car tuned or the PCM reprogrammed.

As I said before you are playing with fire, and missing a bunch of power while your at it.

It is NOT uncomon to pickup 20hp and 50lb's torque on a stock viper with a good tune. Now you have done all this work but still have no additional fuel/and stock ignition to go with it.

Do not believe the a/f ratio's you are getting unless you are getting them from your headers and not in the tail pipe.

Detonation is no joke, especialy on creampuf. Why would you spend all this money just to stop at the most crucial mod?

Get an AEM unit or a Vec 2, and a boost a pump. Even if by some miracle you dont hurt your engine, why would you want to give up so much power that can be attained with no other mechanical work?

 

[SEASNAKE]

Re: Before and After JM\'s Striker Heads - Not so creamy anymore!

3500 miles with no issues.

I will be watching the temp. gauge in the summer time because the car seemed to warm up quicker in the fall, even with the 172 deg thermostat.

I'm not buying your logic on A/F ratios. The A/F ratios would show leaner if anything at the tailpipe and this is only supposed to be at low rpm with lower horsepower cars when atmospheric oxygen can interfere with the test. Generally, 13:1 is considered safe/optimal ratio for normally aspirated and these car ran 12.6 to 13.1 in the runs made at WOT.

AEM + Tuning + Good Fuel System (no booster pumps for me) = $6K. I might go that way someday, but only when I'm doing the bottom end or forced induction.