Well im doing a budget build on my 03 GT 2v. Im going to keep my stock block and use my stock crank with a set of manley rods and stock mach1 pistons with stock ported heads and MHS stage 3 cams. my friend that is building it said it would be around 12:1 compression. Does that sound about right? Also how streetable would 12:1 be for a DD....well not a complete DD maybe drive it 3 or 4 times a week. It just seems a bit high to me but he says ill be fine with a good tune. Id also like to be able to run 91 in it if i make long trips. They sell 93 here in VA but ive gone on long trips where they only have 91. The car is a n/a car with maybe some nitrous added down the road. Id just like your inputs on if i should go with 12:1 or if i should knock it down to more like 11:1. Thanks guys
Caleb03GT
it's not quite 12:1, like 11.8ish... And yes it's doable with enough cam, like those stage 3s, but you better have valve reliefs.
good, compression will actually drop a hair then... it'll be fine.
Youre gonna love it. Gonna be real snappy.
Youre gonna love it. Gonna be real snappy.
That's basically what I got. Works out to about 11.7-1 plus or minus .1. My cams are often referred to as stage 2.5. I got the a lot of advise from Nick and it has worked out great. The tune is a must I am running on a non dyno tune right now with only small idle issues and no detonation (running a little rich). Before the tune the car ran ok cold but as soon as the engine fully heated
up it would go into detonation with any kind of load. IMO the best option for NA is high compression, this thing is a blast its got good power on the low end and feels like a shot of nitrous at 4,000 rpm. My best advise is to listen to everything Nick tells you he is a true guru. Good luck and have fun!!
up it would go into detonation with any kind of load. IMO the best option for NA is high compression, this thing is a blast its got good power on the low end and feels like a shot of nitrous at 4,000 rpm. My best advise is to listen to everything Nick tells you he is a true guru. Good luck and have fun!!
You shouldn't have any issues running your setup on 93 octane gas. 91 will require even more timing to be pulled out.
I have a pretty similiar setup except comp 270's and will be getting dynoed on Friday. I will let you know how it goes. I plan on getting a 93 octane and E85 tune.
I haven't had any issues with a mail order tune from VMP and 93 octane fuel but I wouldn't trust it to race every weekend just because of how hot it gets where I live. It works good around town though.
I have a pretty similiar setup except comp 270's and will be getting dynoed on Friday. I will let you know how it goes. I plan on getting a 93 octane and E85 tune.
I haven't had any issues with a mail order tune from VMP and 93 octane fuel but I wouldn't trust it to race every weekend just because of how hot it gets where I live. It works good around town though.
I have the comp 274 cams and they do seem to like the compression better than most. Right now I have a lot of timing pulled out due to a lack of a proper dyno tune. The car runs very strong but I know there is more to be had in the tune. I found your e85 results looks pretty good unfortunately its not available here in tampa. On a side note I love the exhaust sound these high comp engines make, it just sounds evil :evil:
Cams and compression are tied together, look at the overlap difference to see what is possible with pump gas on the street. The MHS Stage 3 cams have 5 degrees more overlap than the Comp 270 even though the Comp 270 has bigger durations (15 degrees overlap vs 10 degrees at 050 lift). This is the best tool I have found to figure out overlap, opening and closing points for cam specs:
CamChart
CamChart
Yeah I don't think I'd run that close to 12:1.. at least not yet, with any luck E-85 will be more widespread in the next few years then go for it!!
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