Matthew Blunk

So, I'll just cut right to it. I'm currently running about 400/400 on E85.
I'm looking to push it a little higher, without blowing up my stock block and internals. It seems that about 450 is the "safe" limit for a stock block.
I want to push it a little higher and get as close to that 450 limit as I can.
Given that info, I'm wondering what I should do next??
Im still running the stock turbo, but since I won't be able to upgrade my block any time in the foreseeable future, a big turbo seems like overkill at this point.
So I was thinking cams and valve springs maybe....
Any suggestions? Thanks

LetsGetThisDone

iTrader: (1)

400wtq is the limit, not 450hp. you can put an MHI18k, it will make around 460-470whp with all the other bolt ons on E85.

Or you can go to a turbo kit with a Precision gen2 5558 or a garret g-series and make around 550 pretty safely on the stock engine on ethanol.

Matthew Blunk

ok...this might be a dumb question, but, if 400 is the safe limit, how would making 550 with the garret kit be safe on a stock engine? Is this because you talking about increasing the HP, and not the TQ?
Thanks for the info btw

LetsGetThisDone

iTrader: (1)

because right now you make 400wtq at 3800-4000rpms, and to make 400whp you're making about 300wtq at around 7000rpms because the stock turbo peaks early and falls off. The turbo kit will make peak power a bit higher, around 7300-7500. 390wtq at 7400rpm is 549whp. And with proper tuning, boost will be controlled down low so that ~400wtq isn't exceeded. The same principle goes for the 18k, except like the stock turbo, it won't flow up top like the turbo kit does, and will be limited.

Getting a bit more power gets even easier if you do cams- GSC S2's, and appropriate valvesprings/retainers.

RazorLab

iTrader: (8)

Here are two visuals to help you understand exactly what letsgetthisdone is saying:

Matthew Blunk

So the garret will give me better high HP numbers, and help maintain my TQ a little higher in the rpm range.

Is the K18 capable of keeping up the TQ numbers in higher rpms, compared to the stock turbo? Or is that only possible with a kit?

I'm guessing they're roughly to scale with each other, in terms of possible gains in each area? One is just going to give me considerably more.

RazorLab

iTrader: (8)

Here is an example of a MHI18K bolt on:




Here is an example of a GTX3076R bolt on:

LetsGetThisDone

iTrader: (1)

Your 18k chart spools super slow. Last one I did looked like a stock turbo, peak torque before 4000rpm.

RazorLab

iTrader: (8)

Just showing examples to help the OP better understand things. I have zero interest in any dyno/tune/ego/ruler size swinging contests at this point on this forum.

LetsGetThisDone

iTrader: (1)

Relax man. Just making a statement because I don't think that is typical.

RazorLab

iTrader: (8)

Feel free to share your data.

LetsGetThisDone

iTrader: (1)

The three I've done looked exactly like these two on pump, and a smidge quicker on E85 and 400wtq comes below 4000. JohnBradley does all of my tuning, hence sharing these.

https://www.evolutionm.net/forums/ev...30whp-gsr.html

Matthew Blunk

Huh....so in those charts, the K18 makes more TQ but drops it. And the GTX makes less TQ, but holds most of it all the way up. And obviously the GTX makes much more HP.

Is that generally the way they compare?
Aside from obvious price and supporting modification differences. I'm wondering how street-able the GTX is? Do you have to be constantly screaming at 6k rpms or more to really be taking advantage of it?

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LetsGetThisDone

iTrader: (1)

They both make similar torque around 4000-4500rpm. Neither will "require" 6000rpm, but considering you can rev the engine to 8k since a turbo upgrade makes decent power up there, I wouldn't call 6k "screaming"...

Matthew Blunk

Right. Well, I think the price made my decision for me.
The K18 will cost me roughly $2k, plus a re-tune.
The GTX is about $3k, plus new intake and other pipes, new injectors (mine are currently 1050) , whatever else I'm not accounting for, and a re-tune. So I'm guessing about $5k or more?

I'm sure the GTX is worth it, but it not going to happen any time soon for me. But I could have the K18 soon, and ready to install and tune for spring.
Thank for the help