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The MHI housing will move low end power to the left ~500rpm while not losing much, if anything, up top.
Sean,Do you have a graph you can post up from your old stock 8 (non mivec) .
This is my stock engine with mivec on Ethanol. IIRC it was 25psi up to 29psi. On the stock ECU with some tuning. The MHI housing helps alot with spool up and low end torque. I believe the SS housing would make close to the same all in but because it lowers backpressure it will make power EASIER once its spooled up/higher rpm on Ethanol. The OP graph is on pump gas.
Comparing the graph from post #49 to this.
Hard to tell but it looks like the MHI housing on that graph makes 350tq by 4200 compared to 350tq at 5000 from the original post. The SS housing is still a great option , but I'll take the MHI for what I do.
Interesting. What I've been told is that MHI Green spools around 4200 - 4400 RPM, Red around 4400 - 4600 RPM, and Black around 4600 - 4800 RPM. If the SS housing spools 500 - 800 RPMs later, that's like going from MHI Green to Black.
even if the SS flows better up top, it's not worth it to me to deal with 500-800 RPM lag down low for maybe another 20 whp.
Interesting. What I've been told is that MHI Green spools around 4200 - 4400 RPM, Red around 4400 - 4600 RPM, and Black around 4600 - 4800 RPM. If the SS housing spools 500 - 800 RPMs later, that's like going from MHI Green to Black.
even if the SS flows better up top, it's not worth it to me to deal with 500-800 RPM lag down low for maybe another 20 whp.
Between the OP graph, Seans and mine you have three cars on the same type of dyno and get a good idea of when the cars come alive. Just going off the 350wtq number when things are starting to move well.
Mivec 2.0 red Mhi , 350wtq at 4000.
Non mivec 2.0 red Mhi 350wtq at 4200
Non mivec 2.0 red SS 350wtq at 5000
Of course its possible with more tuning things could get better then this , but don't expect alot unless its got rally antilag, nitrous on a 2.0.
So, going off that data the green mhi is going to be 200-300rpm quicker then that . A black mhi is going to be 200-300 behind the red. Now, when I looked at turbo's years ago the red stood out over the black . A few people road raced them and none of them complained about any lag. Most people don't operate their cars on the roadcourse below 3500 anyway. Sidenote, A 2.2/2.3 car with a black should be very responsive with the larger crankshaft.
Another thing to consider is average power and the fact that the MHI housing just adds low end grunt.
Whats important to consider is its not just the peak numbers things make. Stock and small turbo's come on a earlier BUT there is a point the engine can't pump the air out. Compressor surge can also occur. With a stock/small turbo it comes on then then has a shorter powerband and tq tapers.
I quickly found this and it shows 350wtq coming on around 3600 on a dynojet. Stock and MHI greens. Compare the powerbands . You may give up a few hundred rpm with the mhi red but it delivers a wider powerband and can make 600whp down the road if needed. https://www.socalevo.net/threads/135...P-Green-Turbos
We should all be happy that we've got so many options from FP that deliver regardless of size.
One caveat is the OP is on pump gas, and my car had GSC S2's. His car would be at 400wtq at 5k rpm's on E85. If not maybe a bit sooner just from the fuel making more power because it's ethanol, as well as running maybe 1-2 degrees more timing. I even bet it would do it with the same boost level.. So these aren't direct comparison due to different fuel on the OP's car.
I recently put S2's and an SS red on a customers car. I'll see if I can find the datalogs on my lappy this weekend. The road it was tuned on isn't great for VD graphs, but I can post boost vs rpm. It'll be going on the dynojet in September when ER comes down for the dyno day. I drove that car a decent amount, I wasn't bothered by the lag for cruising around on the street.
I think the MHI Red is THE perfect turbo for a track car. It makes power without stressing things too much or making too much heat. When my car becomes more of a dedicated "race" car, I'll probably going the exact same route. If I build a short block, then it will be a no-brainer.
Aug 29, 2018, 02:15 PM
