id say very weird.... what was the spool pattern like ? i could care less about final numbers... i only made 10 more Hp with the cosi's than the S1's at peak, im talking about the spool being so much different

 

This test tells me nothing I didn't already know..

 

lol

funny justin, after brian was telling me about your experience with the cosi's, as well as these knuckleheads back here, i was hoping that they'd help with my turbo as well as my next setup

 

I second to that ^^..

Maybe the spool up delay is because your on the slight bigger turbo than what these were intended for..

I say pick up a set of GSC S2's and try again.. now this would be a comparison.. am on stock turbo and love the GSC's S1 but.. no doubt I'll ditch them if I had a 20G..

 

From what i have read though, the S1's were good for "stocklike" turbos up to the 30R.... which is why i bought them. The numbers i had seen posted looked really good. I figured when i installed the turbo, that the later spool was because of the 20G. Now, i spool like stock or better... i am just confused lol. Not that i care anymore, but still. In a way i feel bad, Greg is a great guy, the product does well on a lot of cars, on mine, id say i had well below average results. When i asked greg about it, he responded with my tune was too aggressive in the timing department. Just doesnt make a lot of sense, but im glad my car is alive again

 

damn you, now I'm considering a cam swap!!!

 

1000 rpms of slower spool from the S1 to the Cosworth 272s... let me ask a quick question. when you made the cam swap did you remove the timing belt or zip tie them to the gears?

 

i sent you a PM greg...

I checked timing before i took the cams out and it was dead on... it was so dead on i was surprised. I have read a lot of times that the timing belt will be perfect up top and then you may be a degree or so off from TDC at the crank. Mine was dead on. Then i zip tied the gears and swapped them out.

 

Did you dyno the car on the same day?

 

Why does one S1 graph show 21psi at 4100rpms and the other at 3300rpms?

 

the 3300 RPM graph is the day after cam install from stock to S1 showing the gains i picked up from stock tuned to S1 with a base tune.

the 4100 graph is what the S1's did with a tune after i installed my 20G... the comparison is what happened when the only change i made was the Cosi cams.

I did not dyno the car the same day, but, as i said, im not interested in what the peak HP numbers were, i expected a slight difference in HP/TQ numbers. I also posted corrected numbers, so that should be weather on the same level. Whichever way they went, S1's higher, Cosi's higher, i knew there would be a difference. What has me in shock is the spool difference. Understand, there was no tuning change from S1 to Cosi install... the same map yielded different spool by a major difference, and just a bit more power up top... but nothing to say damn these S1's suck or anything...

Just for the record, I really liked the S1's. They felt really good... Greg and the GSC crew have outstanding customer service and always back up their product with outstanding customer support. My point of this thread was not to blast them or their product. There are just as many S1 claims to fame as their are Cosi claims which is why i bought the S1's to begin with.... I just wanted to post the difference in spool to let everyone know for one, to have Greg look at it and see what he thinks for 2 and to throw some more data out there for people to consider while cam shopping.

 

Very Nice. Good test.

 

This isn't really a test seeing as how the S1's are not performing correctly. not sure as to why they are spooling up 800 rpms slower than a larger cam. this shouldnt be happening. it is truly the first time i have ever seen a graph like this. especially an S1 cam getting full boost by 4200 rpms.

i'm going to have them shipped to me to cam doctor just so i can make sure their isnt an issue with trigger placement. and to double check the spec's. it almost seems as if the timing was off on them or a slight boost leak was causing the slow spool. especially given that the cams were switched with out any other changes. i'm scratching my head looking at this graph, i've seen too many graphs with Evo Green turbo's and S1 cams in the high 380-430whp range to chock this example up as fact.

 

The two cam profiles require different MIVEC mapping. Furthermore you used meth injection on the cosworths. Is that correct?

 

This a terrible test, so misleading. One question I have, why is A/F ratio so off between the two runs? And the boost is off too. Honestly when you don't have concrete info don't post and mislead people.

I can also give you a perfect example: I have an Evo 8 with all the bolt-ons possible which includes Evo9 turbo and GSC S1 cams. I made about 350 on the dynojet. Now I also have friend with Evo 9 with full exhaust, HKS Intake and Cosworth cams and he made 354 on dynojet tuned by Ivey. We have done multiple pulls side by side and we are right next to each other everytime, no matter what gear so I don't what hear this BS about spool or topend.

GSC S1 One of the best performing and sounding cams