Bullet Ride's 2.8L Stroker Project (Updated: Dyno Plot pg. 6)

[Bullet Ride]

Those are great numbers!
Btw, torque and hp should cross at 5252. I hate it when they give the graphs with speed instead of rpm.

J

yes so 91mph=5252rpm

Oh, I was thinking it was based on the tire size and gear ratios of the car but it's really just the constant from the hp-tq relation. Cool.
I'll fix it. Thanks guys.

[Bullet Ride]

Great job! Did you data log the dyno runs? Mind sharing your msq? I'm curious to see your timing map.

No datalog, I didn't bring my laptop to the track. I can email you my msq. Do you want me to send it to the same email that's tied to your paypal?

[tinkerputzer]

That would be great, thanks!

[downforce22]

Sweet setup, where did you get your cam? Also how do you like tuning it and running the 3.73? It sounds great and pull good in 4th gear!

[Bullet Ride]

Sweet setup, where did you get your cam? Also how do you like tuning it and running the 3.73? It sounds great and pull good in 4th gear!

Thanks. I got the cam fom VAC. Tuning it is pretty straight forward. The only hard part is getting a good timing map and a dyno is the only real good way to do it. I'm going to do some dyno tuning next year as I've spent enough (for my liking) on this project for now. I still use the car on the street for now, so a 3.73 diff is a good choice. If it was a track only car I'd probably try out a 4.10.

[digger]

Oh, I was thinking it was based on the tire size and gear ratios of the car but it's really just the constant from the hp-tq relation. Cool.
I'll fix it. Thanks guys.

You should get the same answer within a few %. What wheels and tires are you running, was it in 4th gear and 3.73?

[Bullet Ride]

You should get the same answer within a few %. What wheels and tires are you running, was it in 4th gear and 3.73?

It was close, the number I came up with to multiply each mph value by was 54.35, using 5252 @ 92mph I got 57.1 about a 5% difference.

[nando]

nice torque curve and power #s! it look's like you've done your homework - the cam timing probably helped you too, a lot of people skip that altogether.

what cam is it? I looked through the thread but the pics are blocked and I didn't see it listed anywhere.

you could probably break 200whp pretty easily by just adjusting your cam, it looks like it's biased towards torque, but on the street you may not want to do that. if it's a 284/272 or a 288 I'd have expected power to start dropping off at 6500 or later which would definitely get you there.

a BBTB might help but you should measure manifold pressure at WOT and see if you have any pressure drop before spending the money - and make sure if you do buy one, that they actually made it with a larger throttle plate (I got one that was supposed to be a BBTB, but it's really dremeled out and still has the stock plate). Also if you still have the stock airbox a large surface area cone filter will make a significant difference; I make less power than you and the stock airbox is a definite restriction.

[Bullet Ride]

nice torque curve and power #s! it look's like you've done your homework - the cam timing probably helped you too, a lot of people skip that altogether.

what cam is it? I looked through the thread but the pics are blocked and I didn't see it listed anywhere.

you could probably break 200whp pretty easily by just adjusting your cam, it looks like it's biased towards torque, but on the street you may not want to do that. if it's a 284/272 or a 288 I'd have expected power to start dropping off at 6500 or later which would definitely get you there.

a BBTB might help but you should measure manifold pressure at WOT and see if you have any pressure drop before spending the money - and make sure if you do buy one, that they actually made it with a larger throttle plate (I got one that was supposed to be a BBTB, but it's really dremeled out and still has the stock plate). Also if you still have the stock airbox a large surface area cone filter will make a significant difference; I make less power than you and the stock airbox is a definite restriction.

Pics are blocked? I can see them fine. Does anyone else have problems seeing the pics? The cam is a schrick 284/272. When I get around to doing some dyno tuning I do plan on playing with the cam timing. I agree, I do need to observe my MAP reading at WOT to see where things are at, I was just speculating that since it's still stock it might be spot for improvement. My current intake is a 3" tube with a K&N cone filter on it, I still need to make a heat shield for it though.

"you could probably break 200whp pretty easily" ... That's what I like to hear :D

[nando]

it's our firewall

yeah, you can defintely extend that powerband a bit with the 284/272. experiment with cam timing on the dyno to find the most power without sacrificing too much area under your torque curve.

a heat shield will make a difference on the dyno, but a much smaller one on the street (at speed, anyway). it's usually only when you're going slow or at a stop that the intake actually heatsoaks.

[tinkerputzer]

Fyi m50 throttle plate is 64.2 mm vs m20 60 mm if your planning to make your own bbtb.

[Bullet Ride]

Fyi m50 throttle plate is 64.2 mm vs m20 60 mm if your planning to make your own bbtb.

Right now I'm actually thinking about building an ITB set up as a winter project, not because the car needs it per se, but because it'll look sweet*, it'll sound sweet**, and the throttle response will be sweet***



* might look sweet
** should sound sweet
*** could be sweet
lol

[blasphemy101]

This seems like a really nice build for an M20. Does this make more power (peak or under the curve) versus an M52B28? It just seems like a lot of work for +45-50whp - not that I don't appreciate the build, because it's great!

[tinkerputzer]

Wow can't wait to see it. Should be nice :)

Right now I'm actually thinking about building an ITB set up as a winter project, not because the car needs it per se, but because it'll look sweet*, it'll sound sweet**, and the throttle response will be sweet***



* might look sweet
** should sound sweet
*** could be sweet
lol

[Bullet Ride]

This seems like a really nice build for an M20. Does this make more power (peak or under the curve) versus an M52B28? It just seems like a lot of work for +45-50whp - not that I don't appreciate the build, because it's great!

A stock M52B28 is rated for 190hp and 210lb-ft at the crank which is approximately 165hp and 183lb-ft at the wheels give or take. I'm not sure what the curve looks like for the M52B28 but for a good portion of my plot I'm above M52B28 peak numbers, so yes, this build is making more than a stock M52B28. However if you were to take an M52B28 do an OBD I conversion add S52 cams and headers it would probably be putting down around 220hp at the wheels.

Someone mentioned the same thing on another forum so I'll just quote what I've already said elsewhere...

A 24v swap would obviously yield better performance/$ but there's not really anything for me to learn from doing a 24v swap because it's already a well documented process. My goal with this project was just to learn about building a motor because it's something I had never done before. I happened to already have an M20 sitting around collecting dust so that's what I decided to use for the base of my build, but at the same time I didn't want to spend the money to rebuild a motor and end up with stock B25 performance so I opted for the 2.8L stroker route.